Bor Yueh BY-201 Front Rack Review

Bor Yueh BY-201 Front Rack Review - Intro

I needed to fit a child seat to the rear of my bike, and wanted panniers for shopping too. So front rack is the route I went. This unlike a "lowrider" rack allows you to use full size rear panniers on the front of your bike.

A few years ago, people would have started talking about centre of gravity, but thanks to the marketing powers of firms like Salsa, "bike packing" sees luggage mounted all over bikes, typically very high up. I am not saying it is good, but it has become more trendy to have an unstably loaded bicycle. So I should not need to justify the whole COG thing.

Update: 06/09/2017

I have tested this rack with a 35kg load. Which consisted of 2 large panniers and a medium sized child. I travelled 10 miles with this load and bumped down curbs, and did some violent steering. All good. So a bit stronger than that 10kg mentioned on the website.

Smallish RAck - Full Size Panniers

Bor Yueh BY-201 Front Rack Review - Fitting

The rack comes with a selection of nuts and bolts for fitting, as well as plates for mounting, and what not. The only criticism here would be that the bolts are all screw driver type bolts and not allen key variants / jobbies.

No Caption - Self Explanatory 

You will require a hole in the fork crown (where the mudguards are bolted on) and also some forward facing rack mounts on the bottom of the forks. I doubt this would fit on to mudguard mounts, although there are some spacers provided which may get this to work.

Bor Yueh BY-201 Front Rack Review - In Use

I have owned one of these a few years ago. They are a good rack. Issues it for 2 or 3 years with no issues. So this is a 2nd purchase, which must count for something.

As mentioned in the intro this puts your luggage above 6" above low rider height. This really doesn't bother me in the slightest, and I can use any of the rear panniers I already have on the front of this bike.

Bor Yueh BY-201 Front Rack Review - Photos

View from Above - Lack of Allen Bolts is a Shame

Fixing are however, Sturdy

Mounting Point at Fork Crown 

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TerraCycle Chain Idler and Chain Tube Guide

TerraCycle Chain Idler and Chain Tube Guide - Intro

I think these chain idlers and chain tubes are mostly used on recumbent cycles, but there is also a benefit to using these on any bike where there is a long run of chain, such as long tail cargo bikes or longtail cargo ebikes.

In fact the latter of these two alternate options is where I am using the TerraCyle idlers and chain tube.

My Bike - Nicer Pictures to Follow

TerraCycle Chain Idler and Chain Tube Guide - Idlers Explained

Idlers are a sprocket which can run on bearing or bushing and provide a mid point upon which the chain may be guided. TerraCycle do two types of idler, one for loaded (power) chain i.e, going towards the pedals under tension, and one for unloaded (return) chain going away from pedals which is normally slack and floppy.

The loaded idlers are toothed, and come with alloy or titanium sprockets, and the unloaded variant come with no teeth.

The mounting brackets for these idlers typically incorporate some sort of lateral slider, so the the idler can move from side to side, but not up and down.

You can buy the idlers separately or buy a kit. The idler will run on a shaft and this shaft is clamped to the bicycle frame. There are a limited number of clamp sizes available. Below nice images courtesy of TerraCycle, terrible blurred scruffy images below courtesy of me.

Note Shaft for Lateral Movement

Loaded chain run over the top of idler. 

TerraCycle Chain Idler and Chain Tube Guide - Chain Tube Explained

The chain tube is used to stop the unloaded chain flopping about during its trip to the rear sprocket. I have often seen these on bike and thought how terrible they are, but in fact they work really well, even on loaded chain, provided the chain does not exit or enter at a steep angle.

Chain Tube

Some very long tails use very long lengths of chain tube. . .

Mega Chain Tube

TerraCycle Chain Idler and Chain Tube Guide - My Setup

So as mentioned I used these on a longtail ebike, I want to introduce a triple chainring up front but I had to divert the chain under the rear foot plates.

Chain Idler used to direct chain under foot plate. 

Through no fault of the idler kit the gearing did not work out, (running 5/6/7 speed chain on a single speed rear sprocket is not pretty or quiet), so I opted for a larger front chainring, optimised to match speed of front hub motor. It is a really good option, and I can use the idler to tension the chain if required.

As above but different angle.

The kit I purchased (for Xtracycle Freeradical) also included a chain tube, which I used to stop the chain slapping against the lower rear chain stay.

Chain Tube - Way better than it looks.

One of the most important things for me is that the idler and tube both run quietly, there is little in any rubbing noises, which I have experienced on say after market chain tensioners in the past.

Most of the attaching for the chain tube is down with zip ties, which means that clamp sizes (as is the case with idlers) do not have to be worried about.

TerraCycle Chain Idler and Chain Tube Guide - Conclusion

Chain tubes are a very easy way to introduce some form of chain management to your bicycle / tricycle / quadracycle, they can be attached with zip ties and simple brackets. 

