ADVICE 18:46 or 18:48

GIGA01 Posts: 2
edited June 2017 in Commuting general
Hello my friends I need advice from you.
I have 26" 1x75 daily commuter singlespeed bike.Every day i have 10km in one way, on flat, with about 1kilometer in total mild uphill.

I need advice which combination is best for me:18:46 or 18:48


  • The Rookie
    The Rookie Posts: 27,812
    As the biggest variable is how fit you are and what your power output is like, the simple answer is no-one can tell you.

    What is the current gearing, does it feel too high or too low?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • fat daddy
    fat daddy Posts: 2,605
    changing the big cog by only 2 teeth doesn't make "that" much difference ... its like 2rpm at 10mph .. at 100rpm its the difference between 20 - 20.9 mph or 5rpm

    I personally would go with the 48 as you will get fitter quickly and hills get easier ... where as spinning your legs of trying to keep up on the down is more annoying when you know you could be going faster.

    go 48
  • mr_eddy
    mr_eddy Posts: 830
    As others have said depends on your fitness / weight / terrain etc. Do you like to spin ? Do you go slowly etc.

    I have a Single Speed and I would say I am a average cyclist (again what is average?). I tend to prefer faster cadence as it is better on your knees and gives me a better work out. I would say aim for any gear that gives you around 90rpm at your ideal nominal speed.

    So basically if you are happy going along around 18mph and you have a flat and shortish run then 46:18 would probably be better.

    As others have said the cog at the back makes the biggest difference so if you wanted to grind along at a low RPM but high speed a 46:16 would be a 'harder' gear than 48:18
  • rick_chasey
    rick_chasey Posts: 74,721
    48 FTW.
  • singleton
    singleton Posts: 2,523
    My last single speed was a 46/18 road bike and I changed the rear to a 17 as I found the standard gearing too low.
    It you're unsure, you could get the 46/18 and change to rear sprocket if you wanted to increase the gearing later on.