Mechanical disc brake tuning

[deliberate]

I just purchased a used bike. I was told initially that both brakes were noisy, but the person I bought it from lubricated the back disc, and now that one does not make a noise when breaking.

That seemed like a bad idea to me. The back also does not function very well as a brake anymore, more as a limited decelerator.

The noise is a constant tone, it is loud, and it emanates from the pad/disc contact during braking.

Cause/solution?
Thank.

[uncle crud]

You need to go beat the shit out of the guy who "lubricated" the rear brake.

Your pads are likely contaminated with whatever Mr Genius used to "lubricate" the rear brake.

You're probably going to have to get new brake pads and also give your caliper and rotor a good cleaning with a good degreaser detergent like Dawn, or some isopropyl alcohol.

Mechanical disc brakes do not need lubrication.

[marshalolson]

seriously. homeboy is fucking retarded.

[chaka]

You need to go beat the shit out of the guy who "lubricated" the rear brake.

Your pads are likely contaminated with whatever Mr Genius used to "lubricate" the rear brake.

You're probably going to have to get new brake pads and also give your caliper and rotor a good cleaning with a good degreaser detergent like Dawn, or some isopropyl alcohol.

Mechanical disc brakes do not need lubrication.

I 2nd all of the Uncle's recommendations... especially the beating part. Once you've convinced yourself the caliper/pad/rotors are clean (probably with new pads) you might also want to replace the cable and housing while you are in there, just to get the system as dialed as possible. Judging by the advice he gave you he probably also dumped a bunch of wet lube down the cable housing and it may now be gunked up

Side note: on a whim, I picked up an Avid Full Metal Jacket housing kit on closeout and used it on my new SS project. I am pretty impressed with the added breaking power of my Avid BB7s a result of reducing loss through cable housing compression. the idea of the full metal jacket kit is to replace every straight run of housing with a stiff stainless tube. I now nervously await that bad crash where the tube gets bent at a 90 deg angle, but we'll see.

[kellen]

seriously. homeboy is fucking retarded.

Agreed.

1234

[RootSkier]

You mean I'm not supposed to spray Tri-Flo on my brakes? No wonder I Goseyed the fuck out of myself last night.

[chaka]

You mean I'm not supposed to spray Tri-Flo on my brakes? No wonder I Goseyed the fuck out of myself last night.

Not tri flo stupid. you have to lather them in Phil Wood bearing grease. that's the ticket

[stompie]

This might be a bit of a hijack but it's mechanical disc brake related.

My friend is having troubles with her avid (5, i think) mech. disc brakes. Every time she goes out she has to re-tighten the pad adjustment and during long rides it loosens off.

Has anyone else had this problem? Is there an easy fix? (other than new brakes?)

[El Chupacabra]

This might be a bit of a hijack but it's mechanical disc brake related.

My friend is having troubles with her avid (5, i think) mech. disc brakes. Every time she goes out she has to re-tighten the pad adjustment and during long rides it loosens off.

Has anyone else had this problem? Is there an easy fix? (other than new brakes?)

I have Avid BBDBs (same as BB7s, I think) on a bike. They do require tweaking of the dials for pad adjustment fairly frequently, but it's super easy to do. I just check them at the trailhead before starting a ride.

[stompie]

She's maybe getting 15 mins of ride time, before there is little brake left.

[El Chupacabra]

She's maybe getting 15 mins of ride time, before there is little brake left.

On mine, it's more like every other ride or 3, where I need to mess with the knobs.

Are her caliper mount bolts coming loose?

[stompie]

Are her caliper mount bolts coming loose?

That is probably the reason. Is that a replace of the caliper or a fix?

[El Chupacabra]

That is probably the reason. Is that a replace of the caliper or a fix?

Fix. The Avid caliper mount is really easy to work with. Basically 2 bolts per brake.

[stompie]

Fix. The Avid caliper mount is really easy to work with. Basically 2 bolts per brake.

Sweet! Thanks

[MikeD]

My Avid mechs had the same problem after about 6 months of use...the adjusters would back out during the course of any ride; they'd be useless halfway through if I was lucky. Then the knobs fell off...so I tossed them and got some real brakes.

Too bad, because they worked pretty well once you learned to tune the grabbiness out of them.

[801 jav]

I started to get pissed at the lack of stopping power and constant adjustment on my Avid mechs... but I was only running them with 160mm rotors... should have switched to 203mm front and 180mm rear?