Changing to a 3-ring chainset - help pls

[swee'pea99]

Met a bloke on holiday who's having problems getting up those S Devon hills with his current 53/39 setup. I suggested switching to a three ring chainset. Is this reasonably straightforward, as in just swap the one for t'other? (& adjust front mech limits) Or would he need a new BB or anything like that? Any advice appreciated. (Oh, it's a modern racer - 16 speed I believe.)

 

[Will1985]

If it's Campag then very easy - change BB and chainset (and possibly front mech). On the other hand, Shimano STIs come in double and triple flavours so they would need to be changed on top of the other stuff.

Dropping to a compact would be the cheapest solution - I find that 50/36 is better than 50/34 for shifting.

 

[Soltydog]

I'm looking to change my shimano 105 compact set up to a triple. The shifter is the same but need front mech, chaninset & bb

 

[e-rider]

Surely you would need to change the left hand shifter, front mech, rear mech (long cage) and BB axle length if it's not a hollowtech II design.

 

[Will1985]

That's what I thought, but it looks like the newest Sora, Tiagra and 105 shifters work with both. Ultegra 6700 and DA 7800 have double and triple specific left hand STIs and 7900 is only done as a double.

The OP talks about an 8sp STI system so we're talking about something quite old without this double/triple feature - presumably a LH shifter with triple compatibility would work (with all the other changes) as long as the rider isn't bothered about looks.

 

[Adrian_K]

i) Get a wider range cassette
ii) As previously suggested go 50/34
iii) grow bigger muscles

I think Will's on the right track - newer shifter are triple - disengage the cable & check.

I have a strong feeling that the axle length is longer for a triple so you get better chain alignment.

That's what I thought, but it looks like the newest Sora, Tiagra and 105 shifters work with both. Ultegra 6700 and DA 7800 have double and triple specific left hand STIs and 7900 is only done as a double.

The OP talks about an 8sp STI system so we're talking about something quite old without this double/triple feature - presumably a LH shifter with triple compatibility would work (with all the other changes) as long as the rider isn't bothered about looks.

 

[swee'pea99]

Thanks for your responses. Should have considered the STI issue - d'oh. And with all the other complivations, I think I'll suggest to him that he tries 34/50 before doing anything more radical.