Changing cassette

eugene1277

Hi

This might sound like a bit of a stupid question, but:

If i change my rear cassette to a different ratio one, would i need to alter my chain length to accommodate this?

My initial thought is no, surely the actual cassette would be the same size, just different amount of teeth, no?

Thanks

delcol

no the chain should be fine..

eugene1277

Thought as much... Thanks

chez_m356

eugene1277 wrote:

surely the actual cassette would be the same size, just different amount of teeth, no?

no, the cassette has to be bigger to get more teeth on it, haven't you noticed that the cogs differ in size, for example, if you went from a 32 to a 36, it may also affect what length cage rear mech you would need, never mind the chain length

eugene1277

Oh right... Well id rather get the same ratio cassette just to avoid any issues arising.. I was just seeing how much of an issue it was changing ratios and how it would effect the chain length.. Never been any good with chains so want to avoid having to alter links etc..

Thanks

gezebo

Will probably be fine. There should be enough play in the system for some change. Unless you are changing from a very small to very big then I can't see any issues. Except of course if your current cassette is very worn and then you would need a new chain anyway!

bennett_346

eugene1277 wrote:

surely the actual cassette would be the same size, just different amount of teeth, no?

No otherwise how would the chain mesh with the teeth if they were closer together?

cooldad

Worrying about chain length is a bit of a silly reason not to change a cassette IMO. Easy enough to measure the length needed. You'll have to do it sooner or later anyway when you fit a new chain.

YeehaaMcgee

And also, to reiterate what Gezebo said - if you change your cassette, then there's a really good chance you'll have to change your chain at the same time.
All parts of the drivetrain wear down - sticking a new cassette, chainring, or chain on an old drivetrain can lead to chain slipping issues.

The Rookie

Most OE chains are too long anyway, but it in 'big big' and take a photo and post it and we'll have a good idea whether it will cope or not....changing it is a doddle.

diy

As others have said the chances are unless newish your chain will not mate well with the new cassette. Besides it often cheaper to buy a chain + mech bundle from the likes of merlin etc. If you have a small cage mech as found on certain bikes you might need to change the mech too. for example some cheaper bikes with 28-12 will not take a 34-11 due to the capacity of the cage.

There are tables in the workshop but google rear mech capacity calculator.