Idlers are trickier to fit, but if you can buy a kit to fit you model of bike then it should be a doddle. 

They really do make for a quieter and more pleasant ride. 

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Bafang BPM Review

Bafang BPM Review - Intro

I you are looking for a large heavy duty hub motor at a relatively low price then look no further then the bafang BPM. At nearly 20cm (8") in diameter it is large. But is is also powerful, with lots of torque.

The Bafang BPM comes in 48v and 36v offering at 350w and 500w power setting, although in reality, these motor can be run at all sorts of wattages and voltages.

In a 20" wheel, the spokes will be short -  110mm approx. 

If you are reading this having noticed that your ready built ebike has a Bafang BPM installed then well done, you worries are effectively over. Spares (yes spares) are available for this motor, including gears and clutch assemblies, so it should last along time. Your main worry would be overheating the motor on a long up hill.

Bafang BPM Review - In Use

In use the most noticeable thing about the BPM is the torque, and how quite it is.

There is a little lag between applying the throttle and starting to go, but the acceleration is rapid, and hill climbing is strong.

Disc Brake Mounts are available.

Bafang BPM Review - RPM Variants

The revs per minute of the motor will ultimately dictate the speed at which you bicycle travels. I have opted for a 230 rpm variant, which with a 20" wheel will give a top speed of approx 14 miles per hour. 15mph is the legal maximum in the UK. So if you are using this motor in a 26" wheel, then you will require a a lower rpm version.

A simple excel sheet can be used to give speed vs rpm.

This RPM vs Speed Spread Sheet can be down loaded here.

Bafang BPM Review - Choosing Voltage

Typically a higher voltage battery pack is more expensive. But if you live in a hilly area it is probably worth it. Here is why . . .

A motors wattage, is obtained by multiplying the volts by the amps it uses, so for example, my 48v motor will use approx 10A of current to produce 500W, a 24 volt motor would have to use 20A of current to produce the same power output.

So if you use lower voltage you will require:

1. A higher performance battery.
2. Thicker wires to connect everything up.

Add to this that fact that a motor normally produces far more power than advertised, and you end up with a powerful 24 volt system drawing 30 Amps sometimes.

Bafang BPM Review - Choosing Wattage

Always choose the 500w variant. If you are legally required to use less power then, use a smaller controller. I have read there is no difference between the 350w and 500w versions. I have also read that the 500w version has wider stators (part of the motor). . .  either way the 500w version is normally the same price.

Clearance for mounting brakes etc. is limited.

Bafang BPM Review - Batteries

I have tried to assemble my own battery pack, and wish I have never started. It is not easy. Read my guide on buying a ebike battery. But ignore the last chapter, building a battery is waaaaaaaaay hard.

Again clearance is limited for forks with wide stanchions. 

Bafang BPM Review - Fitting

Forks. Do not use aluminium. There is a guy on youtube who did this, the torque will split the dropout.

The axle on the BPM is a funny size, it is 13 - 14mm on outer edges, but 10mm on the "flats". I presume this is to stop the axle turning in the fork. The BPM comes with torque washers, and various other wasters.

Steel forks are best. But try and choose forks with narrow stanchions. I had to squash by stanchions in a vice to provide clearance for the hub body and disc rotor, which was not very nice.

So chunky BMX forks, are not a good choice, especially if you choose to use disc brakes. 

Bafang BPM Review - Conclusion

There are better hub motors out there than the Bafang BPM (MAC for example), but I do not think it will be beaten on value. 

It offers bags of power. 

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Thorpy's Guide to Bicycle Sidecars

Thorpy's Guide to Bicycle Sidecars - Intro

This sidecar project is a follow on from my DIY Long Tail Ebike which I think was nor very reliable of useful. The main problem was the drive system, where the rear sprokets kept coming undone during use owing to a reversed thread.

Sidecar for Bicycle. Mixed Results.

So how to get around this? At present I have the pedal chain and the motor chain driving two sides of a flip flop hub, so one thread in the wrong way around. By adding a second driven wheel to the sidecar perhaps this would fix things. No it won't. But I present my findings anyhow.

Thorpy's Guide to Bicycle Sidecars - Research Summary

I know nothing of sidecars, so I did a bit of read on the web first the main thing to realise is that a bicycle side car will need to hinged. Other wise you bike will probably fall over going around corners. A sidecar on the left of the bike for example that is not hinged will result in rubbish left hand cornering, as you will not be able to lean in to the corner.

The only non hinged bicycle sidecars that you see are either the BMX racing ones (where the sidecar is presumed to weighed down with a human whilst riding) or the taxi type things they have in the Philippines (which are named after King Philip of Spain by the way).

So in short unless you side car is heavy or permanently loaded then you will need a hinge.

