Tuesday, 24 November 2015

Fix a Cracked Steel Bike Frame

Fix a Cracked Steel Bike Frame - Intro and Disclaimer

This is the first time I have done this. I'm just throwing it out there (USA) offering it up for scrutiny (UK).

It seems to have worked OK but then it may fail and kill me so please consider this before you choose to use any of the below information. That is your choice.

Fix a Cracked Steel Bike Frame - Causes

Having think about the cause is important.

The crack may have been caused by corrosion of the tubing, or a crash or large impact. Perhaps a seat post extended too far out of the seat tube, perhaps an overloaded rack.

A cracked steel frame - Crack is around 8mm in length.

You need to figure out which one an acute trauma will likley mend up OK, if not too serious. But chronic problems such as corrosion may not respond well after fixing.

The crack I have is located under the crimped portion of the chain stay. Apparently this is an inherently weak part of the frame. So I am attempting a repair.

Fix a Cracked Steel Bike Frame - Method

I have a welder, but have heard that heating up chromoly beyond a certain point weakens it. So I am opting for silver solder. This is not a soilder really but a type of low temperatur brazing which can be down with a normal household blow torch running propane or MAP gas.

I have asked the good citizens of google plus for advice on this one and had some good answers. Post is here. Thanks to +Scott Anderson  +Andy Tong , +Derek Haggerty +David Saul +Seb K and +simon russell-roberts for your answers.

So a 55% silver solder is quite expensive costing around £7 / $12 for  two small rods, buy from ebay with the correct flux. The flux has be be the right stuff.

You will need to clean up the crack and the area around it very well, I used a spinning wire brush thing on a drill. Remember the metal on the frame will be thin so don'y go mad.

Apparently you can use acid based cleaners to get the metal really clean, although some say its OK just to brush.

Once the crack and area around it are clean, prepare the flux. Mix it up like toothpaste and then apply it on the area where you want solder (filler) to go. If the flux is messy the filler will be messy.

For a patch I used the link from a bicycle chain. This (I think) is quite good as it allows you to feed the rod in to the center of the patch (through the two holes). And I should imagine that the plate from a chain has a very high tensile strength. Others may know better (please comment).

Holding the patch in place is tricky but once the flux has been melted it should hold it in place fairly well. Heat up the work, until it is glowing a little, then apply the silver braze / solder rod to the hot metal. It should melt and run in to the joint and beneath the patch very quickly.

If the filler is not taking to the areas where you want it too dip the end of the rod in the powdered flux and try again, it may be that you need more flux.

When finished there should be no gaps, and the filler should be ramped up around  the edge of the patch, and the inside of the holes (if you have any).

Results below. Sorry about blurry photos.

Fix a Cracked Steel Bike Frame - Result

Well time will tell . . . Update: 3 Years Later: Yep still going strong. 

I have painted over this with basic metal paint. I think the soldering will hold, I have tested the strength of silver solder on other objects and it is very high. The only questions are whether the patch is big enough, and whether the frame is not internally corroded.

If this crack were in the main triangle or the (gulp) head tube, I would not attempt a mend.

Environmental Consultants London

DIY Long Tail EBike - Chapter 4

DIY Long Tail EBike - Chapter 4 - The Final Chapter

So its been a while since I posted chapter 3. Its one thing to build a long tail cargo bike or long tail cargo e-bike, but whether it works or not . . well that takes a few months to find out.

Below are described the "few" teething problems and remedies that I have stumbled upon over the last few months. Also a few fatal flaws in the concept . . .

DIY Long Tail EBike - Chapter 4 - Drive Train

You will see chapter 3 that that I have a flip flop set up (more of a flop flop set up really) with the electric motor on one side and the pedals on the other. 

Chain Tugs and a Large Rear Sprocket - Essential

I found that the gearing for the motor was too high, and it was not running at a high enough RPM on hills, so I have added a 24 tooth free wheel (ebay), to lower the top speed and increase torque. You might consider going a bit bigger. Head over to TNC Scooter Parts to find all sorts of handy sprockets etc. Just be sure to get the right gauge!

The next niggle was that the ultra strong loctite used on the non-reversed threads was not strong enough. So I have had to opt for epoxy there. 

Last drive drain mod was to add some tug-nuts / chain tensioners on the slot drop outs as the rear wheel kept moving, this is understandable as you are imputing nearly twice the load (you pedaling and the motor). It also helps with tensioning the chain correctly.

Reversing the drive side of the bike i.e. chainset and sprocket (for pedals) on left hand side of bike. Is . . . problematic. Not only is the sprocket thread now the wrong way around, but also the pedals.  

Most of the problems I have had with this bike. In fact 99% of them could have been avoided by using a hub motor. USE A HUB MOTOR!

DIY Long Tail E-Bike - Chapter 4 - Lights

Hah! The headlight is serious overkill. Splashes light all over the place. So I had to add in a smaller side light so I could switch the headlight off when cars were approaching. 

Monster Headlight / Sensible Side Light . . .
Introducing this side light meant using a switch. To toggle between them. Ebay again held the answer. The switch is an engine kill switch for a quad bike of similar.

Switch for Side Light and (more importantly) "Captain Shakry" Squeaky Hooter Thing

DIY Long Tail EBike - Chapter 4 -Seating

Unless you want your kids to fall off on to the road, then they will need some handles. I have arranged this by using some rope threaded through some 15mm water pipe, and then hole drilled in deck to fasten with a big knot. All very technical.  

Some padding is a nice touch too. Find some bubble wrap or foam and wrap in cloth, then use a staple guhn to attach to the wooden deck.

