Hi people,

I am new here and I am a newbie with bikes etc.

I would like to know what size (diameter) or type I have in my bike.

It's Trek 3700 and the name of type is: Bontrager LT3 26x2.0".

I would like to know it, as I want to set up my new bike computer.

I can choose or 26" (650A) or ATB26x2 (650B) or I can calculate it (tyre circumference) by multiplying my diameter by 3.1416, but I wasn't sure if my tyre is 26" or ATB26" (I'm not sure what ATB means, exactly).

Please help me, thanks!