Chain Tensioner idler gears PIC ADDED

[M5-]

I could have sworn I saw a thread about these on here some place but anyways. I was just changing my oil and tensioning the chains to spec as I always do every ride, when I noticed my drive chain tensioner sprocket is totally screwed. It looks as if the sprocket froze last week maybe when I was having lunch and then maybe when I started off it broke. The sprocket has 3 teeth in a row stipped off and it is cracked in half so basically its NFG. Anybody else have this issue or know of a good steel replacement. The plastic sprocket makes for a pretty chump set up if you ask me.

M5

 

[vmax1200]

Curious how do you tension the chain ,Be cautious thinking that the chain is set dead on , roll the track and see if there are any tight spots and go from these with the correct tension ,to tight will wipe out bearings and especialy the plastic (weak link) sprocket ,the metal sprockets seem to be a two step process fabrication so they are not perfectly true when spun.

 

[powdermuncher]

If anyone comes up with a fix so we can get alluminium or steel idler gears i will buy a set of them.

 

[M5-]

Curious how do you tension the chain ,Be cautious thinking that the chain is set dead on , roll the track and see if there are any tight spots and go from these with the correct tension ,to tight will wipe out bearings and especialy the plastic (weak link) sprocket ,the metal sprockets seem to be a two step process fabrication so they are not perfectly true when spun.

I did all that track roll etc when tensioing. I really think the gear froze to the frame then just exploded when I took off. I've had a few sleds where the upper idlers would freeze up and not spin if its cold which it was the last ride. If you look at the gears three teeth in a row are sheared off and the gear is split right between them. I'm starting to think that the plastic gears won't take any shock loading at all. Surely with all the kits and sled stuff Timbersled has sold they must have a CNC they can use to make some decent gears.

M5

 

[CATSLEDMAN1]

sprockets for sno bikes ?

building another snow bike and not real excited about the sprokets I used on my last bike. I used Martin brand 1" id w 1/4 keyway. Had to machine these to fit 520 chain, and they wear quickly stock. Heat treated them, which is way better.

Been searching the net and talking to local industrial suppliers for some thing better.

Like 520 chain width
Hardened
suggestions for splined shafts with sprokets to fit ? thinking of having a midwest custom sled clutch suppier cnc me a couple of splined shafts, anyone have a better idea ?

 

[M5-]

I should mention here, the gear in the chaincase looks brand new it's only the exposed one that got destroyed. I bought a couple of gears with 6203 RS bearings in them today. They are for a 50 chain so I need to machine it down to make it a 520 but at least it's steel.

M5

 

[the gman]

If you want you can just run a flat idler with no teeth. Mine broke a tooth off and talking to timbersled they said no one else had any problems....ya right

 

[Cberg]

Just installed my kit and was doing a test run today in the fields by my house before going into the back country and my chain was extremely tight when I installed it. After a few minutes of riding my countershaft bearing on my bike piled up and now the idler sprocket looks pretty chewed up. It's the least of my worries right now but still doesn't seem like it should look like it does after less then 10 minutes of riding on it.

 

[teal_210]

If you want you can just run a flat idler with no teeth. Mine broke a tooth off and talking to timbersled they said no one else had any problems....ya right

Haha, I've seen two break in our group this year. One on the drive chain and one in the chain case, the one in the chain case only lasted about 30 minutes! The owner of that bike have them an ear full about it... So they definately know that others are having problems.

 

[Cberg]

My chain was extremely tight when I put the kit on, I had the idler wheel backed all the way off and couldn't even get it together with pliers. I had to pull the strut out and hinge the bike and skid to get it together. I was concerned about it but they said it would be fine and the chain would stretch. I am thinking the tight chain had a lot to do with my countershaft bearing blowing out!