Handles for passengers. Quite . . . handy. Sorry

DIY Long Tail EBike - Chapter 4 - Useability

I am sorry to say this bike will not get used very much. Here is why:

  1. Wrong Frame. If you base a cargo bike a on a BMX it will start out not very ride-able. After all BMX bikes are not meant to be ridden long distances. The rear drop spacing are not likley to accept a hub for gears. 
  2. Complex Drive System. The choice of drive system. A hub motor would allow you to have some gears, and maintain a normal right hand side drive setup at the rear. Sooooo much easier.
  3. Not Powerful enough. In the UK the 250W power limit is too low. What is the point. I get sweaty riding this bike, and it has a limited range probably about 15 miles. My "normal" cargo bike will go all day if I am supplied with pies. 
  4. It is heavy. It must weigh 40 kg without a rider or cargo, so you can only really turn it around whilst rolling it (you can pick the front end up and swing around but this requires a large turning circle).
  5. It is noisy. Wrrrrrrrrr. I like to be able to talk to my kids as we wizz along the country lanes. This is somewhat spoiled with the noise from the electric motor. 
  6. No Luggage to Fit. The wide rear deck, and short distance to foot rests means that panniers will not fit.EDIT: You could add a bicycle side car, for luggage space.

DIY Long Tail EBike - Chapter 4 - Hints for Prospective Tinkerers

1 - For the love of crumb cake. Please use a hub motor on the front wheel.

EDIT: Or move your chain drive motor to the front wheel, it is a lot easier, especially on a BMX!

2 - Even with a BMX Frame, you could still have 3 widely spaced gears by using a 3 ring chainset (with shifter and front mech) up front. Mount a rear derailleur for chain tension only. I was planning to do this and may do in the future. 

3 - Use an MTB Frame

4- Use the online calculator to work out if you can build a bike with useful range. 

5- If you are not using a hub motor. Then really pay attention to the chain and sprocket gauges.


I moved the motor on to the front wheel in the end. - Front wheel chain driven ebike.

I also tried a side car for a time. - Thorpy's guide to bicycle side cars.

DIY Long Tail EBike - Chapter 4 -  Two Years On

It is around 2 years now since I completed this long tail e bike, and I have been improving it over that time so as to make it as good as possible. 

"Nearly Finished"
So what has been attempted.

Cushion on Rear Seat 

This was made with some foam, and black fabric, which I then used a staple gun to attach the wood deck at the rear.

Handy for Long Loads


This took a while to get right, choosing an e bike headlight is tricky just because there are so many options. For a short time, I fitted a very bright light, but you do not really need this. A 3W LED head lamp is probably sufficient. 

A rear light can be found on ebay for not much money. LED lights are preferable. 


I only have one gear on this bike, and that has caused a minor problem in that is is difficult to match you motor speed with your pedal speed. I have successfully used a 3 speed switch , to slow the motor to match pedal speed.

Of course setting you gearing correctly is important. For 15mph speed I have opted for 46 teeth front chain ring, and 14 tooth rear freewheel. 


The smoother the tire the less energy will be wasted, if on roads, so unless you are going off road a lot then opt for a semi slick tire. These provide a smooth center ridge, and so knobbles on the side, this is important as if you do ride a heavily laden bike on a side slope, if it slips you will have to be very strong to stop it.

On this longtail e bike bike both the rear and front tires are difficult to remove, if you get a puncture. I have installed so tire slime, and it has worked very well, I have not had a puncture since!


If the rear seat is taken up with children, then where do you put all of the bags and stuff? Well upfront would be the obvious answer. I managed to fit a front rack. Steco do some good cargo racks, which would do the job well. 

Friday, 6 November 2015

Thorpy's Guide to Balloon Bike Tyres

Thorpy's Guide to Balloon Bike Tyres - Intro

The tyres that you put on you bicycle can make a huge difference to how it performs and feels when you are riding it. Balloon bike is a term introduced by Schwalbe (a company that manufactures tyres), to describe high volume tires with a bouncy feel, which usually have a shallow tread being intended for on majority road use.

Balloon Bike Tyres - Not Just Schwalbe

There are a number of offerings from Schwalbe if you fancy a pair of balloon bike tyres, but other companies are now also starting make to high volume semi slick tyres that give a similar effect, some of which I have listed below.

Fitting Balloon Bike Tyres

All of the below tyres bar 1, are 2.35" or 60mm tyres. Above this is unlikely they will fit in a standard MTB frame. It is important to note that the final width of the tyre will change dependent on the width of the rim on to which it is fitted. 

Choice of Inner Tubes for Balloon Bike Tyres

It is worth noting that is probably worth using a wide inner tubes with all of the below tires, as a general inner tube will be stretched very thin when using a high volume tire and increase the chance of punctures.

Thorpy's Guide to Balloon Bike Tyres - Schwalbe Big Apple 

I first roade these in the 50mm (2") size, and there were a very good practical tyre. However, I have since been running a set of 2.35" Abig Apples, which are superb. They have virtually no tread, and are lovely of tarmac / asphalt.

When compared to normal MTB tires or even touring tires (such as the Marathon Mondial) they seem to almost push the bike along, they have so little resistance. You can cut 5 minutes off of a 45 minutes journey, whilst applying the same effect, and the comfort is much increased.

The big apples with the newer tread design, have an endurance compound rubber, which sits very nicely on the road. A lesser compound which is available on "active line" Schwalbe tyres is not so good, but still perfectly adequate.

2.35" Big Apples are available with a race guard puncture protection, which is OK against most things except thorns, which will punch straight through it.  "Green guard" would offer more protection but is only available in 2.00" and 2.15" variants.

