TT 1x Chain Ring Selection

I am looking to convert my time trial bike to a 1x set up. My question is how do I determine the right size front chain ring? Any resources, advice, or links to previous commentary welcome.

The size that you can turn on your TT courses is optimal; I don’t know if you’ll get any literature on that as the variables are massive!

The biggest you can get, psych out the competition.

i had the same dilemma a couple of years ago, it will ultimately come down to a few things, terrain & distance likely the main ones.

you can try and use a gear calculator type tool to try and get a gauge based on your cadence, realistic speed & then the aim is to have a straight a chain line as possible so where that will land on your cassette but in truth you’ll unlikely find a one size fits all solution unless you only ride 25m/40km TT’s.

i have 54/56/58 and they all see use throughout the season

there is a bit of discussion around 1x in the time trialling thread

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Fully agree. Get a 60. Anything smaller is for children’s races.


I think using a gear ratio calculator to determine which ratios work best for you would be helpful. I would start by looking at the course profile and which ratios would give me the best chain line throughout the effort.

58 gives me a nice straight chainline at 26-27 mph with a 12/28 11 speed cassette. I’m in Florida so no hills.