Contemplating modifying primary clutch

[SportsterDoc]

The primary clutch has the fixed side, next to engine.

A one-way bearing over the shaft for bottom of belt contact during idling, which also permits engine braking (secondary drives primary).

The moveable side (governor cup) has weighted levers to close the clutch (for engagement and for gear ratio) with an over-the-shaft spring with an opposite force to facilitate clutch opening.

I would expect that the spring for the secondary clutch simply maintains pressure on the belt sides, as the effective diameter of the primary changes.

At the sacrifice of acceleration, I am wondering what heavier weights (combined with lighter spring?) are available, to possibly reduce cruising RPMs. I would not expect changing the final drive from 3.15:1 to be an option.

Tslepebull inquired 3-6-19 https://www.spyderlovers.com/forums/showthread.php?119097-Wasted-Power-in-900

I am anticipating some answers to be to the effect that Can-Am has already provided the best balance between acceleration and cruising RPMs (directly related to fuel economy)...and that may be true...but would like to know what options, if any, are available and potential consequences.

There are clutch kits for Can-Am Mavericks, for running larger tires, etc...anything for the Ryker and any performance results?

 

[safecracker]

I would think the aftermarket would be developing different springs, different weights, different angles on the fingers(ramps). Both clutches can be tuned. They have been doing this for more than 50 years in the snomobile industry. Bruce

 

[Rob Rodriguez]

I can't be much help here but......in the snowmobile world primary clutch weights and springs are typically switched out to achieve one of 2 things.

Harder/stronger/faster acceleration which comes with the cost of a lower top speed
Higher top speed which comes with a cost of weaker acceleration

The secondary spring and helix are switched out to change upshift or backsift speed.

Cruising RPM doesn't really apply to sleds because you don't really ride them at a steady speed. So, there is probably a way to adjust the clutches to help achieve what you want but I'm not sure the sled or ATV kits will help since thats not really what they are tuning for. You might be the first person tuning a Ryker for this keep us informed.

 

[SportsterDoc]

I would think the aftermarket would be developing different springs, different weights, different angles on the fingers(ramps). Both clutches can be tuned. They have been doing this for more than 50 years in the snomobile industry. Bruce

Thanks, but the Ryker is very new and the market not yet big enough.
I enjoy research, but have found nothing offered, other than stock parts.

 

[SportsterDoc]

Harder/stronger/faster acceleration which comes with the cost of a lower top speed
Higher top speed which comes with a cost of weaker acceleration

The secondary spring and helix are switched out to change upshift or backshift speed.
You might be the first person tuning a Ryker for this keep us informed.

I only understand the rudimentary basics and would not want to make changes without sufficient info.
Since centrifugal force operates the weighted levers, which is RPM dependent; how does torque affect primary clutch action...or does it? I understood that the primary spring affects engagment RPMs: A weaker spring for lower RPM engagment, such as 1200 RPM instead of 1800.

I would not hesitate to skirt the intake side of a 2 stroke piston on a pre-reed valve thumper or change sprockets for more appropriate gearing, but I do not yet know enough about this clutch. Plus, access to the clutch is not convenient.

This reminds me of my 71 Chevelle. Only a 307, but an after market 4 barrel on an LTI manifold with Hooker headers provided improved performance, which would have been much better if I had changed the differential. A growing family ceased the mods, as the 2 door was traded for a 4 door and never had the chance to make that change.

OTOH, my 1973 Datsun PL620 with a 350, 500 CFM Carter on a SP2P Edlebrock and Hooker headers (circa 1982) utilized a Ford 2.92:1 rear end to prolong rear tire life. Yet it was as quick as a 1982 Corvette, at least 0-60.

Need more info and a higher resolution diagram to properly name the parts.

 

[Peter Aawen]

Thanks, but the Ryker is very new and the market not yet big enough.
I enjoy research, but have found nothing offered, other than stock parts.

But have you been looking for alternatives offered for/by BRP's similarly engine equipped & trans fitted ATV's, SXS's, & Snowmobiles?? :dontknow:

BRP/Can-Am machines with similar if not identical CVT's aren't really all that new, they've been around for a few years now in some of those other machines, and there seems to be a fair amount of alternative/upgrade internal bits available, so it looks like it's 'just' a matter of tracking down what matches/fits! :thumbup:

That said, I haven't got any dog in this particular fight, just a very healthy search for knowledge & trying to help.

 

[SportsterDoc]

But have you been looking for alternatives offered for/by BRP's similarly engine equipped & trans fitted ATV's, SXS's, & Snowmobiles??)

