Replacing cassette, will I need to use a shorter chain?

[djmagnifique]

Hi, I will be replacing the 8 speed cassette on my bike soon (the bike is only used for going to work and back), the current cassette is a Shimano HG200 t12-32. If I replace it with a Sram PG850 t11-30 would the current chain length be ok or would I need to take an extra link out? The chain will be replaced at the same time as the cassette.

I've tried using guides online to work out the chain length but just can't get my head round it.

Cheers.

 

[Nibor]

I don't think you need to worry too much

 

[accountantpete]

It depends on how long your chain is now.

The reduction from 32 to 30 won't make a difference but the drop from 12t to 11t might.

Best try it and see - (I'm with Nibor in betting it will be ok)

BTW- if the cassette is worn then so is the chain.

 

[Ajax Bay]

current cassette is a 12-32. If I replace it with a 11-30 would the current chain length be ok . . . ? The chain will be replaced at the same time as the cassette.

If the current chain is the correct length then replacing it (at the same time as the new cassette) with a chain of the same length will be OK.
When currently on small/small how far (in mm) is the return section of the chain from the chain going round the tension (lower) pulley wheel?
Can you get the chain on large chainring/ large sprocket combo now?
If the answer to the questions is 10+mm and yes, then = OK. Otherwise, come back with answers.

 

[djmagnifique]

If the current chain is the correct length then replacing it (at the same time as the new cassette) with a chain of the same length will be OK.
When currently on small/small how far (in mm) is the return section of the chain from the chain going round the tension (lower) pulley wheel?
Can you get the chain on large chainring/ large sprocket combo now?
If the answer to the questions is 10+mm and yes, then = OK. Otherwise, come back with answers.

Thanks for the quick replies. Everything looks ok from what you suggested to look at so should be good to go.

Cheers.

 

[Cycleops]

I've tried using guides online to work out the chain length but just can't get my head round it.

Cheers.

Large front cog to large rear plus two links (not going through the derailleur)

 

[Deleted member 1258]

https://www.parktool.com/blog/repair-help/chain-length-sizing

 

[bikingdad90]

Don’t forget to adjust the b screw on the mech.