Originally Posted by iomatic
-if I go to 18 spoke, will dropping the top tree be enough to 'readjust' rake and trail to a more stable geometry? Naturally this requires headlight relo, and possibly just going clip ons... oh wait, rearsets...
-will going to 17 mag require a different set of trees (not just for the wider mag width, but overall change in angle geometry). If this is true, will a Thruxton designed wheel (thinking Carrozzeria) set be fairly bolt-on with a Thrux fork set? And would a mag wheel Triumph set of trees be "correct?"
Since you currently have a 19" front wheel and are dropping the front height to 18", you'll want to *raise* the forks in the trees to restore geometry/add stability - not lower the tubes. That being said, I doubt that you would create an unstable ride by dropping the front 1/2" via the rim change...these bikes have pretty conservative rake & trail and actually like a little more aggressive stance.
Why would changing the front wheel require going to clip ons or rear sets?
The triumph mag is of identical width as the spoked wheel hubs. Where the assembly goes awry is when swapping the T100 lower legs to the mag wheel lowers...these result in a narrower space available for the wheel assembly. The problem exists regardless of the mag front wheel you use.
If you were to go to a mag up front and keep your stock lower legs, then everything fits just fine, but now you need to figure out how to lower the front fender so it doesn't look like a dirt bike.
As far as the steering geometry is concerned, either front wheel will likely work fine with your machine without going to thruxton, scrambler, or F3 tubes in the forks provided you stick with the stock length rear shocks. Remember, thruxton/scrambler shocks are roughly an inch taller...without this extra height in back, lowering the front a little isn't going to totally destablize your machine. You may, however, miss the ground clearance.
I went clip ons over the tree on my thruxton without causing issue...so that overall geometry was roughly 1" taller in back and 1/2" lower in front than the your T100. No problemo on stablility, but I didn't like touching down more frequently in corners.