why does my chain keeping rubbing the swingarm?

[atvmxr]

Ok, I am totally confused whats going on and need help. about 4-5 years ago I noticed that my 14 tooth sprocket was diggin into the front of the swingarm and the chain was wearing down the bottom of the swinger at about a 30 degree angle on the bottom half of the swinger. General consensus was that my frame was tweaked and the motor had shifted in the frame due to 10+ years of hard MX use, cracking, welding, and etc or my output shaft bearings were worn. Fast foward to today, I am detailing the R and notice that again the chain is rubbing on the bottom of the swinger at about a 30 degree angle. It looks like its worn almost a 1/4" through the swinger.

Anyone have any ideas? I have a different frame and swingarm than previous, rebuilt the motor with new bearings and output shaft. I am totally lost. will try to take pics tommorrow during the day

[GOTFEAR]

This seams to be a common thing what i have seen is the pivot bolt hols on the frame is a little worn from lots of riding making the front of the arm hitting your front sprocket

[atvmxr]

I'll check it, but like I said I switched frames and dont recall the bolt hole having any excessive clearance...


what about my chain, would this happen if it was running too loose or tight?

[Aceman]

Maybe I'm missing something here, but don't you run a rub block on the front of your swinger?

[atvmxr]

it sawed right through in about 6 months of trail riding... was cleaning the bike and noticed its chewed intol the metal. exact same as last time.. but the sprocket isnt rubbing in the middle anymore, just the chain rubbing....


Im waiting on rebuilt shocks before I take it back to the track..

[atvmxr]

pics, hopefully...

http://i90.photobucket.com/albums/k244/atvmxr/250r/sprocketchain4.jpg

http://i90.photobucket.com/albums/k244/atvmxr/250r/sprocketchain0.jpg

http://i90.photobucket.com/albums/k244/atvmxr/250r/sprocketchain2.jpg

http://i90.photobucket.com/albums/k244/atvmxr/250r/sprocketchain1.jpg

http://i90.photobucket.com/albums/k244/atvmxr/250r/chain.jpg

[atvmxr]

if you look at the last pic, the chain has been rubbing almost half way up the guide, how is that possible???? :huh

[gsxr68]

looks to me like the chain is to loose. and the slack is lifting and rubbing the bottom of the arm.

[pdxbigfoot]

That when the suspension it totally compressed that the angle of the swinger front goes past horizontal and starts to develop a vertical pitch and since the front by the pivot bolt has gone past a 90 degree angle it starts to head downward and runs into a taunt chain.......does this make any sense...i think it does....KINDA...my 2 cents...good luck

[honda380]

i think pdx has it right. is the shock blown or are you bottoming out? i had the same problem on mine and as soon as i rebuilt the shock and replaced the guide block i didnt have anymore problems. Corey

[Scott-300ex]

Yeh, I was gonna say, you must be sitting real low cuz it looks like the swinger is angled up. I'd say your shock or your linkage is all wacked up.

Adjust your chain to around an 1''1/4 play when your sitting on it, so have a friend help.

[atvmxr]

I have a new dual rate Elka (finally! been waiting forever) and just ordered another slider from C&D (good prices!). I have only been trail riding so far, quad didnt seem that low....


so you think the chain is too tight and thats why its rubbing, or its rubbing because my fat butt has the suspension nearly maxed out most of the tiime......

[Scott-300ex]

Well personal question here, how much do you wiegh? LoL

And your chain would be too loose, but it looks like its rubbing cuz of the angle on the swinger.

[atvmxr]

well if its rubbing because of the angle of the swingarm, what happens when you run ZPS or flat track lowered setups?? same thing?

[number5]

The welds are for gussetts or that portion has been replaced?

[atvmxr]

well I determined part of the problem when installing the new slider. looks like the chain sliders are not a "bolt on and go" part. since I was swapping the rear shock I went through the full range of suspension travel. the bottom front of the slider would hit the sprocket at full extension and the top front would hit at full compression. also the top "rib" to guide the chain was not aligned with the sprocket. so after a bunch of prying around and loosening and re-tightening the bolt, I think I have the slider in a better position. But I am going to wait a couple days to see if the slider distorts to being back out of alignment or hitting the sprocket at the top or bottom......

I was going to pull the swinger to check the bearings, but the swingarm moves very freely with no binding, so I am assuming all is good with the bearings.



:cool:

[Aceman]

Originally posted by atvmxr

I was going to pull the swinger to check the bearings, but the swingarm moves very freely with no binding, so I am assuming all is good with the bearings.

:huh

When bearings go bad they get sloppy. Just because it moves freely doesn't mean the bearings aren't toast. I'd at least loosen the pivot bolt nut a few threads to take some compression off the side of the swinger and then wiggle the swinger back and forth looking for movement on the pivot bolt. Lot easier to do now with no shock on, then later.

[atvmxr]

oh, ok I will :D