How do you centre a Brompton wheel?

[rogerzilla]

A standard dishing tool won't fit the small rim.  What do people use, or is it a case of flipping the wheel round in the fork to see if it stays in the same position?

[andygates]

That's what I do for wacky wheels.  Actually for all wheels, as I don't have a dishing too.  It's a bit of a chore but it works just fine (as long as the frame ain't bent!).

[nuttycyclist]

I've just put two bits of tape on the truing jig, where the "ovalness checking bit" is.  That's good enough for me to build centred wheels.  I just flip them near the end of the build to make sure the wheel was put in the jig proper like.

[Ian H]

I've just put two bits of tape on the truing jig, where the "ovalness checking bit" is.  That's good enough for me to build centred wheels.  I just flip them near the end of the build to make sure the wheel was put in the jig proper like.

Yup. The rim is still centred on the axle ends, it's only the hub that's moved over. So flip the wheel in the jig to check the rim's in the same place. I've never seen the point of a dishing tool.

[rogerzilla]

In the end I stuck it face down on a piece of glass and measured the height of the rim, then turned it over and did it again.  I had to compensate for the axle end protruding from the locknut more on one side than the other (and odd bit of Schmidt inconsistency), but it is centred.

It's very hard to get even spoke tension on a small wheel - there's very little elasticity in those tiny p/g spokes, and 1/8 of a turn makes an appreciable difference to tension.