Grinding noise- chain related

[Jethro]

The last few trips on my bike (81 gs1100e) I noticed a serious grinding noise coming from the chain area. I was so bad that I really had to throttle to get the bike moving. It definitely got worse when hot. I ended up putting the bike in the garage and not riding for most of the summer

Last night I finally got around to pulling things apart and getting a good look. I put the bike on the center stand and it looked like the chain was getting tight, then loose. This is a fairly new chain and both ft and rear sprokets all replaced at the same time (maybe 600 miles ago). These are the things I checked and what I found:

1. The chain line looked alright from what I saw- more on this later.
2. The chain had no stiff links at all, and is the correct length.
3. Next, the rear wheel came off. I checked the front sproket for play. There was none. I started up the bike sans chain and put it in gear. The front sproket is perfectly round and not wobbling at all.
4. I removed the rear axle and the wheel hub with the sproket still attached. I clamped this whole assembly in my vice and spun the sproket to check the round- it was perfect. The bearings were also perfect. Here is the abnormal thing I noticed. On the inside surface of the sproket, it looks like the chain is wearing badly into the sproket. I can see the outline of the chain side links wearing away the steel about 1/16 of an inch off the sproket. The outside edge of the sprocket looks like it has little or no wear.

Does anyone know why this could be happening? If the chain line looked off, it would explain this wear, but it's not. I'm also confused why it seems worse when the bike has warmed up a little. Another possible problem is that it seems I can move my swignarm side to side a tiny bit (maybe a 16th of an inch). Is this normal or do you think this could be causing my problem?

I'll try and get pics of the worn sprocket tonight and post them.

[Billy Ricks]

If you're trusting the factory chain alignment marks that could be the problem. They are notorious for not being stamped to where they give you perfect alignment. Do a websearch for motorcycle string alignment. Could solve your problem.

[Jethro]

I was thinking that. I got e-mailed a copy of the string alignment fix recently, that is something I will try.

[SqDancerLynn1]

If the chain gets tight and then loose? The chain is bad and needs replacement. DON"T skimp on a chain the 1100E needs the best chain you can get.
OR Get a shaftie

[Anonymous]

I use a vernier caliper to align my chain. Also another good trick, if the chain is already pretty close to being aligned, is to adjust to the proper tension then give the back wheel a good spin. When it stops spinning, look at how the chain sits on the rear sprocket when looking directly at the back of the bike. If the tooth of the sprocket is not dead center in the chain, then its not quite aligned. Adjust and give the wheel another spin and look again.

[Jethro]

If the chain gets tight and then loose? The chain is bad and needs replacement. DON"T skimp on a chain the 1100E needs the best chain you can get.
OR Get a shaftie

This chain has only 600 miles or so on it. I'm sure the chain is toast now, but the root of the problem is not the chain. If I put another new chain on, what will stop this from happening again?

Believe me, I'd be happy with a shaftie right about now. Ohhhh, I can't believe I just said that...

[SqDancerLynn1]

Did you replace the sprockets when you replaced the chain???
What brand of chain was it??

[Jethro]

Did you replace the sprockets when you replaced the chain???
What brand of chain was it??

Both sprokets were replaced with the chain 600 miles ago. The chain is a top of the line double o-ring RK brand chain.

[KGB]

Geoff,
Check the bolts holding the rear sprocket onto the wheel.
One may be loose allowing the sproecket to move or wiggle at speed.

If one side, inside, of the sprocket or chain is wearing it may be due to alignment.
As to the swingarm play, 1/16 at the front or rear wheel?

[pano]

Did the problem start about 600 miles ago?

[Jethro]

Check the bolts holding the rear sprocket onto the wheel.
One may be loose allowing the sproecket to move or wiggle at speed.

The sprocket bolts are on nice and tight. The crush strip that acts the same as a cotter pin is doing it's job, and the sprocket is on straight as was proved by my alignment/wobble test in the bench vise.

As to the swingarm play, 1/16 at the front or rear wheel?

The swingarm play is evident in two ways. When on the centerstand I can move the rear wheel left and right about 1/16 of an inch. When it is on the ground, if I take my toe and check the chain tension by pushing up on the chain, I can see a small left right movement. I can also feel a slight clunk when I do this.

Did the problem start about 600 miles ago?

A very valid question! Not really. It was actually longer, like 1000 miles ago. I replaced all the gear and everything seemed fine for the first 200 miles. Then it got worse. Remember, the grinding only seems to show up after about an hour on the bike AND way more noticable when I decelerate.