Very Nice Ride! I am very envious of that disc brake.
Your highly desirable 5 speed has better ratios overall than the 4 speed:
4 Speed ratios: 1st = 2.78:1, 2nd = 1.84:1, 3rd = 1.36:1, 4th = 1:1.
5 Speed ratios: 1st = 3.06:1, 2nd = 2.01:1, 3rd = 1.52:1, 4th = 1.21:1, 5th = 1:1.
It still needs lower gearing overall to excel on trails. Right now top end is in the high 60's, you can afford to shave some off of this end.
You very nearly have the overall Trials Gearing spread already, but without the huge gap between 3rd & 4th.
( 4 Sp. only Trials gears: 1st = 3.19:1, 2nd = 1.97:1, 3rd = 1.46:1, 4th = 1:1)
The Pirellis will allow proper "plonking" on trails. A 42 - 44 tooth rear sprocket puts your first gear below the specialized trials gear numbers and will give you a usable 1st & 2nd gear on tight trails. Actual trials use would require much more than that, maybe 50T.
The local dirt bike shop will have a selection of handlebars - go see what feels best for you. Aluminum bars have some shock deadening qualities, something to consider.
I assume the fork part that broke is the alloy axle clamp? These should cure that:
PART No. 92634 ; £10.50 ; CLAMP, FORK SPINDLE, STEEL, EACH
The fork oil may be low or too thin. The Snidal book and elsewhere on this forum have aids to check & cure that. The fork & shock springs are notoriously heavy, and there are softer replacements for both.
The stock footpeg placement on the Bullet is too far forward for stand-up offroad work. The "action" pictures in Hitchcocks accessory section seem to show them about 6"-8" aft of the stock placement, or else the rider's falling off. The Bullet steers very well from a seated position, so it's not mission critical.
PART No. 92519 ; FOOTRESTS, FOLDING TRIALS, PAIR ; £29.50
These universal folding footrests are made specially for competition. They will need to be welded to the frame in the desired position.
Grumbern's Project "Laubfrosch" - the trials hybrid in the Vintage Royal Enfield/Indian section of this forum is astounding - what an artist.
I really like your machine - can't wait to hear how it performs with the real trials tires on it! - ACR -