Yep
There are numerous options and STM asks questions for the best set-up, but most have descriptions such as "smoother", "more belt grip" and other non-tangibles. Even if the clutch assembly were 100% compatible, I find no specs for performance differences. For example, if 7600 RPM is normal for 100 MPH, the "performance" unit would be ___ RPM at the same speed.

http://stmpowersports.com/can-am-stm-clutches/
http://stmpowersports.com/stm-rage-...-works-with-stock-or-stm-long-post-secondary/

Unless a manufacturer/supplier states Ryker compatible, I am unwilling to be their guinea pig.

If I were to buy oversize tires for a 4x4 and it did not work out (without changing gearing), those tires cost less than a "performance" clutch.

There are a couple issues. For one, I am simply accustomed to lower RPMs. Secondly, I would expect RPM reduction to generally increase fuel economy. OTOH, the Ryker is ready to rip at any speed.

On my 2012 Triumph (865cc), 2016 Moto Guzzi (744 cc) , 2014 Honda 1140 cc) , I could ease the clutch at idle speed, without throttle, to begin acceleration.

I suppose 1800 RPMs on the Ryker insures that it will never, ever stall.

 

[Mikey]

What is it your really trying to get out of this when you done? Lower engagement or more top end, or both? Like a lot of guy's above have said this system has been around a while on sleds, atv's, and clutch kits for those price wise aren't that bad, but it is a trial and area thing on the Ryker I think until enough gear heads like you want to soup up there rides, the aftermarket boys won't gear up and make the packages until they see the market!!:dontknow: I am sure that the clutches in the bike are being used in other app some where, and there are weights and springs to be had, and gearing, you just have to decide weather you want to do the R+D for the aftermarket boy's or ride that thing!! Good Luck, Ride Safe!!

 

[Rob Rodriguez]

You are looking at replacing the entire clutch with aftermarket with those kits. Another option is to just replace some of the internals of the stock clutch https://www.straightlineperformance...ces-new-0-3000ft-ski-doo-e-drive-clutch-kits/

But clutching might not be the way to achieve what you want? Maybe a gearing change in the gear box is a better move. Again, very simple to to do on a sled......easier access. Harder to do on the Ryker.

There is a trade off though. Maybe you can find a clutching/gearing setup that gives you 2800 RPM at 60 mph but acceleration to 60 mph might be super slow (if the motor power band could even pull it at all)?

 

[SportsterDoc]

What is it your really trying to get out of this when you done? Lower engagement or more top end, or both?

No need for more top end.
Stock it is capable of 107+
100 up a slight grade and mild head wind.
If I can hit up to ~95, passing a big rig (beginning the pass at 70) on a two lane, that is more than sufficient.
Not interested in cruising more than 80 (Interstate 15 speed limit in Utah, north of St. George), if engine not wide open.

If lower engagement, then less likely for tire spin off the line, but that is only minor.

The main interest is lowering cruising RPMs.
Not seeing the need for 6700 RPM at 75, when my CB1100 (86 HP) could pull 100 at 5000 RPM.

 

[SportsterDoc]

I am sure that the clutches in the bike are being used in other app some where, and there are weights and springs to be had, and gearing, you just have to decide weather you want to do the R+D for the aftermarket boy's or ride that thing!! Good Luck, Ride Safe!!

The trick is finding weighted levers for the Ryker clutch basket.

 

[SportsterDoc]

You are looking at replacing the entire clutch with aftermarket with those kits. Another option is to just replace some of the internals of the stock clutch https://www.straightlineperformance...ces-new-0-3000ft-ski-doo-e-drive-clutch-kits/

But clutching might not be the way to achieve what you want? Maybe a gearing change in the gear box is a better move. Again, very simple to to do on a sled......easier access. Harder to do on the Ryker.

There is a trade off though. Maybe you can find a clutching/gearing setup that gives you 2800 RPM at 60 mph but acceleration to 60 mph might be super slow (if the motor power band could even pull it at all)?

Thanks, Rob, but did you find something on straightlineperformance.com for a Ryker?
A gear change may be all that is needed, but are parts available?
My 4.0 truck cruises 75 in 5th gear at ~2200, but I am not expecting that, perhaps 5000 RPM at 75 MPH?

Signing off now, heading to the top of Lee Canyon. Should be nice at 8500 feet and not too hot upon return.