I have run 2" (inch) balloon bike tires and whilst these would be OK for a light rider, always go for a 2.35" (60mm tyre) if you can fit them in your frame, the balloon effect is much more pronounced.

Thorpy's Guide to Balloon Bike Tyres - Fat Frank


The fat frank can be had quite cheaply online. It offers the main advantage of having the Kevlar protection belts that has been replaced by "race guard" in the newer big apple tyres. Having tried these tyres for that exacting reason, I found them not to offer better protection against thorns, which will go straight through the kevlar belt.

The main disadvantages are that it has a little too much tread for on road use, and that is uses schwalbes SBC rubber compound. The result is a squirmy feeling tire, that has too little tread for off road use, and too much for on road. 

Thorpy's Guide to Balloon Bike Tyres - Big Ben

This is similar to the big apple in every way except for the tread pattern. 

At this point it is worth noting that 55mm Big Ben tyres, and Big Apple tyres are available with "green guard" which is a super tough puncture protection layer within the tyre. I have owned two sets of tyre with green guard (Marathon and Energizer) and have found that it creates a "dead" feeling when riding the bike. Of course this could because I am imagining things. . .

Thorpy's Guide to Balloon Bike Tyres - Supermoto

The supermoto tyre is in apperance exactly the same as the Big apples. However, as it is design for racing etc. it has been lightened up, by removing the puncture protection belt, and uses a kevlar bead.

The one reason why I would like to try these out is becuase they use a "pacestar compound" which is suppoosed to be super gripping, aznd genrally lovely to ride on.

These supermoto ballon bikes tyres are very expensive compared to other offerings.

Thorpy's Guide to Balloon Bike Tyres - Michelin Pilot Sport

So these are not a ballon bike tyre because that is schwalbe brand, but there are high volume and semi slick with a puncture protection belt. Below image from www.cynut.com  .

I have never run these tyres but I am very tempted to try them if I can find them on sale at a good price. There is a review by a chap who has used these Michelin Pilot Sport Tyres here.

Thorpy's Guide to Balloon Bike Tyres - Hutchinson Low Rider

The Hutchinson Low Rider Rigid Tyre has an imposing profile ideal for beach-cruiser bikes. 

The Hutchinson Low Rider tyre in 2.35 is designed for urban/city use. It's ultra-wide cross-section makes it the ideal tyre for a beach cruiser. The large size provides great riding comfort and a unique look. + 33 TPI carcass for faultless reliability and sturdiness  + Reflex: reflective strips on the sidewalls for increased visibility at night + Unique look Weight (manufacturer): 990 g 

Thorpy's Guide to Balloon Bike Tyres - Maxxis Hookworm

These are really a street BMX type tire but function well (so I've heard) as a cargo bike or commuter tyre.  These are BIG, at 2.5" it is unlikely these will fit in a standard frame. Although you may be lucky.

These do not have any puncture protection which is a major disadvantage, although running these with sealant would get around that problem.

Blurb: Urban assault! 26 x 2.5 Inch (61-559 ISO). Bead-to-bead slick tread with wavy water channels. Large air volume for comfort under abuse. Lightweight single ply casing. 60a durometer rubber for long life. Wire Bead. 1250 grams. 65 PSI Max.

Thorpy's Guide to Balloon Bike Tyres - Schwalbe Crazy Bob

This description provided courtesy of Matt.
Essentially dirt jump/skate park kind of tire it has a stiffened sidewall and rim-to-rim tread, and overall a higher weight capacity than the same size in either Big Apple or Big Ben. No puncture protection belt, but with Stan's sealant in the tubes I've had no issues with mine for several hundred miles now. 

I believe they're grippier feeling and the stiffened sidewall actually helps improve the feel. I think Big Apples felt a little slower, maybe because the sidewall was a bit too flexy. Nominal size is 26x2.35 but mine (on 39mm wide rims), blow out to a massive 2.50!

Tuesday, 27 October 2015

James Bond - Spectre - Review

James Bond - Spectre - Review

The opening scene that we all know and love comes to us from "day of the dead" in Mexico City. Here Bond is pursuing an assassin with a greasy unkempt pony tail, one glance at that oiled tangle of hair and we instantly wish him dead. There is a lovely opening sequence where he is walking over the roof tops casually adjusting his shirt cuffs, and unfolding a nasty looking assault weapon. Various exploits ensue including an exploding building and a brief rest on a conveniently placed sofa. Some of these bits are a little CGI heavy for my taste, but very enjoyable non the less.

The titles (you know naked ladies covered in syrup etc.) are visually stunning with the usual girls and guns, but also a large octopus. My favorite bit was the beauties with squid ink hair, which looked amazing. Whoever thought of squid ink hair should get a medal. Sam Smith provides the vocals, and the song is ideal.

I will get my only negative point out of the way now; that is the running themes of the Danial Craig films almost becomes a bit repetitive. Again we see the female protagonist (2) telling bond he "has a choice" and doesn't have to be a spy. This is all a bit Vespa. Also we see continued the distrust between M (now a man) and Bond, this is confusing as they ended Skyfall on such good terms . . .  .

The globe trotting in the film is extensive Mexico, Mountains (Alps?), Chile (Perhaps), Italy (Rome), London (Obviously) and Austria (Why not?). In what other film would see a car chase interrupted to linger on the views across Rome. . . only Bond!

The humor in the film is just great. The cinema rippled with laughter on numerous occasions. This spurred from the following:
  • Malfunctioning Car Gadgets
  • Name Calling between M and C
  • Bond's Dislike of Health Drinks
The film makers are obviously starting to enjoy them selves a bit more, and the realism of the film gives way to crazy stunts and very unusual chase scenes (think twin engine plane chasing land rovers, whilst sliding across snow with no wings).

