sequence of event before my belt blew

[m8matt]

This is a video of exactly what I was doing before the belt went. We were in Sicamous B.C. this weekend. Crusty snow with lots of footing. Sorry the video is so long, there is a bit of commentary that ends at the 9:30 mark. I'm thinking that the top sprocket got real hot.


http://www.youtube.com/watch?v=YIls3hCk3Qo&feature=youtu.be

 

[m8matt]

trying to get the video up...bare with me.

 

[akmclean]

Upload to vimeo/youtube and post a link. I think youtube allows a 15 minutes with a basic account.

 

[richracer1]

sorry...the video is way to long I guess...mountainhorse can you delete this thread for me?...once I figure out how to shorten the video I'll repost.

FYI, you can delete your own thread, no need for MH to do it for you.

 

[AK IQ Pilot]

Can you just tell us what the sequence of events were before the belt blew. You think the top sprocket got hot. How hot? Would it sizzle snow? Was the brake rotor also hot.

I may just have to wait for the video.

Thanks

 

[paulharris]

says it has been removed because its too long

 

[m8matt]

http://www.youtube.com/watch?v=YIls3hCk3Qo&feature=youtu.be

finally got the video cut down. Please give me your opinion.

 

[m8matt]

Can you just tell us what the sequence of events were before the belt blew. You think the top sprocket got hot. How hot? Would it sizzle snow? Was the brake rotor also hot.

I may just have to wait for the video.

Thanks

Yes if you put snow on it it would sizzle off pretty quick. The heat must come from the rotor??

 

[AK IQ Pilot]

Yes if you put snow on it it would sizzle off pretty quick. The heat must come from the rotor??

Of all the testing I did last weekend none of the sleds had a hot rotor. All of them had a hot or very warm upper sprocket. On our sleds the heat is not associated with the rotor in any way.

 

[m8matt]

Of all the testing I did last weekend none of the sleds had a hot rotor. All of them had a hot or very warm upper sprocket. On our sleds the heat is not associated with the rotor in any way.

In that 9 min of riding the top sprocket was hot enough that you couldn't touch your hand to it. It took probably 5 handfuls of snow to cool it down enough to work on.

 

[knifedge]

--that hill is too big to be playing on for something that is built like a kids toy and do not try to get a little air off small jumps like that at the bottom

--this sled is for boondocking only -- and do not ride to fast down the trail either, you might overheat or break something

 

[pacian]

--that hill is too big to be playing on for something that is built like a kids toy and do not try to get a little air off small jumps like that at the bottom

--this sled is for boondocking only -- and do not ride to fast down the trail either, you might overheat or break something

 

[knifedge]

--All that I am saying is, concerning the QD, Polaris built it contrary to what Gates recommends for a center to center belt drive, and then Polaris installed a nice big heat generator(brake system) right beside it using shared components for best heat transfer. --its pure genius-- --it is also difficult to change gearing also due to space restrictions and proprietary components

--The QD system, in its current design, is just BLING to sell sleds-- as is the driveshaft in order to be able to advertise more weight reduction -- no practical, reliable functionality, just BLING -- imo -- hope Polaris builds it right for 2014

 

[Flygti32]

Im just thinking out loud here. Do you think, having the sled leaned over to the drive belt, side on long hard pulls like you were doing creates any excess pressure on the driveline system on that side and its causing it added stress? Like i said just thinking out loud.

 

[m8matt]

Im just thinking out loud here. Do you think, having the sled leaned over to the drive belt, side on long hard pulls like you were doing creates any excess pressure on the driveline system on that side and its causing it added stress? Like i said just thinking out loud.

That could be. I also noticed I feather the brake a bit when I do a down hill turn. Maybe I gotta stop doing it. It's just something i do without even realizing it. I find it helps me set the sled on its side going down hill. Old habits die hard.

 

[AK IQ Pilot]

In that 9 min of riding the top sprocket was hot enough that you couldn't touch your hand to it. It took probably 5 handfuls of snow to cool it down enough to work on.

Yep. The top sprocket on all the sleds I was with last weekend were very warm or hot to the touch. Way to hot to work on. The rotors were rarely hot. I took temperature readings dozens of times and normally the rotor was 30-50 cooler than the top sprocket.

I was measuring temperature with a digital temperature gun.

--All that I am saying is, concerning the QD, Polaris built it contrary to what Gates recommends for a center to center belt drive, and then Polaris installed a nice big heat generator(brake system) right beside it using shared components for best heat transfer. --its pure genius-- --it is also difficult to change gearing also due to space restrictions and proprietary components

--The QD system, in its current design, is just BLING to sell sleds-- as is the driveshaft in order to be able to advertise more weight reduction -- no practical, reliable functionality, just BLING -- imo -- hope Polaris builds it right for 2014

The heat I witness during testing was most likely coming from the muffler or possibly from friction between the upper pulley and the belt. It definitely was not coming from the brake.

