The bobbins were pretty much seized. So the semi floating discs were fixed but not fully aligned. This gave a soft and vague feel to the lever and robbed power. The lever feel is now much more solid and perhaps it's an illusion but the brakes feel more powerful as well.
A buckled rim unless visibly out of true , wouldn't impact the brake test unless the disc mounting area was also out of true - which I'm sure you would notice brakes on or off Bearings would normally show signs of wear / noise and be picked up by the tester before the brake test They're cheap though so why not replace them , clean the bobbins and calipers again and see how you go with a re-test
Update: Got new bearings and replaced those. Getting the old ones out was a massive pain, ended up paying a garage £20 to do it for me as I was getting nowhere with a hammer and modded screwdriver. Cleaned the bobbins out again with the wheel off so that they all feel finger loose. Still the same problem. Wheel STILL makes kind of a funny uneven sound as it spins round with calipers detached, and the irregular on/off scrape noise with calipers attached. I did notice that the front axle was possibly not 100% straight. I rolled it on a glass table and noticed some light shining though at some locations...very small gaps (<1mm probably), but I'm wondering if that's the issue. Had to book the MOT re-test for tomorrow as that's the 10 day limit for the free re-test...figured I might as well try since it's free. I'll try find a machine shop in the area that can confirm the straightness of the axle and possibly straighten it...not sure if anyone around here has the capability to be that precise though...the bend, if there, is very minimal. The other thing I want to try is loosening the allen bolts on the bottom yoke to re-align the forks, but it looks like I need to remove a whole bunch of fairings before I can access that bolt, so that's a job for next week.
Possible! I'm thinking it could have also happened when: 1) A car came out a junction and wiped me out. Bike was a CAT D write off but I bought it back and fixed it up. Could have missed any damage to the front as it's so subtle. 2) When a car cut me off on a roundabout by moving from inside lane to outside with no warning/mirror check...I ran into a kerb at 20-30mph. I managed to not drop the bike, but it did leave a black rubber mark on the kerb where the bike tyre hit. Bike seemed fine at the time and I let the guy away with a telling off but no details. In hindsight I should have gotten details in case my bike was actually damaged, but too much adrenaline (and holding up rush hour traffic) made me not think right.
Have you checked the forks are straight - and level? See if one leg pokes out the top of the triple clamp (top yoke) more than the other. Clean the spindle with brake cleaner or acetone, then oil it with engine oil refit and test. Use grease for final fitting. Buy a new spindle/axle.
Might be worth making sure everything is lined up. Good video on you tube by Del boys garage. Might need forks out and checked over. Depending on milage may not hurt to get them serviced. Sent from my HTC One using Tapatalk
What deflection are they classing as a fail, are they using a roller brake tester?. We class over 25 KgF as a fail, if it's on the limit it's an advisory. If there's any damage to the rotor it only has to be minimal to throw the reading out. Maybe take the disks off and check the hub surface for corrosion?. Next step is take one front caliper off (put a flat spanner the width of the disk in to stop pads compressing) and do the brake test again to check one side/ reverse to check the other side. This will at least narrow it down to one disk hopefully to replace with genuine disk. You'd have to get the bike shop to do that for you though but would save you buying 2 new disks.
Thanks for all the input everyone! I got the free MOT re-test and it passed with no advisories! KeithMac - yes, it was a rolling brake tester. On the first test, the values were jumping from 1 to something high even with no brakes applied. To fix the issue I did the following: - Cleaned off the floating brake disc bobbins to ensure they had movement - Took off the calipers and cleaned out the pistons and brake pads - Replaced the wheel bearings - Took the front axle to a machine shop to check for straightness, turned out to be 1mm out, so they attempted to straighten it slightly on the lathe. - Ensured to 'bounce' the front suspension when refitting the front wheel to ensure proper alignment. The tester said there was actually still a very slight pulse, but not enough to be a concern. Regardless, next time I remove the fairings I will also loosen the bottom yoke to re-align the forks.
I think they all played a part. I started out by cleaning the floating bobbins, then I actually took it back to the rolling road just to test it - it had improved a little but not enough to pass. I then noticed the noise when the wheel was spun without calipers. Replacing the bearings improved it a little, but there was still a noise there. Straightening the axle helped reduce the noise further. I still think that my forks need to be re-aligned, or my rotors are slightly warped, but the issue is much better. New EBC rotors are £300 on eBay...might get some eventually if I run out of other things to spend money on.
Nice to see you've got it all sorted, bouncing to help settle it all out on the front was a good idea. Normally if it's badly out ot would cause the forks to stick.
