Changing chain set and rear cassette.

[Chilli9236]

Hello,

I wondered… Does anyone know or can give me some advice on changing my chain set and rear cassette on my road bike.

My bike is brand new however I want to upgrade the chain set and cassette.

My questions is regarding the chain.

The current chain set is a compact 50-32 and rear cassette is 12-27.

I have purchased a 52-39 chain set and a 12-25 cassette.

Will the new existing chain be long enough to run correctly on the new configuration or will I need to buy a new one of those as well? If so what length would it need to be?

Your help will be greatly received.

Regards

Chilli

[fastpedaller]

Chain will be correct length. If you add together the largest chainwheel number and the largest sprocket number for the old setup, and compare this to the new setup the difference gives the chain length increase or decrease in teeth for complete rings (if that makes sense) As the chain runs (roughly speaking) over half the teeth of the chainring and sprocket, divide the difference by 2 to get the chain increase in length . For the sizes you have specified 50+27 =77. For new setup 52+25 =77 so no difference. If (as an example) you changed to 60T chainring but kept 27 tooth sprocket the difference would be roughly 5 inches.

[timdownieuk]

Hello,

I wondered… Does anyone know or can give me some advice on changing my chain set and rear cassette on my road bike.

My bike is brand new however I want to upgrade the chain set and cassette.

My questions is regarding the chain.

The current chain set is a compact 50-32 and rear cassette is 12-27.

I have purchased a 52-39 chain set and a 12-25 cassette.

Will the new existing chain be long enough to run correctly on the new configuration or will I need to buy a new one of those as well? If so what length would it need to be?

Your help will be greatly received.

Regards

Chilli

I think your chain should be fine but I'm wondering why you're changing. I'd much prefer your present set up on my bike than your planned one! Each to his own however.

[meic]

Hello,

I wondered… Does anyone know or can give me some advice on changing my chain set and rear cassette on my road bike.

My bike is brand new however I want to upgrade the chain set and cassette.

My questions is regarding the chain.

The current chain set is a compact 50-32 and rear cassette is 12-27.

I have purchased a 52-39 chain set and a 12-25 cassette.

Will the new existing chain be long enough to run correctly on the new configuration or will I need to buy a new one of those as well? If so what length would it need to be?

Your help will be greatly received.

Regards

Chilli

You are not going to sneak that one past us.

[reohn2]

The chain will be long enough but is it wise to fit your present partially worn chain to a completely new drivetrain?

Are you sure the present chainset isn't 50-34t?

[fastpedaller]

OP said:-
My bike is brand new however I want to upgrade the chain set and cassette.

[reohn2]

OP said:-
My bike is brand new however I want to upgrade the chain set and cassette.

Sorry must have missed that bit

[Chilli9236]

fastpedaller - you made perfect sense thanks for the advice.

timdownieuk - Reason for changing - Fairly new to road riding and just want to experiment with different gearing ratios. I got a good deal on my bike but wanted to upgrade some components. If it doesn't work out then I'll switch back no doubt. Thanks

Meic, reohn2 - Yep my mistake, got the tooth count wrong.

Thanks for all your advice. Until next time

[niggle]

fastpedaller - you made perfect sense thanks for the advice.

timdownieuk - Reason for changing - Fairly new to road riding and just want to experiment with different gearing ratios. I got a good deal on my bike but wanted to upgrade some components. If it doesn't work out then I'll switch back no doubt. Thanks

Meic, reohn2 - Yep my mistake, got the tooth count wrong.

Thanks for all your advice. Until next time

It is surprising to me that you are choosing to make the bike's gearing quite a bit higher if you are new to road riding. Are you coming to road riding from some other highly competitive branch of sport cycling like track racing or something?

[karlt]

Unless it's pancake flat around Chilli's way I think he'd be making a mistake. I've got 11-30 with a 52-40 up front on my commuting bike and that low gear is really needed at the end of a tiring day with some of the 14-15% drags around here. The Sunday best has 12-26 with 50-39-30 and while I don't use the 30/26 often, well, Winnats....

Yeah, I know, when I were a lad 52/42 with 14-23, but I also remember pushing the bike up a lot of hills.

[mercalia]

he must be young and fit and have very strong legs