Yet Another Cycling Forum

General Category => Audax => Topic started by: aidan.f on 15 January, 2015, 07:43:07 pm

Title: [HAMR] Disc Brakes for Dummies
Post by: aidan.f on 15 January, 2015, 07:43:07 pm
Even the bike shop in MK with a  workstand and the proper disc trueing tool could not  get the front BB7 cable caliper to run quiet on the green bike with short lever travel.
Think it may just be new pads that need bedding in
Followed this http://howtosetuptheavidbb7.weebly.com/how-to-set-up-the-avid-bb7.html (http://howtosetuptheavidbb7.weebly.com/how-to-set-up-the-avid-bb7.html)
when I go back I had another go and got it a bit better. Hope  Steve approves.
Title: Re: Disc Brakes for Dummies
Post by: LEE on 15 January, 2015, 07:57:56 pm
I had to straighten the rotor on my BB7 setup.

The gaps are very tight so even a slight warp causes pad rub.

Easy enough to do, just line the jaws of a big Monkey wrench with insulation tape (to avoid scratching) and bend away.
Title: Re: Disc Brakes for Dummies
Post by: Deano on 15 January, 2015, 08:03:02 pm
It's the nature of disc brakes. They sometimes just make a noise.

Ask interzen for a more detailed rant about BB7s.
Title: Re: Disc Brakes for Dummies
Post by: mattc on 15 January, 2015, 08:03:17 pm
Is this on Steve's "No 1" bike? (damaged in his icey off?) So we assume he's been riding a spare today.


Or are you hoping he'll help YOU to fix YOUR commuter? ;)
Title: Re: Disc Brakes for Dummies
Post by: Kim on 15 January, 2015, 11:27:13 pm
It's the nature of disc brakes. They sometimes just make a noise.

First rule of discs:  Ignore any noises they make  a) on the workstand while the wheel turns freely  and  b) after braking in reverse (ie. holding a bike on an uphill slope)  - these noises don't count.  If it's making noise you can hear while riding along after a few hard stops, then you can start mucking about with the pads etc.  To do otherwise leads to insanity.

That said, rotors can go out of true if bashed or forced while re-fitting the wheel, especially low-end ones that are made of cheese.  Adjustable spanner sorts them out.
Title: Re: Disc Brakes for Dummies
Post by: Gus on 16 January, 2015, 12:11:25 am
easy adjustment of BB7 : http://youtu.be/NasGJFtgq0A?list=PLkbvI8p8EZ8eRiApXIXSe4UpH9QkdPCF8 (http://youtu.be/NasGJFtgq0A?list=PLkbvI8p8EZ8eRiApXIXSe4UpH9QkdPCF8)
Title: Re: Disc Brakes for Dummies
Post by: frankly frankie on 16 January, 2015, 11:49:09 am
It's the nature of disc brakes. They sometimes just make a noise.

'Self-adjusting' hydraulics always rub, but cable discs (BB7) shouldn't.  But if Steve wants a really short pull on his levers (OP) then in grotty weather like this there will be some noise, as moisture gets onto the rotor.  Likewise with such tight settings fork flex may have some effect - I know my rear BB7 rubs a bit when I stomp on the pedals, due to the rear triangle flexing - and I don't have it set as tight as Steve apparently wants his.
Title: Re: Disc Brakes for Dummies
Post by: vorsprung on 16 January, 2015, 07:50:33 pm
if I ride on clean roads with BB7 that are bedded in they are occasionally quiet.  The rest of the time there are random noises
Title: Re: Disc Brakes for Dummies
Post by: aidan.f on 16 January, 2015, 09:53:43 pm
Well that  is  encouraging, They  are always  noisy - My DB experience  is limited  to  Shimano Deore on tandems  two and  three wheel versions.
Steve has only ridden one bike,  so far with one chain & cassette  swap. I had  the  priviledge  od  a rest  ride on #2  only a bit  small for  me! but wheels  roll well
Title: Re: Disc Brakes for Dummies
Post by: jamesld8 on 19 January, 2015, 09:01:41 pm
if I ride on clean roads with BB7 that are bedded in they are occasionally quiet.  The rest of the time there are random noises

indeed---my normally quietish mid lever travel BB7 are currently horrid noisy day after due to general mess / rust / grime build up on rotors. After a few good stops they go quieter-ish as rubbish is scrubbed off. I imagine Steve`s bike will be doing same after 150-200 miles on salted roads daily.