Trying to get the rear bb7 working nicely on my Cotic X and beginning to pull what is left of my hair out.
I suspect contaminated pads and have ordered some new ones, but has anyone get any tips to getting these bloody things working nicely.
The front is set up perfectly, but I just can’t seem to get the rear working with the power and modulation it should have,
Any tips/hack/suggestions?

Ta

I found this incredibly useful

Link

Use good, low friction cables, pull them tight and take up any slack with the in-line adjusters. Set the pads as close as you can without rubbing. I think the instructions recommend setting the caliper slot with a 2:1 gap on each side of the disk.
I always found them a bit fiddly to set up, and you need to keep them adjusted regularly for best performance.

It’s really just the same as the mtb BB7s, but the problem you are having is probably too much flex in the brake levers IMO.

If a cable brake is properly made, problems with modulation etc are very rarely the brake’s fault, but lie with flex in the brake lever or compression of the cable outer (more obvious in long lengths), ie too much of your lever arc is being wasted in lever flex and compression of the cable outer.

It’s hard to improve road brake levers, they are built very lightly and don’t need to be any better than they are for their traditional job of operating a flexy calliper brake.

Thus the next option is reduce the amount of compression in the outer cable. I use a length of aluminium tubing (cheap from B&Q) to replace the static parts of the cable – ie the bits attached to the frame.

In this pic you can see how I have done it. The tubing is bent just using my thumbs to fit exactly. I used some small diameter teflon airline as a liner (available from any industrial hardware or air tools shop), and for the connection to ordinary cable I used a flexible V-Brake noodle.

I used this video

Plus one for that Volagi video above ^

Compressing the calipers a little and taking a bit of the ‘dead play’ out was the key for me.

Infact it was this Volagi vid Link at 4:05 in the vid.

Nice one epicyclo! As an aside, what seatpost is that?

Epicyclo that is, indeed, epic. Good work, I’ll be scouring the local hardware stores to try and replicate that.,,

I’ve got Shimano 517’s on my X with 5700 levers and Ashima Action cable.

What works for me is getting the non moving pad as close as possible first them playing with position of the moving pad. This gets me a nice braking action with plenty of bite and no possibility of pulling the lever to the bar. Not sure what adjustments BB7s have but assuming they’re similar.

Shimano CX77 here

I found getting the non-moving side up against the disc first, then winding it off very slightly, before setting up the moving one worked for me.

Very rarely have to adjust them, probably once a month or less. Sintered pads fitted.

Funnily enough I have much the same on my X. Having a split rear outer doesn’t help much.

What’s the problem that you’re trying to solve? Is the brake lever pulling all the way to the bar too easily? Or is it just that the brakes don’t seem powerful enough?

If it’s the latter, it may just need the pads bedding in properly, particularly if both pads and rotor are new. The difference between fresh-from-the-box and properly bedded in was absolutely huge on my bike.

If it’s the former, then check the setup: use the cable adjuster or set the cable length so that the arm on the caliper is *just* starting to move i.e. make sure that there is no slack in the cable. Then adjust both pads as close as possible to the disc without rubbing.

Thanks guys. Once the new pads arrive I’ll have another go.
New disks and pads should be a good base to start from.

I’ve had another go at it today. New pads made no difference so I turned my attention to the cable. Sure enough, there was corrosion near the top end and it was bloody stiff to get out. I’ve lubed and installed a new inner, which has improved things significantly, but I need to do the outer as well to resolve things completely. But that’ll involve retaping and if I’m going to do that, I may as well get the replacement bars that I’ve been considering 😛

Make sure any cut ends of outer are perfectly flat, makes a huge difference. I use gear inner in brake outer on my mtb cable brakes to reduce cable friction, gives a lighter action and I’ve never snapped one or pulled a nipple off

How did you manage to contaminate cable discs ?

How did you manage to contaminate cable discs ?

Well it appears I hadnt, but I suspected overzealous use of GT85

Plus one for that Volagi video above ^

Compressing the calipers a little and taking a bit of the ‘dead play’ out was the key for me.

Infact it was this Volagi vid Link at 4:05 in the vid.

Will watch that later, thanks.