Converting 2by9 to 1by9

[finnfish27]

Hi,

my bike is currently running a shimano 2by9 set up and i am finding that i dont use the lower chainring. Is it worth converting to 1by and if so what kind of chainring would i need (tooth wise)? It currently has a 22 and 36 tooth at the front and a 11-36 tooth at the back/

thanks finn

[Jeff Barber]

32-tooth is pretty standard for a 1-by drivetrain, but since it sounds like you’re used to staying in your 36, a 34 would probably be fine. Or maybe you just want to stick with 36.

The process and pieces you’ll need to convert the crankset will depend on which one you have and how it’s set up.

[Bike Nerd]

If you just remove the small chainring and the front derailleur/shifter, you might have chain drop problems.  You might need some type of chain retention devive for the front chainring.   Modern 1x drivetrains have rear derailleurs and chainrings designed to keep the chain from dropping.  2x and 3x drivetrains are designed so that the chain slips off the chainrings easily and then the front derailleur acts as a chain retention device.

Before you spend a lot of money making a 1×9 work, you might want to look into the price of a 1×12 Sram Eagle SX drivetrain.  I have a 3×9 drivetrain on an old bike of mine that still works just fine which I’ve always wanted to convert to 1x.  But in the end, just leaving it the way it is just made the most sense moneywise.  In addition, I don’t think I could ever be happy with the narrow range that an 11-36 cassette provides if used as a 1x.

[Author]

Posts