Clutch tech for high hp big motors, Stock, Comet, STM billet

[mrrpm]

Let's resume the clutch discussion in this thread.

Where were we??
I think we were dis/cussing the stock clutch?

[got wake?]

we were at the point of discussing the stock secondary vs. a roller secondary. my point of view is that because the secondary is already being loaded at idle while in gear (when using the stock primary), the initial reaction time of the secondary at engagement will not make a difference between the stock secondary and the roller STM secondary. but the roller secondary would shift out sooner than the stock because the friction (more correctly stiction, but most people don't associate with that), would create more resistance and increase the force needed to shift out. would it be noticeable? probably not. is there a measureable force there? yes. the roller secondary has substantially less friction and reacts much faster to changes in load, and friction is the enemy of an efficient clutch system.


we also got to talking about the ECU limitations on the '09+ bikes. 800Vtwin posted that it is speed limited. i would like to know more about that, since i'm sure someone with a newer bike could unplug the speed sensor and take a few passes to see what kind of difference there is. HIGHOCTANE would then have the bottom end that is lacking on the new bikes and it would also confirm that its the ECU limiting the bottom end that i have believe for so long. if it is indeed limited in the stock ECU, then 800Vtwins piggy back system would be a huge upgrade for the newer bikes. there have been talks on other forums about putting '07 ECU's in the newer bikes and having them run like scalded apes. the piggy back system he's developing would be about the same cost as buying an older ECU from the dealer, and give so much more tuning potential. hopefully someone can do some testing and make some timed runs so that we can all see the results. i don't have access to a newer bike at this moment, otherwise i'd go outside and make a couple runs


regardless of how the newer bikes are limited on the bottom end, we all have heard that the older bikes have more bottom end and get to shift out much faster. since the clutching is the same, all the clutching in the world won't make the new bikes as fast off the line as the old bikes with identical clutching. i will say that the QSC clutch weights i've installed in two '09 renegade X's have done very well on the bottom end. i can just imagine what they'd do on an older bike. but with them, it is still relying on the stock primary that when pushed hard, will destroy belts. the 6 weights are great from a tuning aspect, but the sheaves not being keyed together is a problem. does the stock clutch work? yes. are there other weight options for it? yes. could you get better results with an aftermarket clutch? absolutely. is it worth the $1300-1500 for the STM primary? that's a personal call. to me it definitely is. would another option similar in cost to the comet be a more feasible option for substantially more people? definitely.


anyone know what kind of clutching history other bikes have? the can-ams started with the dalton kits, renegade clutch weights, modified or 650 helixes, and more recently the EPI and QSC weights. those are ok options, but with what greg did with the comet primaries and now the STM clutches, the development and power transfer has expanded leaps and bounds. with the STM secondary we now have real helix options and secondary spring options. their current primary is a work of art and offers a ton of tuning ability. having four weights just for the low end where more belt clamping force off the line is needed is an amazing idea. and being able to dial in where during shift out they stop being effective is great. it'll allow you to get enough belt clamping force off the line for big tires, big motors, or both, while not affecting the top end pull. usually there is a trade off, bottom end pull yeilds less top end pull and vise versus. the 8 weight STM allows for much more tuning of both ends of the CVT's actions. plus being able to custom order helixes in multiple angles is a huge improvement, along with using a roller secondary for more efficient operation. these advancements are what will put can-ams ahead of the pack in more venues than just mud pit racing.

[800VTwin]

Has anyone tried putting 3 small grooves in the taper? 6 sharp edges should bite better. Granted its not a keyway but it should help. Loctite also has a product called sleeve retainer (the green stuff) that works very well for situations just like this.

Or instead of a keyway, 2 small pins (180 apart) into the crank.

I understand the benefits of a $1500 clutch, but there's many who would rather by a 912 kit for the price. Or cams, springs and head work. Or an ecm kit with a barrel of race fuel/mini laptop or stage 1 suspension all around or a 912 kit.

(opps- didn't mean to bring that thread here)

[got wake?]

greg tried keying the outer half of the primary and it sheared right off. the problem is because these motors are odd fire, it works like an impact gun. i'm wondering of can-am decided to use a system that was not keyed for that very reason. i know the threaded on clutches can get TIGHT. that makes it very difficult to service them. when assembling a threaded on clutch like the comet, loc-tite is very useful since it'll also help preven the clutch from tightening during operation. just heat it up with a torch and its much easier to break apart. heck, i bent an 8' bar one time when i was trying to get my comet apart. i never thought of that aspect, but that could be a big reason why can-am chose the design they did. same with the secondary. the can-am clutches are very easy to work on and service.

[warlock]

The secondary clutch will be awesome because it up shifts and back shifts way better than a button friction clutch. For general riding and hill climbing it will make the difference since it will be shifting down and you wont lose the momentum you already have going. plus the adjustability of the helix should be great. Both clutches together should be an awesome setup..

I have both of them sitting on my bench and need to get off my but and get testing.

[got wake?]

i would have them installed the day i got them, lol. once my friend pays me back, they are right at the top of the list of stuff to buy.

[mrrpm]

I have always thought they made the clutch with that little taper for conserving space. The stock clutch is waaay shorter than almost anything made for a sled. Of course they could have made it so it would give a little, IDK, but it looks like they would have belt issues a lot worse that way it's made, come to think of it, maybe they made it like that to sell belts!

[Go Hard]

I have been testing and running all three set ups, I also did try unplugging the speed sensor, I could not see a difference???

But I did install a 2007 ECM onto my 2009. Day and night difference but what we need is the 2007 up to mid, the mid and top end of the 2009 ECM. So it looks as if we will be purchasing the aftermarket ECM!

Ok, back to clutches, as WAKE said, a 2007 with same clutching will smoke the 2009 out of the hole if you can control the launch, it get's hairy on the 2007's when clutched with these new set up's. It's tons of fun.

From all of the clutching that I have, bins of springs and a pile of weights, helix's, Comet's, STM, (some snowmobile stuff). The STM roller is the best that I have found yet, the performance on the trail far surpasses $475.00! But like everything else, it needs to be set up correctly. It feels smooth, it back shifts like no other! If you have two identical bikes and then you put a roller on one, it will beat the other no question.

If you have seen the STM primary, well then you would know what Wake is talking about, I don't even want to run mine, it's that nice!

Adjustable 1st stage for aiding in engagement (roller size options, the point at which the 1st stage quits helping with shift out can be adjusted). Then the second stage 4 fly weights have heel, mid, tip weight adjustment). Really the sky is the limit!

But not needed unless you run big tires or big HP or both, or if you simply want the best!

[warlock]

Quote: Originally Posted by got wake?

i would have them installed the day i got them, lol. once my friend pays me back, they are right at the top of the list of stuff to buy.

Ive just been to busy and worn out from running around to work on my toys. They are so bad ass they are a work of art I almost want to just put them on display. The wife saw them and was like hmmm what are those things Oh you know parts.. Hehehe then her brother comes over and hes not an offroader but he saw them on the desk and was like wow those are cool and they look spendy(wife 15' away other room) Shhhhhhhhhh. oh .. I am looking forward to running them since theres a lot of lost power to be found especially on mine since its a Turboed Prowler. and Im sure that its been slipping bad.

[got wake?]

that's interesting info go hard. if 800Vtwin can get the low end from the '07's and the top end of the '09's, i think his piggy back system will be setup really well from the start. just gotta dial in the fuel a little for the particular bike it is on and run the hell out of it. this stuff does get pretty expensive after a while, though. good thing that money tree out back hasn't withered away, yet, lol.