 

[Rob Rodriguez]

Thanks, Rob, but did you find something on straightlineperformance.com for a Ryker?
A gear change may be all that is needed, but are parts available?
My 4.0 truck cruises 75 in 5th gear at ~2200, but I am not expecting that, perhaps 5000 RPM at 75 MPH?

Signing off now, heading to the top of Lee Canyon. Should be nice at 8500 feet and not too hot upon return.

Those are not specific to the Ryker. Those are specific to the clutch used on the Snowmobile with the 900 Ace Engine. I'm sure if you checked part numbers the clutch on the Sleds/ATV's and the Ryker are pretty much the same so those parts "should" work on a Ryker but of course its a guess and most likely the "kit" they are selling for the sled will not lower the RPM as you are trying to do. I was just pointing out that you don't need to replace the entire clutch and can just replace some components.

 

[SportsterDoc]

I was just pointing out that you don't need to replace the entire clutch and can just replace some components.

My initial interest was changing the centrifugal parts/spring, rather than an entire new primary clutch assembly. I was answering, the "have you researched" question.

18 year old grandson arrived from Georgia last Thu and a trip to our AZ ranch precluded any riding for 8 days.
Rode up Mt Charleston this morning with display in RPM mode.
Glad to report that Deer Creek Road from Kyle Canyon to Lee Canyon is now open.

With grades 6% + and elevation to 8,500 feet, I would not want to give up any acceleration capability.

Coming back Interstate 15 from Lee Canyon, contemplating the potential effects of a two speed axle or larger diameter primary clutch, I thought I had a bit of headwind, glanced at the speedo and it was 87, tach about 6700. Realizing my speed, I backed off to 75.

I suppose I just need to become accustomed to higher RPMs, somewhat like a sport bike (never rode one).

Today was an enjoyable 83 mile ride, 2130 miles on the clock in 72 days.
Sportsmans warehouse still out of ammo, Walmart discontinued sale of handgun ammo.
Should have stayed in the mountains longer, but wild horses not to be seen at Lee Meadows this morning.

BTW, took it out of eco mode for this trip. No issue pulling back onto highway from gravel shoulder with normal mode...zero tire slippage with gentle throttle.

 

[Tslepebull]

Yeah Doc, Im buying what you are selling. I would be willing to give up some low range power for reduced RPM at cruising speed. I can't use all the power my Rally makes off the line without burning off tire tread. I would also like to get better fuel mileage than my Colorado diesel truck gets on the highway.

 

[lugnut1009]

I know I’m resurrecting an old thread, but just bought my daughter a Ryker 900 and was curious about clutch kits. I’m familiar with the Can-am Atv world and clutch tuning there is pretty simple. I really think it would be as simple as replacing the spring in the secondary with one a little weaker. We used to do the opposite with our ATV’s for a cheap lower gear, using a stiffer spring, holding the secondary closed longer. Seems the inverse would work great using a weaker spring allowing it to open sooner, pretty much giving a higher final gear ratio to the transmission or gear box.

 

[Raven]

This was on a snowmobile show this morning.
You might try Dalton Industries.
They make clutch kits for sleds and atv's
[email protected].

 

[Raven]

Quick newbie question.
I understand that having the clutch pack ramp up sooner will lower RPM and slow down acceleration.
But I can't see it affecting top end.
If the belt is at the top of the pully the gearing should be the same or would it keep the motor from reaching redline?
Be like accelerating your truck in 5th gear, slower, but same top end.
Bruce

 

[lugnut1009]

Quick newbie question.
I understand that having the clutch pack ramp up sooner will lower RPM and slow down acceleration.
But I can't see it affecting top end.
If the belt is at the top of the pully the gearing should be the same or would it keep the motor from reaching redline?
Be like accelerating your truck in 5th gear, slower, but same top end.
Bruce

It does affect acceleration to a degree I guess, but more like changing the cruising speed. You can do all sorts of things to these clutches, change secondary spring rate, primary spring rate, primary clutch arm weight, arm shape, and on some even the secondary ramp angle. You can make it hit that top hp rpm quickly and stay there like a stall converter in a car (racing applications) or make it be able to still hit that rpm when needed (excess load applied through drivetrain) and at the same time lower cruising rpm’s. Seems the engineers decided to maximize the fun factor while sacrificing efficiency on these.

 

[lugnut1009]

This was on a snowmobile show this morning.
You might try Dalton Industries.
They make clutch kits for sleds and atv's
[email protected].

Don’t remember if I reached out to dalton, I know I reached out to several different companies though.

Treal Performance actually said it would be available very soon.