can I change my chainring on chainset???

ILM
ILM Posts: 41
edited July 2009 in Workshop
Hi

I have a specialized Allez double 18 speed.
http://www.evanscycles.com/products/specialized/allez-18-2008-road-bike-ec001390

I'm struggling up some steep hills and was wondering if firstly I could swap my 34t chainring to a 30t and if so is it worth it?? the large chainring is a 52.
If I change to a triple then I need to buy a new left sti shifter, whole crankset and ? front derailleur. Reason I ask is that I have seen Tiagra triples with a 52,39,30t chainring, so all I'm doing is missing the middle ring out, is that do-able or not??

thanks

Comments

  • Mister W
    Mister W Posts: 791
    No, you can't fit a 30 tooth ring on that chainset. The 30t ring is the inside of a triple and won't fit on a compact.

    The cheapest way to get lower gears is to put a different cassette on....... ah, I've just read the spec and you've already got a 28. You can't go any bigger than that with that rear mech. You could fit an MTB rear mech and use an MTB cassette but TBH if you're fit and healthy the best way to get up the hills is to keep working at them and get stronger.
  • sub55
    sub55 Posts: 1,025
    not
    constantly reavalueating the situation and altering the perceived parameters accordingly
  • ILM
    ILM Posts: 41
    thanks

    best get practising those hills!!!!
    one last question, if I do decide on getting a triple now, how do I know if my left double shifter can cope with a triple chainset??
  • ohlala!
    ohlala! Posts: 121
    No, you can't fit a 30 tooth ring on that chainset.

    Yes you can fit a 30T chainring, just make sure that it is a 130 BCD. Stronglight do them. I'm not sure whether TA has it .
  • ILM
    ILM Posts: 41
    my large chainring is 50 not 52 as i stated earlier.
    why are there conflicting responses?? not sure what to do now.
  • redddraggon
    redddraggon Posts: 10,862
    edited June 2009
    ohlala! wrote:
    No, you can't fit a 30 tooth ring on that chainset.

    Yes you can fit a 30T chainring, just make sure that it is a 130 BCD. Stronglight do them. I'm not sure whether TA has it .

    How the hell can you get a 30T 130mm BCD ring when the bolt holes are where the teeth are.

    Smallest 130mm = 38T
    Smallest 110mm = 33T

    So there's no way the OP is fitting a 30T on his double unless it's an MTB double.
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  • ILM
    ILM Posts: 41
    hi

    thanks for your response reddragon, looks like i'll be looking for a triple chainset then,
    will my sora 9 speed doube flightdeck work on a triple??
  • ohlala!
    ohlala! Posts: 121
    dude look up stronglight they sell them
  • redddraggon
    redddraggon Posts: 10,862
    ohlala! wrote:
    dude look up stronglight they sell them

    Yes, stronglight do sell 30T chainrings for road chainsets. IN 74mm BCD.
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  • redddraggon
    redddraggon Posts: 10,862
    prodTableaupltxrouteImgHR.jpg

    Stronglight are definitely not listing 30T 130mm BCD chainrings.
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  • andy_wrx
    andy_wrx Posts: 3,396
    It's not a double, it's a compact, so it's 110 BCD.

    However, smallest I know of is a 33 tooth ring to fit 110BCD

    ILM, going from 50/34 rings to 50/33 is certainly possible and quite easy, but won't gain you a lot.

    You already have 11-28 cassette, so difficult to gain a lot there either.

    But you are 9sp, so can fairly easily get a 9sp MTB cassette from Shimano or SRAM, in 11-30 or even 11-32, but you'll need a MTB rear mech too, as your existing mech would foul this bigger cog at the rear.

    You will need a new (longer) chain, but the problem is that in order to accommodate the you-shouldn't-use-them-but-are-bound-to-when-you're-tired opposites of 50-30 and 34-11, you're going to have to set-up the mech and chain rather sub-optimally : you'd be OK for most sensible middle gears but would have a loose, clattering about chain at one extreme and have it fouling the mech at the other extreme.

    You'll also have great big gaps between each of the gears.

    I'd consider such gearing as a one-off, to do Fred Whitton or go touring in the Alps or something, but in the UK 50/34 x 11-28 should really be getting you up almost anything.

    'Fraid you do need to get fitter !

    If not, you'd be better off going to triple - your Shimano 9sp Sora ST-3400 shifters will do double or triple.
    That would be a much better long-term technical solution.
  • sportbilly1976
    sportbilly1976 Posts: 524
    ok,

    following on in a similar manner:

    I currently have a Trek 1.2T (so a 50/39/30 chainring with a 11-26 9 sp cassette)

    I have recently been debating whether to change this to a double set-up but the hassle of changing the gearing completely seems too much.

    So I am now considering whether it might be simpler to just alter the largest chainring to that of a double - i.e to change the 50T one to a 53T one.

    How difficult is this with the current bike set-up - is it something I could have a go at or should I take it to my LBS?

    also - cost wise...the current chainring is a FSA Vero one, is it possible to buy just the 53T part?

    thanks
  • sportbilly1976
    sportbilly1976 Posts: 524
    is it possible to buy one of these, or sohuld I try to get a FSA one?

    (I admit I would NOT get a campag one for potential compatibility issues)....


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