Cassette Increase

jayhorner7
jayhorner7 Posts: 4
in Workshop
Hi All

I currently have a 9 speed Triple Chain ring ( 50-39-30 ) with a Shimano 105 RD 5600 GS (12-26).

Is it possible to change my cassette to a 11- 30 (or even a 32) keeping the same rear mech. I believe the max this mech can handle is 37-39t

Thanks

Jay

Comments

  • joe_totale-2
    joe_totale-2 Posts: 1,333
    edited January 2021
    According to this the largest cassette sprocket it can manage is a 27 tooth one so no:

    https://si.shimano.com/pdfs/si/SI-5VN0B-001-ENG.pdf

    That would also make sense given that the total capacity is 37 teeth, seeing as there's already a 20 tooth gap with your triple you should be able to squeeze in a 11-28 cassette but nothing bigger than that.

    I'd probably just stick with your 12-26.
  • dj58
    dj58 Posts: 2,217
    You would need to swop your RD to a 5701 GS to go to a 30/32T low sprocket.
  • jayhorner7
    jayhorner7 Posts: 4
    Many thanks for the responses, much appreciated.
  • d00d4h
    d00d4h Posts: 67
    dj58 said:

    You would need to swop your RD to a 5701 GS to go to a 30/32T low sprocket.

    I don't think the 5700 RD is compatible with 5600 shifters.
  • brundonbianchi
    brundonbianchi Posts: 689
    d00d4h said:

    dj58 said:

    You would need to swop your RD to a 5701 GS to go to a 30/32T low sprocket.

    I don't think the 5700 RD is compatible with 5600 shifters.
    You’re correct It isn’t. The pull ratios are different.

  • brundonbianchi
    brundonbianchi Posts: 689
    Get one of these. There’s no need to get a longer cage RD then.

    https://www.sigmasports.com/item/Wolf-Tooth-Components/Road-Link-Rear-Derailleur-Hanger/DOQG

  • joe_totale-2
    joe_totale-2 Posts: 1,333
    brundonbianchi said:

    Get one of these. There’s no need to get a longer cage RD then.

    https://www.sigmasports.com/item/Wolf-Tooth-Components/Road-Link-Rear-Derailleur-Hanger/DOQG

    No they shouldn't.

    "Triple chainrings are not supported (medium cage rear derailleurs cannot accommodate that big of a change)"

    "What the RoadLink does not do is expand your derailleur's capacity"
  • gethinceri
    gethinceri Posts: 1,517
    What? His advice is incorrect?
  • jayhorner7
    jayhorner7 Posts: 4
    So it looks as though short term I can change to a 11-28 or a new long cage derailleur.

    Would I see much of a difference from a 26 to a 28 on the hills (8-15%)?
  • jayhorner7
    jayhorner7 Posts: 4
    It’s my age and arthritic knees that I’m forced to use my granny gear 😄. I live and ride in the Yorkshire Dales so the odd steep hill is a bit if a challenge.
  • piker2
    piker2 Posts: 50
    joe_totale-2 said:

    brundonbianchi said:

    Get one of these. There’s no need to get a longer cage RD then.

    https://www.sigmasports.com/item/Wolf-Tooth-Components/Road-Link-Rear-Derailleur-Hanger/DOQG

    No they shouldn't.

    "Triple chainrings are not supported (medium cage rear derailleurs cannot accommodate that big of a change)"

    "What the RoadLink does not do is expand your derailleur's capacity"
    Rear derailleurs have a maximum rear sprocket size and a maximum chain wrap ( i.e. the amount of slack chain they can take up). A road Link gadget will only allow a bigger rear sprocket ,it will not give you any more chain wrap. However you are never going to use small sprockets and your small chainring together so as long as your chain is long enough for big sprocket and big chainring ,lack of chain wrap is not a problem. I know you are not going to use big/big either but if you do by accident and your chain is not long enough you will have a disaster. If you use small/small by accident you just have a droopy chain.
    I ran a 12/29 cassette and 50/39/28 chainset with a Campag centaur short cage rear mech. It worked fine.

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