Life in the old mechanism yet it seems

Post by **Stuart** » Sun Jul 13, 2008 8:24 am

I see from MCN that Yamaha have filed a new patent regarding CVT 's for a dirt bike. Wonder what form it will take?
If they are that serious about it (putting it onto competition bikes) they may have made some big improvments to it.

Post by **Byrdman** » Mon Jul 14, 2008 11:45 pm

Let's face it, CVT's are the future. Designing an engine to run at one speed where it's most efficient is going to be a reality, even if us die-hard shifter guys aren't happy about it.

I could see a future CVT being like a variable hydraulic pump with some sort of swashplate that adjusts final drive ratios.

It may just take a giant Japanese manufacturer (like Yamaha) to bring this concept to reality.

oilburner · Post by **oilburner** » Tue Jul 15, 2008 12:44 am

Honda has already a swash plate / hydraulic CVT in production since 2001 in the Rubicon quad and in the new 2008 DN-01 motorcycle. Check this link for pics and info.

http://www.sae.org/ohmag/techinnovations_10-00/04.htm

Unfortunately it's not a standalone unit (yet) but uses a computer to control operation.

andrewaust · Post by **andrewaust** » Tue Jul 15, 2008 9:17 am

Yeah a lot of thought has gone into the technology, damn! It's going to be a bummer when all cycles go to a CVT, will take all the fun out of thrashing those gears.

Reliability is a big factor for myself, nothing like being stuck in the middle of nowhere with a broken CVT belt

Honda Odyssey's where good for that one.

Wonder if all dirt bikes will convert to CVT? Our roadies certainly look like it will go that way.

Post by **Byrdman** » Tue Jul 15, 2008 2:07 pm

oilburner wrote:Honda has already a swash plate / hydraulic CVT in production since 2001 in the Rubicon quad and in the new 2008 DN-01 motorcycle. Check this link for pics and info.

http://www.sae.org/ohmag/techinnovations_10-00/04.htm

Unfortunately it's not a standalone unit (yet) but uses a computer to control operation.

I have seen the Honda hydraulic CVT, it's a very nice unit. When I was with Yanmar, they had us buy one of those ATV's and send it back to Japan for some sneaky reverse engineering!

I was thinking about a similiar concept but not hydraluic. Like a simple, dry CVT transmission but instead of speed and centrifugal force adjusting the diameter of the sheaves, it would be some sort of variable swashplate that would adjust depending on driver input.

oilburner · Post by **oilburner** » Wed Jul 16, 2008 2:10 am

The Milner roller based friction CVT appears to be the ideal solution for motorcycles. The 15Kw (20hp) version is said to be no larger than a soda can!

Visit the link below for an overview:
http://www.intersyn.com/index_files/MilnerCVT.htm

Click http://www.intersyn.com/index_files/Page383.htm for animation and much more detail.