Monica Bellucci has a fairly small role, although she looks hot as hell. Lea Seydoux is a great bond girl, and looks fairly convincing whilst running about, and stunning in roughly 10 changes of outfits. Regarding running about: This is not easily done. Remember Denise Richards in World is not enough, her running about was terrible, very unnatural. This curse befalls Jennifer Laurence in Hunger Games also. So well done Lea for convincing brisk on-screen movement.

The problem I have with going to see any bond film is that I have such high expectations. . . . the fact is that this film is easily as good as any of the other films. I love all the bond films (even Diamonds are Forever!), and although a young family + lack of baby sitters prevents a 2nd viewing, I am very much looking forward to DVD o'clock, where upon I an absorb the quirks which make a Bond Film , a Bond Film.

Environmental Consultants Bristol

Thursday, 24 September 2015

Busch and Muller Lumotec IQ-X - New for 2015

Busch and Muller Lumotec IQ-X - Intro

The advances in LED tech over the last 10 years have been amazing. Light provided per watt of power used is ever increasing, and for those cyclists sticking with dynamo powered lighting, the rewards are great.

Busch and Muller form the back bone of the dynamo power cycle lamp market, and they have announced a new headlamp in August 2015.

I won't lie I am quite excited about it. It is similar in build to the Edelux 2, with an aluminum body and 100 LUX rating. Being the beam is wide this probably translates to around 500 lumen, from a 2.4 watt LED.

Busch and Muller Lumotec IQ-X -How Powerful?

The Cyo headlamp from Busch and Muller has proven very popular, and is generally held as being very reliable. At 100 lux, this new addtion trumps previous 60 and 80 lux versions of the Cyo. It features a super wide beam similar to the Luxos range of lights offered by Bush and Muller.

The below beam pictures taken from the Bush and Muller Website  show comparisons between the old CYo Models and the New Light IQ-X.

60 Lux - I ride with this light at present. It is OK off road, Ample on Road)

80 Lux - I have just purchased this light so will report back soon.

100 Lux - Maintains Light Range and adds to Spread.
It is important to note that the beam of these headlights is well placed on the road. With most off road battery powered headlights, there is a great deal of "splash" from the beam with light shooting out all of the place. This is handy off road as it enable you to spot overhead branches (!) etc.

Busch and Muller Lumotec IQ-X - What Will it Look Like?

Below pictures courtesy of Tour Magazin DE.

Busch and Muller Lumotec IQ-X - Is it Worth Buying.

Reading reviews on the web there has been mixed reviews with regards to the casing design of the Luxos Range, most reviews are favorable. The Edelux II has good reviews and is powered at around 90 LUX. With this light I think Busch and Muller are trying to amend there casing design (?) and up the power a little.

If you cycle in the city or other roads with their own lighting, then this light would be serious over kill. By means of comparison a 60 LUX light such as Busch and Muller Lumotec IQ Cyo T  will give adequate light for 30mph road riding on unlit roads. Off road you will have to slow down a bit.

One of the the thing often overlooked if the pattern of the beam. A very powerful light will "project a spot on the moon" but will  give little light for peripheral vision. From the beam shots above I would say this new IQ-X from B&M gives not only a far reaching beam, but a wide one too. Which would in my opinion warrant an upgrade. Of course if you are alreday using a quality 80 or 90 LUX light then the gains will be less.

Waste Transfer Station Permit

Illustrator Devon

Energy Strategy

Monday, 14 September 2015

The Martian - Book Review - Andy Weir

The Martian - Andy Weir - Book Review

I would rate this book 5 stars. I purchased the book thinking it would be a dry read, but despite the subject matter it is a brisk read and highly enjoyable.

The main character (Watney) gets stuck on Mars after a trip there is aborted due to a large storm. And so we end up with the main character, figuring out a way to firstly survive and then gets back to earth. Watney's exploits are recorded in the first person (very informal) by means of a "ships log" type format. If you have read historic ships logs (such as Shackleton and Cook) then you will know they are a bit dry in places. But Weir gets around this by only having Watney reporting on significant events, which fits well with his rebellious or impatient character.

The book is fairly humorous for me there were around 12 laugh out loud moments, normally placed to break the tension of some catastrophe, which made them so effective.

The sections of the book dealing with NASA response are more "normal" in terms of their format. The characters here are fairly type cast as you would expect for any governmental sort of scenario, but there we are. Expect people calling each other by the surname and drinking lots of coffee. I do not suppose that could be helped.

There are some third person paragraphs which lead up to some of the main disasters in the novel. In the first instance I found this to be really effective, but on the second appearance of these sections I found it forewarned you of the impending doom.

Lastly but not leastly the absolute best thing about the whole book is that it reads like the best ever episode of MacGyver you ever saw, with a Science Fiction twist, I was in heaven. From basic chemistry to hitting stuff with rocks the inventiveness of the main character is a joy to behold. As are his mistakes  . . .

Best book I have read in a while.

If you liked this book then you should read South by Shackleton, a real life story of the guys who went to the Antarctic ahead of the attempt on the South Pole (it is free on Kindle). It is similar story in a lot of ways but a real story.

