OK, I have a Trek 7.5 FX and my 9 speed Shimano Tiagra rear derailleur recently broke and it needs to be replaced.
My questions are:
- Can I upgrade to the 10 speed Shimano Tiagra (RD-4601), or should I buy off ebay the 9 speed Tiagra again (RD-4500)?
They are near in price so I was hoping I could just do the 10 speed and not sure if differences matter in this case. Does anyone know?
- What cage size do I need? There are 3 rings so I am guessing medium or large. Also--what the hell is the GS version of these derailleurs?
Any recommendation on chain? I was thinking just a modest priced KMC.
I have no idea how to figure out the size of my bike, does anyone know if there is a model number, measurement I can take, or quick pointer that will indicate size of my frame (13, 15, 17, 19)?
This image shows EXACTLY what my bike looks like, minus the broken derailleur.
Here are the specs, which can also be accessed here.
Frame - FX Alpha Black Aluminum
Fork - Bontrager Satellite Plus, carbon
Sizes - 13, 15, 17, 19"
Wheels - Bontrager SSR w/Clix
Tires - Bontrager Race Lite Hardcase, 700x32c; 60 tpi
Shifters-Shimano Deore, 9 speed
Front derailleur- Shimano Deore
Rear derailleur - Shimano Tiagra
Crank - Shimano M443 Octalink 48/36/26
Cassette - SRAM PG950 11-26, 9 speed
Pedals - Alloy body w/alloy cage
Saddle - Bontrager Select FIT Basic
Seatpost - Bontrager Sport
Handlebar - Bontrager Crowbar Sport, 25mm rise
Stem - Bontrager Select, 10 degree
Headset-Aheadset Slimstak w/semi-cartridge bearings, sealed
Brakeset-Avid SD-3 w/Tektro adjustable reach alloy levers
Extras- Bontrager Satellite FIT grips
Any help appreciated!! Thank you.