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Rear tire rubbing on exhaust silencer....WTF?

14025 Views 25 Replies 9 Participants Last post by  sguyer
Back in it's dirt days, I ran a 120 dirt tire, which always rubbed on the stock silencer a little bit. (pictured below). I had hoped that with the smaller diameter Supermoto wheel, it wouldn't be as bad.....well I was wrong!

The subframe is good and straight, and I even spaced the silencer out using a couple of 1/2" nuts as spacers, still rubbing, bad. I even stiffened up the shock a little bit, and it's still rubbing.

Outside of making the rear so stiff that I'll hate it, anybody out there have any suggestions? Of course, me losing weight, or spending more that $7 is out of the question :laughingr
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A little heat and a pair of vice grips on the welded tabs should do the trick. Just don't bend them too far outward!
hammer the can until its so dented that it clears. :D

or just do what racer187x said, and move it over a little more. it cant be rubbing very much, or it would be touching lower on the pipe.
A little heat and a pair of vice grips on the welded tabs should do the trick. Just don't bend them too far outward!
Right now I have 1/2" nuts between the tabs on the subframe and the mounts on the silencer, so it is shimmed out. Although I think I see what your saying, If I bend the tabs on the subframe, rather than simply moving the silencer away, it would twist the silencer, giving me more clearance down low.....right?
Correct. I would use your "shims" though as well. Obviously, you can go too far so watch that. I have a little rub on the lowest part of the can usually. I crashed last time out and ended up bending the tabs inward so I had massive tire rub for the rest of the ride. Easily fixed with the vice grips.
Thanks!
I'll try that tonight. I just love trying to bend aluminum!!

I'll either be singing your praises tonight, or cursing your very existence. Either way should make for a good post tomorrow morning!!
Those tabs are thicker than the can so be CAREFUL when trying to bend them or youll bend the can itself and not the tabs.

My FMF carbon 4.1 rubbed just like that...I took my can off and heated the tab up untill they were glowing red...they bent OK and I didnt ruin the carbon fiber canister...

good luck
Thanks!
I'll try that tonight. I just love trying to bend aluminum!!

I'll either be singing your praises tonight, or cursing your very existence. Either way should make for a good post tomorrow morning!!
use a torch!
if you try to bend thoes tabs without heating it up, you wont have a happy post tomorrow. :thumbup:
Wait?!?!?!

Should I be bending the tabs on my subframe, or the silencer? (or both?)
Wait?!?!?!

Should I be bending the tabs on my subframe, or the silencer? (or both?)
if it was my bike, id do it to just the can... unless you tweaked the frame, but it doesnt look like it in the pics.
ahh, now I see! That's why you mentioned using the torch. It all makes sense now.....

I've already fell for the heat the aluminum until it's cherry red trick. Ended up with a puddle of aluminum that used to be a brake lever, and several amused friends......
ahh, now I see! That's why you mentioned using the torch. It all makes sense now.....

I've already fell for the heat the aluminum until it's cherry red trick. Ended up with a puddle of aluminum that used to be a brake lever, and several amused friends......
lol, i didnt read his post..
yea.. you heat it until its shiny enough that it wont fatigue when it bends, and then STOP :laughingr

i didnt fall for that aluminum trick, but i fall for that "stick a piece of aluminum in with the stainless hes welding" trick.. everything was going together just fine until i went to weld in the piece they swapped on me.. then i couldnt weld for crap, was melting metal.. it wouldnt "stick". and i was left going WTF?!:lol: goodtimes. :thumbup:
I say take the can off the header and bend the tabs back. A lot of the time, especially on off road bikes that get crashed, the tabs bend inwards. Pull the can off and look at the bike from the rear. You can tell if the tabs have been bent inwards. And careful with that torch!
Whaler,

Trying to bend those 1/4" thick tabs on the silencer is not gonna work if they are straight and in thier original position. When you bend those tabs it will make the inlet not compatible with the header pipe. Can you take a few pics of the entire system you have and what the mounts look like? I think part of your problem is that the header itself does not have the original amount of bend near the frame mount and this is causing the header to can mount be in the wrong place. And are you sure the sub is not bent? Sure? Has the header been bent before and repaired?
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OK, time to revisit this one....

After trying several things, my tire is STILL rubbing. I've heard from several people that "they do that", but I just can't accept that.

I know that it rolled off the assembly line intended to be a dirt bike, and running a 160 rear on it was not what it was made for (like a SMR), but there has to be a way to get the pipe to clear the tire, be it conventional or a little "inventive".

I currently have two 20 mm spacers that I made pushing the can away from the subframe, while it has helped, it's still hitting.

Questions...

I have read that the SMR header has a different bend to address this issue, my bike is an '04, I don't think they made an SMR in '04, so my closest option would be an 05 SMR header. Would that one bolt up? You guys think it would help?

I have looked at the FMF speed slip on. From the pictures, it appears that that the pipe itself is shorter, and it uses a mid pipe to go to the header. Anybody out there have one? FMF doesn't post specs on it, and the guy I got on the phone didn't have the info I needed. I'm thinking if the pipe is shorter, and with a mid pipe, that it might be enough to clear.

Here are some pics I snapped off...what do you guys think?

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custom make your own can and make sure it's slim enough so it'll clear the tyre? don't think there's a lot of other options left if you allready tried everything else.

I did notice the bottom end of your can is pointing inwards a lot, on my '05 I still had rubbing issue (this being in the middle part of the can and not the bottom like on your bike) but it was placed more to the right.

you could try the smr can I'm not a 100% sure it'll be a simple swap job, exc and sx pipes are interchangeable that I do know.

check the spacing on this smr, mounted a lot more to the right compared to your bike.
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since its so close to the header, you could try tweaking the header so that it was further from the tire at that point.. then tweak the tabs to match..

doesnt look like you have much room to work with though.
:headscrat ........Loosen all of the mounting points including where it goes into the head and see it you can tweak it?

Has the sub frame taken a hit?
I think the head pipe and subframe is all where it should be, it just wasn't designed with a 160 tire in mind.

The two thoughts I had was to try to make an offset bend in the head pipe, or make a small offset bend "mid pipe", then shorted the stock silencer the length that the new mid pipe would take up.

I just don't want to kink anything trying to tweak it. I've heard of guys filling pipes with sand, than heating them and bending them, the theory being that the sand inside the pipe will keep it from collapsing and kinking.... I dunno....
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