So my brakes got a bit rubbish and I'm trying to find the problem and fix them myself because I figure I need to learn this stuff... From what I can tell, both of my rotors need straightening slightly, as they both rub at a certain point. Can I use pliers for this or do I need a tool? Second thing is, where is the larger gap meant to be between the pads and the rotor, nearest the wheel or furthest away? Thirdly, how much give should there be on the caliper arm bit which holds the brake cable? Should that arm be moving fully up and down when I'm braking or just a tiny amount?
Adjusting bb7 disc brakes - help
- Thread starter sazzaa
- Start date
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Tried following this, I end up with both adjusters turned out quite a lot because if I turn them in more than a few clicks the rotor rubs. And if I press the brake lever now there's no tension in it at all.
Front brake seems to be the bigger problem, I can't seem to mess around with it all enough to have a light braking point in the lever, the lever is almost touching the drop bar to brake 
Will buy a truing tool I think. Although I'm wondering if it's worth taking it all apart to see if there's any muck in the pads or anything?
Will buy a truing tool I think. Although I'm wondering if it's worth taking it all apart to see if there's any muck in the pads or anything?
PaulSecteur
No longer a Specialized fanboy
- Location
- Walsall, West Mids.
You can straighten the with pliers but you can also get disc truing forks that seem to make it easier and more accurate.
Yeah! I reckon if my rotors are fixed with a tool then it should be all I need as I'll be able to tighten the adjuster bits properly. I hope it's as simple as that anyway. At least I know my way around the brakes now, been putting this off for about a month!
No, haven't done this. But I stuck some white paper on the floor below the bike and spun the wheel slowly so I could see where things were rubbing, and it looks like the rotor is just slightly out of shape.
Cubist
Still wavin'
- Location
- Ovver 'thill
Having watched the video, it seems that only the outboard pad actually moves when you activate the brake. When the pads wear you need to dial the wear out so that you get the optimum clearance. Once you've centred the caliper the inboard pad needs only to be dialled outwards enough to clear the rotor, and then only once you've dialled in the slack you want using the outboard adjuster.
I probably adjust them a few times a year as the pads wear.
A pair of pads last me about a years hard commuting.
Cubist
Still wavin'
- Location
- Ovver 'thill
All rotors have a small amount of run-out, you only need to worry if it is obviously warped, or you simply cannot get enough clearance through pad adjustment.
Ok, soooo, if I don't fix the rotor and leave it as is (adjustment dials clicked out a fair amount), how do I get my brake lever to have more tension? I've pulled the cable as much as I can through the caliper arm and the barrel adjuster, when adjusted fully, is still letting the brake lever hit my drop bar.
If the rotor isn't running out wildly,ie;no more than 2mm in total,setting up BB7's is a simple task.
First ensure the brake arm is back on it's stop by slacking off the pinch bolt.
a)slack off the two caliper mounting bolts slightly,so the caliper will wobble from side to side.
b)dial in the inner and outer adjusters so they grip the rotor,but with the rotor held in the middle of the slot it passes through in the caliper.
c)tighten up the caliper mounting bolts.
d)back off each adjuster one click at a time until the rotor isn't rubbing.
e)pulling on the loose end of the inner brake cable with pliers,tighten the pinch bolt but without pushing the arm off it's stop.
Now operate the brake at the lever a few times.dail in teach adjuster in turn one or two clicks,unitl the rotor starts to rub,then back off one.
The aim is to get rotor juusstt missing the pads,but you can back the pads off more if you feel there's not enough free play in the brake lever.
First ensure the brake arm is back on it's stop by slacking off the pinch bolt.
a)slack off the two caliper mounting bolts slightly,so the caliper will wobble from side to side.
b)dial in the inner and outer adjusters so they grip the rotor,but with the rotor held in the middle of the slot it passes through in the caliper.
c)tighten up the caliper mounting bolts.
d)back off each adjuster one click at a time until the rotor isn't rubbing.
e)pulling on the loose end of the inner brake cable with pliers,tighten the pinch bolt but without pushing the arm off it's stop.
Now operate the brake at the lever a few times.dail in teach adjuster in turn one or two clicks,unitl the rotor starts to rub,then back off one.
The aim is to get rotor juusstt missing the pads,but you can back the pads off more if you feel there's not enough free play in the brake lever.
Done all that.
Not sure what "without pushing the arm off it's stop" means?
Brake lever is just feeling too slack.
