ratcheting issues??

[off road rider]

last ride of the season my 136 tracked hawk was making a terrible noise, sounded like bad ratcheting. it was happening in deep wet snow and on hill climbs. Ive got it apart now and dont see anything.. wouldnt you see evidence of slippage on the drivers or track lugs..what about the cog drive belt.. everything looks great.. Any ideas??

 

[cjgodden]

This is the reason we came up with the chain drive system. In the heavy snow there is too much load on the Tls and it slips in undesirable places. But I didn't think the 503's had the TLS?

 

[off road rider]

This is the reason we came up with the chain drive system. In the heavy snow there is too much load on the Tls and it slips in undesirable places. But I didn't think the 503's had the TLS?

I dont know?? its got a cog style belt not sure what the TLS is..I do think its different than the 6 and 800..
chain drive might be a consideration. this thing wont be stayin with a 56hp motor for long...

 

[cjgodden]

The TLS stand for Toqure limiting system, The drive shaft sprocket has a clutch plate system in it taht is supposed to slip under excessive load, this was devoloped to make belts last longer. Whats your bottom spocket look like?

 

[off road rider]

It just looks like a cog sprocket on a shaft.. I dont think there's a clutch there..

 

[cjgodden]

does the belt itself look worn at all?

 

[IbBroken]

Check the width of your belt. The 503 runs a smaller belt than the 600 and 800. maybe some one who is still running a belt could post the measurments.

 

[off road rider]

The belt that was on there, was new,as I broke one in the first 3 min of that ride. upon inspection I see no signs of any slippage..I tried tightening both the track and the new belt during the ride.. nothing helped

Wouldnt you see evidence of the track ratcheting if that was what was going on??
the last thing I need after building this thing up is issues with ratcheting..

 

[TLKDPROD]

HhHAaaaaaaaaaaaaaaa hahahah !

Been through this myself Off Road Rider !

The 503 doesn’t have enough juice to make a TLS to slip (unless you put oil in there to “lubricate”) IF you have one which I don’t think you do according to what you said above. Some 503 were retrofitted with the TLS to get rid of the narrow 36mm wide cog belt snap problems when guys were landing on hardpack @ fuell throttle ! If I had a 503 (or modded 550!!!) I’d stick with the direct drive cog belt system or if I’d go with a chain drive system, I’d use a smaller, lighter chain like a 520 instead of a 530 like we do on liquid cooled machines.

I think what you heard was track/drivers ratcheting: Suspension swinging the rails/track around a weird path causing the track to get tighter or looser throughout that path/stroke which finally gets your drivers not to be able to grab each tooth on the inside of the track. Makes a weird noise and big vibration too. Design flaw on this system is all I have to say, period. How to get it to work: you could redesign the whole thing if you know what you’re doing but that’s a lot of work let me tell ya !

My suggestion : Get a pair of Anti-Ratchet Drivers first and run the track looser. You’ll need to split the frame to get them in with the driveshaft but that’s not that much of a big deal now that my hawk is just 2 piece of aluminum held by 2 aluminum cross bars… ! You also might wanna have a look at a pivot relocation bracket. You can’t just use the swignarm bracket as it’ll screw up the whole thing because the 503 suspension is a coupled/parallel bar rear suspension. You’d need to relocate both: the upper swignarm pivot AND the upper (and maybe the lower too) rear parallel bar pivot (the black plastic piece hanging from the shock upper pivot down to the rails).
That’s not something joe-blow can patent in his garage in an afternoon, you’d need a guy (like me!) to simulate it on CAD to get the rails properly swung so the track doesn’t get tight or loose throughout the stroke… If someone somewhere did his job perfect on a certain thing, we wouldn’t have this thread going on… I’m willing to help you on this if you ever want to solve the problem at the root, not just patch over a screw-up.

Thierry

 

[off road rider]

HhHAaaaaaaaaaaaaaaa hahahah !

Been through this myself Off Road Rider !

