Chain jerking

[2good]

Replaced parts on my drivetrain:

Replaced bottom brackets and crank from fsa omega to shimano sora ( same Size of chainrings-triple)

Replaced front and rear mech with same parts

New chain as well, it was well worn.... I cut the chain to the same size as the old 1


Everything is fine in the bike stand all gears index fine, but when on the bike and under pressure the chain jerks like its slipping... It dosnt jump sprockets tho

I didn't change the cassette so thinking the new chain was the problem I put the old one back on ...it's not as bad but it still slips....


Any ideas?...is this because of the new crank/chainring?

 

[boybiker]

You might have a stiff link in the new chain, did you use a quick link? Apparently when fitting them you need to flex them side to side a bit as well as lubricating the whole chain of course.

 

[2good]

Yes used a quick link and lubed the chain

 

[boydj]

Sounds like the cassette is worn. Use a chain for too long and the cassette will wear along with the chain. Put a new chain on the old cassette and the chain will jump, particularly on the most-used gears. The old chain matches the cassette better, hence less jumping.

 

[400bhp]

Sounds like the cassette is worn. Use a chain for too long and the cassette will wear along with the chain. Put a new chain on the old cassette and the chain will jump, particularly on the most-used gears. The old chain matches the cassette better, hence less jumping.

+1

 

[2good]

How do you know its slipping?

 

[400bhp]

How do you know its slipping?

It will skip on the cogs (not change up or down), generally when under load.

 

[GrasB]

Better with the old chain? That'll be a worn cassette, it works better with the old chain becasue they're keyed to each other.

DO NOT use that cassette with the new chain. Buy a new cassette & then use the new chain else you'll be buying another chain to go with the new cassette

 

[2good]

Gave up took if to lbs.... Chain was 2 short.

I cut the chain to the same size as the old 1.

Confused!!!!

 

[rusty bearing]

Bottom line, if you change a really worn chain then you should change the cassette as well, they wear to fit each other so if you put nice new chain on an old cassette 9 times out of ten you get the problem you describe because the cassette teeth dont mesh properly and vise versa.

 

[400bhp]

Gave up took if to lbs.... Chain was 2 short.

I cut the chain to the same size as the old 1.

Confused!!!!

so am I? You cut the old chain with exactly the same number of links (not length)?

How many links did the lbs put in?