Discussion
Had a bit of a squeaky bum moment on wednesday.
Going round the M25/A20 roundabout and then heading up the sliproad to the M25, the front brake suddenly came on hard enough to stop the bike in the middle of the road (S1000RR). I had no time to get to the side of the road, and all concentration was on not binning the bike.
Was a bit embarrassing as I then couldn't move the bike to the side of the road. Blocked the slip road for the length of time it took to pivot the bike around its side stand and bump the locked front wheel across, which seemed like forever with cars accelerating up the sliproad not expecting me to be there!
I eventually managed to undo the front brake bleed nipple with the toolkit and with brake fluid everywhere and no working front brake it released and I was able to get home on the back brake only.
Sooo. took the front calipers apart yesterday and went through them with a fine tooth comb, finding no reason they would lock up. In fact the bike is working fine at the moment and the problem has obviously gone. Tomorrow I am going to take the piston on the handlebar apart to look for any seizing of that. But reliving the experience, this didn't happen while pulling the brake. So the question is for anyone who knows ABS systems on recent bikes better than me. Could the ABS unit be responsible?
Going round the M25/A20 roundabout and then heading up the sliproad to the M25, the front brake suddenly came on hard enough to stop the bike in the middle of the road (S1000RR). I had no time to get to the side of the road, and all concentration was on not binning the bike.
Was a bit embarrassing as I then couldn't move the bike to the side of the road. Blocked the slip road for the length of time it took to pivot the bike around its side stand and bump the locked front wheel across, which seemed like forever with cars accelerating up the sliproad not expecting me to be there!
I eventually managed to undo the front brake bleed nipple with the toolkit and with brake fluid everywhere and no working front brake it released and I was able to get home on the back brake only.
Sooo. took the front calipers apart yesterday and went through them with a fine tooth comb, finding no reason they would lock up. In fact the bike is working fine at the moment and the problem has obviously gone. Tomorrow I am going to take the piston on the handlebar apart to look for any seizing of that. But reliving the experience, this didn't happen while pulling the brake. So the question is for anyone who knows ABS systems on recent bikes better than me. Could the ABS unit be responsible?
Trouble with it being the master cylinder is how it comes on when you aren't pulling the brake.
How does an ABS unit in a motorcycle work?
Obviously there has to be a set of solenoids, and there has to be a motor to create pressure. Is it possible that pressure is being shown to the system when it shouldn't or am I not understanding how they work.
How does an ABS unit in a motorcycle work?
Obviously there has to be a set of solenoids, and there has to be a motor to create pressure. Is it possible that pressure is being shown to the system when it shouldn't or am I not understanding how they work.
I’ve had it happen with a bike that has crap aftermarket levers fitted, that I borrowed. It applied the brakes gently, not enough to cause noticeable friction and then after a spirited ride, I had just pulled in when the front locked up.
After it all cooled down, it was fine.
Put the standard levels back on and all is good.
After it all cooled down, it was fine.
Put the standard levels back on and all is good.
CousinDupree said:
Krikkit said:
underwhelmist said:
I think the toxic nerve has nailed it.
Yeah I reckon so as well. Not had it on a bike, but did on a car with a sticky caliper.Biker's Nemesis said:
CousinDupree said:
Krikkit said:
underwhelmist said:
I think the toxic nerve has nailed it.
Yeah I reckon so as well. Not had it on a bike, but did on a car with a sticky caliper.Biker's Nemesis said:
That video you posted made me jump when I saw it, dunno if you still have it.
I remember that one...https://youtu.be/dQw4w9WgXcQ
clen666 said:
Biker's Nemesis said:
That video you posted made me jump when I saw it, dunno if you still have it.
I remember that one...https://youtu.be/dQw4w9WgXcQ

the actual vid

https://www.youtube.com/watch?v=Fl6V09J3Qxg
I’m another aftermarket lever victim.
I bought a daytona with some crap Chinese levers fitted, was out one day giving in some beans when all of a sudden the bike slowed down at a rate similar to what you’d use pulling up to a junction. As you found out it’s bloody hard to move a bike with a locked front wheel!
Turned out the lever constantly had a slight amount of pressure on the MC which added to some heavy braking caused the issue. Stock levers for me these days. Or at least well regarded brands.
I bought a daytona with some crap Chinese levers fitted, was out one day giving in some beans when all of a sudden the bike slowed down at a rate similar to what you’d use pulling up to a junction. As you found out it’s bloody hard to move a bike with a locked front wheel!
Turned out the lever constantly had a slight amount of pressure on the MC which added to some heavy braking caused the issue. Stock levers for me these days. Or at least well regarded brands.
clen666 said:
Biker's Nemesis said:
That video you posted made me jump when I saw it, dunno if you still have it.
I remember that one...https://youtu.be/dQw4w9WgXcQ
anonymous said:
[redacted]
Jazoli said:
Wow. I thought it was going to be the guy in front doing something after he nearly ran off the track at the corner before. Thanks for all the suggestions. No aftermarket stuff on the bike, its completely original Nissin kit on a 2010. As I said before front calipers no trace of problem. Took the master cylinder apart this morning.



I think I'm going to go for this as the problem. Just now wondering whether I have to take the whole ABS system apart to clear the crud out of everything or I can use some sort of flush. The crud you can see is rubbery with small grit like bits in. And although this obviously isn't good, I still cant get my head around why the brakes came on without touching them. Even if all the holes on the master cylinder were completely blocked. I think I'm not going to be happy until its ALL apart.
Anyone know where to get a master cylinder seal kit. Caliper kits are easy to find, but master cylinder not so much. Everywhere seems to have been COVID up.
I think I'm going to go for this as the problem. Just now wondering whether I have to take the whole ABS system apart to clear the crud out of everything or I can use some sort of flush. The crud you can see is rubbery with small grit like bits in. And although this obviously isn't good, I still cant get my head around why the brakes came on without touching them. Even if all the holes on the master cylinder were completely blocked. I think I'm not going to be happy until its ALL apart.
Anyone know where to get a master cylinder seal kit. Caliper kits are easy to find, but master cylinder not so much. Everywhere seems to have been COVID up.
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