Illustrator Devon 

Wednesday, 9 September 2015

DIY Long Tail EBike - Chapter 3

DIY Long Tail EBike - Chapter 3 - Electrics and Drive System

It would appear that building the frame and doing the normal bike stuff was the easiest part of this DIY Long Tail EBike, when you go off piste trying to think about an ad-hoc drive system the project becomes tricky, but certainly not impossible. In Chapter 1 we saw the concept and beginning of the frame. Chapter 2 saw the frame being welded and first test ride. In this chapter I will explain how I fitted the electric drive system.

Rear Wheel Drive - Things can get complicated even without gears.

First off for your own sanity I would advise a front wheel drive system, this allows for standard configurations at the rear of the bike, were you may need gears etc. and lets face it the rear wheel hub area of the bike is complicated enough as it is.

So for those of you looking for guidance at this stage I would suggest a front wheel drive set up for simplicity.

DIY Long Tail EBike - Chapter 3 - The Law

In the UK you are allowed 250w for a normal bike or 300w for a tandem.

This kind of power will propel 200kg of rider and passengers at around 10 mph on flat terrain, perhaps a bit faster dependent on gearing. But you WILL need to pedal quiet hard on a moderate hill, and you will be pushing up a steep hill. One bonus is that if you a carrying a load the bike will push itself up the hill, you can run along side it if you like!

Please Ignore the Color Scheme.

The law state 15.5mph as a maximum speed which is fine, as this feels quite brisk. But if I were to be asked for my opinion I would ay that the wattage could be raised to 1000w (or removed all together) to allow for hill climbing with a load, so long as a max speed limit of 15mph was maintained. After all you can pedal a lot faster than that on the flat any way! Also speed is a lot easier to measure (by the police) than wattage. To measure peak wattage of a setup, the policeman, policelady or policeperson would have to ride the bike up a steep hill whilst looking at the results from a amp meter and then work out the results based on the voltage. Based on the above it is unlikely you will ever get caught for riding an over power e-bike so long as you do not go over 15 mph.

The regulations also state that you should have a metal plaque on your bike stating the manufacturer and wattage and voltage. As my daughter made up the name for the bike (The Happy Uphill Bike) she is elated at the thought of having the bike labelled as such.

This bike is what is known as a "twist and go" I the throttle in independent of the pedals. After January 2016 bikes like this will not be legal, and all e-bikes will have to be pedal sensor type.

DIY Long Tail EBike - Chapter 3 - Voltage

Most motors aviable are 24 or 36 volt with some being 48 volt. The most obviously advantage to my untrained mind with a 24 volt system is that you only need 2 x 12 volt batteries. Which keeps things simple.

However this leaves you a bit stuck if you want to up your voltage.

A Wide Seat = Plenty of Room for Batteries.

I chose two 12 volt 22ah Panasonic Sealed Lead Acid (SLA) batteries. I am still unsure if this was the right choice. Most SLAs require that they are run at 50% discharge as a maximum, meaning a 22ah battery will only give you 11 ah. Looking at the manufacturers specs however, hundreds or cycles are achievable at 100% discharge, which is similar to the alternative that is lithium ion batteries. Expect to pay 3 times the amount for reputable lith-ion batteries of the same capacity.

You see as you increase voltage the required amp hour capacity of a battery decreases. A 36v motor running at 250 w will require a lower current than a a 24v motor doing the same work.

So if you decide to embark on a project such as this choose 4 x 12v batteries at around 10ah. These can be configured as two sets of 12v in parallel to give 24v or all in series for 48volt.

DIY Long Tail EBike - Chapter 3 - Wattage

It would appear that the wattage written on the side of any motor is a made up figure. A 500w motor may be labelled as a 250w motor so it will sell better in an country (like the UK) where 250w is the legal limit.

For testing I have been running my 250w motor with a 500w controller. And that seems to work fine, and gives much more power than when using a 250w controller.

 DIY Long Tail EBike - Chapter 3 - Fixing the Motor

For those of you daft enough to be considering a chain drive motor solution. You can mount using per-manufactured mounting brackets or build a mount with metal, hacksaw and a welder. In may way fixing the motor is quiet easy. the main problem is how to keep the pedals (required by law) and introdcue a motor without having to pedal "through" the motor.

When mounting the motor, try to place some rubber blocks between the frame and motor mount to reduce vibration noise. I used a chopped up bike tire. The motor mount has to be solid, even a small motor produces a strong twisting motion when under load, so the mount should be securely attached to the frame. I initial bolted the motor to the underside of the wooden deck, but this was not good enough and had to weld a mount in place.

Run Two Chains - Note Chain Tensioned for Pedal Chain

Chain Tension - Only One Side can be conventionally tensioned.

The way I got around this was to buy a flip-flop BMX rear wheel, which as a thread for a freewheel on both sides. However, these hubs are not intended to be used both sides at once as the threads will be opposite when mounted on the bike. One freewheel must therefore be glued ( I used strong LOCTITE) in to position to stop it coming undone when in use.

Most flip flop BMX hubs have two different thread sizes for the 2 freewheels so make sure to get the right size freewheels. One is normally standard size the other will be 30mm size.

On tension of the chain. Whilst you can tension the chain by moving the rear wheel as is normally the case. It is unlikely you will end up with a tight chain on both sides. So I have opted to tighten the chain via moving the back wheel on one side (motor side) and with a chain tensioner on the other side. This works fine, but you will need a rear mech hanger welded on the frame some where so as to attach the tensioner. You can buy a steel mech hanger on ebay for £1.50 so don't go hack sawing one off of another bike!

 DIY Long Tail EBike - Chapter 3 - Gearing

The motor chosen is the Unite Motors MY1016Z2, which is a 24v 250w motor with 10:1 reduction gearing. You will need reduction gearing if you intend to run a chain drive motor. Most motors will produce a bout 3000 rpm, if ungeared and so if you "do the math" multiplying rpm by wheel circumference you will get an answer some where in the region of 150mph as a top speed, which is not realistic.