 

[Ephratafarmer]

I also believed the brake was causing the extra heat. I was wrong, the heat gun showed top cog pulley 40 to 50 degrees hotter than rotor. I believe the belt is causing some of is own heat and the muffler heat transfer is helping heat it up. Each time ya stop the temp reading on the very top of the belt continues to rise as ya set there. I believe this is from the top cog pulley and the exhaust transfer. It would rise at least 30 to 40 degress very quick. With Turbos its even hotter.

 

[geo]

M8Matt, at the end of your video you said something about ratcheting the day before and you thought your belt was gonna go. Did you mean track?

I've been checking my QD belt from the beginning and proved to myself it is not the brake that causes the heat at the top sprocket. But, if you do brake hard for a long time (like playing snowcross) it really doesn't add too much more heat to the belt while moving. It just adds a longer cool-off time (because of more mass) when stopped to the top sprocket (five handfulls of snow instead of three LOL).
IMO, if heat is an issue to this belt compound (they are shearing not delamb though), it is happening while sitting still. A plastic-rubber engineer would need to come in with some info here.

Another thing that happened to mine (but no others have noted this so,,,) is the top pulley bolt came loose twice . It didn't fall out it just lost it's torque. 3rd time I used high heat green and torqued to 35 ftlbs. That has stayed tight for 400miles.
I would not have found this had I not spun the drive line (to check sprocket run out) using the top sprocket bolt. I checked it again 75 miles later and it became "just loose" again (using blue locktite and 29ftlbs) and this time noted the washer had worn the coating off the sprocket so maybe the bolt was not backing out but the sprocket surface wearing.
Has anybody that has had to remove there belt noted the fit of the top sprocket to shaft? Is it wobbly-loose when slid on by itself? Maybe mine is just different.

Best sled I have ever owned to date but I'm a little anal about checking things 'cause I go out on my own too much so I develope "habits".
I had to chuckle to myself the other day. Out with a bunch of friends for a "Sunday" ride (you know poking at hills then sitting and talking about it) and when I got to the "gathering" I opened the exhaust side and grabbed a handful of snow to jam onto the top pulley.
My buds said WTF, did they move the clutches over lol. For years while riding Doo's and Cat's, I have been like the rest and opened up the clutch cover to let things cool. In less than a half of a season my habit changed.
I don't need to worry about the clutch belt anymore lol. Now I cool my QD belt. Oh well, at least I still open something lol.

 

[m8matt]

M8Matt, at the end of your video you said something about ratcheting the day before and you thought your belt was gonna go. Did you mean track?

I've been checking my QD belt from the beginning and proved to myself it is not the brake that causes the heat at the top sprocket. But, if you do brake hard for a long time (like playing snowcross) it really doesn't add too much more heat to the belt while moving. It just adds a longer cool-off time (because of more mass) when stopped to the top sprocket (five handfulls of snow instead of three LOL).
IMO, if heat is an issue to this belt compound (they are shearing not delamb though), it is happening while sitting still. A plastic-rubber engineer would need to come in with some info here.

Another thing that happened to mine (but no others have noted this so,,,) is the top pulley bolt came loose twice . It didn't fall out it just lost it's torque. 3rd time I used high heat green and torqued to 35 ftlbs. That has stayed tight for 400miles.
I would not have found this had I not spun the drive line (to check sprocket run out) using the top sprocket bolt. I checked it again 75 miles later and it became "just loose" again (using blue locktite and 29ftlbs) and this time noted the washer had worn the coating off the sprocket so maybe the bolt was not backing out but the sprocket surface wearing.
Has anybody that has had to remove there belt noted the fit of the top sprocket to shaft? Is it wobbly-loose when slid on by itself? Maybe mine is just different.

Best sled I have ever owned to date but I'm a little anal about checking things 'cause I go out on my own too much so I develope "habits".
I had to chuckle to myself the other day. Out with a bunch of friends for a "Sunday" ride (you know poking at hills then sitting and talking about it) and when I got to the "gathering" I opened the exhaust side and grabbed a handful of snow to jam onto the top pulley.
My buds said WTF, did they move the clutches over lol. For years while riding Doo's and Cat's, I have been like the rest and opened up the clutch cover to let things cool. In less than a half of a season my habit changed.
I don't need to worry about the clutch belt anymore lol. Now I cool my QD belt. Oh well, at least I still open something lol.

Yes I got in a situation where I was wot then had to do a sudden brake. (Long story) It felt like the belt skipped. Can these belts take any amount of skipping?

 

[AK IQ Pilot]

I also believed the brake was causing the extra heat. I was wrong, the heat gun showed top cog pulley 40 to 50 degrees hotter than rotor. I believe the belt is causing some of is own heat and the muffler heat transfer is helping heat it up. Each time ya stop the temp reading on the very top of the belt continues to rise as ya set there. I believe this is from the top cog pulley and the exhaust transfer. It would rise at least 30 to 40 degress very quick. With Turbos its even hotter.

That is exactly what I found too. Under normal mountain riding the rotor has no affect on belt and pulley temp. Top of belt will continue to increase in temp after the sled stops.

A heat shield is in the works and will be installed before my next ride. I will continue to measure belt temp and post my results.