Help! Stuck with an 8 speed!

expatbore

I have an older giant carbon bike - with Shimano 105. Trouble is the lowest gear is -err - not very low, causing me to lose cadence even on the surrey hills! Front cogs are 52 and 39 but the rear cassette only has 8 gears - up to 24 teeth on the largest.

Question is - is it feasible with my old 105 kit, and derailleurs, to upgrade to a 9 speed cassette, or indeed maybe a triple on the front? Budget, as ever, is tight...

Grateful any thoughts.

nicklouse

a 9 spd cassette will fit.

minimum other things. rear shifter/brake lever assy, chain and maybe new jockey wheels (MTBers dont notive the difference but on a roadie?)

the rest can work with minimal probs. so chainset and front mech could be done later if really needed.

ash68

would 8 speed sora cassette fit If so could try using a wider range cassette, up to say 32 teeth.Would save upgrading shifters,mechs etc.

nicklouse

it would fit as all shimano 8/9 freebodies/cassettes are the same width and same spline patteren.

But you will have to check that the rear mech will cope with the bigger large cog

andrew_s

Road rear mechs won't go bigger than 30T without the top jockey getting too close to the sprocket, so you'd need an MTB rear mech as well as the cassette (and probably chain).
30T may or may not work - try fiddling with the b-screw and chain length.

Another possibility is a triple converter chainring.
This is a middle chainring that you can bolt an inner ring to, rather than the cranks directly. It would allow an inner ring down to 24T. You may require a slightly longer bottom bracket, and your front shifter may not be suitable (count the clicks - may be necessary to back off the mech limit stops or disconnect the cable).

aracer

It's unlikely a 32 would work with your current mech, but if your only issue is lack of a low gear and you're not bothered about getting big gaps, the cheapest option is definitely a new cassette with a 32 and an MTB mech (Deore recommended). You'll almost certainly get a 28, and possibly even a 30 to work with your current mech though if those are small enough for you, and 8-speed cassettes with thoese as biggest sprockets are certainly available (though I'd recommend going for a mix and match, using small cogs from your current cassette, as you'll not be needing the 11 top sprocket which comes with a 28/30).

maddog 2

8 speed 11-28 XT cassette will work with a roadie rear mech

http://www.chainreactioncycles.com/Mode ... ModelID=47

if you want the 11-30 then you might get away with the road mech, otherwise a short cage MTB one


why don't you just fit a compact c/set?

Uranus

I reckon the compact would be better than fitting wide-spread gears on a road bike. GB cycles have been advertising Bianchi carbon compacts for 70 quid or even better value, Campag alloy ones for £40, + cost of BB but that wouldn't be much for the cheapest Campag one. Doubt if there will be an issue with the Shimano front mech., see Chris Juden's advice on the CTC website.

Going to a 34 inner ring as opposed to a 39 will feel like two extra gears on the bottom end, probably just what you need. On the other hand, the change to 50 from 53 will feel like you've lost a gear at the top, how often do you use the highest ratio?

nick hanson

Uranus wrote:

I reckon the compact would be better than fitting wide-spread gears on a road bike. GB cycles have been advertising Bianchi carbon compacts for 70 quid or even better value, Campag alloy ones for £40, + cost of BB but that wouldn't be much for the cheapest Campag one. Doubt if there will be an issue with the Shimano front mech., see Chris Juden's advice on the CTC website.

Going to a 34 inner ring as opposed to a 39 will feel like two extra gears on the bottom end, probably just what you need. On the other hand, the change to 50 from 53 will feel like you've lost a gear at the top, how often do you use the highest ratio?

Much sense spoken here.I run a compact chainset,& with this you can get any chainrings to fit,between a 34 inner &,I think,a 54 outer.Good value rings are available from SPA cycles in Harrogate.
In other words,you can have your compact on,& pick the chainrings to suit

acorn_user

What chainset and chainrings do you have up front?
The value option is definitely a new cassette and chain (+mech if needs be)