rear mech hangar is too short for my needs

vermooten
vermooten Posts: 2,697
edited April 2008 in Workshop
Hi,


I'm trying to fit a 30-tooth sprocket to my cassette. All is well except when I try to shift the chain's onto that sprocket the rear mech collides with the chain - and if I were on the road there would be a big problem.

If the hangar which connects the rear mech to the frame were slightly longer - say, 5mm - then this collision would not occur.

The frame is Cervelo R3. You can buy replacement hangars, but there's no long version.

Has anyone got any suggestions? Think there are little workshops where men who know what they are doing can knock one up for me?

Andy
You just have to ride like you never have to breathe again.

Manchester Wheelers

Comments

  • redddraggon
    redddraggon Posts: 10,862
    30 tooth sprockets normally need a MTB mech - do you have one?
    I like bikes...

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  • vermooten
    vermooten Posts: 2,697
    aha - I do not but I totally understand. I wil look into that, thanks redddragon!

    EDIT: next problem is: can I get a MTB rear mech compatible with Shimano 10-speed? Any thoughts?

    NUTHER EDIT: Sheldon Brown suggests that any Shimano rear mech is compatible with any no of speeds except where there's a 10-speed hub - so it looks like I'm in the clear as my hub is 9-/10-speed.

    Yes?
    You just have to ride like you never have to breathe again.

    Manchester Wheelers
  • redddraggon
    redddraggon Posts: 10,862
    Sheldon Brown wrote:
    Rated maximum rear sprocket size, however, is also commonly much lower than what actually works. For instance, Shimano's models designated as "road" derailers are generally listed for a "maximum" sprocket of 27 teeth...because 27 teeth is the largest size that they make in a designated "road" cassette. However, in almost all cases, these derailers, even the short-cage models, will handle rear sprockets as large as 30 teeth in practice. (This somewhat depends on the design of the frame's derailer hanger, so once in a while you will find a particular installation where you can't use a 30, but I've never seen one where a 28 wouldn't work.

    So I think you might get it to work if you change the hanger, and if you change to a MTB mech I think that should work aswell.

    I'd imagine changing to a MTB mech would probably be cheaper than getting a custom hanger.
    I like bikes...

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  • redddraggon
    redddraggon Posts: 10,862
    vermooten wrote:
    aha - I do not but I totally understand. I wil look into that, thanks redddragon!

    EDIT: next problem is: can I get a MTB rear mech compatible with Shimano 10-speed? Any thoughts?

    NUTHER EDIT: Sheldon Brown suggests that any Shimano rear mech is compatible with any no of speeds except where there's a 10-speed hub - so it looks like I'm in the clear as my hub is 9-/10-speed.

    Yes?

    Yeh, any Shimano RM should be fine.
    I like bikes...

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  • vermooten
    vermooten Posts: 2,697
    Fantastic! Thanks, you've saved my bacon.
    You just have to ride like you never have to breathe again.

    Manchester Wheelers
  • Pirahna
    Pirahna Posts: 1,315
    I have to ask, why are you trying to fit a 30 tooth sprocket on an R3?
  • vermooten
    vermooten Posts: 2,697
    Your question is a fair one, and has the makings of a "Well I wouldn't start from here..." type of answer.

    The answer: because I'm an idiot who didn't train due to both illness and indolence, and who hasn't lost enough weight, and has to get up Hardknott Pass in 3 short weeks from now.
    You just have to ride like you never have to breathe again.

    Manchester Wheelers
  • gkerr4
    gkerr4 Posts: 3,408
    aha - makes sense - good luck getting it to work out.

    off topic - how you getting on with that iphone of yours?

    I bought a new one (again!) when they lowered the price last week - £169 for the 8Gb model - I just hacked it and put my old sim in it thought - it still isn't worth the contract rate (imo) - it's a much better device when it is 'open'
  • vermooten
    vermooten Posts: 2,697
    I love the iPhone - I have to put my fingers in my ears and go la-la-la whwn i ghear about price cuts and new 3G models coming out but still... it's a phone that works! Email and web everywhere, yeah love it. I don't like taking it out when i'm riding though so i might buy a cheapo pay-as-you-go for that. Not jailbroken it yet, not yet seen any apps worth doing that for.
    You just have to ride like you never have to breathe again.

    Manchester Wheelers
  • gkerr4
    gkerr4 Posts: 3,408
    true - there aren't any great apps out. there are some cute 'powertoys' and tweaks though - like a 'finder' application + preview as per leopard. also there are some games and stuff

    nice to have MMS back too - swirlyMMS app works ok and V1.0 should be better still.
  • aracer
    aracer Posts: 1,649
    I still don't understand people who spend several hundred pounds on a phone gadget when they could buy a nice cassette for their bike instead.
  • dennisn
    dennisn Posts: 10,601
    aracer wrote:
    I still don't understand people who spend several hundred pounds on a phone gadget when they could buy a nice cassette for their bike instead.

    Whoa, how much is that in US dollars?? I'm thinking I don't really want to know. On the other hand if it will make me go 5 or 10 times faster, well, maybe I should think about It.
    I remember when I spent 500 dollars on a rear wheel that was supposed to make me "go faster". The wife couldn't believe it, "what, 500 dollars for a wheel, for a bicycle wheel".
    She was even more shocked when she found out it didn't come with a tire.

    Dennis Noward

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