I am looking to build my own bike and was wondering whether the bike and the drivetrain would work better with matching parts or not. I work at a bike coop and it would be much cheaper to be able to use random parts. I want to know if that would be smart or if I should by the parts in a set from the manufacturer (with a price tag if possible). Thank you! If you need me to be a little bit clearer feel free to ask.

  • 3
    Given you're working at a bike cooperative, just grab whatever looks unworn and try it out. I suspect you'll get a lot more MTBs and BSOs than quality bikes, we do. Learn to spot good stuff.
    – Criggie
    Jan 14, 2017 at 9:39
  • 4
    Up to 8-speed systems everything is very forgiving compared to higher gear counts, where there is still cross-compatability but you have to be more careful. Perhaps you should tell us a little bit more about what you're aiming to build (Road/mountain/etc. and how many gears)
    – Chris H
    Jan 14, 2017 at 9:41
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    The main issues are between the rear derailer and the corresponding shifter, which must match in several ways, and within the components in the bottom bracket, where thread/taper/etc must match. And if you want to use brifters, the brakes and derailers must be in some sort of agreement. Jan 14, 2017 at 12:57
  • I think smartness is a trade-off between how much money you wish to spend, and how much time you're prepared to spend researching/tinkering.
    – PeteH
    Jan 14, 2017 at 19:46

2 Answers 2


It's complicated.

There are many groups of parts that will work together just fine, and many that will not. You can mix and match brands in any number of ways and have it work fine.

Buying everything together is an expensive way to guarantee that everything will Just Work.

You can put something together for much, much less money using random bin parts from your co-op. But, you will still have to pay for it with your own research work, in learning all the different ways that the components have to fit together.

The good news is, putting a bike together isn't rocket science. There is detail that you will need to learn, but you can learn it.


The answer is "it depends". Some parts are cross compatible, some are not and some can be made to work with adapters, non-standard cable routing etc.

If you have access to the parts, you can measure most dimensions yourself. Calculating cable and derailleur movement and actuation ratios takes some simple math, otherwise you are fine with just measuring.

A great resource for looking up compatibility is Sheldon Brown's crib sheets. Actually, reading through entire site will answer a lot of questions.

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