The International CBX Owners Association

My 1979 Z model has vibration under medium braking feels as though the rotors are bit out true and it actually looks that way as a can glimpse them while driving
can they be turned to true them?
Also are they stainless steel and I’ve been told it’s not easy to cut them is that true?
As far as performance of the system I clean discs with scotch bright pad and brake cleaner about every 300 miles or so and it helps braking performance but not a lot,I’ve tried various brake pads and fair braking only is it that single piston calipers of that era don’t have much power or feel
any way without changing master cylinder to get little more power
Advice please TIA

Guys with a little digging I see that True Disc are the ones to fix me up and spoke with them Thanks Nils but still would like opinions on how to get the best performance with stock brake system and again. TIA

Ummm, you’re welcome? But I’m not sure for what.

Artie, in my opinion those brakes just SUCK. And I just got to the end of a multi-week battle to get my latest set to fully bleed. All I can offer is that you should leave no stone unturned: Make sure the calipers and pistons are clean and working well, make sure the sliding pins on the calipers are spotlessly cleaned and lightly lubed with high temp brake grease, make sure the pads are spotlessly cleaned and flat, switch to steel brake lines, keep the fluid clean, and failing all that, consider swapping to a slightly smaller diameter master cylinder.

What Nils said!
You can try to find CB900F front hangers and go to the dual piston late model calipers, there are better aftermarket rotors out there but this can become a rabbit hole to dive into.

Thanx guys I’ll start with TrueDisc resurfacing and go from there all other brake components are rebuilt and working as they should per 1979 tech
Nils I’ve wrestled with brake bleeding so many times and always dreaded it on full system rebuilding until Dave McMunn clued us in with his method which makes it easy peasy my description of it is remove whole system and lay flat on the bench I put a handle bar or round stock in vise to hold Mc and put wrench of something between calipers to prevent pads coming out to far with everything spread out on the flat you can get it rock hard lever in no time then drape the whole mess back in place which is kind of a PIA but effective and Done!

Truedisk.net
Recently did 6 for me.
Sticky calipers can ruin rotors.

https://truedisk.net/

I don't want to throw cold water, BUT, in my experience, TruDisc merely (and to good result) resurfaces the rotors, the process does not do much to take out any warpage. At least it didn't on a set of Pro-Link rotors had done. I would love to have someone tell me I am totally wrong, but that was my experience. I would call them and specifically state your problem and whether they can address the warpage.

Dave

daves79x wrote: Tue May 13, 2025 8:27 am I don't want to throw cold water, BUT, in my experience, TruDisc merely (and to good result) resurfaces the rotors, the process does not do much to take out any warpage. At least it didn't on a set of Pro-Link rotors had done. I would love to have someone tell me I am totally wrong, but that was my experience. I would call them and specifically state your problem and whether they can address the warpage.

Dave

Tom at Truedisk (how he spells it) does all the work. He endeavors to remove the least amount of material.
I've seen his fixtures and every rotor that was returned to me is perfect. I can only guess that the wheel hub they attached to, on that particular bike had bad run-out.
Like anyone else, if you aren't happy with the outcome, I'm sure he'll make it right.