Trail is the distance the front tire's contact patch follows behind the steering axis, and it is the single best predictor of how a bike steers. Enter three numbers.
Monsoon Cycles, Colorado Springs · Updated August 16, 2026
= 57 mm of trail
This is the identical formula inside the Frame Lab solver, which matched a published factory trail figure to 0.2mm in validation. Rules of thumb: mid-50s mm is neutral road manners, low 40s is quick criterium steering, high 60s and beyond is the stable push of loaded touring and modern MTB.
Road bikes cluster between 50 and 60mm. Lower feels quicker and busier, higher feels calmer and more stubborn. Touring bikes run high, track sprint bikes run low, and none of them are wrong.
Half your wheel's bead seat diameter plus the tire: a 700c wheel with a 28mm tire is 311 + 28, about 339mm. The wheel circumference chart lists bead seats.