Hey guys, I have a 2006 GS500F and about 10 months ago I replaced my rear tire with a 140/80 Perelli Sport Demon. When I first put it on, there was about 1/8 inch between the side of the tire and the brake caliber rod. Over the past couple months however I believe I made a few mistakes when adjusting the chain tension nuts on the rear swingarm. I guess I tightened one side more than the other which slightly changed my tire angle which in turn caused the tire to start rubbing the brake rod. In addition, the left bracket that you use to tension the chain started bending in, which I believe is either a result of the rubbing or not tightening the nut on the axle of the tire tight enough.
Anyways, before I realized this I started hearing what sounded like the chain rubbing about every .5 seconds at low speeds and increasing as my I increased my speed untill the road noises started drowning it out. When I started hearing this, I noticed the bent bracket, and the rubbing marks on the tire which were worse on one portion of the tire than they were on the rest which makes me think that the angle was off. I replaced the bracket, banged out the brake rod a bit, and made sure when tensioning the chain that I did it evenly. Although the tire no longer rubs I still hear the noise described above. When rotating the tire on the center stand the chain is tighter at certain points than others and it doesn't turn real smooth. I was wondering if someone can suggest what may be the problem... Could I have bent the rim.... the rear sprocket... done damage to the chain... got my tire out of alignment... Thanks for any advice and let me know if I can clarify anything described above.
Matt
Your chain is toast. It has what I call a "flat" spot. Its a section of the chain about 2-3 links long that are seized up enough to bind but still get the chain to turn. Thats why your chain is tighter at some points.
That seems likely... any other suggestions or things that could be causing the noise...
as far as the noise goes, i'm guessing it's the chain. if you ride with the rear wheel angled long enough you'll really do a number on the chain, and both cogs.
use the string method http://www.yamahafz1oa.com/sportryderswheelalignmentmethod.shtml (http://www.yamahafz1oa.com/sportryderswheelalignmentmethod.shtml) to align your rear wheel with your front. it takes a little while to get the hang of it. the final result is quite good, and it costs nothing but your learning curve (time).
a buddy to watch for mistakes is a good thing too. :)
good luck !
You can put the bike on the centerstand and spin the rear wheel to see if it's bent, not likely it is. Check for a bad wheel bearing, see if wheel turns smoothly by hand without any clicking noises. A 140/80 Demon shouldn't rub on the brake rod but if it did it should rub all the way around if the wheel is straight and the tire is properly mounted. Did you mount the tire or have it done? If wheel bearing is failing the axle nut can keep coming loose and slip back as the bearing disintegrates.
You may need to pull the wheel to check bearings. If they seem OK try aligning the wheel properly and tighten up the axle nut tight and see if it stays that way. If you have a bad wheel bearing it could have been caused by loss of the spacer between the left wheel bearing and the cush drive bearing during the tire change 10 months ago. Sounds like you need a new chain, it's usually kinking if it gets tight and loose as you turn it around like ImportBabe said.
Thanks for the input... I did the install with the help of a coworker of mine who's been doing it himself for years. I don't remember any missing parts when we mounted the tire and as far as I know everything went on the same way it came off. I'll go ahead and order a new chain and re-balance the tire, and I'll try to stumble through aligning the rear tire with the front one. I'll take the chain off and see how the tire spins... hopefully if all that goes smoothly i'll be good to go... let me know if there's anything else that would help