Single Speed Bike Gear Ratio

[novocaine]

It's single speed, it doesn't matter the ratio, the rule of thumb is that it will be wrong 80% of the time. that's half the fun.

 

[danc]

It's single speed, it doesn't matter the ratio, the rule of thumb is that it will be wrong 80% of the time. that's half the fun.

Using my amazing powers of maths: if being wrong 80% of the time is half the fun then single speeds are 160% fun, which sounds about right.

 

[bikeworkshop]

Cheapest option is to fit a multiple freewheel and then you can experiment.
Everyone has a multiple freewheel somewhere.

Might be a challenge though if the frame is 120

Otherwise buy a smaller chainring
We've got a box of them somewhere, not worth much.
Probably all 52s

 

[jim haseltine]

Thank you Jim.

Is there a formula to calculate that or does that come from your experience?

(Chain ring teeth / sprocket teeth) * 27 = gear size in inches.
Actually means nothing at all, it's just a way of comparing gear ratios without the awkward 2.1564:1 stuff as you can relate that <60" is really low while >80" is high and anything over 100" is really high. Our continental friends used to use 'development' (maybe they still do) in which they would use the circumference of their wheels in place of the 27 in the calculation. So a (say) 72" gear would actually be 5.629metres development for a 700x25c tyre, assuming the tyre circumference to be 2111mm - which again is an approximation as it depends on the tyre pressure and the weight of the rider but then if somebody is worried about such things they should take a deep breath and get a life.

 

[Glug]

gear-calculator.com will show the options:

https://www.gear-calculator.com/?GR=DERS&KB=50&RZ=16,20,22,25&UF=2125&TF=90&SL=2.6&UN=MPH&DV=speed

 

[Jonny69]

50/18 or 50/19 will do you.

 

[3wheeler7]

Here's the gear inches for 27" wheels, 700C will be a bit lower and 26" lower still.

 

[hamster]

Fixie? You now a hipster?

 

[Battersby]

I'd say on the road anywhere between 68-73 is a good idea depending on terrain and fitness. Pre covid I was on 72 but happy pottering around on 70 now. This is all down south west so YMMV.

 

[novocaine]

I'd say on the road anywhere between 68-73 is a good idea depending on terrain and fitness. Pre covid I was on 72 but happy pottering around on 70 now. This is all down south west so YMMV.

no, his mileage will be the same, just it might be easy or hard.