djnotts wrote:Brucey wrote:djnotts wrote:.... I very much like my xtr hubs!
unless they have disc mounts on them you shouldn't be thinking about other brakes, should you...?
BTW a 90mm brake would definitely be 'too much brake' for that frame. A 70mm front brake, if set up/bedded in correctly, is likely to give you more than enough stopping power for normal use.
cheers
The current xtrs don't, but if I went disc could get suitable hubs of nearly equal quality. And drums surely a weight penalty which is the last thing I need as I enter what will almost certainly be my last year pre-electric.
Well IMHO there are two assumptions at work there; bearings and weight.
1) bearing quality; the SA brake hubs are of almost unequalled bearing smoothness and have been used in numerous HPVs to break speed record; so if you think bearing drag is going to be higher in the SA hubs, you've got it the wrong way round.
2) weight; by the time you have beefed up a steel fork to cope with disc brake loads it is invariably considerably heavier. Disc brake hardware (which is any good) is also not lightweight. The net result of this is that if you have a choice between a frame with a 1" steerer originally designed for rim brakes, but fitted with 70mm drums, and a steel frameset with a 1-1/8" fork meant for disc brakes, with disc brakes fitted to the bike, there's sod all in it. In fact the bike with drums might often be a bit lighter. Both will be appreciably heavier than rim brakes on that bike.
IMHO if you are worried about weight, the last thing you should be thinking of is converting that frame to disc brakes, and the automatic assumption that drums would be heavier is just that, an assumption. I actually bothered doing the sums and it didn't come out as I expected, even though there is clearly little attempt made to make the SA drum brakes super lightweight or anything.
cheers
hasn't the bike in the OP got V brakes?
