[Question] Site to Match Gearing Between Bikes with Different Tire Sizes?

Equipment
1

Does anyone know of a good site that will allow you to figure out how to match gearing between bikes with different tire sizes?

For example:

  • Bike A (Road bike) has 50x34 with 11-30 cassette and 28mm tires
  • Bike B (Gravel) has 50mm tires - what chainring size will give the same top gear as the 50x11 & 28mm tires if the small cog is a 10?

In the example above, given the significant difference in tire outside diameter, it wouldn’t require ~45tooth chainring to match the largest gearing between the two bikes. I get that tire inflation will impact this, but looking for a way to estimate this

2

I expect you can work it out using the sheldon brown calculator here - it might need to be by trial and error though

3

https://www.gear-calculator.com/ is one I have used, you can manually enter the roll out if you want to get a little more accurate.

I like the visuals on this one as well and usually use this one Bicycle Gear Speed Table | BikeCalc

4 Likes
4

Top one is great and you can do a direct comparison on screen IIRC.

5

Same as @mrtopher1980 https://www.gear-calculator.com/ is my go to since you can directly compare them without having to resubmit the form each time like the Sheldon Brown one.

6

Thanks everyone