The 503 doesn’t have enough juice to make a TLS to slip (unless you put oil in there to “lubricate”) IF you have one which I don’t think you do according to what you said above. Some 503 were retrofitted with the TLS to get rid of the narrow 36mm wide cog belt snap problems when guys were landing on hardpack @ fuell throttle ! If I had a 503 (or modded 550!!!) I’d stick with the direct drive cog belt system or if I’d go with a chain drive system, I’d use a smaller, lighter chain like a 520 instead of a 530 like we do on liquid cooled machines.

I think what you heard was track/drivers ratcheting: Suspension swinging the rails/track around a weird path causing the track to get tighter or looser throughout that path/stroke which finally gets your drivers not to be able to grab each tooth on the inside of the track. Makes a weird noise and big vibration too. Design flaw on this system is all I have to say, period. How to get it to work: you could redesign the whole thing if you know what you’re doing but that’s a lot of work let me tell ya !

My suggestion : Get a pair of Anti-Ratchet Drivers first and run the track looser. You’ll need to split the frame to get them in with the driveshaft but that’s not that much of a big deal now that my hawk is just 2 piece of aluminum held by 2 aluminum cross bars… ! You also might wanna have a look at a pivot relocation bracket. You can’t just use the swignarm bracket as it’ll screw up the whole thing because the 503 suspension is a coupled/parallel bar rear suspension. You’d need to relocate both: the upper swignarm pivot AND the upper (and maybe the lower too) rear parallel bar pivot (the black plastic piece hanging from the shock upper pivot down to the rails).
That’s not something joe-blow can patent in his garage in an afternoon, you’d need a guy (like me!) to simulate it on CAD to get the rails properly swung so the track doesn’t get tight or loose throughout the stroke… If someone somewhere did his job perfect on a certain thing, we wouldn’t have this thread going on… I’m willing to help you on this if you ever want to solve the problem at the root, not just patch over a screw-up.

Thierry

This 503s going to kick ***..motors apart and changes are happening..
the steeped head is trowing me a curve, but theirs lots of room for porting.... keep laughing..I hear you..
The cooling issue is not going to be a problem
I can understand some ratcheting as being part of the game, however no one elses machine was doing this on this day riding side by side.. Its not normal..
shouldnt you see wear marks on the drivers or track from it ratcheting??

 

[TLKDPROD]

By the way, I wasn't lauging at you Off road Rider , i'm laughing at the fact that the same problems is gonna happen to most of us an also that we have to support each others !

Did anyone else had a "503 suspension" with a 136" track like yours that day ? A design can work for a 121 but may have problems with a 136".
Like the one I designed for my 150 track, I simulated the exact same pivot points for a 144 track (rear idlers were just not as far) and I had the track to loose up at the end of the stroke. I know exatly which pivot to relocate and where tot get rid of that but these are the thing you need to take some time to do, not just throw rail extensions at it and away you go like ADB did.

I'm glad you're getting at it man ! There's a lot of stuff that can be done to a 503 i'm sure, no one has actully gotten at it far enough ! I can't wait to try that thing at 2010 Hawkfest... !

By the way, if you ever get a new secondary, have a look at the new Team tied, probably the best one available right now... you can run a 14 degree steeper helix apparently because the system is so efficient... That would help getting the most out of your Mod503F ! Thinking about it myself...

 

[off road rider]

By the way, I wasn't lauging at you Off road Rider , i'm laughing at the fact that the same problems is gonna happen to most of us an also that we have to support each others !

Did anyone else had a "503 suspension" with a 136" track like yours that day ? A design can work for a 121 but may have problems with a 136".
Like the one I designed for my 150 track, I simulated the exact same pivot points for a 144 track (rear idlers were just not as far) and I had the track to loose up at the end of the stroke. I know exatly which pivot to relocate and where tot get rid of that but these are the thing you need to take some time to do, not just throw rail extensions at it and away you go like ADB did.

I'm glad you're getting at it man ! There's a lot of stuff that can be done to a 503 i'm sure, no one has actully gotten at it far enough ! I can't wait to try that thing at 2010 Hawkfest... !

