are road bike oversize bars the same Diameter as mtb oversize?

just looking to change the stem on this new Ribble road bike (because i’ve bought one too big – doh!) and noticed that all the road stems are quoted as 31.7mm but MTB oversize is 31.8mm.

Is this correct?

It just seems a bit odd that they would differ by only 0.1mm

I thought they were all 31.8

so did I, but on the Ribble website they are quoted as 31.7mm

its the same. its just manufacturers putting their slant on measuring.

In roadbike terms 31.7 is 31.8. If you were to measure them, they would be the same.

HTH

Cheers gents

As Steve-Austin – some manufacturers round up and some round down.

It’s actually 1.25 inches, which is 31.75mm by my calculations. But they are fully interchangeable.

STW truly is the font of all knowledge