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Like many others I decided to quit waiting for a decent electric road bike at a reasonable price, so I built one out of a spare bike I bought off eBay for about $700. I based mine on a '82 Yamaha turbo because 1) I have the ICE version (hence the spare), 2) I like that it is fully faired so it looks 'normal' and 3) it's a shaft drive and one of my main goal was to make it as maintenance free as possible. Shaft drives weigh a lot more and are not as efficient as chain drives, but they are maintenance free. Here is a picture of the finished product. Like Stryker (who built the 72 volt version) I live close to work so distance was not an issue, but speed and performance were, as I have over 3 miles of a rather steep curvy road to go home on. One big thing to consider when doing this is the finished product. Like Stryker I am using AGM sealed lead-acid batteries because of convenience. But since I like the final product so much my goal has always been to upgrade it to some Li-Ion or Ni-MHyd batteries as soon as the become commercially available. It would shave 100 lbs off and give me twice the range, so it's an investment worth making.
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Signing UpStep 1First, find a donor bike
I have an 1982 Yamaha Turbo. It looks like this. I also had a spare-parts bike (that I bought off eBay for ~$700). It was, for the most part, complete but in pieces.
I decided that I was probably not going to use the spare-parts bike for anything so I stripped it.
I decided that I was probably not going to use the spare-parts bike for anything so I stripped it.
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motor start and run capacitors are they not required for your conversion?
as you have not included that in your list..
Similarly you can buy a thick plate (deep discharge) battery in a wide range of sizes regardless of what they are called, though it is often the case that the most popular sizes used cost less.
Additional gears also mean additional weight and complexity too. Most productions EVs (Leaf, Focus, EV1...) only had one gear. As a matter of fact, the EV1 was the fastest production car GM had ever made up to its demise in 1995; it could go 183 mph on one gear...but it also had a 20,000 rpm motor :)
The trick is to decide what range of top end you want and work out the tire rpm vs. motor rpm to put your motor in it's sweet spot . I use the belt drive to get me that ratio. If you don't do this (and just go direct) you run the risk of bogging down the motor and buring it up. Does that help you a bit?
I see you asked this question in the comments under another step too and no one has answered. I believe no question is a bad question if you don't know the answer, and if you are afraid to ask you may never learn. I'm just sorry you had to wait till now to get a response which you might not even see. (I'm not sure how the notifications work on this site)
There is no transmission so no shifting. In this project the motor is directly connected to the drive shaft by a belt that looks similar to the ones used on Harleys. The author suggests using a chain drive bike as opposed to a shaft drive, for better efficiency. (The shaft must turn some gears back in the differential where it connects to the back wheel which makes it less efficient but also lower maintenance.) If you did this the motor would be connected directly to the chain by a sprocket. Still no shifting.
As for any compromise in torque or speed you don't need to worry. Electric motors have so much more torque than an internal combustion engine that special steps need to be taken to keep it from ripping apart the drive-train, and speed is determined by volts so it's all about the batteries you choose.
Hope this helps.
Thank you for answering this question. More towards your question; any time someone asks me a question or makes a comment about an I'be that I authored I get a notification sent to my appointed email (as your comment did). More so, I try to get back to them in a timely manner, but if the notice comes when I 'm not in the office and/or it gets lost during the holidays it may get deleted.
However, I often find that if somebody asks a question that is already answered in the I'ble itself by the time I get to answering them they have already finished reading through the I'ble completely and found the answer themselves; they just don't post the retraction of the question. Or, as in this case, usually some interested 3rd party restates the I'ble as an answer. Either way the systems seems to work.
I also know that if they have a question that cannot be answered in the I'ble, and no one has asked the question before in the comments section, most I'ble readers get an answer in a few hours (a day or two at the latest). Most I'ble authors are that diligent.
Accordingly, if the question is legit, and has not been addressed before (including in the comments section) and was not promptly answered by the author, most I'ble readers will hound us two or three times before we realize we over looked the question. This is acceptable as well.
In summary, I do appreciate you answering this readers question. However, if you read through the whole I'ble, and though all of the comments as well, you will have seen that his question was already answered [several times] in several places. If I didn't answer this question, and the reader didn't bug me for a reponse, and if nobody else bothered to answer him (as you did) chances are the question ahs already been asked and/or answered some where in the I'ble. Chances are it didn't get ignored on purpose.
Great instructable by the way. I'm now itching to try this myself. I have a very long commute so it wouldn't work for that, but I could always use it for short local jaunts.
search "Irobot battery"
Ed
A Marine (or RV) battery may not beable to deliver as much power instantly but can hold a much larger charge and deliver power for a much longer time. This type of battery usually weighs considerably more than a starter battery of the same physical size and voltage.
The bottom line: the more AmpHr rating, the further you can go.