What is the Real Purpose of the Rollers in the New Secondary Clutch

[RickM]

I have wondered why this happens in my attached photo of the Driven Clutch on the PC800. After you ride and stop and look at the driven clutch rollers, the clutch has back shifted but the rollers are not touching the helix ramps.

I know its a compression spring, I also know you can twist the movable sheave
forward so the rollers do not touch the helix ramps. There is not any thing to really twist the sheave back (as a torsion spring would do ) in this clutch.

If the sheave is twisted off the helix ramps and say you were to load the driven quick from landing under power after jumping, looks like it could just spread the sheaves as you would only be relying on the compression spring to stop any slippage.

I have been reading all the posts on belt issues (sticky) and thought I would post this question here. I need comments from RKTek, Geo, or any one else
that may have information. Please look at my photo of the helix and rollers.
Tell me why the clutch is doing this.

Thanks. RickM

 

[aksnopro]

as soon as the track has any load on it the roller will make contact with the sheave.

-Aksnopro

 

[RickM]

Aksnopro

That is correct,as long as there is slippage from one side of the sheave, if the sheave's do not slip on the belt and both sheaves turn the same, wouldn't the rollers fail to contact the helix until drive ratio decreases as the clutch opens up and then the rollers will hit the helix angle. Hope I am saying this correct.
I am just trying to figure out this clutch, Rickm

 

[snosumitcsr]

mine does the same thing and i believe all of them do the same. I know of someone who has already broken a roller from the hit back to the ramp.

 

[RKT]

IMO, this is not such a big issue.

The rollers can never touch the plastic ramp .. The actual sheave will touch the plastic ramps but not the roller.. The roller can really only come off the helix ramp a little (like in your picture) so, th eimpact is very minimal..IMO..

I suspose, that if you were airborn and hit the brake,, then the roller could leave the helix an then slam back onto it.. but the slamming is very little..

You can very easily add a torsion spring to this clutch by simply drilling 2 holes for the spring ears and adding the spring.. Give that a shot if you want to test anything..

I, personally, like the way the clutch works.. is it perfect?? no, but it seems to work well.. Like stated earlier, if the sled is moving foreard, the rollers are in contact with the cam. MOST of the time, the sled is moving forward.. But the rollers can never contact the plastic pieces. The clutch movement in that direction is very minimal and very limited.

Kelsey

 

[volcano buster]

I'm guessing, but is the plastic piece there to force the sheaves open slightly for reverse? This opening of the sheaves would allow the primary to close enough to substantially increase the clutch to belt surface area hopefully decreasing a burnt belt in reverse. Thoughts?

In some ways, I do like the openness of the roller track. The Polaris set up is a tighter runway and you need to run the clutch forward before opening the secondary up to take a belt off. I don't see where this clutch would bind up if you tried to open it right after using reverse.

 

[snodad]

I'm guessing, but is the plastic piece there to force the sheaves open slightly for reverse? This opening of the sheaves would allow the primary to close enough to substantially increase the clutch to belt surface area hopefully decreasing a burnt belt in reverse. Thoughts?

In some ways, I do like the openness of the roller track. The Polaris set up is a tighter runway and you need to run the clutch forward before opening the secondary up to take a belt off. I don't see where this clutch would bind up if you tried to open it right after using reverse.

Volcano Buster,

I finally had to tear my secondary apart to answer some of my questions and also to have an idea of what might be deficient in the case that I also start having belt problems. The plastic ramps are there to keep the rollers from getting too far away from the their ramps...just like RKT said. It is hard to see assembled but when the secondary opens up there are two ridges on the fixed sheave down under the rollers that ride the plastic ramps and kind of act like an encapsulated helix, except that they don't act on the roller. Like I said, easier seen when torn apart. When the secondary clutch is closed however, the two sheaves can rotate substantially which moves the rollers away from the ramps and then the tips of the plastic ramps can ride over the top of the ridges mentioned above rendering the clutch unable to upshift until a the torque pull from the belt rotates the plastic ramps back off of the ridges and the rollers toward the ramps again. The tips of the plastic ramps are not square, they have a overhanging lip that I believe is there to keep the clutch from opening up in reverse. Several people, including myself, have damaged the ends of the plastic ramps or the aluminum ridges because we tried to take off our belts when the rollers were not on the ramps and found that the clutch does indeed bind up in that condition.