Chain that skips

sebzzz

Hi,

I recently bought a 2000 or 2001 Specialized Hard Rock MTB. When I bought it the guy told be to check and possibly change the chain since it skips a lot.

I went to the local bicycle shop to tune it up and they called me back a couple of days later to tell me that it really needs a new chain and cassette. I make them to the necessary to get a good ride.

Well, not I got it back and the bad news is it still skips. Not on all gears, but some do make the chain skip. I just had a couple of rides to date with it so can't tell exactly which gears cause a problem, will get you updated. For now, all gears in the back seem fine as long as I'm on the smallest one in the front. When I engage the second one in the front, it starts to skip.

Now, I bought a cheap MTB last summer that had this same problem and it bothered me a lot, went for a free tune up once but the problem reappeared as soon as I removed the back wheel the change tire and put it back on. It is one of the reasons why I sold it, I couldn't stand this skipping chain.

Should I run to the store to tell them something is still wrong or is there anything I should try before doing that? One thing is that I sold my car so now my bicycle is my only means of commuting.

Also, any good books that would help with all those small problems especially for someone like me who plans to use only his bike for all his everyday needs?

Thanks a lot in advance.

dabac

Worn cassette and/or worn chain is a very common cause for the chain to skip. Replacing them both usually fixes the problem.



Taking it back is certainly an option, but if it's a LBS that's more concerned with its turnover rate than with the quality of its work you might need to try do diagnose the problem yourself in order to get them to do the right thing for you.
Try to figure out if the chain is skipping while still lined up well with the sprocket, or if it's skipping because it's trying to climb on to another gear. If it's the latter, read up on "ghost shifting" specially if you're a heavy/strong guy.



Does it skip at the back or at the front? Chainwheels also do get worn out, although less frequent than the cassettes. Have a good look at the chainwheel, see if the teeth looks symmetrical and how the chain meshes with the teeth. Even if you have to replace the whole crank it doesn't have to cost you much.



Don't know about books, but http://www.parktool.com/ and http://www.sheldonbrown.com comes highly recommended.

Trainingwheelz

Which gears is it skipping in? I'd be interested to know if you have a freewheel or a cassette. MTN bikes usually have a freewheel. I'd check to see if the splined bearing that the freewheel spins on on the wheel is bent or out of whack somehow. Then I'd check to be sure you have good teeth mesh on the front and back gears. ring alignment could be an issue.be sure that the chain runs straight from front to back on gears that are in line with eachother. also, are the shifters and derailuers compatible? sometimes the travel is different on a shifter and it will not coorespond to the derailure travel (??)

just thoughts.

chas0039

I remember a skipping chain that drove me crazy until I found a stiff link due to breaking the chain and reassembly. You might look at that.

artemidorus

No they don't, they use freehubs. I've never seen an MTB with a freewheel.

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kdelong

I have a 1994 Mongoose that has a freewheel.

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artemidorus

I knew that someone with an old MTB would post!
My '91 MTB has always had a freehub.

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Albert 50

You have answered your own question

DJA

If you have replaced the chain and cassette for skipping there's a good chance that the chainwheels that are most used are wore as well. (usally middle and big ring and will only show up under load) By using the chain well passed it due date you will wear out both cassette and chain rings as the chain stretches. You can buy gauges that will indicate when to change the chain before it has stretched to far.

My current MTB which is used to commute has had the chain wheels replaced twice before I found out about the gauges. Still got 20K out of a set but now almost double.