Advertise on Bikeforums.net



User Tag List

Results 1 to 3 of 3
  1. #1
    No one carries the DogBoy
    Join Date
    Feb 2004
    Posts
    2,255
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Changing the middle chainring on a roadbike

    I just dropped off my bike for a tune-up and the mechanic indicated that my middle chainring probably only had about 1000 miles left. That would be only 2200 miles on the ring. First off, I thought that was low, considering that I lube my chain every other ride and clean my chain every other week. But that's not the point of the post.

    Since I'm going to have to replace it soon, I was wondering what I need to determine to see if I can change the ring from a 42T to a 39T. Currently I have an FSA crankset and DA 9'spd deralliers (sp). I want to switch to the 39T because I'd like to get the feel for what its like to ride a double. The small ring is a 30T and the large ring is a 52T. So, what do I need to look at to figure this out? Or, is this even an option?

  2. #2
    Senior Member sydney's Avatar
    Join Date
    Jan 2004
    Posts
    9,428
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by DogBoy
    I just dropped off my bike for a tune-up and the mechanic indicated that my middle chainring probably only had about 1000 miles left. That would be only 2200 miles on the ring. First off, I thought that was low, considering that I lube my chain every other ride and clean my chain every other week. But that's not the point of the post.

    Since I'm going to have to replace it soon, I was wondering what I need to determine to see if I can change the ring from a 42T to a 39T. Currently I have an FSA crankset and DA 9'spd deralliers (sp). I want to switch to the 39T because I'd like to get the feel for what its like to ride a double. The small ring is a 30T and the large ring is a 52T. So, what do I need to look at to figure this out? Or, is this even an option?
    Sounds like BS to me. A middle ring should not wear out anywhere near that fast. You need a 130 BCD 39 ring and for best shifting it should be pinned and ramped like the original. Chainrings at www.peterwhitecycles.com
    Don't buy that drivel of his that the difference between middle and big can be no more than 10 teeth. It's a misquote of somethng entirely differen from Shimano.

  3. #3
    feros ferio John E's Avatar
    Join Date
    Jul 2000
    Location
    www.ci.encinitas.ca.us
    My Bikes
    1959 Capo; 1980 Peugeot PKN-10; 1981 Bianchi; 1988 Schwinn KOM-10;
    Posts
    14,819
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    I do not replace any chainring until the chain runs noisily or skips on it. To maximize chainring and cog longevity, replace your chain as soon as it has elongated by 0.5%, i.e., 1/16" per 24 half-links [sheldonbrown.com].

    Some manufacturers specify different 52/53T chainrings for use with a 39T or a 42T inner/middle, but I really don't think it makes much difference. In fact, unless you shift under power, pinning and ramping really don't make much difference, anyway. In the good old days, cyclists did just fine without ramps, pins, or indexing, provided that they eased up on the pedal load while shifting, which is still good advice with today's equipment.
    "Early to bed, early to rise. Work like hell, and advertise." -- George Stahlman
    Capo [dschaw'-poe]: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger, S/N 42624
    Peugeot: 1970 UO-8, S/N 0010468
    Bianchi: 1981 Campione d'Italia, S/N 1.M9914
    Schwinn: 1988 Project KOM-10, S/N F804069

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •