From double to triple - what do I need to change?

dttlincs Posts: 384
edited September 2008 in Workshop
My new bike has standard chainset 53/39 with 12/27 rear cassette. 105 shifters and I think the rear mech is short.
If I get a triple, to put on when I take on a tricky sportive for example, what other components will need to be changed?
Is it correct that 105 shifters can do both double and triple?
Still thinking!


  • Gary D
    Gary D Posts: 431
    New rear mech - change to the medium cage (GS). If it is the short cage (SS) fitted, it will only cope with a 16T difference on the chainrings. Assuming you are fitting the 105 triple (50/39/30) then you have a 20T difference. It also has a total capacity of 29T and you would need it to cope with 35T.

    New front mech - they are double or triple specific.

    Yes, the 105 left hand STI is double or triple compatible.

    Hope this helps.
    Oh and I feel like I've been raped by an Orangutan :shock: And I've got legs like Girders :lol: