Gear Question - I'm a complete idiot when it comes to gears

davebc

Hi,
I'm currently looking at upgrading the gears on an old bike, however I don't know what the best way to do it is. I live in place where there are minimal hills - odd 1 or 2 major hills over a 40 mile cycle. I don't know how to tell what I have on my bike currently either - It has a tiagra at the front, sora at the back, sora flight deck shifters. Apparently, by my own research its 8 speed. I have no cassette or hub as I took the wheels off for another bike so will start from scratch regarding the real wheel.
I would like to go to maybe a combination of ultegra and 105 components but when it comes to buying them they are all like Ultegra 10 Speed 32/40 - what do you guys think? Do they all have to have the same speed in so like 9 speed 105 components aren't going to work with 8 speed tiagra?

Thanks.

ChrisSA

Do you want to stick with 8 speed or get more?

Shimano have recently released 10spd Tiagra.

John.T

The shifters, chain and cassette must all be the same speed. They do not have to be from the same group but must be the same make (or compatible). The mechs can be any speed, best the right one or one lower (8sp mech on 9 etc) and the same make. Cranksets are pretty interchangeable but need to be close to the speed used. I would not try an old 7sp on 10sp but 8 on 9 and 9 on 10 is no problem. Current Shimano freehubs will take 8, 9 or 10sp cassettes.
I hope this helps.
Check the width between the rear dropouts. Current hubs are 130mm OLN (over lock nuts) but old ones were 120mm. Your frame may be for these depending on age.

Hoopdriver

I know this can get all confusing, but the chain and the cassette do NOT need to be the same make - you can (and many people do, including myself) run KMC, Wippermann,SRAM chains etc on various manufacturers' cassettes. In my case I have a SRAM chain running on a Shimano XT cassette on my expedition tourer, and a Rohloff chain on a Shimano Ultegra cassette on my Audax bike. They run just fine.

They do need to be the same speed though, as a rule, although here again you can get away with running a 9-speed chain on an 8-speed cassette; it'll just wear out a bit faster

John.T

Quite right, but I was trying to avoid over complication. Cassettes can be Shimano, Sram or any compatible make. Chain can be almost any of the correct speed. Shifters must be Shimano. Please don't mention Shiftmate or any of the other 'bodges'. They are fine if you know what you are doing but the OP admits to not doing so.
Have edited the first post.