Safe to be 10mm below top of thomson stem or not. Will I almost certainly die.
I'd say no- thats below the top bolt is it not?
Maybe a little below the center of the top bolt or just in line with the center.
I'm with rockthreegozy - I would say anything below any part of the top bolt would be a no? I know I am stating the obvious...but just in case (we all have our moments!)....you don't have any spacers under the stem do you that can be removed?
What headset? If it's a sealed bearing jobby you can often remove the top cap and just leave the conical split washer under the stem.
CK head set. Think I may have to fit a low stack top or bottom.
What forks then? If marzocchi then it's cheaper to get a new steerer pressed in than a new CK headset.
Magura wotans. Non removable steerer. Might just get a zero stack headset an fit either top or bottom. Top I think as not to change geometry.
Perfect opportunity to get a better fork.
try and find an older thomson stems with the internal wedge jobbo rather than the two external bolts as the clamp mechanism is well inside the stem and will give you the extra space whilst still holding the steerer tube.
[img] http://http://www.jensonusa.com/store/product/ST707A09-Thomson+Elite+Mtb+Stem.aspx [/img]
The safe preload space from stem to steer tube is 3 - 5mm. Less than that will half the clamping force on the steer tube.
The Thomson elite XC with one clamping point i.e. the wedge already has half the clamping force.
It doesn't seem safe to advise using only half of the available clamping force to secure an ill fitting fork.
A cheaper headset with 5mm lower stach height would be a safer option.
But if you can afford a king headset, you can afford a better suited fork. It's cheaper than medical bills or time off work.
Skyline
Why the hatred for the wotan. Just measured the depth and its actually only 5mm so should be ok yes.
