9 Speed shifters on 8 speed bike

iljs
iljs Posts: 78
edited March 2010 in MTB beginners
Hi,
Not sure if this is a daft question. Can you put 9 speed shifters on a 8 speed bike.
I am currently looking at upgrading the brakes on my bike, but it comes with brake gear lever combo, which means when i get knew brakes i will need new shifters. I would like to eventually upgrade to a better chain set which would be 9 speed.

Whilst on the subject could you use a SLX rear mech on a eight speed cassette? is it just a matter of adjusting the high and low screw so it doesnt come off?

All a bit random i know but if this is all possible i can go for a gradual upgrade.

Your help and advice is appreciated.

Cheers
Tim

Comments

  • nicklouse
    nicklouse Posts: 50,673
    you can if you change the cassette and chain to 9spd as well.

    9spd shifters are not compatible with 8spd cassettes and chains.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • stumpyjon
    stumpyjon Posts: 3,983
    It's to do with the amount of movement the derailleur has each time you click the lever. 8 & 9 speed cassettes are the same width so the sprockets are closer together on a 9 speed cassette (and the chain is slightly thinner). The shifters are set to move the derailleur the correct amount between sprocketts. You won't have to replace the rear derailleur though as it's a dumb spring, the indexing is all sorted by the shifters.
    It's easier to ask for forgiveness than for permission.

    I've bought a new bike....ouch - result
    Can I buy a new bike?...No - no result
  • iljs
    iljs Posts: 78
    Thanks for the help. Suppose i will just go with 8 speed shifters for now.
    As for the rear durailleur, could i still upgrade just that for now? (rather than pay for a complete groupset in one go) as it doesnt matter if its 8 or 9.
    I think thats what you were getting at stumpyjon.
  • RichMTB
    RichMTB Posts: 599
    You can run a 9 speed deraileur with an 8 speed cassette no problem
    Step in to my hut! - Stumpy Jumpy Pacey
  • trek3900
    trek3900 Posts: 16
    yes u can the only thing is youl miss out by 1 gear but that doesnt maken a difrernce you wont notice it
  • Andy B
    Andy B Posts: 8,115
    trek3900 wrote:
    yes u can the only thing is youl miss out by 1 gear but that doesnt maken a difrernce you wont notice it
    er, nope 9spd shifters will not work with an 8spd cassette for reasons already given in the posts above.
    2385861000_d125abe796_m.jpg
  • krazykayaker
    krazykayaker Posts: 109
    My 9 spd shifters work perfectly with my 8 spd cassette
    On One Inbred 456
    On One Inbred SS
  • supersonic
    supersonic Posts: 82,708
    They can't do.

    To the OP - DO NOT USE this combo.
    GT ZASKAR CARBON TEAM

    VOODOO CANZO

    Come and see me at https://www.facebook.com/biketyke/
  • krazykayaker
    krazykayaker Posts: 109
    WELL THEY DO !

    when i upgraded my brakes to hydraulics, i changed the shifters to nine speed with the intention of upgrading the cassette to 9 speed at a later date (i had dual control shifters before the upgrade)

    I am running an 8 speed cassette with 9 speed shifters with no problems
    On One Inbred 456
    On One Inbred SS
  • nicklouse
    nicklouse Posts: 50,673
    sorry they wont. you will have issues with with the middle gears as the chain will not be in the correct place.

    an 8spd cassette is the same width as a 9spd on. so they mech will not be positioned correctly for every gear except for the first and last.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • krazykayaker
    krazykayaker Posts: 109
    Well no problems with mine so far and they've been on a while
    On One Inbred 456
    On One Inbred SS
  • supersonic
    supersonic Posts: 82,708
    krazykayaker wrote:
    WELL THEY DO !

    when i upgraded my brakes to hydraulics, i changed the shifters to nine speed with the intention of upgrading the cassette to 9 speed at a later date (i had dual control shifters before the upgrade)

    I am running an 8 speed cassette with 9 speed shifters with no problems

    I repeat to the OP.

    DO NOT DO IT!
    GT ZASKAR CARBON TEAM

    VOODOO CANZO

    Come and see me at https://www.facebook.com/biketyke/
  • davewalsh
    davewalsh Posts: 587
    krazykayaker wrote:
    Well no problems with mine so far and they've been on a while

    I suspect your rear mech hanger is bent seriously out of shape for it to work.
    supersonic wrote:

    I repeat to the OP.

    DO NOT DO IT!

    +1
    Blue Pig
    Inbred

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