Bro....biult a couple of these trike thingy's, from experience DON'T use the front wheel as a drum, OR handbrake it, use discs all round, and brake the rear via a clutch slave cylinder "wired" in tandem with the rear brakes. use XS1100 front forks if not leading link, or square section tyre with AP racing front wheel (twin front disc and harley wide glide rim........)
beware of sprung weight of front as using auto box, assume its a 1.3??? and careful of exhaust, will need supertrapp or similar for noise regs now as trikes are subject to them...
Advice here if required.
Mike.
Sixstring,
Not sure if you agree, but I wouldn't advise using twin disc's on a metro engine trike, I had a metro engine trike few years ago, and I could lock up the front with a single disc set up, and you could make some lovely number 1's on the tarmac

.
Personally I would go single small disc, and think about putting a bias valve in the braking system on the front, that way, if you're out and about, and it rains, you can back off the front brake so it doesn't lock up, and when the roads dry off, resume the level you had it set up when you started out.
I would aim for roughly 70% to the rear, and 30% to the front on a metro trike, as like you said it's finding the right balance.
If you want, you can pm me, and along with others I'll try to help out where I can, if I can ?.
This was how my trike looked when I got it

And this was how I changed it

Also owned a very rare Moto Guzzi V1000 Convert custom trike, and that pulled like a train, wish I never got rid of it now !
