Just fitted a Thomson stem and I am slightly concerned about the steerer tube . It sits about 2cm down into the stem , instead of the 1cm that the previous stem had.
There is a spacer in the stack so I can get another spacer if neccessary.
The stem is the one with the 2 half cups that converge on each other as you tighten them up. Both of the clamping cups are totally covered by the steerer tube, so that they are clamping onto steerer, not thin air.

By my reckoning all should be fine as the clamping force is on the steerer. Any helpfull thoughts? cheers.

All the clamping force is on both the steerer and the clamping cups. At the least I would want both 100% covered, and would prob go for 5mm gap.

IIRC Thomson themselves say there needs to be at least 39.5mm steerer for the stem to clamp onto for it to be effective.

Q – What is the minimum insertion length (height) for the steerer tube into the stem?
A – 39.5 mm. Insertion length must be measured after any spacers are added below the bottom of the stem.

Out with the tape measure tomorrow night then . Ta .

double trouble . run faster hamsters.