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  1. #1
    Junior Member
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    Jun 2020
    Mid Missouri
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    1970 Honda CT90 Electric Conversion

    I have a 1970 Honda CT 90 Trail that I've owned since it was new. About the only time I ride it now is to the mail box in summer. Recently my son, who is a motorcycle mechanic, had to rebuild the carb due to a leaking float. It runs like new again.

    Being a retired electrical engineer, I've been thinking about converting it to electric for several years. Recently I decided to go ahead with the project and have already made a couple of mistakes. I want to keep the bike looking as original as possible. My first thought was to use a mid mount motor and keep the original rear wheel and chain drive. Due to problems with the chain drive and lack of space for batteries, I decided to go with a hub motor and use the engine space for batteries.

    I bought another swing arm from eBay to modify for the extra width of the hub motor. I want to keep the chrome rear wheel so it matches the front. I decided on the QS250 3000W 50H V3 Spoke Hub Motor with drum brake. I contacted Buchanan Spoke & Wheel in CA. and they indicated that the hub motor could be laced into the 17" wheel. After receiving their reply, I ordered the hub motor and a new chrome rim and had them shipped to Buchanan. Immediately after buying the motor and wheel I received another message from Buchanan, "Just a warning, that chrome rim going to one of those large motor hubs is not the best idea. Those motor hubs are generally 8-10 inches in diameter which is much wider than a CT90 at just over 5”. You’ll be running into quite a bit of bowing, even if we only run that wheel cross 1. An aluminum rim would be a much better bet. If you buy one pre-punched elsewhere at least there is a chance that we might reangle it to mitigate some of the spoke bowing issues, and if you buy one from us we can angle it for that large hub. A chrome rim is, pun intended, set in steel and there isn’t any adjustment to be made. We can certainly do it, but we definitely do not recommend that." GREAT, after I've already spent $750!

    I sent them a reply asking if they had a 17" alum. wheel in 1.4" to 1.6" wide. I just replaced both tires on the bike and any wider wheel would cause problems with the rear fender. Presently waiting on a reply and doing a lot of thinking!
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    Last edited by MegaWatt; 19 September 2020 at 0907.


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