Chain skipping - help!

[dand_uk]

Hello. So I'm having problems with my Trek 2.1 2010 road bike. The chain is skipping whenever I push harder on the pedals - I think it is more of a problem in the faster gears on the rear. Can anyone help me solve this problem?
- I have just replaced the gear cable to the rear mech since the thing snapped.
- I have also just replaced my favourite chainwheel (middle) on the front, and the chain - I adjusted the chain length using the large sprocket /large chainwheel method so that two chain sections were overlapping.
- I have adjusted the barrel adjuster on the rear mech until the gears shift correctly when the bike is on the floor upside down.
- I have had the bike since Jan 2010 and probably done 6-8K miles in all weathers except snow/ice.
- chain skips when I push hard - can be twice per pedal revolution.

Any advice please - this is driving me nuts!

 

[arranandy]

Sounds like the rear cassette is worn and needs replaced. 6000+ miles out of a rear cassette is good going though.

However I would take the bike to my LBS for their opinion

 

[compo]

My immediate thought would be the cassette after the O/P's stated mileage.
There isn't much else left.

 

[PatrickPending]

indeed 6K miles is a good distance, the bad news when replacing your chain you'll most likely have to replace the cassette, possibly chain rings on the front and jockey wheels

 

[boydj]

New chain, old cassette - bad combo - especially when old chain was well worn. New cassette required and no need for lbs unless you need help fitting the cassette.

Buy a chain wear indicator and replace the chain when the wear is between 0.75 and 1.0 and your cassette will last for several chains. Worn chains will wear out cassettes and chainrings quickly.

 

[andrew_s]

The rear cassette generally has to be changed when you put a new chain on, unless you keep a check on chain wear and change chain at a fairly low mileage.
If the old chain measures any more than 12 1/8 inch for a nominal 12 inches (24 links), you will almost certainly need a new cassette. How many miles that takes depends on cleaning, lubrication, weather, where you ride etc, but can in some cases be as little as 800 miles, though something like 1500 is more usual.

Basically, you can either carry on using the same chain until you get problems, at which point you change chain, cassette and possiobly chainrings, or you keep an eye on chain wear and change chain before it has worn enough for a new chain to skip on the cassette. The relative cost of the cassettes and chains you use will have some influence on what's best.

 

[Lee_M]

Did you stretch the cable before fitting it? If not that would have an impact, plus changes when the bike is upside down aren't the same as the tensions on the chain are different

So check the cable, and as everyone else says check the cassette

 

[02GF74]

it won't be the cable since the OP states jumping occrs when pushing harder on the pedals by which i infer no jumping when pedallin lightly.

time for new cassette i'm afraid..... well i'm not afraid but you know what i mean