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Shimano 105 RD with an 8spd cassette?

JohnRetJohnRet Posts: 192
edited March 2012 in Workshop
I'm sure this will have been asked before but I can't find it using the search function.

I currently have a crappy Shimano 8 speed rear derailleur with an 8 spd cassette and shifters.

I'd like to upgrade to a better rear mech, which all seem to be 9 and 10 speed (without having to upgrade the cassette AND shifters).

So in a nutshell, for example, will a newer 105 rear mech work as an 8 speed so I can keep my current shifters and cassette?



  • rakerake Posts: 3,204
  • JohnRetJohnRet Posts: 192
    Easy as that. Cheers.
  • JohnRet wrote:
    Easy as that. Cheers.

    Yep and you will find it just as good as 105 throughout, no kidding!
  • andy_wrxandy_wrx Posts: 3,396
    Alternatively, assuming your existing 8sp mech is not damaged or worn, you might find it'll make no difference at all.

    Bike manufacturers regularly sell bikes with an 'upgraded' rear mech, e.g. the Sora-equipped model has a Tiagra rear mech, the Tiagra model has a 105 rear mech, etc

    Marketing spin : gives us as buyers a warm fuzzy feeling that we're getting an 'upgraded' bike - it might just be Sora, but a bit of it is Tiagra !

    Rear mechs are about the cheapest bit of the groupset, particularly at the manufacturers' volume OEM pricing, so this gets us to buy their brand of bike, whilst costing them very little, and making little distinguisable difference at all on the bike.

    Upgrading the shifters, or particularly the wheels, would - but costs a lot more
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