Track/slide drag

[Studroes144]

Been hearing of a lot of cases where people aren't seeing very good top speeds. As of a few days ago I was running mine in the field some on bare grass and was able to get 98mph out of mine and was getting full shift of the clutches. Went out again tonight with a buddy who has a nytro and right from the start I could tell something didn't feel right. We raced and he took me by about 2 sled lengths while in prior races I would beat him by about that much. The same exact field that I was getting 98 in two days ago I could only get 84mph in tonight and nothing has changed on the sled. Anyways we rode up on tug hill and got out on a mile long reservoir and raced again against a different sled. This reservoir was perfect for speed! Glare ice with 1 inch of fresh fluff on top. I thought for sure I was going to see 110 on my speedo..well same thing could only get 85mph out of it..clutching was still spot on for rpm. So I talked with my dealer and he said the procross chassis is notorious for having a lot of drag with the track on the slides. He said last year the had an f800 that they could only get 100 mph out of..went back to the shop and changed slides, added extra wheels and pulled limiter strap up and the next day did 116mph. Does any of this sound right to the guys familiar with this chassis? I fine with buying the wheels and putting new slides on but I just want to make sure it's gonna work. To me it's the only thing that makes sense because the clutching was working awesome in my sled prior to tonight and nothing changed on the sled since 2 days ago. This may be a solution to the speed issues some people r having.

 

[sk-rx1]

Seems odd, you would think if the slide friction were slowing it they would show some wear in the affecting areas. But I have not heard anything about this. I did notice that mine were showing some roughness on the bottom but no noticeable wear. Maybe the Yamaha Dupont slides would be a solution. Certainly an interesting test to test your sled, then install the Dupont and retest?

 

[Studroes144]

Just seems like there are a lot of guys very disappointed with top speed on this sled. I for one was very pleased early on that the sled would do 100 with stock clutching. Other guys have a hard time doing 80 with the same exact stock sleds. Granted improper rpm will hurt a lot but I seen 100 with my sled with the rpm running low aswell so I'm ruling out clutching on this one. I'm hoping that simply pulling up limiter straps will do the trick and that will be an easy fix for everyone

 

[Nytros rule]

Not sure where notorious for drag came from, maybe the department of misinformation (hard core sledder) but if the procross or proclimb skids were that bad you should smell your slides melting as your driving and be burning them off in a few hundred K.

 

[DeerHuntr]

Seems weird that your problem would come on so suddenly and be caused by rear suspension settings when you said you didn't change anything. I'd start by trying a different belt or possibly cleaning your clutches. Just seems weird to me.

 

[Studroes144]

I'm thinkin the same thing. To me it's been noticeable that it's been slightly loosing top end grunt but it was very noticeable last night that it was just a dud. I actually did install a new belt a couple hundred miles ago just because of the wear that the original belt had from being taken on and off so much while doing the clutching

 

[DeerHuntr]

Belts can do allot of funny things. I'd try a different belt and scuff up your sheaves with a scotch Brite first

 

[snowbeast]

I'm thinkin the same thing. To me it's been noticeable that it's been slightly loosing top end grunt but it was very noticeable last night that it was just a dud. I actually did install a new belt a couple hundred miles ago just because of the wear that the original belt had from being taken on and off so much while doing the clutching

If the new viper belt is anywhere near as hard as our 8dn belts for the apex was,you may of slipped the belt bad enough to have glazed it over enough that it is now slipping bad,one way to tell is go run hard like top end and pull right over rip the side panel off and feel the belt and secondary,or both if you cant hold on to them for 10-15 seconds you have smoking hot clutches from a slipping belt. Also see if you can find an aftermarket belt gates makes some belts for all applications that are cheap but softer compound also ultimax pro belts work good and are cheap around 65-70 bucks for a direct rplacement,the softer belt will grip better,but may take some fine tuning with weights or helix to bring rpms back up at full shift.

