amrgardner said:Hi,
I'm very new to bike upgrading (very new) and have a little question.
Now all the other compatibility issues aside (which I'm pretty sure are sorted), will I need a new chain?
Also, can any one point me to a good guide for rear derailer installation?
Many thanks in advance.
Andre.
Try your current chain, first. Otherwise, you will want a Shimano chain with a IG-n0 designation (Shimano's 8-speed chains) where 'n' is a number between 5-and-9.
Others have disagreed, but I have found that (and, this is may not apply to you) IF you are setting up a triple with Shimano STI shifting, then you want to match the chain to the front derailleur -- with a double, I would opt for the slightly narrower, 9-speed chain.
But, with the 9-speed chain, you will probably need a new chain tool -- I recommend the LIFU because it is less expensive [if you can find one ... usually only through mail-order] and well made.
The 9-speed Shimano chains are labeled HG-n3 chain (where 'n' is a number between 5-and-9) ...
If you are getting a new rear derailleur, let your budget be your guide ... ALL Shimano rear derailleurs are equally good from a functional point of view ... the difference is mostly in weight & fit-and-finish, IMO. The better (as in "more expensive" -- i.e., Ultegra & Dura Ace) rear derailleurs will have better pulleys (bearings instead of bushings).
Whether you can use your current rear derailleur depends on what you are currently using ... the inner pulley cage on less-than-8-speed rear derailleurs MAY interfere with the rear wheels spokes!
You will need a 5mm Allen wrench to attach the rear derailleur ... and a small flat-blade screwdriver to adjust the stops.
FWIW. I adjust the high-low stops on a new derailleur BEFORE I put the chain on ...
Adjusting the indexing is another issue ...