I've been trying to determine what size road or mountain bike I should purchase. All the charts I've found suggest what frame size I should have, but online shopping only lists wheel sizes. How do I determine what wheel size is best for my height?

  • 2
    What web sites are you looking at that only include wheel size?
    – jqning
    Apr 9, 2016 at 22:18
  • Frame size is normally independent of wheel size for mid-size adults. Kids bikes use smaller wheels, but bikes for very tall people rarely use larger wheels. You can buy mountain bikes with wheels from ISO406 to ISO787, for example (although the common size is ISO559/26")
    – Móż
    Apr 10, 2016 at 1:08
  • @jqning Amazon mostly Apr 10, 2016 at 16:25

1 Answer 1


Generally, there are a few wheel sizes for adults on the market now:

  • 700c: This is the standard adult road bike wheel size. For mountain bikes, this is often sold as 29" and is also the standard (where they're said to roll over bumps easier than a 26" but at the cost of manuverability and weight). The rim diameter is 622 milimeters.
  • 650b: This is becoming more popular with shorter riders for road and mountain biking (where its often sold as 27.5", as a compromise between 26" and 29"). It is smaller than 700c with a rim diameter of 584 millimeters.

Less commonly, you'll find:

  • 26": This was the old standard size for mountain bikes. The rim diameter is 559 mm.

All these wheel sizes are available for a wide range of frame sizes (usually reported as some number of inches or centimeters, e.g. 58cm for a road bike or 23" for a mountain bike, or small/medium/large/etc.). My guess is that you're reading the frame size and thinking it is the wheel size.

Note that frame sizes are not standardized between bike models or even related models (e.g. a bike that is sold in both a 26" and 700c wheel version), so you need to try the bikes to see if they fit you well, and/or compare their geometries (e.g. standover height, top tube length, etc.).

Useful links on tire sizing: Rivendell Useful links on bike sizing: Sheldon Brown

  • Would you advise against online shopping if all that's listed is the wheel size? It sounds like the frame size is much more relevant in determining whether the bike is a comfortable fit or not. Apr 9, 2016 at 17:52
  • 1
    Yeah. I would generally advise against online shopping for people who don't know what kind of bike they want specifically. Theres enough variation for bikes marked as the same frame size (e.g. 58cm's) that unless you know the specific class of bike well and what measurements you need, you're probably not going to get a well fitting bike (especially if you're tall/short/have odd proportions like long legs).
    – Batman
    Apr 9, 2016 at 18:31
  • 1
    Go to your local bike shop and try some bikes (and/or have a bike fit) and buy there. If you're not used to bicycle repair, you'll likely want to have them fix it up for you after assembly if you buy online anyway (and this will kill a good bit of the price difference between a quality bike bought online and in the shop, especially if its a name brand bike). Plus, they'll likely give you a discount on accessories like a good helmet, locks, lights, etc.
    – Batman
    Apr 9, 2016 at 18:32

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