Forum menu
Quite happy with my 30:18 gearing on a 26” single speed.
An upgrading to 29” frame so what gearing do I need to keep it similar?
I used 32x18, 19 or 20 depending on how hilly the area
About a 30:20 by my reckoning.
30/18*26 = 43.3333
30/20*29 = 43.5
You might want to check your actual tyre OD.
Edit
Use a gear calculator to compare old and new. Sheldon Browns Gain Ratio includes wheel and tyre size in the calculations
I used 32:16 on 26" and went to 32:18 on 29"
https://www.sheldonbrown.com/gear-calc.html
30:18 on a 2.1" 26" tyre is nominally 43 gear inches, while the 32:16 I used would be 51.9 gear inches
With a 2.1" tyre on a 29" wheel, 32:17 would have given me 52 gear inches, so the 32:18 I used actually made it slightly easier for me at 49.1 gear inches
to get close to your current ratio, 30:20 would give you 41.4 gear inches