View Full Version : Cvt

06-15-2009, 10:46 AM
Does anyone know of a good CVT? Our CVTech CVT sheared off the plastic buttons on the secondary twice. Once in March and the other in Wisconsin at this years event. I saw some teams running Gaged Engineering. Does anyone know how well it worked for them.


06-15-2009, 08:46 PM
The buttons are a maintenance item and need to be replaced every season. If you didn't get too many miles out of the 2nd set of buttons you likely scored your helix up and it's eating the buttons. The helix needs to be smooooth to work properly you probably need a new one. Wouldn't hurt to replace the big outer bushing too (the one the helix fits into, not sure the name of it) as it will let the helix bind a bit and also prematurely wear the buttons out

06-15-2009, 10:06 PM
Hi, welcome to MBN.

First, did you see this thread on the SAE forum? (http://forums.sae.org/access/dispatch.cgi/bajasae_pf/docProfile/103072/d20090414194233/No/t103072.htm) Same problem as what you described, in fact was that your thread? I am Justin that posted the long reply there.

The other options that I am aware of for Baja SAE CVT's are Comet, Polaris, and Gaged. Comet's are fairly reliable but since they are of a similar design to the CVTech, they can also break the buttons off. Polaris driven clutches have a different design, but still use plastic buttons which can (and do) break off. However there is a kit to make Polaris clutches use rollers instead of buttons. The Gaged clutch is very nice and does not use any plastic bits, but they are new to the Baja scene so their reliability is not proven that I know of. However they are definitely worth looking into since I have seen their clutches in person and the build quality is in another league compared to the cast parts on the other CVT's.

06-17-2009, 06:42 PM
Yes, I was the one that posted this problem on the SAE Forum. We replaced the buttons in March and only put on 5 hours of drive time on the CVT. The ramps were smooth when we put the CVT back together. It seems that when the car stops the secondary snaps closed too fast. When the buttons broke during the race it also wore away the aluminum behind the button and started to unwind the spring. Thanks for the other CVT brands. I am really interested in the Gaged CVT.

06-21-2009, 12:26 AM
Check out the TEAM secondary clutches. They have a captured helix and use rollers so they stay engaged to the helix at all times. They are darn near bulletproof as K-Fab can attest.

06-27-2009, 09:09 PM
I'm curious about reliable CVT's as well. . .we ran a 5-spd manual transmission w/a centrifugal this year (our first time in the Baja series) and it worked good (once we pinned the gear selector arm to the gear selector shaft after the steel shaft ate the splines in the aluminum lever!!!) but we were down on top speed down the long straight-away . . .it was one of the only places that I got passed, the other time we got passed was the big, long uphills. . .we just didn't have enough torque to drive our gearing up the hills and if we got stuck in a crowd at the bottom of the hill and weren't able to carry our momentum up it we would stall the engine . . .

. . .I'm not a big fan of CVT's because they start slipping so badly once they get (and they will get wet no matter how well you think they are sealed). . .at least that is my experience with quads. . .

. . .I had heard of Team Industries just recently but I'll be checking out Gaged as well. . .I think that in order to have a cost effective transmission that I won't be down on the top speed and can still keep the engine happy when crawling the hills I'm gonna have to break down and go with a CVT. . .I just don't have the time to make my own transmission. . .which would be my preference given what my other options are. . .