cassette Q

Dr M
Dr M Posts: 171
edited November 2008 in Workshop
I'm thinking of changing the 12-25 cassette for a 12-27 one. The shimano site lists the 3 largest sprockets as an interchangeable unit (21-23-25 or 21-24-27). Anyone know where to buy these from, or is it not much cheaper than changing the whole cassette?

2ndly.. is there any differnce really between 105 and ultegra cassette? only about 2g in weight, just wondered if there was any difference i construction or ramping on the sprockets which might make shifiting better with the ultegra. Rest of groupset is ultegra


  • John.T
    John.T Posts: 3,698
    You can not buy the unit separately. You have to get a complete cassette in the UK. You may find them in the US or germany via the internet. As these cogs get less wear it is probably as well to get a cassette anyway.
    I have found Ultegra to be longer lasting than 105 and much better than the cheaper ones. Shifting is much the same.
  • peanut
    peanut Posts: 1,373
    edited December 2008
    most folk are attempting to do the same as you and change from 12-25t to 12-27t
    but it might be worth putting a wanted ad in a few forums.
    I recently bought a 105 cassette and I couldn't detect any difference between that and the ultegra cassette in terms of construction or finish. I'd be willing to bet they are the same item .
    12-27 10 speed 105 are only about £20 new and i'd bet Shimano would charge the same for the bottom 3x sprockets and carrier if it was available.

    I went the same route and put the 12-25t on a spare wheel and the 12-27t on my main rear wheel. That way I can swop instantly if I get an overnight flat or broken spoke :wink:
  • There's not much if any difference between 105 & ultegra cassettes. Lot's of people user cheaper 105/centaur cassettes for this reason as they're a consumable part.