Cassette for Trek 1.2 Alpha.

tcooley

hey all,

need a new cassette for back wheel.

There is one on Chain Reaction for a Shimano Tiagra

However, my bike has Sora written just above the brake levers. This cassette is for a
Tiagra.

Will this make a difference or do I have to but one specifically for Sora?

Cheers,

quozl

Sora is at most 9 speed and depending on how old it is it could be 8 speed.

Tiagra is 10 speed for 2 years now. So the cassette on Chainreaction isn't going to work for you.

Count how many sprockets you have on your gear cassette at the back and get a cassette with the same number of sprockets and that is also Shimano or SRAM compatible (ie don't get a Campagnolo compatible one).

quozl

It occured to me that you might be new to bike maintenance so if you are then you won't be able to change the cassette without the relevant tools.

You may be better off getting it done at your local bike store even if the cassette costs that bit more. Otherwise you'll need to borrow or buy the tools and learn (via youtube) how to do it. It's really easy but you do need the tools.

Also if you need to change your cassette then if it's because of wear you're almost certainly going to need to change your chain at the same time or an old worn chain will damage the new cassette quite quickly.

tcooley

Hey Quozl, thanks for reply.

My bike is 10 speed..... 25/ 11 on the sprocket ratio.

This Tiagra one is also ten speed.

quozl

There are no ten speed Sora...

Something doesn't make sense here!

Trek also say that the 1.2 alpha is 9 speed Sora. You really sure that it's 10 speed? http://www.trekbikes.com/int/en/bikes/road/performance_race/1_series/1_2/

tcooley

not a clue how to do it Quozl but my mate does his all the time so no problem there. If this cassette is not going to work my bike shop sais he'd charge me 90 euro. Would be just cheaper the other way.

tcooley

All I know is it says Sora on brake levers but it is definitely ten speed.

tcooley

I'll check when I get home. I have doubt now

quozl

tcooley wrote: »

not a clue how to do it Quozl but my mate does his all the time so no problem there. If this cassette is not going to work my bike shop sais he'd charge me 90 euro. Would be just cheaper the other way.

F*cking hell. 90 euro? That's a bit steep.

tcooley

Exactly what I thought!!!!

quozl

If it does turn out to be 9 speed then you can get a new cassette for 14.49 (old 9 speed Tiagra)
http://www.chainreactioncycles.com/ie/en/shimano-tiagra-hg50-9-speed-road-cassette/rp-prod387

or 18.99 (SRAM PG950 - compatible with Shimano and also very good).
http://www.chainreactioncycles.com/ie/en/sram-pg950-9-speed-road-cassette/rp-prod17902

9 speed SRAM chains for 11.49
http://www.chainreactioncycles.com/ie/en/sram-pc951-9-speed-chain/rp-prod9911

or 13.49
http://www.chainreactioncycles.com/ie/en/sram-pc951-9-speed-chain/rp-prod9911

You will need a new chain unless your old chain is pristine (unlikely!) and you're not getting a wider ratio cassette (thereby needing a longer chain) . I like the SRAM 9 speed chains because they use a re-openable quick-link so you can easily take them off for cleaning.

tcooley

Great stuff Quozl. Will check this evening. Thanks.

fillup

quozl wrote: »

There are no ten speed Sora...

Something doesn't make sense here!

Trek also say that the 1.2 alpha is 9 speed Sora. You really sure that it's 10 speed? http://www.trekbikes.com/int/en/bikes/road/performance_race/1_series/1_2/

I'll second that - i've the 1.2 and it's a 9 speed Sora

tcooley

Yeah you're right lads... 9 speed. and its 26/ 11.

Thanks for you're help.