Context: My 90s MTB still has its original Shimano chainring (crankarms say Alivo). The cassette was replaced several months ago, as was the chain and bottom bracket. No wear on the chain right now.

The derailleurs are Alivio, and probably the original ones from the mid-90s. I don’t have any reason or intention to replace those, although, I do have a Deore LX on my decommissioned 90s MTB that I could likely drop in, but I digress. LOL

I guess two questions:

  1. What would I need to provide to my LBS as far as measurements to get me a replacement? I understand that I’ll likely need another BB and maybe(?) a chain, but I plan to stick with the same gearing.
  2. Ideally, I’d want to find a 3x chainring where I can replace the crank arms and individual chain rings when needed. Will this be easy to find, considering the age and group set?

Thanks in advance.

  • @j4k3M
    1•6 months ago

    My current road crank has around 70k miles on it, just for reference. It doesn’t shift great, but that is from the frame design. I’ve run triples before. They are hard to dial in perfectly. When I commuted with one, working at my first bike shop, I had one absolutely dialed. It took having a fine threaded inline barrel adjuster and the one built into the down tube to get that thing just right.

    Chainrings rarely cause issues. Even the ramp shape profiles have very little impact on the actual shift. Almost all of the force of the front shift is handled by the little ramp inserts.

    It is extremely hard to quantify wear on chainrings unless you have an identical ring to compare directly. The profiles made to allow the chain to seat earlier and smoothly make the ring wear deceptive visually.

    I’m not saying I know better. I’m simply an experienced former Buyer for a chain of bike shops. Some people swear that changing chainrings is important. They are generally a minority. Most of the mechanics that actually ride and race, only change them if they are sponsored to do so.

    • @[email protected]OP
      2•6 months ago

      I appreciate the insight. I’m not actually having issues with the chainrings/front shifting, but I did with the cassette, which is why I replaced it. I figured I might as well replace the chainring too, since it’s over 30 years old and wouldn’t be that expensive anyway.

      But I guess it’s one of those “if it ain’t broke” situations, so maybe I’ll leave it as is. 😂