Dave - I am looking at replacing the old brakes on the speedmachine myself. Currently tecktro discs and they seem to eat pads and become quite inneffective. Is it easy to replace with hydraulics - cable lengths an issue? and what would be a good set?
Mine came with Hope hydraulics from new as Darth Stuart built it up from a frame kit, but replacing mechanicals with hydraulics shouldn't be too difficult. IIRC when I replaced the ones on my SM last summer, I cut down the "rear" line to make a front and bought a couple of metres of hose to do the rear, as they come from The Shop set up for MTB use. Bleeding is not difficult - I've found Hopes to be easier to bleed than Maguras. Hope do a bleeding kit (called "My Little Bleeder"
) which attaches to the spare wheel of one's motorcar and does the job very quickly. However, they changed the design of the lever last year, which means that the old My Little Bleeder doesn't work with the new levers chiz, so you have to faff around with tubes and things.
IIRC mine has a 183 mm front rotor and 160 mm rear - they're both the spiffy saw disc floating rotor ones (with red centres to match the rear hub, coz I is a tart), M4 front caliper and Mini rear. Someone less portly than me could probably go down a rotor size and save a few bob and grammes by having a two-pot front caliper instead of a four.
The only other discs I've tried for more than a lap of Eastway have been Magura Julies (came as new on the Baron, not terribly impressive) and some awful Avid mechanical ones on Garrie Hill's Jester, which were marginally more effective than putting a foot on the floor, but not by much.