John in CR wrote:...It's not just the width at the axle, but the CG and wheelbase. I typical DS MTB puts you so far back relative to the rear contact patch that you simply won't be able to make use of all that power. Look how far rearward LFP's rear tire is relative to his saddle to be able to handle crazy high power...
Beachcruzer wrote:How about a mid-drive? Fabricating a frame mount for that motor won't be any more involved than building a whole new swing arm. Left-side chain straight to a bolt-on sprocket. Keep the donor-bike pedal drivetrain on the right. No need to mess with complicated reductions, but the chain drive will allow you to fine-tune gearing. Now your 30-lbs motor is in the center of the bike. Yes, you'd have to switch donor bikes, but yours isn't really the best for this build anyway. Switch it for something steel with plenty of space in the triangle. Then you can weld on it, stretch it, bend it. Spend the savings on components (brakes and, um, brakes) because the weight savings of your aluminum frame is insignificant compared to the motor and batteries. And you're going to have too much power to worry about weight anyway.
John in CR wrote:With a 50lb hubbie I hope he wasn't thinking about trials or other off road type riding. BTW, even with a far longer swingarm and much lower saddle and my big wide load leaning forward my Hubmonster driven SuperV has no problem lifting the front wheel. Actually, for me that is a bit of a problem...at least until we have a better means of throttle control. In the meantime I need to stay away from ebikes that are almost unicycles with a training wheel for street riding, and leave getting airborne to you experts. That doesn't mean I don't want to help come up with an ebike for you that meets your fun quotient going downhill, and is loads of fun on the way uphill, since at some point in the future downhill racing will actually be a lap instead of just downhill.
MadRhino wrote:John in CR wrote:...It's not just the width at the axle, but the CG and wheelbase. I typical DS MTB puts you so far back relative to the rear contact patch that you simply won't be able to make use of all that power. Look how far rearward LFP's rear tire is relative to his saddle to be able to handle crazy high power...
True that for pure acceleration on pavement, a longer wheelbase that is obtained by extending the swingarm will make the bike much easier to control by placing the weight in the front. Then, one may consider that trial motorcycles are not designed with a longer wheelbase nor place the pegs further forward, despite the extreme torque that they are capable. For some riders, lifting the front is not an inconvenience that limits the use of the full power, but a desirable consequence of the torque required to control the bikes vertical acceleration as well as the more conventional horizontal displacement.
dozentrio wrote:drill holes around the perimeter of the "rim" and lace it. May need custom spoke lengths. Should work, in theory. Can't say how well. Good luck!
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