Cassette Change Q Tiagra 9sp Cassette

FatSh!te

Quick question for the better bike mechanics than me:

I've a 12-25 on a 9sp tiagra standard double groupset, can I change the cassete to a 12-27 or will there be any issues with rear derailleur?

Cheers.

Seaneh

12-27 will be fine, if it's a shortcage derailleur the highest you can go is 28 tooth I think.

funnights74

Yes you can, i had mine changed to exactly that recently, derailleur will be fine but a new chain is recommended and a new gear cable will be required but having the 27 will make climbing that little bit easier.

FatSh!te

sound guys, thanks.

two follow on q's:

I have new chain at the ready also - is there a quick and easy guide to how many links to leave on for a set up like this?

New Gear cable - I assume this is this only if the length on the current one is too short to work on the new 27 tooth ring?

funnights74

FatSh!te wrote: »

sound guys, thanks.

two follow on q's:

I have new chain at the ready also - is there a quick and easy guide to how many links to leave on for a set up like this?

New Gear cable - I assume this is this only if the length on the current one is too short to work on the new 27 tooth ring?

The lbs did mine but the new cable was required for the extra gearing, first part not sure.

Eamonnator

funnights74 wrote: »

The lbs did mine but the new cable was required for the extra gearing, first part not sure.

I can think of no reason, why you would have to instal new cable, to make the change, as outlined by O.P.

route66

FatSh!te wrote: »

Quick question for the better bike mechanics than me:

I've a 12-25 on a 9sp tiagra standard double groupset, can I change the cassete to a 12-27 or will there be any issues with rear derailleur?

Cheers.

I changed from a 25-11 to a 27-12 on a 9 speed Tiagra setup about a year ago. You'll be fine with 27 - it will make hills a little easier. I miss the 11 sometimes, but the 27 makes up for it. I didn't change my gear cable and can't really understand why you'd have to - unless it was incorrectly cut from day 1.

Chain Length? I knew my new chain had to be longer, but by how much? I didn't want to make a mistake so adopted the measure twice a stupid number of times / cut once methodology. I used (at least) these 2 sites: link & link. Got it right too!

FatSh!te

thanks again.