What sizes of MTB components are still present from BMX bikes?

[Manc33]

I always thought MTB's came about off the back of BMX bikes. I think this is probably true because if you go looking for a MTB handlebar, it will typically have a bar diameter (where gear shifters, brake levers and bar grips are situated) of 22.2mm.

That's the same size as BMX handlebars, which got me thinking, hardly anything else on a MTB is the same size as it was on BMX like that is, everything else seems to have adapted or evolved, yet the grip area on the bars is still the same.

It is only the grip area though because BMX bars clamp to stems at 22.2mm while that area has fattened up on MTB bars to (usually) something like 31.8mm, so that part has changed.

Apart from the bar diameter on the grip area carrying over from BMX, has anything else stayed the same size?

I put this in this forum because this topic can't really help anyone, it is more of a wondering about it.

GO GO GO!

[rjb]

I have a falcon k2 MTB converted to a drop bar tourer. When I purchased it in 1987 it came with a BMX sized steerer 21.15mm if my memory is correct. When I did the drop bar conversion I installed a standard 1" quill stem but had to ream out the fork steerer tube to 22.2mm (7/8"). Took me several hours of effort.

I believe they changed the standard to 22.2 pretty quickly.