 

[bleedyamaha]

gates

I bought one off ebay 3 days ago from gates for 65.00 new free shipping. I see they went up 10 bucks today. Got it today. Thinking about switching out after all the blurps on the throttle during break in period.

 

[Studroes144]

I'm thinkin the same thing. To me it's been noticeable that it's been slightly loosing top end grunt but it was very noticeable last night that it was just a dud. I actually did install a new belt a couple hundred miles ago just because of the wear that the original belt had from being taken on and off so much while doing the clutching

If the new viper belt is anywhere near as hard as our 8dn belts for the apex was,you may of slipped the belt bad enough to have glazed it over enough that it is now slipping bad,one way to tell is go run hard like top end and pull right over rip the side panel off and feel the belt and secondary,or both if you cant hold on to them for 10-15 seconds you have smoking hot clutches from a slipping belt. Also see if you can find an aftermarket belt gates makes some belts for all applications that are cheap but softer compound also ultimax pro belts work good and are cheap around 65-70 bucks for a direct rplacement,the softer belt will grip better,but may take some fine tuning with weights or helix to bring rpms back up at full shift.

There is a lot of heat coming from the secondary. After 3-4 runs down the field it's hot to the point that I couldn't leave my hand on them for even a second. Belt slipping is definitely the biggest issue but I think I'm going to put on DuPont slides and add extra wheels just to get that extra edge. As far as switching belts that may be something I'll look into as well.

 

[09nytro]

Not a big fan of the Yamaha belts , I think they are way to hard , I've always run ultimax xs but they aren't making them yet for the viper , they say they will have them out this month , hope so because I have no spare belt at the time because I'm waiting for ultimax

 

[canadianhunter]

Anyone have the part numbers for the Gates belt and the Ultimax Pro ?
My belt make a bit of a squeal at times, will have to check temps. and clean/scuff up clutches and belt.
For my riding ultimax belts have always work better.

 

[fxnytroxtx]

I personally don't think that it's ether clutching or drag. I was was riding my sled one day in tug hill after the last big storm and the trails had loose snow on tthem and all it would do is 85-90, but as we headed towards old forge where there was less snow and we hit some lakes that had about 2-3 of hard wind packed snow the sled would easily hit 100 and get there fast too. So im thinking this chassis is really sensitive to conditions it's riden in or spins a lot in the looser stuff?

 

[09nytro]

I will e-mail ultimax to see if they got a belt out yet !

 

[Studroes144]

I personally don't think that it's ether clutching or drag. I was was riding my sled one day in tug hill after the last big storm and the trails had loose snow on tthem and all it would do is 85-90, but as we headed towards old forge where there was less snow and we hit some lakes that had about 2-3 of hard wind packed snow the sled would easily hit 100 and get there fast too. So im thinking this chassis is really sensitive to conditions it's riden in or spins a lot in the looser stuff?

I'm def having clutching issues as after looking at my belt it's glazed over. Feels like wax paper. And I am getting a lot of heat on the secondary. So that issue needs to be addressed. As far as the sled being sensitive to trail conditions I'm going to add extra wheels and DuPont slides. Other than that I think that's about all that can be done in theory to make the sled be faster other than aftermarket parts. Talked with some big speed guys last night and they say this chassis has a lot of slide rail drag but it's hard to tell. They did testing last year on a perfect ice surface where speeds should have been very fast and they weren't. Went back to their shop. New slides, extra wheels and pulled up limiters and got 10+ mph more out of it in the same exact day. One thing I'm curious about is whether or not an improperly adjusted rear suspension will make the sled seem slow in certain snow conditions. We all know this sled is set up stiff and maybe having the shocks revalved will help a lot here and it will be more designed for each specific rider and will help with keeping the track and suspension running smooth on the ground. On a trail with 1 foot moguls I can hold mine wide open on long straight aways and my buddy on a skidoo 600 can pull ahead of me a couple sled lengths all because the suspension is working better. On a flat hard pack trail in a drag race my viper will pull away no problem. I think suspension setup and fine tuning will help this sled a lot as far as being more versatile on the trails for speed.