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Cassette change

pollys_bottpollys_bott Posts: 1,008
edited September 2015 in The workshop
The wife currently has a 12-30 (105 5700) cassette on her Contessa and given that a) we're doing a ride next month that has a few steep hills in and b) she wasn't born a grimpeur I'm looking at sticking a 12-32 on to provide a little extra help. Two questions:

1) will the rear mech (105) handle the extra two teeth?
2) would I need to add a link to the chain?

Clearly the long term solution to climbing better is to ride more & shed some pounds and to her credit she has made a good start, going from minimal mileage in July to doing 460+ in August losing 11lbs in the process :D; in the meantime I just want to give her as much equipment help as possible.

Thanks..

Posts

  • The wife currently has a 12-30 (105 5700) cassette on her Contessa and given that a) we're doing a ride next month that has a few steep hills in and b) she wasn't born a grimpeur I'm looking at sticking a 12-32 on to provide a little extra help. Two questions:

    1) will the rear mech (105) handle the extra two teeth?

    Not usually no, the short cages only go up to 30T (technically only 28T but 30T is possible). I think 32T wouldn't work.

    Where you getting a 12-32 from anyway, they aren't standard for 10 speed. Mind you neither are they for 5700, it's likely to be a 4600 or 6700.
  • imatfaalimatfaal Posts: 2,716
    12-32 is an SRAM sounding size - pretty sure I have bought 12-32 Apex.

    You can probably pick up a 105 GS on ebay for 15-20 quid - and that will take upto 32 (I think)
  • what chainset does she have? with a compact 50-34 the lowest 34-30 gear you have at present is a really low gear as is
  • SRAM yes, a PG1070.

    dgunthor - yes, a compact; am aware that 34x30 is very low, but she's no Twiggy so was just curious as to the ease of making her lowest gear even lower. If it involves a new rear mech as well then not worth it, she'll just have to obey Rule 5...
  • oxomanoxoman Posts: 10,480
    How about replacing the front chainset to a smaller stronglight 46 /30, that would make it a lot easier for your wife.
    Too many bikes according to Mrs O.
  • How about replacing the front chainset to a smaller stronglight 46 /30, that would make it a lot easier for your wife.

    +1 i'd change the chainset to a smaller one if 34-30 needs to be made a little easier

    could also look at shimano MTB double chainsets which would offer lower again? e.g. 40 / 28
    you might find that a MTB double 38 / 24 with a closer ratio rear cassette e.g. 11-25 (or 11-23) would give a good useable range
  • Aye, hadn't thought of the chain set... not sure of cost but wouldn't be cheaper than a cassette & rear mech... cheapest compromise I can think of would be to put a 32 chain ring on instead of the 34, but would the front mech handle it?
  • Aye, hadn't thought of the chain set... not sure of cost but wouldn't be cheaper than a cassette & rear mech... cheapest compromise I can think of would be to put a 32 chain ring on instead of the 34, but would the front mech handle it?

    may not be cheaper but would give a better spread of gears (i.e. if you have an 11-32 cassette you are going to have some large gear ratio jumps in there)

    not sure if you can get a compact 32 ring?

    front mech can cope with 16T difference, so you'd need a 48 chain ring to go with it
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