Front brake binding

[Andrew 789]

Hi all,

Has anybody had issues with the front brake binding?
The bike is a 2020 gsa with only 2000 miles.
Going to work this morning used the hill start control at traffic lights and it didnt seem to release correctly.
Bloody disc is a lovely blue colour now so probably boiled up the fluid as well GRRRRRR.
Shouldnt happen on a £20K bike

 

[knutk]

Hi all,

Has anybody had issues with the front brake binding?
The bike is a 2020 gsa with only 2000 miles.
Going to work this morning used the hill start control at traffic lights and it didnt seem to release correctly.
Bloody disc is a lovely blue colour now so probably boiled up the fluid as well GRRRRRR.
Shouldnt happen on a £20K bike

No it shouldn't.

But I don't think it relates to the HH function, as the HH activates the rear brake only, even if you may trigger it by using the handlebar brake lever.

 

[Santa-2512]

Hi all,

Has anybody had issues with the front brake binding?
The bike is a 2020 gsa with only 2000 miles.
Going to work this morning used the hill start control at traffic lights and it didnt seem to release correctly.
Bloody disc is a lovely blue colour now so probably boiled up the fluid as well GRRRRRR.
Shouldnt happen on a £20K bike

?? how did you know it didn't release correctly, and how far did you ride to blue the disc, ??

 

[Andrew 789]

?? how did you know it didn't release correctly, and how far did you ride to blue the disc, ??

Probably no more than half a mile to escape the heavy traffic.
Disc was smoking lovely by then and had to use a lot of throttle to keep moving.
Just checked the bike now that everything has cooled and brakes have released and wheel turns fine.
Maybe just a sticky piston that has released itself?
Didnt realise the hill start only activated on the rear disc.

 

[Alan R]

A few things spring to mind, I have witnessed a mates bike have the front brake lock on and be unaffected by anything he did with the brake lever. The bike eventually relented and returned to normal function and the wheel turned freely. We suspect that the cause was something to do with the abs unit holding pressure in some manner but never really got to the bottom of it as the condition never returned. His bike had both front discs heated up but not blued. Hence the reason we thought the problem was not to do with the callipers as it would be unlikely for both to independently seize and release simultaneously. You didn’t make it clear if both discs were affected. If only one side, then yes the problem may lie with that calliper or the hose supplying that calliper. Hoses can collapse internally. At 2000 miles, unless you’ve ridden it up and down Pendine Sands for those miles it seems unlikely that internal corrosion in the calliper is the cause. Again, at that mileage and age of bike - the dealer is your best bet for a resolution. There may be something recorded as a fault in the bike’s memory.
AlanR

 

[bosnjo]

If pads fail to retrieve just a bit and keep on dragging, again, just a bit, the temperature of the brake fluid will rise. If the temperature of the brake fluid rises enough, the fluid will expand inside the caliper and make pistons go out, bit by bit, that will increase the temperature even more and the fluid will expand even rurther. That circle would finish when brakes lock completely.
I'm speaking from my own experience. Many years ago I had a problem with just one of the pistons not returning freely. Front brake locked and hat to wait for one hour (in the summer) to cool the caliper down and retracted the pads back with screwdriver. The rest of the trip home was done using only rear brake. Caliper serviced and cleaned, problem solved.

 

[autogs]

on my first 600 mile service they casually mentioned they had sorted a binding front caliper

 

[Andrew 789]

If pads fail to retrieve just a bit and keep on dragging, again, just a bit, the temperature of the brake fluid will rise. If the temperature of the brake fluid rises enough, the fluid will expand inside the caliper and make pistons go out, bit by bit, that will increase the temperature even more and the fluid will expand even rurther. That circle would finish when brakes lock completely.
I'm speaking from my own experience. Many years ago I had a problem with just one of the pistons not returning freely. Front brake locked and hat to wait for one hour (in the summer) to cool the caliper down and retracted the pads back with screwdriver. The rest of the trip home was done using only rear brake. Caliper serviced and cleaned, problem solved.

I think this may have happened. The bike was filthy dirty so it is possible the pad was dragging a little and started to overheat.
Bike was fine this morning.
Will keep an eye on it and report to dealer after lockdown.