How do I know if I need a cassette spacer or not

Whiteeddymurphy
Whiteeddymurphy Posts: 169
edited August 2014 in Workshop
Bought some wheels (ultegra) and the guy removed his 105 10 speed cassette to put my tiara one on. His came off with a spacer but when he tried to fit mine it wouldn't tighten up so he put cassette on without it. It seems to have worked fine. I am putting an ultegra one on tomorrow do I put the spacer in or not? How do I know / what is it for. Thanks

Comments

  • Tiagra (and I believe Sora) cassettes has some dimples on the rear that act as a spacer thus negating the requirement for one. All the 105 and above that I have fitted require the spacer.
  • sungod
    sungod Posts: 17,435
    tiagra 10-speed uses no spacer

    105 etc. uses a spacer
    my bike - faster than god's and twice as shiny
  • Thanks very much gents for the replies
  • roux_guy
    roux_guy Posts: 88
    Hmm... I recently fitted my 9 speed Sora cassette onto my new Mavic wheel and used the supplied spacer without thinking. It works perfectly and didn't need adjusting. What speed is your Tiagra, 9 I presume? basically, I guess the rule is that if your cassette is wobbly and your shifting suddenly declines, use the spacer?
  • hypster
    hypster Posts: 1,229
    Just to clarify things there are actually two widths of spacer for use with Shimano cassettes - 1.85mm and 1.0mm.

    The 1.85mm is necessary if you have an 11-speed freehub but are using a 9 or 10-speed cassette.

    The 1.0mm spacer is used if you are using a 10-speed cassette, the 10-speed cassette actually being narrower than the 9-speed.

    I personally don't bother with the 1.0mm spacer on my 10-speed equipped bikes but do use the 1.8mm spacer on my Mavic 11-speed freehub wheels. I have Ultegra, XT and SLX 10-speed cassettes on three sets of wheels that I interchange between two road bikes and don't have any rear mech issues when swapping the wheels over.

    I haven't heard of Tiagra 10-speed cassettes having dimples on the rear and not needing the 1.0mm spacer. It seems a bit inconsistent and unnecessary to me but stand to be corrected never having used a Tiagra cassette.
  • majormantra
    majormantra Posts: 2,094
    hypster wrote:
    I personally don't bother with the 1.0mm spacer on my 10-speed equipped bikes but do use the 1.8mm spacer on my Mavic 11-speed freehub wheels.

    Um, why? Just because it works without doesn't mean it won't work better with. There will be less play if you include the spacer, and they come with the cassettes so why wouldn't you? And on the Mavic freehub, you should use both the 1.85 and 1.0mm spacers for best results.

    And yes, Tiagra 10 speed is the exception to the rule. No spacers required on a 10 speed freehub.
  • roux_guy
    roux_guy Posts: 88
    Hypster may have a point, kind of. My new wheels only came with a 1.85mm spacer, presumably for 8 and 9 speed cassettes. There was no sign of a thinner spacer in the packaging.
  • majormantra
    majormantra Posts: 2,094
    That's because, as I said above, the thin spacer comes with the cassette.
  • majormantra
    majormantra Posts: 2,094
    (10 speed Shimano cassette, that is. No others.)
  • roux_guy
    roux_guy Posts: 88
    Cheers for explaining. Didn't realise and it's always nice to learn summat new :-).
  • hypster
    hypster Posts: 1,229
    hypster wrote:
    I personally don't bother with the 1.0mm spacer on my 10-speed equipped bikes but do use the 1.8mm spacer on my Mavic 11-speed freehub wheels.

    Um, why? Just because it works without doesn't mean it won't work better with. There will be less play if you include the spacer, and they come with the cassettes so why wouldn't you? And on the Mavic freehub, you should use both the 1.85 and 1.0mm spacers for best results.

    And yes, Tiagra 10 speed is the exception to the rule. No spacers required on a 10 speed freehub.

    On one of my frames, the chain just touches the chainstay when in the smallest cog on the big ring with the 1.0mm spacer in. Rather than have the faff of keep switching the 1.0mm spacer in-and-out when I swap wheels, I just left it out on all of them. I adjusted the rear mechs on both bikes accordingly and it doesn't cause any problems.

    Others might have a different experience such as maybe the lockring not clamping the cassette up tight so will have to do whatever is necessary. I'm just pointing out that you don't necessarily have to use the 1.0mm spacer. There is no "best results" only what works for you.
  • hypster wrote:
    I haven't heard of Tiagra 10-speed cassettes having dimples on the rear and not needing the 1.0mm spacer. It seems a bit inconsistent and unnecessary to me but stand to be corrected never having used a Tiagra cassette.

    I dug out the 10-speed Tiagra cassette that came off my CAADX to fit to my wife's road bike at the weekend. Mana faded to confuse myself as I'd stuck it in a 105 box and was left scratching my head wondering where I placed the spacer.

    I then recalled when I had changed the cassette from an 12-28 Tiagra to an 11-28 105. I removed the Tiagra from the wheel and, due to finding no spacer there, fitted the 105 minus the spacer. Result? It locked up the free hub so was quickly removed and refitted with spacer in place.

    A close look at the back of a Tiagra 10 speed cassette shows several raised points (dimples isn't the correct word) that sit a little proud of the rest of the cassette thus providing correct spacing.
  • sungod
    sungod Posts: 17,435
    hypster wrote:
    There is no "best results" only what works for you.

    it's not about "best results" it's about using components correctly

    if one frame has an issue the correct option is resolve that, not bodge things by reducing safety margin on all the others, which is what you're doing by reducing clearance between rear mech and spokes
    my bike - faster than god's and twice as shiny
  • majormantra
    majormantra Posts: 2,094
    DHA987S wrote:

    All except the part about Tiagra cassettes. :wink:
  • hypster
    hypster Posts: 1,229
    sungod wrote:
    hypster wrote:
    There is no "best results" only what works for you.

    it's not about "best results" it's about using components correctly

    if one frame has an issue the correct option is resolve that, not bodge things by reducing safety margin on all the others, which is what you're doing by reducing clearance between rear mech and spokes

    Yeah, whatever.
  • thefd
    thefd Posts: 1,021
    I've just upgraded to the 11 speed 105 from the 10 speed 105 - my Mavic Ksyrium Elites had the 1.85 spacer with the old 105 but I've just fitted the new 11 speed with no spacer!
    2017 - Caadx
    2016 - Cervelo R3
    2013 - R872
    2010 - Spesh Tarmac
  • hypster
    hypster Posts: 1,229
    TheFD wrote:
    I've just upgraded to the 11 speed 105 from the 10 speed 105 - my Mavic Ksyrium Elites had the 1.85 spacer with the old 105 but I've just fitted the new 11 speed with no spacer!

    Am I missing something in your post? That's the way it's supposed to work.
  • thefd
    thefd Posts: 1,021
    No - I probably shouldn't have put in the explanation mark at the end. My post was to help the OP.
    2017 - Caadx
    2016 - Cervelo R3
    2013 - R872
    2010 - Spesh Tarmac