cueball's brake thread!

[anonymous-user]

[redacted]

[Big Al.]

Can't see any reports that have come in, or any evidence that it's been removed!

[mikedxb]

I saw it!

[Big Al.]

anonymous said:

[redacted]

Just for clarification when you say cueball's thread is that member "the cueball" if it is I can't see that he has a thread running called that.

[the cueball]

Sorry, you’re not going mad, I deleted it in case of the small chance of the wrong person seeing it.

Potential warranty claim

What was your reply? Lol

Ever had that happen to you?

[the cueball]

Cheers... it’s a really odd situation.

I’m happy the brake system was put together correctly, the only thing that wasn’t done was putting the pads in the calipers as they came supplied with them already in place from a large Italian manufacturer with red boxes.. so I expected them to be ok, and I have verified that they are correct and original (well real)

I also checked for warm discs, and had nothing... even coming off the Autobhan at 100+ I was able to stop within the slip road without actually using the brake... and the discs were not hot! I could touch them with my bare hand. It doesn’t make any sense to me, I would expect them to be red hot.

You can push the bike around and nothing seems out of place... they are 100% binding on though but only when the air temperature seems to be warm.

I have another bike to clean the calipers on tomorrow (my daily commute bike) so I’ll just pull these off as well and give them a check/clean etc. and go from there.

Quite frustrating though.

As for not riding it, I had to ride it 1000 miles home! Lol

I strangely don’t feel nervous that they’ll lock on me. I probably should.. in fact I know I should... I’m just not feeling that - as I say... weird.

Edited by the cueball on Saturday 19th September 19:39

Edited by the cueball on Saturday 19th September 19:40

[Tom Logan]

You seem to have investigated and dicounted a brake issue.

In which case I would be suspecting a potential gearbox problem. Is the back of the crankcase grtting hot?

[Steve Bass]

the cueball said:

Cheers... it’s a really odd situation.

I’m happy the brake system was put together correctly, the only thing that wasn’t done was putting the pads in the calipers as they came supplied with them already in place from a large Italian manufacturer with red boxes.. so I expected them to be ok, and I have verified that they are correct and original (well real)

I also checked for warm discs, and had nothing... even coming off the Autobhan at 100+ I was able to stop within the slip road without actually using the brake... and the discs were not hot! I could touch them with my bare hand. It doesn’t make any sense to me, I would expect them to be red hot.

You can push the bike around and nothing seems out of place... they are 100% binding on though but only when the air temperature seems to be warm.

I have another bike to clean the calipers on tomorrow (my daily commute bike) so I’ll just pull these off as well and give them a check/clean etc. and go from there.

Quite frustrating though.

As for not riding it, I had to ride it 1000 miles home! Lol

I strangely don’t feel nervous that they’ll lock on me. I probably should.. in fact I know I should... I’m just not feeling that - as I say... weird.

Is it posible you're misdiagnosing the issue?

You sday you can push the bike about and nothing feels out of place and when coming to a stop from 100+ without using the lever, the discs don't feel hot.

I'd say you have a dragging brake but not binding. A friend had exactly this on his old Fireblade. When you span the wheel, it wouldn't complete a full rotation but out on the track, they never overheated or gave any indication of poor functionality or misoperation.
You might find as the pads wear, the component tolerances will open up a little and ease the issue. But, if you're not experiencing excessive heating of the discs in normal use, you don't have a problem.

However, one other thing to try is to reset the front wheel tightening. if the wheel was incorrectly mounted the forks might be turned in, closing the caliper to disc dimentions.

Undo the wheel nut, undo the wheel nut side axle pinch bolts, pump the front suspension a dozen times, tighten the pinch bolts back up then the axle nut. DO NOT over tighten the axle nut as this pulls the foks back in again. The pinch bolts are your main bolts to hold the axle, NOT the axle nut.

[Jazoli]

It would, the discs would be red hot, if the discs are not getting warm then it simply isn't a brake problem, its not possible to stop the bike without generating heat, so it must be something else, I'd be very wary about riding it anywhere until the issue has been found.

[Steve Bass]

anonymous said:

[redacted]

Funnily enough, not always.

Yes, braking creates heat but it's possible to have the pads drag sufficiently that they'll prevent the wheel making a full rotation when spun but don't have enough friction to actually heat the pad & disc beyond what the ambient air can dissipate.
As said, we had exactly this on a friends CBR when he fitted brembo T drive rotors and brembo calipers and it wasn't a problem. We did find that he was incorrectly tightening the front wheel which exacerbated the issue.

[the cueball]

Yeah anything is possible I guess, sounds about right too, there is enough drag to stop the wheel rotating, but maybe not enough to ‘bind’ it.

The front wheel/fork/caliper alignment was all done as per the service manual, but basically what’s described above.

I’ve removed the new calipers anyway, after giving them a good clean which didn’t improve the situation, in preparation for sending them back and put the old ones back on.

Had a test ride and there isn’t any issue when I come off the throttle, so I’m happy the bike is OK and the issue isn’t the gearbox/transmission or anything else but the new calipers.

