What diameter

[fatblokish]

is my Mercian Audax Special steerer tube?

I need a replacement stem and can't get through to the shop, and CBA to undo the fangled nut

Ta

 

[raleighnut]

It'll be 1" or it might be 1 1/8th", depends on the fork specified when it was built, likewise it could be a threaded or A-head fork again depending what was specced.

 

[fossyant]

Most likely 1 1/8. Undo the top cap and check you lazy locknut.

 

[fatblokish]

Most likely 1 1/8. Undo the top cap and check you lazy locknut.

All right, all right.
Anyway, for what it's worth, having you-tubed how to use my vernier calipers, it turns out to be a 25.4mm plain steerer tube.

Wiggle here I come.

 

[raleighnut]

All right, all right.
Anyway, for what it's worth, having you-tubed how to use my vernier calipers, it turns out to be a 25.4mm plain steerer tube.

Wiggle here I come.

So it's 1"

 

[fatblokish]

That's right.