 

[powdermuncher]

If you have a kit with a adjustable length rod the chain tension drops if you shorten the rod Had to do that on a KTM 530 just to make it fit , same with my SX kit on the WR 450 the Yamaha Guys with standard kits and Fixed rods are up SH:T creek -- all you can do is grind some of the bottom of the adjuster, they come silly tight . I personally would never run them that tight . An other option is to cut up a used bike chain that usually does the trick . Once the chains have 10 hrs on them they usually fit fine.The question is what will wear first the chain, countershaft bearings or in some it may wrecks the case.

 

[summitboy]

Can you elaborate on that ? All fine and dandy you dont want it adjusted but how about the because piece ?

 

[M5-]

Here's the gear. The chain was set to spec and I check it every ride. If the chain was too tight you would think it would melt the gear. When I installed my kit the chain was so tight I had to go to the dealer and buy a 12 tooth sprocket so I could get the chain on and set to spec. I rode the bike and after the chain stretched I put my 13 back on and et it to spec. It seems to me that the gear is freezing and the the chain is skipping shearing the teeth off.

M5

 

[adamd1979]

Quick question about proper chain tightening. They say it needs 5/8 inch of play. To get that, do you put tension on the chain to get the first reading and then pull it in the opposite direction to get the proper play. Or do you just measure from where it hangs naturally and then pull it up to get the reading? It makes a big dif on the enclosed drive section. Last weekend I checked the enclosed drive chain for play and noticed it had about 1.5 in of play and I could see where the chain was slapping around a bit. On the flip side, I don't want to over tighten them either.

 

[up-high]

5/8 total movement

 

[CATSLEDMAN1]

loosey goosey

chains and sprockets and snow have a long history. In wrong conditions and almost all snow conditions the snow going through the chains sets up into ice on the sprocket and chain pins making chains tight as a guitar string or tighter.

No big deal breaking the tracks off a d7 cat or excavator or cracking the drive sprockets or taking out the bearings or just real premature track chains pin and sprocket wear. so riding your sno bike around with a tight chain is way not good, or then cutting left side side hill and POP goes the chain, watched that on new kit, fortunately the cheap oem chain went and not the cases on a new scooter.

so slapping and flopping loosey goosey chain might be better than breaking down the cases on your new orange bike to put in a new counter shaft bearing, unless you need $1100 worth of cases and a new bearing.

run my chain loose on my wr, checked chain tension today when the bike was a ball of powder n ice up on Mineral ridge, chain alarming tight, just those conditions today.

 

[Ausm7499]

I think I know what maybe causing some of the idler sprocket damage on the drive chain. If the sprocket combination you are running requires very little tension to be taught then the distance between the idler sprocket and the top of the drive chain are so close that the chain is contacting the teeth on the idler sprocket and breaking them off.

 

[M5-]

I think I know what maybe causing some of the idler sprocket damage on the drive chain. If the sprocket combination you are running requires very little tension to be taught then the distance between the idler sprocket and the top of the drive chain are so close that the chain is contacting the teeth on the idler sprocket and breaking them off.

That thought crossed my mind as well. I was thinking that maybe a 13 tooth idler might give more clearance than the 15. Seems like you can't win, too tight and you are hooped and too loose same thing.

M5

 

[Cberg]

Heads up for anyone installing a new kit on there bike, if the chain is way too tight get a smaller sprocket, even if your are told it will be fine and the chain will stretch.

This happened in about 5 or 10 min of my first test ride on my bike with the recomended size sprocket. Now I have a pretty good repair to do.. I knew better but listened to other opinions and well now I won't be riding for awhile..

 

[Ausm7499]

Heads up for anyone installing a new kit on there bike, if the chain is way too tight get a smaller sprocket, even if your are told it will be fine and the chain will stretch.

This happened in about 5 or 10 min of my first test ride on my bike with the recomended size sprocket. Now I have a pretty good repair to do.. I knew better but listened to other opinions and well now I won't be riding for awhile..

I would suspect that your CS bearing was already toast if you lost it that fast. I had to use a c-clamp once to get my chain down on the sprocket to get the master in and made one ride that way without any issues, I was nervous the whole time but it didn't cause any problems.