Thorpy's Guide to Bicycle Sidecars - Motor Driven Wheel on Sidecar

So with nothing but I skewed common sense to guide me I built the side car, welded it on, use some heavy door hinges (steel not brass!) I mounted the motor and went for a test drive.

Note Mounting Plate for Motor

The result. With a hinged sidecar there is not enough down pressure on the wheel to create adequate traction. Of course when loaded this would work OK, so if you had you side car mounted with big heavy seat or a heavey wooden box, this approach may work. It didn't for me.

Thorpy's Guide to Bicycle Sidecars - In Use

So since this first failed attempt I have switched the motor on to the front wheel to make a front wheel drive chain driven ebike. This has proved a really good move, and I now have a reliable drive system. But I thought I would test out how usefull the sidecar was being I had gone to the trouble of making it.

So apart from the extra width when empty you would not even know the side car was there, the bike corners as normal, and when the hinges move the tire moves in and out from the bike  slightly, which you think would be noticable but whilst moving it isn't.

Right Hand View

BUT what about when you load up the sidecar? Oh dear. I put 50 kg - 60 kg of logs in sacks in the sidecar, and things went wrong. Now there is a greater deal of pressure on the sidecar wheel, and as a result the friction with the road is greater, the hing effect is now very "sticky" and this had some "interesting" effects on steering.

Hinges

Hinges

Something that is also perhaps a bit dangerous is that when you turn right the cargo bed widens, and loose sacks of say logs, will slump down in to this new widened space, and you will not be able to get the bike upright.

The ONE thing that is good, is that the bike will stay upright when you are loading it, although you have to be careful not to knock it over.

Thorpy's Guide to Bicycle Sidecars - Recommendations

Some really big spring in stead of hinges might be an idea. So you bend when going around the corner, and the hinging effect is limited.

I have seen design with a stabalising bar that you can use when loaded, and take off when empty. Best of both worlds.

Side Car Size Based on Euro Crate Size 400 x 600mm

Rear Dropouts Made from Plate Steel

 A side car seems to bring all of the disadvantages of a car, with all of the limitation of a bike. So Is not really very good. It would be OK for large light loads, but so would any long tail cargo bike + ratchet straps.


A sidecar would be useful for a permanently loaded application such as a rickshaw with heavy seat and canopy, or perhaps some sort of micro coffee kiosk. But for the occasional /one way cargo carrier it represents a world of confusion.

I will be hack-sawing this off in the next few days.


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Chain Driven Front Wheel Drive Ebike

Chain Driven Front Wheel Drive Ebike - Why?

If you are trying to do an ebike on the cheap then you might be a bit resistant to the thought of spending £200 on a Chinese no name hub motor, with lots of plasticy control and unessassary electronics.

This is why I purchased a chain drive motor, it was about a third of the price of a cheap hub motor. In fact I got everything I needed to electrify my bike for £180 including batteries (Panasonic Batteries!).

Be Prepared for Ugly

The result is a dog ugly bicycle that I know I can get parts for if they go wrong becuase I bought all of them individually.

Chain Driven Front Wheel Drive Ebike - How

You will need the motor. Unite Motor Company make lots of different electric motors. You will need one that is geared down for torque.

You will need to mount the motor above the tire quite high up, where it will not stick out too much. Or you can mount is sticking out of the side lower down, which make the bike less wobbly (lower centre of gravity).

BMX Rear hubs are 110mm OLD, i.e. the drop out are 110mm spacing. Front forks are 100mm spacing so you do not need to widen them much to fit in a BMX rear hub.

In my case I sawed off the drop out on the left hand side (right hand side in pictures) and welded back on. This was an easy job as you can use the axle to hold everything in place. Just be sure to warp some tape around the axle to stop the weld blobs sticking to it.

Note Re-positioned LH Drop Out (Right Hand in Picture)

Being you have just misaligned the drop out the wheel will not sit centrally in the forks so you will have to dish the wheel a little more so that the rim comes back to centre. You will need a spoke key to do this.

Plate Welded on to forks

The plate will need to be quite thick, even a small motor will flex a thin plate, a diagonal support to the rear will help keep things ridgid. Mark the holes for the bolt carefully, and lengthen the hole with a file so you can slide the motor away from the motor to tension the chain. Nyloc nuts are advisable.

This is so much simpler than trying to fit a chain driven motor to your rear wheel, whilst keeping the pedals. If you are running a low voltage (24v) system like this one here you will need fat wires to avoid reistsance as the wires will have to run from the back of the bike to the front, which in this case is about 1.5 meters.

To look at the whole bike, please visit my DIY Long Tail E Bike Page

Close-up of left hand drop out.

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Illustrator Devon 

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.

NOT FINISHED - FURTHER "IMPROVEMENTS".

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

Lights

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. 

Speed 

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. 

Tires

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!

Luggage

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. 

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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.

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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.

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