Rubber cushion drive in rear motorcycle wheel

General Discussion about large electric scooters and motorcycles and other things with no pedals.
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Harold in CR
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Rubber cushion drive in rear motorcycle wheel

Post by Harold in CR » Nov 15, 2017 11:42 am

Is there any logical reason why I need to use the rubber cushion drive on my 3 wheel motorcycle drive system using an electric motor and a 2 speed dog clutch tranny ?

I have extensions made for the swingarm and ready to weld in place and have to cut off the 5 "fingers" on the Can Am Spyder belt sprocket and drill 6 holes in it to mount a 3/8" steel plate from it to the rear wheel.

The tranny should only be shifted in a really slow or stopped speed once I get off this 1200' elevation down to the main road. I can't see why the rubber is necessary with a belt drive and electric motor instead of a pulsing engine gear drive on a normal motorcycle.

What say ye??
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mistercrash
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Re: Rubber cushion drive in rear motorcycle wheel

Post by mistercrash » Nov 15, 2017 2:17 pm

I'd say the cushions will help in making the belt last longer, but if you have to get rid of them then just do it.
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Chalo
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Re: Rubber cushion drive in rear motorcycle wheel

Post by Chalo » Nov 15, 2017 2:50 pm

Cush drive is like a shock absorber for the drivetrain. It stores and gradually releases transient force peaks, reducing the maximum forces that are transmitted to the drive components. The biggest peaks aren't generally related to the pulses of combustion, but rather to inertial loads from hard shifts or from wheel feedback. If you have reason to believe that those forces will be lower in your vehicle than in the vehicle as designed, then it may not be a problem to omit the cush drive. I'm guessing that leaving it off would at least increase wear, though.
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fechter
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Re: Rubber cushion drive in rear motorcycle wheel

Post by fechter » Nov 15, 2017 2:57 pm

I had those on my old Honda. Without them, you run the risk of breaking gear teeth (in the original setup). If you're using a belt, the belt will give a considerable amount of shock absorbing like those cushions. I'd say get rid of them.
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Harold in CR
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Re: Rubber cushion drive in rear motorcycle wheel

Post by Harold in CR » Nov 15, 2017 4:16 pm

This will be a toothed belt similar but more stout than a timing belt. No shifting under load and a 3 to 1 ratio for less stress at takeoff.

Will wait for a few more comments and appreciate those already posted.

Thanks guys.

Harold
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Buk___
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Re: Rubber cushion drive in rear motorcycle wheel

Post by Buk___ » Nov 15, 2017 4:20 pm

Harold in CR wrote:Is there any logical reason why I need to use the rubber cushion drive on my 3 wheel motorcycle drive system using an electric motor and a 2 speed dog clutch tranny ?

I think I would look at it the other way around. Is there anything to be gained by removing it?

Harold in CR
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Re: Rubber cushion drive in rear motorcycle wheel

Post by Harold in CR » Nov 15, 2017 6:13 pm

I think I would look at it the other way around. Is there anything to be gained by removing it?
Yes, there are 5 of the fingers to be removed, and, no way to attach it to a flat disc to bolt it to the wheel. I also reduce nearly 1.5 inches of width so it all fits in the swingarm.
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John in CR
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Re: Rubber cushion drive in rear motorcycle wheel

Post by John in CR » Nov 20, 2017 9:22 pm

If you have a choice, keep it to reduce shock in the drive system when you activate regen.

Harold in CR
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Re: Rubber cushion drive in rear motorcycle wheel

Post by Harold in CR » Nov 20, 2017 9:24 pm

They are already cut off and the sprocket is mounted on the wheel with a 1/2" thick spacer.
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Re: Rubber cushion drive in rear motorcycle wheel

Post by John in CR » Nov 24, 2017 10:24 am

If this will be powered by your MidMonster, then the 2 speed solves all the dual use (big road top speed and quite slow steep climbs with a big load) worries I had in terms of gearing. Just be sure the low gear goes fast enough for your most used riding within a few klicks of the house, and high gear isn't geared for an unattainable top speed for use on the big road. Something around a 2:1 gear ratio or slightly less should accomplish that. If you need to switch to high frequently, then you'll end up too steeply geared for much of your more local climbs.

The 2 speed also makes it less important to push to as high a voltage as possible. I'm running my stock MidMonster at somewhere around 15kw peak input with a 30s pack, but I'm only able to go that high because my small wheel puts me geared just right for my roads and load. If I ride foolishly with too many full turbo takeoffs, then I could heat damage my system, so I save that for the opportunities to teach motorcycles a lesson in electrics. 28s and a pair of the max 70A controllers I mentioned is perfect and economical for your needs. Gear for a no-load speed of 95-110kph in high and 55-70kph in low, I think would be the optimum gearing for your needs...maybe a bit slower for low gear if you want less than a 30mph top speed for local riding.

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