TTI boxes are great, I visited the factory a couple of years ago, they are 80 miles away from me. Bruce is a nice guy and his team are enthusiastic. I too would fit one if my Commando boxes wear out.
Don't forget friction is directly proportional to load, so weight on the front gives extra front tyre grip allowing more cornering power and stronger braking.If u check yr bathroom scales by say 5, 10, 30 kgs plus all weights, each time u use yr scale for yr bike, u will
know the deviation factor or "bathroom-factor". What I found out by weighing my Norvin: It had the same
weight distribution, like my Honda RC31 (650 Hawk), which - in my opinion - is the best road holding bike
in the 60hp class. These bikes have a lighter front wheel load, than rear, and this seems to be for the changing
load with braking. If u study modern superbike tests, like BMW 1000RR, Honda CBR1000RR, etc. , they all have
heavier front wheel loads. I asume, that this is for compensating the aerial lift at speeds over 140mph, to keep
these bikes steady at full throttle on the motorway. As we do not have this kind of lift with our bikes, they
should not have the same weight distribution, like modern Super Bikes, to submit an enjoyable ride at lower
speeds, even on track. In other words, a good Vincent, on road or on track, should have abt 40% load on the
front and 60% on the rear. Original brakes in good nick are fine on a Comet, but will need some improvement
on the front with twins.
Roy told me that he has blown up more than one of these Triumph 5 speeds. They are said to be a lot stronger than the AMC .Yes, that keeps cropping up. Mine is a "standard" Rapide, maybe 8:1CR, 28mm Delortos, Mk III cams, nothing at all spectacular.
However, I took the opportunity to support the outer end of the sleeve gear in a bearing as I believe the factory racing Commandos did. It only needed a few thou of hard chrome and a precision grind to fit into a half inch wide ball race which in turn lives in the 1/2" engine plate.
You can see in one of the pics above that I used a Vincent slipper chain tensioner.
I dont go with the folklore regarding the "heavy Commando clutch" I dont see why the weight of the clutch would have any influence at all. It is simply the force generated by the power of the engine which pulls on the wee spindly shaft.
There are other separate g/boxes which are up to it. Roy Robertson's race bike runs a box which looks like a Triumph and that motor makes plenty grunt. I recall him telling me it has 5 speeds.