Friction noise?

[production]

I had my 250GS for a year and half,. Almost 4000 miles now. Can get about 73 miles per gallon. It does run better after couple thousands miles. No big problem, but some small problems. I list them in the following.

1. The battery connector was broken. This is because they bent the metal too sharp an angle.
2. The ignition cable got in contact with the engine and almost burned through before I discovered it.
3. The spark plug gap was too small.
4. The ruber bands used to hold the battery and other parts all disintegrated.
5. The transmission lever became loose.
6. The gasolne tank leaks near the cap when I drop my bike. Fromtme to time some sticky staff came out near the cap.

Recently I discovered that the chain was too loose(this could be dangerous and everybody should check it out). So I bought a big lug wrench and loosed the rear wheel. Adjusted the chain tension by the adjusting screw. But afterwards I began to hear a friction sound. It seems the sound happens when the wheel rotates to a certain position. Does anyone have an idea as where this sound comes from? I checked both the front and the rear wheel and didn't see anything. Thanks for any info.

[gs250]

Need to chek chain tension all the time. Also the manual says to lube the chain every 500mile. It's important part of service of any type of bike. Did you use a torque wrench to retighten the axle nut? You should or you might overtighten and damage hub. You need to use a torque wrench.

Also when retightening the rear axle you must check wheel alignment as adjustment of the chain tensioners will probably cause wheel alignment to become incorrect. This could cause chain links to be stressed and sprockets could suffer premature wear. Best to get a bike shop to reacheck your adjustment.

[production]

I think you are right. It's the rear wheel alignment not right. Probably the sprocket is touching the side of the chain causing the friction like sound. Thanks. I didn't know the rear wheel alignment is so touchy. Actually I did it as careful as I could.

[production]

There is another possible cause. It could be the rear brake rubbng against the brake disc.

[gs250]

Yeh ok , it doesn't sound like a big problem. May be the brake pad scraping on the disc as you say.

Re wheel alignment, I read a few different forums on the topic and some riders use a string alignment taken off the front wheel and use this alignment to check the rear wheel by running the string down the side of the bike either side of the rear wheel to get the correct alignment. I tried that method but I noticed in my case the marks on the rear swing arms are pretty spot on, so that makes the rear wheel alignment easy to check and adjust on this bike. It depends on the build quality of each riders bike though to get the best method of aligning the rear wheel.   

[production]

This is a follow up. I never find the root of the problem. But lubricating the chain reduced the noise significantly, if not eliminate it.