With a 10:1 reduction I ended up with an rpm of 315rpm, further reduce at a ration of 9:16 by the drive sprocket and freewheel gearing. The tire circumference for a 20" wheel is approx 157cm. A simple excel spread sheet is handy, as you can tweak the numbers and watch the results change.

Excel Spread Sheet to Calculate Speed in Relation to Gearing
I have opted for low gearing as I live in a hilly area, to assume that a 250w motor will pull 200kg up a hill, at 15mph incorrect. In fact it will not even pull 200kg at 10 mph as geared above. An increase in the rear freewheel size to 24 teeth gives a top speed of 7 mph. With more torque for hill climbing.

DIY Long Tail EBike - Chapter 3 - Chains and Sprokets

Who knew!? Did you now there are different sizes of chain? I did not. The most important measurement is the pitch this the the length of each link. Most motors come with a #420 sprocket, this to fit #420 chain, this is a heavier grade chain than normal single speed bike chain, the rollers are larger, although the pitch is the same.

My motor sprocket comes with a sprocket that fits normal BMX chain, and that made things easy.

DIY Long Tail E-Bike - Chapter 3 -Wiring

 The ampage involved is considerable.  A household kettle draws a current of 13A, and even a small e-bike motor will draw the same current albeit at a far reduced voltage. For higher powered motors say 500w the current will increase to 25A and you should start to think about the sizes of the wires you use.

Wiring for a brushed motor is relativity simple. Note doubled up wiring. Switches for lights and "Ignition".

I was using bits from the garage and so I have chopped up an old extension lead, which is 13A. I have then doubled up on these wires, using to parallel wires for each high amp connection. If you wanted to do a proper job then head down to your local motor factors and buy some 25A or even 50A wire.

The thick wire need only be used for the follwing connections:

  • Motor to the controller.
  • Controller to batteries.
  • Battery to Battery Connnections.
You can use thinner stuff for the other connections. The controller came with plug in style connectors, I have cut these off and soldered all of the joints.

The complexity of the other wiring will depend a lot on the controller you are using. Some have more "tails" than others. If you have an ignition switch tail then this will need to be sorted out with a toggle switch, so you can turn the controller on and off. However other tails such as brake lights, can be left unused if you want to.

DIY Long Tail EBike - Chapter 3 - Lights

Joy! With a normal dynamo operated push bike you are limited to 6v systems, but with a huge battery to power the motor and the new generation of LED lights you can have some serious fun with the lights. For the rear light I got some cheap LED side lights for about £6. For the front light I purchased a 12V 27W LED flood light, which is just awesome.

A Front fork with V Brake Mounts is preferential over U-Brakes (as pictured)

A Massive front head lamp will be great to use this winter.

In time I will fit a low power "be seen" light and switch the main front light independently so as to effectivly have a dip and main beam. Alternatively you could fit a hood over the front lamp to direct beam away from drivers eyes.

DIY Long Tail EBike - Chapter 3 - Lessons Learned

  1. 250w will not get you up a hill without pedalling.
  2. Don't buy purple pedals. Even if they are cheap.
  3. SLA batteries are fine. 
  4. A bank of smaller batteries is more versatile than two larger ones. 
  5. FRONT WHEEL DRIVE is easier. Perhaps opt for a hub motor.
  6. You need a geared motor.
Did you miss Chapter 1 or Chapter 2.

Read on in Chapter 4

Please leave any questions or comments below.

Environmental Consultants London

Tuesday, 4 August 2015

DIY Long Tail EBike - Chapter 2

DIY Long Tail EBike - Chapter 2 - The Frame

The mechanical elements and the electrical elements of an e bike overlap some what. You may have to add in extra mechanical elements (extra rear sprockets & battery storage) to allow for conversion.

I have ordered most of the electrical parts needed, but some are coming from Germany etc. so  for now I am concentrating on the frame. In Chapter 1 we saw the basic concept of the bike, and the initial welds, over the last few weeks I have been "sourcing" some thinner tubing and building the rear seating and battery housing section. If you would like to learn about the electrical system the please go to chapter 3.

The main consideration is a large area in which to place the batteries. I had originally looked at using leisure batteries at around 50ah, but these were very heavy and so have opted for 22ah AGL Lead Acid Batteries, which seem to offer a good compromise. I am opting for a 24 volt system.

I have opted for a  a brushed motor, rather then a hub motor. So there is a space requirement for this too. Below is shown the space allowed within the frame for the batteries and motor. Note Duplo Brick for scale, or size 10.5 plimsoll trainer if you prefer.

A large area needed for batteries and motor.

The whole design of the bike is based around allowing enough space for large batteries, which should give very good range during use. For more detail on specification of electrical systems please see Chapter 3 (coming soon). The width of the rear seat makes it look as though it will be comfy.

Do not Underestimate Heel Clearance
Another major factor is heel clearance. It is amazing how much space you need between the bottom bracket and any protrusion further back.

Rear Frame (needn't be this complicated)
You rear frame needn't be as complicated as this one. I was working with thin tubing (10mm), and so I had to allow for frequent supports. After this ran out I switched to thicker 15mm tubing (galvanised electrical conduit), for the lower rack sections. The result is very strong.

The main tubes (dark grey) are a strong carbon steel  tube around 25mm in diameter, with a 2mm / 3mm wall. These were left over from my other cargo bike build and so they are tried and tested as strong enough.

