switch from a 12-27 to a 12-25?

evsy
evsy Posts: 111
edited August 2011 in Road beginners
hey every1

my 105 cassette has gone on my bike (havent actually done that many miles as well). anyway i was going to get a straight replacement (shimano 105, 12-27) but when looking i noticed that a couple of places had the 12-25 in stock for £5 cheaper.

was just wondering what the difference is on the road between the two??

thanks

evsy

:D

Comments

  • tim_wand
    tim_wand Posts: 2,552
    Not a lot. . Basically you ll lose some low range climbing ability and gain a quicker high range gear and a casette which probably has closer ratios and shorter steps between each cog.

    Casettes dont usually wear out that quick , How many chains have you been through.
    I tend to do 3 chains to every casette. So if your changing the casette then change (Or at least check) the chain.
  • Hierotochan
    Hierotochan Posts: 108
    The cassette will have a closer ratio & lower climbing gear.

    What that means is that when shifting between the middle gears to will have a more gradual ramping, so smoother up/down movement between rings & less of a jump in the amount of resistance.

    However if you find yourself using the 'easy' gear alot you may struggle with climbing.
    All in all it'll make you fitter & improve your technique (hopefully!)
    Welcome to Hoogerland, Population: Heroes.

    Danny Hart; How does he sit down with balls that big?
  • oldnslowcp
    oldnslowcp Posts: 81
    The 105 12-27 cassette has:- 12-13-14-15-16-17-19-21-24-27

    the 105 12-25 cassette has:- 12-13-14-15-16-17-19-21-23-25

    It's only the two largest cogs that differ. If you rarely used the 27 on your last cassette then try the 25, I've recently gone 12-27 after years of the 12-25, but then I'm getting older and can benefit from the 27 on the steep part of climbs :)
  • John.T
    John.T Posts: 3,698
    You would only use the 2 big sprockets on the small ring, the others gears are the same. It makes sense to have the lower gears. The 21/23/25 are too close together IMO.
    My Fleet.
  • Rodu
    Rodu Posts: 16
    I changed my 105 to the 12-27 last year, it's a small difference but I really like it. If there was a 28 I might have taken that as I like to spin up hills becasue I am not that fit and don't bother getting out much. But when I do, the easier gear reduces the suffering and makes it much more enjoyable - which it should be. Infact, I would take a triple if it was a direct and easy replacement for the 50-34 but its not so, I'd better ride harder and get fitter.

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