Interesting clutch stuff, Viper clutches & floating secondary

[Doowithblue]

I believe it has to do with the tune you are running and how hard on it a guy is too. Seems like tunes under 260 or so real HP don't have nearly the problems the big tunes do. I saw lots of stock rollers push the bushing out the side and quit rolling also, I would just push them over if they didn't flat spot and keep riding. Seems like one day rollers would be good the next they'd be toast.

I run 290 all the time. Never change it. The odd time I get the lights amsoil dominator boost solves it. Perhaps driving habits yes and mine's a 129 less rolling resistance etc and I'm a lighter guy.

 

[race24x]

Big guy 300 Lbs STM arms and still stock Yamah Rollers from new about 5k Miles

 

[Sidewinder Bob]

I am using evo4 with 5500 miles on sled. last year installed viper primary with TP clutching and 911, with 3000 miles on it. still like new, and cool clutches. There is something about the older clutches. I thought the sheaves have different angels, or they are progressive.

 

[KnappAttack]

I run 290 all the time. Never change it. The odd time I get the lights amsoil dominator boost solves it. Perhaps driving habits yes and mine's a 129 less rolling resistance etc and I'm a lighter guy.

That's great if you are not having roller issues, consider yourself lucky there. What are you running for RPM? I wonder if perhaps its a RPM harmonic thing happening. I can't imagine any of them are that far off though.

I am using evo4 with 5500 miles on sled. last year installed viper primary with TP clutching and 911, with 3000 miles on it. still like new, and cool clutches. There is something about the older clutches. I thought the sheaves have different angels, or they are progressive.

Sheaves are the same angle and shifts to the same spot as the winder as well. I figure its the design, maybe gusseting or the metal being used. Seems all that have switched have had good success with the switch.

 

[Fleecer]

When Yamaha introduced the Winder and it's new clutches, I faintly remember reading somewhere that the new primary had more overdrive. Anyone else recall this?

Tonight, I put both Winder/Viper primaries on the bench and ran some comparisons. I closed both clutches w/o springs on a belt to mimic full shift and they both seem to push the belt up the same distance.

I compared fixed sheave dimensions and both clutches appear to have the same size fixed sheave. When comparing the moveable sheaves however, the Winder primary sheave is almost 3/32nds bigger than the Viper primary.

Perhaps this is the overdrive Yamaha was referencing? Has anyone else measured and/or compared moveable sheaves and found any descrepencies?

 

[Sidewinder Bob]

Mike , I am running about 9200 rpm, and viper primary is cut for od.

 

[KnappAttack]

When Yamaha introduced the Winder and it's new clutches, I faintly remember reading somewhere that the new primary had more overdrive. Anyone else recall this?

Tonight, I put both Winder/Viper primaries on the bench and ran some comparisons. I closed both clutches w/o springs on a belt to mimic full shift and they both seem to push the belt up the same distance.

I compared fixed sheave dimensions and both clutches appear to have the same size fixed sheave. When comparing the moveable sheaves however, the Winder primary sheave is almost 3/32nds bigger than the Viper primary.

Perhaps this is the overdrive Yamaha was referencing? Has anyone else measured and/or compared moveable sheaves and found any descrepencies?

Yamaha either lied or changed something prior to production, because what you found Fleecer is the same thing I found to be true. The difference is in the secondary. The old secondary goes into coil bind using stock helix's and stock secondary springs. This is where one needs to be careful in allowing the old button secondary to open up far enough to allow the belt to use all the primary travel. This is also where the drill press scale comes in handy as you can see what the secondary is doing on the bench in relation to coil or hub bind.

Most of the aftermarket helix's are machined on the hub to allow more travel. The problem then becomes the secondary spring being used. The spring pocket on the old button clutch is tighter than the winder clutch, springs that don't bind on the winder secondary could and will bind on the old button clutch as it is tighter. For instance, I can only wrap up the original V1 Dalton Black/Orange up to 65* before coil bind on the button clutch, wrapped to 70 it binds pretty good and hard.

The stock winder Yellow does not bind on the Winder clutch wrapped at 60, try using it on the old button clutch and it binds super hard on any wrap. It actually should not be used in the button clutch. Even the White attak spring needs .060" of shim at 60* on the old button clutch. Its important to check every spring for coil bind on the drill press for bind for full shift, even if not checking it for pressure on the scale.

Also, the added dia. on the winder movable is just along for the ride, done just for strength because the weight placement has been moved out. Everybody gets wigged out about the difference in dia., but it has no bearing on belt ride height, belt travel or any other thing.

 

[Byam]

When Yamaha introduced the Winder and it's new clutches, I faintly remember reading somewhere that the new primary had more overdrive. Anyone else recall this?

Tonight, I put both Winder/Viper primaries on the bench and ran some comparisons. I closed both clutches w/o springs on a belt to mimic full shift and they both seem to push the belt up the same distance.

I compared fixed sheave dimensions and both clutches appear to have the same size fixed sheave. When comparing the moveable sheaves however, the Winder primary sheave is almost 3/32nds bigger than the Viper primary.

Perhaps this is the overdrive Yamaha was referencing? Has anyone else measured and/or compared moveable sheaves and found any descrepencies?

Stock SW clutches . personally i have never been able to get more than 0,93 overdrive

Good OLD school. I have removed 0,030 to each sheaves . I think i am gona be able to get 0.88 out of them .
Testing next week!

 

[mrtwostroke]

 

[Doowithblue]

That's great if you are not having roller issues, consider yourself lucky there. What are you running for RPM? I wonder if perhaps its a RPM harmonic thing happening. I can't imagine any of them are that far off though.

8850. I may try backing off secondary tension tomorrow and see if it still grips the 825. Seems too good to touch anything but we'll see.

 

[KnappAttack]

View attachment 152038 View attachment 152037

Those Ratio figures are accurate if you allow the secondary to Coil bind on the old button clutch the way it came from the factory, but if you fix the coil bind on the secondary of the old button clutch and allow the secondary to travel fully you end up with the same ratio as the winder.

 

[1nc 2000]

Mike, when you are testing secondary clutch springs in your scale does shimming out the helix .070" change the final spring rate much?
I know about the coil bind. Thanks.

 

[Sidewinder Bob]

That's why we shimmed stock helix out with washers to let it shift out.

 

[KnappAttack]

Mike, when you are testing secondary clutch springs in your scale does shimming out the helix .070" change the final spring rate much?
I know about the coil bind. Thanks.

It depends on the spring, the short Yamaha springs yes it has about 5-10 lbs of effect, the longer Cat secondary or Dalton secondary springs not much if any change at all.

It really depends on the spring being used.

There is nothing better than the the bathroom scale on the drill press to tell the whole and complete story about full secondary travel, spring bind and secondary belt pressure. What is does not tell you however is how much force it exerts on the belt when under power from the helix force. It's only giving you a look at the mechanical side pressure you are making for the belt thru the spring and helix installed, but non the less its giving you good valuable information.

 

[Stubbs]

Mike, I’m running a 48-40 Advantage-Edge with Yammy white spring at 60* in the old button clutch......your saying it will cool bind badly at full shift? I was led to believe that they cut their helixes to enable a little more overdrive with the right set up, but also machined the spring pocket area enough to avoid binding issues. I’ve never checked for it myself.