Allow for chain routing. Run a string from the top of the chain cog to the place where the rear sprocket will be, this area needs to be kept clear. I have opted for a smaller front chain ring to allow for a lower rear deck.

For welding I have been using by old gas-less MIG welder, which is cheap and reliable. TIG welding would be neater, as would brazing, but both are more expensive. and TIG welding I have found tricky to master. A gas-less MIG welder can be had cheaply on ebay, and is useful for so many things, particularly if you like fixing things.

The supports rear of the rear axle - Not so good.
The supports to the rear of the rear axle, did not go so well. I am happy with them strength wise, but the design is poor. Vertical drop outs would allow for a stronger rear facing join in this area, but as they are slot drop outs have to be kept clear to allow for insertion of the wheel.

After welding and brushing of joints comes painting. I had some orange metal paint left over from the last bike I built so I used that. TEMAC Howard Rotovator Orange from Mole Vally Farmers.

DIY Long Tail EBike - Chapter 2 - Kit List

Ingredients for frame:

  1. BMX Frame
  2. 15mm Metal Tube Mild Steel (Galvanized Electrical Conduit £11 for 6 meters)
  3. 10mm Mild Steel Tube (sourced from child's play pen, or similar)
  4. 25mm Carbon Steel Tuve (bought from steel stock holder)
  5. Gasless Mig Welder
  6. Gloves
  7. Wire Brush
  8. 4" Angle Grinder with flap disc
  9. Tape Measure
  10. Permanent Marker
  11. Spirit Level
  12. Straight Edge
  13. 2 roles of 0.8mm MIG wire
  14. Hack saw
  15. Approx 12 hours of time.

DIY Long Tail EBike - Chapter 2 - Lessons Learned

  • Always wear gloves when working with metal. Sharp edges can delay things if you cut your hands.
  • If your garage floor is flat then assemble the parts on the flat floor and then add them to the main assembly. 
  • Once you have a few parts lined up using measurements or spirit levels, line up the other parts by eye, it is quicker.
  • Cutting tubes badly and filling with weld is quicker than filing tubes to fit curved edges.
  • Even thin tubing can be very rigid is the framing supports are closely spaced.
If you have question please ask away in the comments section below.

Learn about the electrical system in CHAPTER 3.

Flood Risk

Waste Transfer Station Permit

Monday, 27 July 2015

DIY Long Tail EBike - Chapter 1

DIY Long Tail EBike - Chapter 1- Intro

It has been a few year now since I built my first DIY Long Tail Cargo Bike, and it has been very handy for the right sort of trip. (Skip to Chapter 2?)

A long tail cargo bike is excellent for transporting large bulky items that are light in weight think planks of wood, big boxes and christmas trees. But although I regularly use it for transporting my two children on short journeys (combined load of 40 kg), carrying a heavy load really reduces range.

The main problem is that I live in a hilly area, and any journey involves lots of hills, and lots of sweating. Anything over 15 mils carrying two kids means you will want a day or two off, there is also the the problem of gearing, as typical MTB gears just aren't low enough to pedal up the steepest hills, and pushing a heavily loaded bike is no fun (its actually more strenuous than pedaling). 

The Result

So . . . an electrified long tail will enable me to carry kids around in hilly terrain, for useful distances, more quickly, and if I need some exercise I can always hop back on my "analog" bicycle.

As with all by builds I like to keep budget way low, so I am starting off with bits I have in the garage. Which is a BMX frame!

DIY Long Tail EBike - Chapter 1- Why Use a BMX Frame?

So why use a BMX frame?

  1. Smaller Wheels = Low Center of Gravity
  2. I happen to have a BMX frame spare.
  3. BMX parts are cheap.
  4. Small Wheels equal lower gearing (motors are typically for 26" wheels).
  5. Many have 14mm axles for heavy loads
Humble Beginnings - A Mission "Grave Digger" Frame

DIY Long Tail EBike - Chapter 1-  Getting Started

You will need a welder and a hacksaw a a minimum. Do not be put off by welding, it is very easy. I would recommend a gas less MIG welder for the how user it is cheap and simple.  One can be had on ebay for less than £100, and they are handy for all sorts of things.

Before you start draw a scale drawing of you proposed bike on a sheet of graph paper, a 1 to 10 scale is good and will allow you to use a normal ruler to draw  and scale off with. 1cm = 10cm. So a BMX wheel at 50cm diameter will be 5cm.

A Scale Drawing can help you decide on dimensions and order enough steel.

A rear deck length of  As well as all the normal considerations you will need to leave spaces in the frame adequate for batteries and motors.

To preserve the bottom bracket height measure the gap between the base of the shell and the floor, after you have welded everything back together this will have to be the same as when you stared.

Draw a Line on the floor to help line things up.

Cut the frame (wear gloves) to separate the rear triangle, this frame has wish bone stays which is ideal and saves much faffing. To help get everything lined up draw a line on the floor using a straight edge, this can be used to line everything up. Once welded, it is hard to get everything apart again. 

Again you can see the line on the floor is useful for lining things up. To check for uprightness, hold a spirit level against the bottom bracket shell. There are not many points on the bike were you can put a spirit level without getting a false reading.

Here she is with the lower strut welded in place. Next up is to check that the bottom bracket is at the right height. I will need a front wheel to do that which is in the post!

We are a fair way from mounting the motor and batteries! That's for sure, but you should have already have an idea of what to use so as to leave room for them in you design.

The frame starts to come together in Chapter 2. . . 

Planning Consultants

Environmental Consultants London

Friday, 17 July 2015

"Where does the urge come from? Feeling's believing."

"Where does the urge come from? Feeling's believing."

