Originally Posted by
dabac
Oh, and a proper bedding-in.
I think "bedding in" is one of those things people tell you to do so that you'll go away and get used to poorly functioning disc brakes. I have never "bedded" a rotor or a pad. I just ride and use the brakes. Any "bedding" should occur through use.
Originally Posted by
User1
Hello all,
I'm not a noob to disc brakes. Granted I'm definitely not the ace-know-it-all either! I do have some experience with disc brakes and I've used them alot in my MTB riding. I figured in this day and age they would have progressed quite a bit since they've been out there forever, it seems. So anyways on my discs in question are on a CX/touring setup. The bike is only 2 years old and they have, what looks like are good quality brakes. They are the mechanical Hayes CX Expert brakes. I bought the bike and the guy advertised that he put 200 miles on the bike. Going to see it and it was VERY clean. He then said he probably put 50 miles on the bike. That seemed more accurate. I tested it and brakes were crappy. This was on bike that was way over $1k new. I got the bike home and cleaned up the surface of the discs with alcohol. This gave me some braking power back, but nowhere near what it should be. Going down a paved hill I think I should be able to apply good pressure and lock up the back brake, but nothing. The front it should be if I applied good pressure I should be in danger of flipping if I'm not careful, again not close. There was even evidence of the brake fading going down one hill!
So I know if I had bank, you end up pulling the brakes and putting the best brakes money can buy, but I don't have bank. Roughing up the discs might work, but does that mean maintenance work down the road? I do have bank for the best pads money buys, as long as they aren't diamond encrusted.
Any ideas? Thanks for reading this and I most welcome any and all replies.
How much lever travel is there before the brake pads contact the rotor? I've found that disc brakes are very sensitive to excess lever travel...much more then rim brakes are. If the lever is set up for the "usual" pad contact happening at half lever travel that some people use for rim brakes, disc brakes will perform very badly in my experience.
The levers need to be set so that the pads contact the rotor with minimal lever pull. Hayes says that there should be a 0.3mm (0.0118") gap between the pad and the rotor. That ain't much.