Rs Brake Failure

Yikes, Mark! Glad you’re no worse for the wear. But it must’ve been a puckering situation. Please keep us posted on what you find out. I ride a 2019 Speed Triple RS and just had my front brake pad recall done about three weeks ago. So far so good but your experience makes me a bit nervous.

 

Sounds like your getting air into the brake system

 

That's scary. Has the fluid level gone down?

 

Definitely would like to know what happened to cause that
With no lose of fluid or visible damage it is concerning this has happened, as mentioned, air in the system is the most likely cause but how!

I have a 2010 speed triple pre ABS and I wonder if during the service on yours if something wasn't tightened up properly or a banjo washer was missed, a pad put in wrong or the oil/dust seal was missing or damaged

So glad it didn't happen at a more critical time when riding and you are safe

 

Maybe brakes stuck on and boiled the fluid. Was the disc hot?

 

Well expect some flannel from whoever last worked on it........

 

Just in case this is of any help, my son had a Daytona 675R (with similar Brembos) and was pushed over (relatively gently) by a careless motorist who was turning right, but then went left instead.

The bike seemed OK but once on the road, it exhibited the same issue as yours.

The lever appeared to work as normal, but would suddenly squeeze all the way to the grip...then it would be OK again. The cause turned out to be a slightly warped disc.

I wondered whether any damage could have been inflicted without you knowing (theft attack or similar?) but I'd expect the symptoms would show immediately and not mid-ride.

Glad to hear you're safe and sound - and hope you find out what has caused it without a fight.

 

I’ve had exactly the same happen to me on a ZX6R many years ago. This was an 89 bike, so well before ABS.
This was a very slightly warped disc that was pushing the pistons back into the caliper while travelling, requiring several pumps before pad to disc engagement. Very unnerving at the time and like explained by the OP, nothing looks untoward on a roadside inspection.

 

this doesn’t sound like a warped disc - I’ve never had one but would expect an initial soft lever as pistons move but then full function but with pulsing through the lever as the warped disc causes the pistons to reciprocate their movement.
I suspect it’s no coincidence that you’ve just had it serviced - sounds like air in the system to me - not much else it could be . . Master cylinder activated by brake lever, pushes on fluid which actuates pistons which push on pads. If the brake lever moves in and brakes don’t work, either fluid is spurting out somewhere or air is being compressed - I can’t see any other possibilities but do keep us posted as I have a new 2920 RS still awaiting pad upgrade.
Anyone know what is supposed to be wrong with the pads??????

 

Agree. No observable fluid loss? Service cock up. Have you looked in reservoir? On the positive side, you'll have a remarkably shiny face after all the flannel you are going to get.

 

The timing is beyond suspicious.

 

Being a 2020 bike, it might not need the pad recall. It was found if the backing plates started to corrode, the pad material could come off.

 

There is also the very reasonable chance of crud in the brake lines. It doesn’t take much.

 

Well . . . only one that that could be and that IS a warped disc. I presume if you then pump the lever or maybe just release and reapply the brake, it's back working again??
It's strange that you don't feel it pulsing when you have the brakes applied but hey ho - there really isn't anything else that could be. Where's your centre stand when you need one!!!!?? It would be very useful to simply turn the wheel with the bike supported on a centre stand.
Thanks for posting this . . . I will make a mental note to release and reapply if ever this happens to me, I might otherwise have simply panicked . . . probably still might!!!!!