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Chain / sprocket problem GSX750F

Discussion in 'Technical and Troubleshooting Torque' started by I'm Simon, Oct 3, 2008.

  1. Riding home from work last night and I notice an unusual "clunking" noise happening periodically from underneath the bike, usually when I was going over a bump etc.

    Cut a long story short, when I got home I wanted to lube the chain, popped the bike up on the centre stand and notice that the chain is as loose as anything...a good 3-4 inches of play, I am like WTF, how does the chain become so loose so quickly :-k

    Out come the tools and I tension the chain, first time I have ever done it but it it is a relatively simple task. I tension the chain to the manuals specs, I then start the bike and kick it in to gear and let the back wheel turn for a minute on the centre stand, turn the bike off and the chain is now over tensioned - is this normal ? I back the tension off a little and repeat the process, chain is now too loose, repeat the process, this time the tension seems fine.

    Whilst I am running the bike I notice the chain being a little "jumpy" and hear some noise coming from the area of the front sprocket.

    I haven't pulled the bike apart to have a look, will prolly take it for a short ride tonight to see what is happening, but for those that are mechanically minded I have a couple of Q's.

    How could the chain become so loose so quickly?

    Is it normal that after tensioning the chain to the manual specs, is it common for the chain to be over tensioned after running the baike for a short time?

    After seeing how looses the chain became, and between the chain being twitchy and hearing some noise, is it possible for the front sprocket to throw a tooth or 2 or is it something else?

    I think that this may be beyond my (very limited) spanner skills, I may have to take it into the shop.
  2. It sounds like your chain has developed a tight spot.

    Whenever adjusting a chain, it should be adjusted where it's tightest. Put the bike on the stand and slowly rotate the rear wheel manually, checking for the tightest spot. When you've found it, adjust the chain to give the correct free play.

    This may mean your chain is too loose everywhere else which means it's time for a new one.

    The noise you hear is the tight chain cracking over the sprockets. Overtight chains put extra strain on the chain itself, the sprockets and the gearbox output bearing. Plus it will interfere with the smooth operation of your suspension. If your chain has fine dull red powder on it ("chain blood") it's pretty much fooked.
  3. Chances are that the chain is worn and has tight spots ,when you adjust it adjust the tension at the tightest spot.See how that goes and if the variance is too much and still too loose in spots replace chain and sprockets :grin:
  4. Sprockets

    Time for new chain & sprockets. Don't replace just the chain as the sprockets will be worn as well. It sounds like the chain has stretched so I wouldn't leave it too long before replacement to avoid snapping a chain.
  5. Thanks for the replies all....looks like time for a new chain & sprockets...
  6. Rubbish! Buy some snags and we'll fix it at a spanner night at my house. Save you $50 - $100.