Chain Rubbing Against Rear Cylinder Exhaust Header

[Vishwacorp]

Hello,

I was riding my 2006 M620 and hit a huge pothole here in NYC at around 25-30 mph. I even got some unintended time aloft but thankfully I didn't fall off and maintained control of the bike. However, since then, my bike started making a loud metal-on-metal rubbing noise. I'm pretty sure it's the chain rubbing against the exhaust header from the rear cylinder, like this picture (not my picture, found it on another thread here). The noise isn't constant, but it lasts for about 1/4th of the chains revolution.



It's kinda dark out now so I haven't had a chance to attempt to fix anything. Could it be that the exhaust header has moved out of the way or maybe the wheel has shifted out of alignment? Either way, would it be fine to ride it around 10 miles to a shop for realignment?

[Howie]

Could be either.  If the header moved you should see damage to the pipe where it hit.  More likely the rear wheel is out of alignment.  If so, make sure the adjusting shoe in the swing arm functions

[talljoker]

I had this happen to me. It seemed like it was going on for a long time since it grounded down through my Termi...didn't notice it but JB welded it...(temp fix) and now I have to get it cut out...lovely isn't it. I would check alignment

[Vishwacorp]

I took a look today and the header pipe was hit right under the engine. I'm guessing that pushed the pipe from the rear cylinder much closer to the chain. Until I get new hearders, I'll just try to hammer some distance between the pipe and the chain. I'll go search the forum to check rear wheel alignment since I have no idea how to do that.

[Vishwacorp]

The wheel may or may not be out of alignment. I haven't had a chance to check that yet. But the exhaust was definitely hit hard. See pics below!

[Monster750ie]

Ouch that must have been a nasty bottom out.

[Roaduser]

thats an awesome effort!! looks like your headers may have touched the bottom of your engine case too!

[thought]

if you get the headers off, you can try the freezing ice trick to see if it will pop out the dent.

[Vishwacorp]

I've never heard of the freezing ice trick. I'm googling around to see what it is but any tips?

[Monster750ie]

From what I've read cap off one end, fill with water, cap the other end and place in freezer. Next day the water should have expanded. Hopefully it expands and presses out your dents.

[thought]

I've never heard of the freezing ice trick. I'm googling around to see what it is but any tips?

i saw it on a thread on this site, it's basically what m750ie said.

the important part is that the water covers the dent completely so it's forced to expand into it... you'll have have the header angled in such a fashion that that happens.

from what that other thread said, the first time didnt work that well at all, but multiple applications of it did the trick.