Cheers all for your thoughts and help.

[Steve Bass]

the cueball said:

Yeah anything is possible I guess, sounds about right too, there is enough drag to stop the wheel rotating, but maybe not enough to ‘bind’ it.

The front wheel/fork/caliper alignment was all done as per the service manual, but basically what’s described above.

I’ve removed the new calipers anyway, after giving them a good clean which didn’t improve the situation, in preparation for sending them back and put the old ones back on.

Had a test ride and there isn’t any issue when I come off the throttle, so I’m happy the bike is OK and the issue isn’t the gearbox/transmission or anything else but the new calipers.

Cheers all for your thoughts and help.

Have you checked the calipers dimensions and mountings? If the 'bind' disapperars when you fit the original calipers, there's definately a minor dimensional variance at play with the aftermarket calipers..

[the cueball]

Steve Bass said:

Have you checked the calipers dimensions and mountings? If the 'bind' disapperars when you fit the original calipers, there's definately a minor dimensional variance at play with the aftermarket calipers..

Not yet, but I’ll have a look when I’ve spoke to the supplier to see where we go from here.

The kit has a bracket which goes into the original caliper mounts, which then attach to the new calipers, so it’s a potential issue.

I have previously used the supplier for a ‘big brake’ upgrade on another bike, so know they are a decent company, so I’m hoping it’ll get sorted out OK.

[Steve Bass]

the cueball said:

Not yet, but I’ll have a look when I’ve spoke to the supplier to see where we go from here.

The kit has a bracket which goes into the original caliper mounts, which then attach to the new calipers, so it’s a potential issue.

I have previously used the supplier for a ‘big brake’ upgrade on another bike, so know they are a decent company, so I’m hoping it’ll get sorted out OK.

So the calipers bolt to a bracket that bolts to the fork feet? Is this an axial to radial change as well??

!0/1 there's a minor dimensional discrepancy in the adapter or it's for a diffeent bike ........

[the cueball]

Steve Bass said:

So the calipers bolt to a bracket that bolts to the fork feet? Is this an axial to radial change as well??

!0/1 there's a minor dimensional discrepancy in the adapter or it's for a diffeent bike ........

Yes, but not a change to radial ones, just a reposition of the calipers.

So think 6 pot Tokikos over to 4 pot P4 Brembos...

Already asked if the kit was correct as well, great minds and all that! Lol

The issue I have with your idea, and I have thought about it too, was everything was OK in the U.K. and when they were put on/checked/ran in.

The issues I have only came to light when the ambient temperature went up when I rode into 30 degree heat and it got slightly better again when I returned to the U.K. and cooler temps.

[Tango13]

Steve Bass said:

So the calipers bolt to a bracket that bolts to the fork feet? Is this an axial to radial change as well??

!0/1 there's a minor dimensional discrepancy in the adapter or it's for a diffeent bike ........

When I fitted a Lockheed big brake kit to my M5 the kit contained a couple if sachets of copper shim washers of various thicknesses to get the caliper spaced evenly over the disc and the maximum run out allowed on the 14" disc was 0.001" or 0.025mm (depending on which century you were born in...)

[Steve Bass]

the cueball said:

Steve Bass said:

So the calipers bolt to a bracket that bolts to the fork feet? Is this an axial to radial change as well??

!0/1 there's a minor dimensional discrepancy in the adapter or it's for a diffeent bike ........

Yes, but not a change to radial ones, just a reposition of the calipers.

So think 6 pot Tokikos over to 4 pot P4 Brembos...

Already asked if the kit was correct as well, great minds and all that! Lol

The issue I have with your idea, and I have thought about it too, was everything was OK in the U.K. and when they were put on/checked/ran in.

The issues I have only came to light when the ambient temperature went up when I rode into 30 degree heat and it got slightly better again when I returned to the U.K. and cooler temps.

Another thing to consider then, especially if they were ok and then not, you might have a sticking piston that's causing the drag.The increased temps is a red herring, brakes see hundreds of degrees with no problem.

I'd bet a piston is sticking causing the drag. It'll be one piston in one caliper and not enought to superheat the pad/disc but dragging all the same

[the cueball]

Steve Bass said:

Another thing to consider then, especially if they were ok and then not, you might have a sticking piston that's causing the drag.The increased temps is a red herring, brakes see hundreds of degrees with no problem.

I'd bet a piston is sticking causing the drag. It'll be one piston in one caliper and not enought to superheat the pad/disc but dragging all the same

I’ll bet it’s the lower inside piston on the left caliper (as you sit on the bike) that’s stuck and causing the issues

Cheers for the help

[Steve Bass]

the cueball said:

I’ll bet it’s the lower inside piston on the left caliper (as you sit on the bike) that’s stuck and causing the issues

Cheers for the help

Clearly you know something I don't

Good luck, I think you'll find this an easyfix

[carinaman]

Reminded me of that:

https://www.790dukeforum.com/threads/front-brakes-...