By the way, if you ever get a new secondary, have a look at the new Team tied, probably the best one available right now... you can run a 14 degree steeper helix apparently because the system is so efficient... That would help getting the most out of your Mod503F ! Thinking about it myself...

My hawks brother was there as well, both from the factory with 136 tracks.
I need to figure this out before spending alot of coin..
If both machines where having issues then I can see that driver mods are necessary. but only my hawk having issues concerns me..
Im removing the shocks and will see what happens to the suspension under full movement...

 

[TLKDPROD]

You may want to play with your limiter straps and the eyebolt adjustment you have at the end of the parralel bar, maybe you have a different setup. That might get the problem solved.

As far as i'm concerned, the limiter straps on a 503 are useless since it's a parralel bar design. Put them too tight and you won't be able to use the full stroke the suspension was designed for. If you want to "raise" your limiter straps so you don't trench as much, lenghten your rear parralel bar in the back, that'll raise the front of your rails. Again here it might be a compromise to get the track to work right !

Let us know how she works !

 

[off road rider]

so if I understand you.. let the limiter straps out as far as they will go and loosen the nut on the parallel bar..

 

[TLKDPROD]

Yeah that's right. Put the limiter strap as loose as you can, Further in the season if you find you're trenching too much, you could always raise it up a bit.

Play with the adjustment at the end of the parralel bar, you might get it to work properly just with this adjustment.

 

[J&L Snowhawk]

track slip

sounds to me like skipping the track drivers.

 

[off road rider]

sounds to me like skipping the track drivers.

wouldnt there be some sort of evidence, worn lugs or drivers???
the more I look at it the more I think it may be the belt...
the straps, and parallel bar where already out all the way

 

[TLKDPROD]

wouldnt there be some sort of evidence, worn lugs or drivers???
the more I look at it the more I think it may be the belt...
the straps, and parallel bar where already out all the way

You won't see clear evidence of worn lugs/tooth or worn drivers unless you really over-do it for like one complete season I think. Could you see the track getting tighter or looser throughout the stroke without the shocks ?

It doesn't take long for a belt to let its teeth go once it slipped once... From the time it first slipped on me, it took about 3 pulls in the deep for it to rip half of the amount of teeth right off. It felt like a tire that's got half of the knobbies missing !!! Check if there's any tooth missing or if belt starts to shave off on one side, might be your problem.

 

[off road rider]

You won't see clear evidence of worn lugs/tooth or worn drivers unless you really over-do it for like one complete season I think. Could you see the track getting tighter or looser throughout the stroke without the shocks ?

It doesn't take long for a belt to let its teeth go once it slipped once... From the time it first slipped on me, it took about 3 pulls in the deep for it to rip half of the amount of teeth right off. It felt like a tire that's got half of the knobbies missing !!! Check if there's any tooth missing or if belt starts to shave off on one side, might be your problem.

The track was a bit looser in the full extended position and tightens up when compressed. it looks like I am getting full motion. I do think I had the track a bit to tight, I had tightened it in the field trying to eliminate the noise, did the same thing with the belt. No signs of damage on either..
Im pretty concerned about this.. The machine was basically unrideable..

 

[TLKDPROD]

The track was a bit looser in the full extended position and tightens up when compressed ... QUOTE]

How tight did she gets ? "Not too bad tight", "pretty tight" or "DARN FKN TIGHT". A good way to tell would be to put you shocks back in, spin the track by yourself on your Hawk's stand, remember how she spun. Then lock your suspension right up at the end of the stroke and spin the track by yourself again, compare. A tight track doesn't spin as free as a "perfectly slack" track.

I've had this exact problem while testing some bad pivot relocation brackets retrofit. Track got tighter once compressed as the whole tranny still have momentum, when it reaches the point where it's too tight and drivers do have problems having it just to spin around the suspension system; drivers end up slipping some tooth every 2nd or third on the track. (It was basically unrideable too just like you said) Then as the suspension gets back to its original position, it still looks like it "performs" normal.

This is my idea of the problem if the belt looks fine and you've got enough tension on it. Check your tension on the belt, they need to be pretty tight unlike your track !