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Oh the chain, the chain


Andy Bloot's picture

By Andy Bloot - Posted on 13 September 2007

Has anyone ever experienced any shifting problems with an HG93 chain? I recently swapped the running gear (except derailleurs) from one bike to another recently purchased (2nd hand), including my HG93 chain. All the shifting problems I had with my previous bike have been transferred to my current bike. I only swapped a new XT cassette and cogs + the chain. Talking to Tien, he said he had similar problems that were solved when he replaced his 93 chain with another brand. I bought a few of these chains from torp 7 for $20 and don't want to buy another chain unless I have to.

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Rob's picture

... that does sound odd. Never had any probs like this with said chain.

When you say you have 'shifting problems' can you elaborate? You mean the chain jumps about on the rear cassette and won't stay in any particular gear? Or it does this at one end of the gear range? Or what? Are the shifters good? Is the cable running nice and smooth and not full of sand or other crap?

Or maybe your chain is bent or has a duff link or something, degrease it and lay it sideways on something real smooth and flat (like your marble kitchen worktop Eye-wink) and see if it has any such problems.

Funkychicken's picture

if the whole drivetrain sans RD is new. Could be a number of things:
1. cable full of sand like Rob sez - replace cable
2. der not adjusted properly - make sure high and low limits properly set
3. chain too long? - check chain tension and remove links as necessary
4. der or der hanger bent? - replace either or both
5. "user error"? - replace user! Sticking out tongue

Andy Bloot's picture

Main prob is changing from mid to small ring to carry momentum into a climb. Say I'm in 2/5 on the flat going into the climb. Just before the gear becomes too high to maintain, I back off the pressure and shift down to 1/5. But it stays in 2nd gear. 1/9 is not a good substitute for 2/5. It will shift from big to mid OK, and rear gearing OK.
It could be me (still only been riding less than a year), but the bike seemed to shift fine previous to drive train swap. Bike addiction mentioned after they did the swap that the bike was a little slow in changing from mid ring to small. Said it might be fr. der. but, as I say, seemed to be shifting fine until the running gear was swapped. Shifters are 07 LX and cable seems smooth. What is really frustrating, and makes me think it could be me, is that if I inch my way to the top in the mid ring, once I'm on the flat it shifts OK. Is it a technique thing?

Rob's picture

Rear fine you say? It just won't shift from middle to granny ring as you describe? And BA did this swappy stuff for you?

Well then, take it back to BA and tell 'em they stuffed the front adjustment on the switch and get 'em to fix it.

Either that or play with the screws on the front derailleur. Download the gumf from the vendor's website and read how this is done. It's sort of black magic but the front is easier than rear.

Stuart M's picture

If you have trouble changing from small up with shimano shifters then the best thing to do is push slightly past the click. If the problem, as you say is coming from larger to smaller then adjust the cable tension slightly using the adjuster up at the shifter pod, this should if my memory serves correctly, help the gears come back down properly.

I've gotta say though that if your local did it then they should be the first port of call to fix it.

Flynny's picture

Second hand.

You mention some second hand parts. Have the you check the chain isn't stretched? A worn chain wont mesh with a new cassette.

Other things to check.

Deraileur alignment. If it changes one way fine but not the other it usually signifies a slightly bent hanger.

B tension. Not enough B tension (the screw at the back of the deraileur) means the jocky wheels are too far away from sprockets. This there is enough room for the chain to have a bit of sideways play before it gets to the sprocket. Most noticable in the small sprockets.
Too much tension and the jockey wheels hit the sprockets. Most noticable in big sprockets.

Stiff link in chain. This will cause the chain to jump especially in the smaller sprockets

If the main problem is only on the front rings check the deraileur hight and alignment.
in first gear the deraileur should sit about 3mm above the big ring teeth and should run along the same line as the frame forward to backward.

Matt's picture

You need to back off the lower limit screw on your front deraiileur, this will likely be on the top of the stationary part of the derailleur. You can tell which screw it is by shifting down to small ring and then looking to see which screw is in contact with something, that's the one to back off.

If when you're in small then neither screw's in contact with anything then that's not your problem and you might need to look at cable tension and chain-line... more on that if need be.

Ta,
Matt.

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