Put on a roller secondary!

[Tbyrd]

Still in testing phase but very impressed so far.

 

[UP bushman]

Same here still in testing phaze with my YVX secondary but this is what I have so far. I have 11,500 rpm at holeshot down to 11,300 rpm straight shift out to top end. Still need some good snow to get a base to hook up from the holeshot. Sheaves are cool to the touch and belt is barely warm to the touch. Great low to mid response with a quick response at 35mph on the roll. This is the setup that works good for me a bush riders setup.

I replaced the stock MTX 8 tooth drivers with 9 tooth anti ratchet drivers for less rolling resistance. When changing drivers up or down on the driver teeth will change gearing equivalent to gearing up or down 2 teeth on upper chain case gear. Taller gearing is not always the answer you are always looking for efficency under load to maxamize track speed and top speed. You have to choose what you want to accomplish.

I will updating this post periodically with changes and updates on performance.

Setup 1:

Gearing:
17/41 2.41 gear ratio with 9 tooth Avid Anti Ratchet Drivers

Primary:
MTX stock spring Green-Yellow-Green 90501-605G7
Supreme Tool Super Tip Cam Arms at 42G base weight
8G in heel only, engagement 4300 rpm

Secondary:
43 degree straight helix 8BV-17604-31
YVX Green spring 90508-556A2
60 degree spring twist angle

Result is good low end pull with great midrange pull with 70 mph on top end and barely warm sheaves. 11,800 rpm at holeshot and 11,300 rpm at top end.

Setup 2:

Gearing:
17/41 2.41 gear ratio with 9 tooth Avid Anti Ratchet Drivers

Primary:
Green-Gold-Green 90501-607G4
Supreme Tool Cam Arms at 42Gram base weight
4G in heel, 2G in the middle, engagement 4300 rpm

Secondary:
43 degree straight helix 8BV-17604-31
YVX Green spring 90508-556A2
60 degree spring twist angle

Result is good low end pull with great midrange pull with 75mph on top end and totally cool sheaves. 11,800 rpm at holeshot and 11,600 rpm at top end.


We are on our own to figure out a great setup with only a few of us having the roller secondarys. I will be trying a silver spring on secondary but have to get a different primary spring to match for shift out.

Setup 3:

Gearing:
17/45 2.65 gear ratio with 9 tooth Avid Anti Ratchet Drivers

Primary:
MTX stock spring Green-Yellow-Green 90501-605G7
Supreme Tool Cam Arms at 42Gram base weight
4G in heel, 4G in the middle, engagement 5200 rpm

Secondary:
43 degree straight helix 8BV-17604-31
YVX Silver spring 90508 556A7
50 degree spring twist angle

Result is great snappy low end and midrange pull with 70 mph on top end and cool sheaves. 11,600 rpm at holeshot and 11,400 rpm at top end and 11,300 rpm under load climbing. This is a great deep snow setup with great overall performance and quick backshift.

Setup 4:

Gearing:
17/45 2.65 gear ratio with 9 tooth Avid Anti Ratchet Drivers

Primary:
MTX stock spring Green-Yellow-Green 90501-605G7
Supreme Tool Cam Arms at 42Gram base weight
4G in heel, 4G in the middle, engagement 5200 rpm

Secondary:
43 degree straight helix 8BV-17604-31
YVX Silver spring 90508 556A7
40 degree spring twist angle

Result is great low end and midrange pull with 75 mph on top end and cool sheaves. 11,600 rpm at holeshot and 11,400 rpm at top end and 11,300 rpm under load climbing. This is a great deep snow setup with great overall performance and quick backshift.

Setup 5:

Gearing:
17/45 2.65 gear ratio with 9 tooth Avid Anti Ratchet Drivers

Primary:
Pink-Yellow-Pink 90501-604G0
Supreme Tool Cam Arms at 42Gram base weight
4G in heel, 4G in the middle, engagement 5200 rpm

Secondary:
43 degree straight helix 8BV-17604-31
YVX Silver spring 90508 556A7
50 degree spring twist angle

Result is great low end and midrange pull with 70 mph on top end and cool sheaves. 11,700 rpm at holeshot and 11,500 rpm at top end and 11,200 rpm under load climbing. This is a wet and crusty snow setup with great overall performance and quick backshift.

 

[Tbyrd]

My roller secondary came with a 49-45 helix and my rpms are too low but it pulls hard. After hearing you say you went to a 43 straight im going to try a 43-34. I ride alot of mountains and am hopeing for real good back shift under heavy load. Also installed heel clicker primary weights that have 3x the clamping force and a tone of adjustability to drop rpm.. Where did you buy your 43 straight helix. Only place im finding them that shallow is out of canada and they want as much to ship as it cost to buy it... Thanx

 

[UP bushman]

You can change your primary spring rate to bring up your rpms it's cheaper than a helix. I got my 43 degree helix from Hartman Inc. but can you use stock Yamaha helixes on your secondary. I am looking for a 45 or 47 degree helix for testing also for I ride flat land only.

