Belt slipping.

[Menace1]

Hey guys, I was out in revy this weekend, my belt was slipped a few times. When i got home i stripped it down. I was hoping someone might be able to give me some advice on what may have caused this. Stats include: BWB primary spring, supertips w/ 80 grams, most of it at the heel. Secondary: green cat spring (holes 1,0), 45 degree straight cut helix,. 19/40 gears, avid drivers, 174 2.5" track. Propane turbo. My rpms never got over 8500, Im dropping the wieght in the clutch, but does being to heavy somehow cause the secondary to slip? as you can see the belt appears to ride nice and high up front still. Thanks for viewing and any help.
On a side note, lots of nice builds in revy this weekend. Couple rediculous nypex's and tricked nytro's! Good snow!
Guy parked next to me almost had his truck and sleds ripped off from the Peaks hotel parking lot, luckily they couldnt get it started. Brutal!

 

[Turblue]

guy in the video claims gearing them down is bad with so much power.....

http://www.ty4stroke.com/viewtopic.php?t=97328

 

[ROBERTSONYAMAHA]

check to make sure your belly pan didn't fall off! lol
Seen that all too many times now...

 

[Menace1]

Gear change

Wow thanks for that, makes sense, you think going from a 19t to a 20t would be enough?

 

[Reg28]

I have an HP3 propane nytro and blew 2 belts in one day 2 weeks ago in Revy. All I did to fix it was use duct tape around the primary clutch plastic. Snow was getting in through the seam in the plastic and causing the belts to slip and blow.

 

[Tuesday]

moisture from snow/steam and heavy/loaded deep snow conditions are hard on the belts. That 174 has massive resistance esp when loaded with snow. Revy is just plain hard on belts.

Minimize snow ingestion, give your belt the occasional cool down, and when taking off try to minimize belt slip. Clutching and gearing always help but belt management goes a long ways as well.

GL

 

[NM]

moisture from snow/steam and heavy/loaded deep snow conditions are hard on the belts. That 174 has massive resistance esp when loaded with snow. Revy is just plain hard on belts.

Minimize snow ingestion, give your belt the occasional cool down, and when taking off try to minimize belt slip. Clutching and gearing always help but belt management goes a long ways as well.

GL

I agree with this. The snow last weekend was really heavy and I seen a lot of blown belts. A good break in is also important. People should take the time to put a new belt on before heading down the trail at the end of the day to insure a proper break in.
I am also going to gear my sled up. I can fully pull the clutches with 20/40 gearing and I don't think the belt likes being buried in the secondary. I have never wrecked a clutch yet though.

 

[Menace1]

I agree with this. The snow last weekend was really heavy and I seen a lot of blown belts. A good break in is also important. People should take the time to put a new belt on before heading down the trail at the end of the day to insure a proper break in.
I am also going to gear my sled up. I can fully pull the clutches with 20/40 gearing and I don't think the belt likes being buried in the secondary. I have never wrecked a clutch yet though.

Thanks for the input, might try the 20/40 next time, or maybe the 20/39. I didnt have any snow or condensation in or around the clutch compartment so Im thinking gearing is next thing to look at. If it was snow, it would be slipping at different spots of the clutch, not just at the bottom as seen in the pics. Just my thoughts. Your sled was sure working well hey!

 

[NM]

Thanks for the input, might try the 20/40 next time, or maybe the 20/39. I didnt have any snow or condensation in or around the clutch compartment so Im thinking gearing is next thing to look at. If it was snow, it would be slipping at different spots of the clutch, not just at the bottom as seen in the pics. Just my thoughts. Your sled was sure working well hey!

I think stock gearing is really good for most boosted sleds. If the gearing is too low, then it is far to easy to overdrive the clutches and bury the belt in the secondary.
Ya my sled was working the best it ever has. The new box seems to work well. Release coming soon!

 

[Turblue]

I think stock gearing is really good for most boosted sleds. If the gearing is too low, then it is far to easy to overdrive the clutches and bury the belt in the secondary.
Ya my sled was working the best it ever has. The new box seems to work well. Release coming soon!

I agree totally....with all this horespower gearing down and when the clutches are fully shifted and the motor has more to give starts slipping on the secondary...almost like 4low gearing down ....I believe the primary on the Nytros spin 1000rpm or so faster than the apex (no gear reduction correct?)....which would make gearing and clutching all that more critical...

I dont know i have had really good luck with 51 helix and epi purple, no clutch or belt problems for 4 years.....apex thou

 

[Turblue]

they are always slipping/failing when fully shifted...so it has to be either getting wet or the primary is overpowering the secondary forcing that belt to the bottom and slipping?

 

[Sleds R Fun]

I ride in Terrace BC, thats coastal snow @ its best. Your running that belt @ 0-1, how the hell does it even back shift!!!! Your pulling that belt right to the bottom of the secondary as soon as you touch the gas. Try 3-3 and your belt issues will be gone. Generally taller gearing will make belt life worse.

 

[doctorspeed]

Secondary clutch

Ya, to me it looks like you want to gear back up to a 20t . You don,t want run that low in your sec, efficiency drops way off. You will want to stay 1:1 ratio or lower. 1:1 ratio is the best at efficiency try to get for top rpm. Also I would add a few degree to sec too. Maybe go to 50 or 60. I run mine at between 50 and 70 degrees all the time.
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[DooTraxx]

I ride in Terrace BC, thats coastal snow @ its best. Your running that belt @ 0-1, how the hell does it even back shift!!!! Your pulling that belt right to the bottom of the secondary as soon as you touch the gas. Try 3-3 and your belt issues will be gone. Generally taller gearing will make belt life worse.

What is the rest of your clutch set up? Just saying try 3-3 means nothing without knowing your helix, both springs and what primary weights you are running. Also good info would be your horsepower you are running and what track you have under her. I am just trying to figure what works and what doesn't but find guys just give one piece of the puzzle that can then lead you down the path.

 

[Sleds R Fun]

Hey DooTrax good point. I did PM Menace1 with my setup, just figured it would be more helpfull on a PM.
Cheers

 

[paulharris]

Guy parked next to me almost had his truck and sleds ripped off from the Peaks hotel parking lot, luckily they couldnt get it started. Brutal!

i cant believe this crap is still going and the police still have not gotten it under control

 

[Menace1]

Hey DooTrax good point. I did PM Menace1 with my setup, just figured it would be more helpfull on a PM.
Cheers

Yes he did, and thank you too all that replied and pm'd. Going with 3,3 , try that out then if clutches are still hot will gear up one. Will post findings at a later date.

 

[mule got beer]

u could talk to the boys at alpine and see what they run on there boosted nytros with a174 , there always helpful and good custmer suport