bike/scooter cvt

[minimac]

If that's true, that's really awesome for the notched V-belt. The advantages sure would outweigh the roller chains.

[Grant-53]

It is likely cheaper to manufacture a sheave system than to cut a bunch of gear teeth.

[Stubby79]

If you ask me (even though you didn't), the way to go would be to have a CVT for getting up to speed, and then be able to switch it in to a fixed gear once up to speed.

I also assume the reason belt driven CVTs are only 80% efficient is slippage, which is the main reason friction belts are less efficient than chains, and why a timing belt is not. The other losses come from flexing/compressing/decompressing the rubber.

[Grant-53]

A dual belt system with a V belt over a timing belt and a timing sprocket at the drive and the base of the sheave. Hmmm

[ASV]

i believe the most common problems with the gy6 CVT are
the constant movement of the belt
(the clutch is on the wrong end)
and gearbox final drive
( each gear interaction cost a few percent efficiency)

I would move the clutch to the drive pulley like a comet.
A giant 17 inch serpentine pulley on the back wheel and a 2 inch
pulley on a real swing arm axle jackshaft
it would weigh less handle bumps better
and be more effective

[johnny77]

I have a bit larger bike I have tried using a flat cog style belt to compare to a sealed roller chain mind you this is final drive not in the transmission. This set up lost a average of 1.25 to 3 mpg on a 83 550 Yamaha Maxim. I tried thinking the weight reduction would help however it didn't. I put back on my chain after trying several adjustment. I even went as far taking drive pulley off and machining as much mass off as i thought remotely safe to do. http://www.cyclingnews.com/features/...ve-whos-faster found this link when i was trying to figure why.

[ASV]

I had read the study a number of years ago

a chain starts off with fantastic numbers at lower speeds and power levels
but the friction builds fast as power goes up

with a conventional motorcycle belt you start with crummy numbers
from the needed high pre tension
but it never really gets much worse even if you pour on the power

yeah that's why I prefer a microv belt, with as little as 10 pounds it becomes self locking
and it still has the self leveling friction curve but has far better power consumption at low power levels
this is what makes it a favorite with car designers

[cRiPpLe_rOoStEr]

The advantages I see with belt drive is that it won't require the sprockets to get also replaced like it's done everytime a chain-driven motorcycle has the chain replaced, plus it won't require lube.

[gil]

Originally Posted by cRiPpLe_rOoStEr

The advantages I see with belt drive is that it won't require the sprockets to get also replaced like it's done everytime a chain-driven motorcycle has the chain replaced, plus it won't require lube.

One of the things that I don't miss about "real" Motorcycles.

Gil

[cRiPpLe_rOoStEr]

Originally Posted by gil

One of the things that I don't miss about "real" Motorcycles.

Apart from Harleys and similar models, and also the BMW G 650, I can't remind of any other belt-driven motorcycle.

BTW what are the other things you don't miss about them?