 

[Tbyrd]

Well im no clutch guru by any means but I was under the impression that primary spring rate pretty much controlled engagement rpm My helix is too steep for sure and with the adjustability of the heel clickers in primary im looking for an overrev scenario then I can fine tune with the heel clickers to bring down rpms. Thanks for the hartman advice, i'll give him a call. Oh yeh my secondary is a hyper lite and it takes Cat helixes..

 

[Lashcat]

Tybrd, where did you get the secondary from? As soon as I finish my superchrger I plan to put Heelclickers on the primary, so that I can change weights easily depending on where I ride. Riding around the house 800 to 1500 feet in elevation, I will have it heavy. riding in the mountains I will have to drop weight.

You are right according to what I have read. The primary is used to control RPM. You should never us the secondary to control RPM. I will hve to get back into the Clutch Tuning Handbook to make sure.

 

[Tbyrd]

hey, sorry been off awhile. Got the roller secondary off ebay. It is a hyper lite, they do not make them any more. I did end up having to machine the splines on my jackshaft because they would not let the clutch slide on far enough. Upbushman I think machined the splines out of the secondary clutch to get his to fit. Probably an easier way to go. So far im very impressed with the results but have a new helix on the way so hopeing it gets me where it needs to be. I will say this sled wants to wheelie all the time now. And im loving the heel clickers!

 

[blueironranger]

I'd leave the primary spring alone and strictly deal with secondary to get the RPM you desire since you had the Primary setup well to work with the stock secondary. Stiffer spring on the Primary will bring up the RPM but also increase belt grip which is wasted energy. I've always tried to lighten up both springs as much as possible without having too much belt slippage.

So what is your RPM drop now going from Hardpack to Powder? I've been looking at going roller to cure that issue on mine. I run about 11,200 on trails but it drops off to ~10,500 in powder @ WOT due to mediocre backshift.

 

[Tbyrd]

I dont have the right helix yet, the roller came with a 49/45 witch is obviously too tall so my rpms are 4 to 500 to low. The cool thing with heel clickers in primary is that it produces 3x the belt grip over stock but rite now i have all the weight out of arms to keep rpms up. This is why im looking for an over rev scenario so i can utilize the adjustability of the heel clicker. The more weight u add the more belt grip and rpms go down.

 

[UP bushman]

Update on setup 2 above.

 

[Tbyrd]

My roller takes cat helixes and was having trouble finding a place in usa to get the right one. All were from canada and wanted more to ship than the cost of helix. Anyway found a outfit that will make one for me finally. Having a 40/35 made and I was told should be here next week sometime. I will definately post when I get it installed and run it.

 

[RJH]

you are over revving on the start...a bit

need to hold it back a so it pulls straight to what Yamaha indicates is max RPM...

 

[UP bushman]

Finally got some good snow and found the setup above is a good lower snow setup or trail sled setup. I will be gearing down now that I have been able to load test the clutching. Rpms stayed at 11,300-11,500 anywhere in the shift out under 8"-10" of snow load. Midrange is great but want more low end grunt which will also be easier on the clutching.

 

[UP bushman]

An update with final testing time and dialed in clutching with preferred setup. The setup above in setup 4 with lower gearing is what I have choosen to stay with for the final performance. It has smooth engagement with great ski lift low range to WOT full shift out pull on flat or climb. Lucky for me I have a Timbersled Skid you still have to steer a sled at times. The setup 3 was great with smooth engagement but was to snappy wicked low to midrange for the short tight stuff I ride. It would be fine in a more wide open type of terrain. Setup 1 & 2 with taller gearing would be more for trail riding and some off trail with smaller track and lighter rider.

 

[blueironranger]

Did you feel any gain going to the 9 tooth drivers? I'm happy with the 19/41 gearing with the 8 tooth but there is a GT 9 tooth axle assembly that has been floating around on Ebay for 6+ months for 40$ that I've been thinking of trying with the stock 17/41 gears. I really don't feel the need for Anti-ratchets, I run my track with 1"+ free sag and have never ratcheted and 9 tooth should have more bite on the track. I'm also thinking of a bigger wheels on the axle also, I'm just wondering how much HP I can free up! I haven't seen any track dynos comparing stock to bigwheel to ported track to see how much, if any, gain there is. If we could bump our sleds to 50-55 track HP that would be very comparable to NON-powervalve 600 and newer PV500 sleds. Right now My neighbor can't keep on his 583 144" summit, and thats a 95hp mill.