Re: [ElectricMotorcycles] NooB to Ecycles

[Kevin Caldwell]

High centre of gravity doesn't hurt bike handling, except when stopped. In fact, if all the weight is as close as possible to a line through the rear contact patch and the CG, the roll rate will be maximized, and the higher CG actually helps. The roll is almost entirely generated by the front tire countersteer force, and the longer moment arm it has, the faster the roll rate. (Ref.: "Motorcycle Dynamics", Viatore Cossalter) Of course more mass does hurt handling and loads up the tires more, which is the real problem with adding batteries, not the high CG. Plus  a heavy bike with a high CG is easy to drop when stationary. Kevin Caldwell Andrew Wowk wrote: If you have 20 miles one-way than you just might be able to do it. You'll need a lot of batteries, though. Shooting for anything more at highway speeds is not a good idea unless you know how to build a BMS (battery management system) and have enough money to shell out for Nimh, Nicad, or lithium ion batteries.  Most EM conversions will probably crap out at less than 15 miles at freeway speeds. Keeping speeds below 50 will really help. A Zivan charger, charging from a 120v outlet could probably completely charge the batteries in 2 hrs or so. With lead-acid you are pretty much stuck with a crappy range, or a slightly-better-than crappy range. In the latter case you have to pile the batteries on, meaning handling suffers, and the weight needs to be placed higher in the frame making the bike a lot harder to corner. A few ideas to play around with to maximize range: 1. Use lead-acid batteries with rectangular cells instead of spiral wound to fit more in a smaller space. B&B are a good example. http://www.bb-battery.com 2. Strategically pick the bike you wish to convert. The more space you have down lower the better. You also want a light frame, and a sports bike with plastic to reduce drag would certainly help. Design your battery supports to put the batteries as low as possible while still maintaining enough ground clearance. You could put batteries underneath the existing frame cradle. 3. Pre-heat the batteries before use. I have yet to see how well this works. An electric blanket might do the job well (running from a 120v outlet, NOT the batteries). 4. Removable range-extender batteries of some type. This way you can chose when your bike will feel and handle like crap to get the extra range. Adding battery capacity results in a fairly linear increase in range, i.e., doubling the capacity will double the range. good luck, Andrew