Bent chain link and bike slips in and out of gear

[Undeaded]

Hey guys,

I was googling around for on this matter, but it seems there could be a variety of reasons for this. I bought a second hand bike (2009 Scott Contessa 30) and after a few weeks of riding it realised that sometimes as I was cycling the bike would go quickly out of gear and then back into it. There is also a bent link in the chain.

What's your opinion guys? I think the chain isn't tight enough. If you want pictures I can get some of the bike for you.

Cheers!

[DaveM]

A bent chain link could certainly cause that (although there could be other things going on.) I wouldn't change anything else until you correct that.

Proper fix is basically to buy a new chain and cassette.

Short term fix is that you can sometime straighten a benk link by grabbing the bent one on the pins on either side of the bend with two pair of pliers and twist it back to straight. But note that this is a "hack" at best and even if it works, definately leaves you more at risk for broken chain or other problems. But it might at least tell you if the bend is what is causing the gear skip. You can also just remove the bent link. That will probably leave the chain a link short, but not a big issue if you're careful to stay out of the big gear-big gear combination.

Note that you can't really "tighten the chain" on a multi-gear bike. The chain is either the right length or it's not. Jumping gears are usually caused by misadjusted shifters, bent derailleurs, bent chains, worn chains/cogs, etc.

[AndrewB]

You don't always need a new cassette. Depends on how much wear the chain has, and if the cassette is worn. A bike tech can offer their professional opinion. If you replace the chain before it's worn too far, you won't need a new cassette in most cases.

I'm guessing a 2009 hasn't been ridden thousands of miles that might wear the cassette.

5300+ miles on my bike, third chain, first cassette.