This is a quote from a BBC documentary which I first saw in April 2015. The documentary tells the story of Captain "Winkle" Brown, a Pilot, Test Pilot and Naval Officer, who started off flying bi-planes and finished up flying cold war nuclear bombers.

In the documentary there is a black and white news outtake from the 2nd World War era where Captain Winkle Brown Lands a "Vampire" Jet on an Aircraft Carrier.

The pictures show the flight crew of the carrier crowding around the plane after the successful landing, at which point the narrator explains what has been done, points out the pilot, and asks:

"Where does the urge come from? Feeling's believing."

Now I don't know why but this short sentence struck a bit of a chord with me, which is why I have bothered to make a note of its origin here.

Three cheers for Captain Brown and pilots of his generation. Inspirational.

Video of clip from program:

Monday, 13 July 2015

Wide Slick Tires for MTB (559)

Wide Slick Tires for MTB (559) 26"

Here is list of wide slick tires for 559 size (MTB), they are all 2.3" (60mm) or OVER.

Most recently found first!

It is worth noting that the below "official" width measurements are often way off. So when you are buying a 2.5" tyre, it may actually measure at 2.3" or less!


  • Mafia LAGOS Snakeskin 26" Bike/MTB Tyre - 26 x 2.5
  • Schwalbe Crazy Bob - 26 x 2.35
  • Cult X Vans 26 Tyre - 26 x 2.3
  • Schwalbe Super Moto X - 26 x 2.4 (But closer to 2.2)
  • S&M Speedball 26" Tyre - 26 x 2.4
  • Michelin Pilot Sport 26×2.3 Tires (Discontinued)
  • Try-All 26 x 2.35 (Discontinued)
  • Schwalbe Big Apple 26 x 2.35
  • Schwalbe Fat Frank 26 x 2.35
  • Schwalbe Super Moto 26 x 2.35
  • CST Cyclcops 26 x 2.4
  • Duro 26x2.30 Slick Beach Cruiser Mountain Bicycle Tires
  • Duro 26" x 3.0" DB1012 Beach Bum Black Tires
  • 26” x 2.45 BOA-G TIRE
  • 2PAK Sunlite Vee Crusher 26"x 3.5"
  • Maxxis 26" x 2.5" Hookworm
  • Hutchinson Low Rider Rigid Tyre 26x2.35
  • Kenda Kiniption 26-Inch Wire TyreTyre - 26x2.3
  •  DMR Supermoto 26-Inch Wire Tyre - Black/Black , 26x2.2
  •  Vittoria Booze Light 26-Inch MTB Folding Tyre - Black , 26x2.3
  •  Vittoria AKA 26 x2.2
  •  Vittoria Tattoo 26 x 2.3
 Life Cycle Assessment (LCA)

Thursday, 9 July 2015

Top 5 Schwalbe 26" (559) Commuter Tires

My preference for tires is a wide, comfortable,  puncture resistant tire. And the below list reflects that.  . .

Top 5 Schwalbe 26" (559) Commuter Tires - Number 5 - Marathon Mondial 

These suckers are a little knobbly for an all tarmac / asphalt commute. They do come with "double" defence puncture protection as an option, which will mean you will hardly ever get a puncture. Life span for these tires is very high, and they will likley last for 12,000 kms.

These tires and there predecessor get very good long term reviews.

Marathon Mondial - Good on Tow-paths, Fire Trails and Dirt

Top 5 Schwalbe 26" (559) Commuter Tires - Number 4 - Marathon

The "classic" marathon tread is available in lots of different sizes, and different grades. For every day value look for the marathon green guard, or for biog spenders there is the marathon deluxe, with double defence puncture protection. Green guard is very good, and I have ridden these for 100's of miles with no punctures.

 Marathon "Green Guard"- Low Rolling resistance and a little tread for the rough stuff.

Top 5 Schwalbe 26" (559) Commuter Tires - Number 3 - Citizen

These tires can be had very cheaply and although they are not as puncture resistant as the previous two offerings I would not hesitate to buy a pair if you are on a budget.

These come in thinner sizes and so perhaps are not ideal if you are a heavy rider or carry a lot of weight in bags etc.
Citizen - Nearly Slick but not quite, very good value.

Top 5 Schwalbe 26" (559) Commuter Tires - Number 2 - Energizer

These tires are made to go on e-bikes, and for some reason this discourages people from putting them on normal bikes. In fact they are fine, they come in a pro version and a plus version. Plus as usual means extra puncture protection.

Energizer - E-bike . . . ANY bike.

Top 5 Schwalbe 26" (559) Commuter Tires - Number 1 - Big Apple (or Fat Frank)

Despite an effective downgrade in the new big apple, they are still a great tire for commuting, you may also wish to consider the Fat Frank. The big apple comes in variety of width sizes, and has "race guard" puncture protection which is the tire's only down side. Which is why you may want to consider Fat franks for the 2.35" size as they are "Kevlar Guard" and in my humble opinion a fair bit more puncture resistant.

If you fancy 26 x 2.15 size. . .  Lucky you, there is a "Plus" option with green guard.

Big Apple - Fat (or Phat) Rolls Lovely and Very Comfy

Top 5 Schwalbe 26" (559) Commuter Tires - Conclusion

Any of the above tires will give you many miles of puncture free commuting, the big apple is such a nice tire to ride on, I am slightly miffed that schwalbe do not offer the 2,35" in a higher spec, but there we are. If you are looking for a 2" (50mm) tire then choose one of the few available with "double defence", as they offer very good puncture resistance with little compromise on performance.

Let me know your thoughts.

Illustrator Devon

Energy Strategy