I recently had the rear brake lock on solid whilst riding. Fortunately I was poodling in town (on my way to hosptial as it happened) and noticed things were far from well whilst slowing for a set of lights before the rear locked solid and stranded me in the middle of the high street (until the rear brake cooled). I had adjusted the rear brake to counter the soggy performance and excessive length of travel which is a feature of the Multistrada - I subsequently discovered. I have owned bikes for 35 years and use the rear brake from my two stroke days (remember them?) so I have successfully adjusted the rear brake a few times over the years, obviously leaving some free travel before finding the bite point that felt right. Whilst at the side of the road absorbing the love of the passing motorists I rang the dealer who was not phased and normally associated this with incorrect adjustment or aftermarket levers since the same can occur on the front. I think the root cause rests in how hot the fluid gets at the back due to the proximity to the exhaust and leaving more travel than on other bikes is crucial. He referred to reference marks but I could not see any and there is no set up guidance in the handbook whatsoever. Does anyone have any detail on the correct set up or rather what we can get away with? This time round I was lucky. Nine times out of ten I would be heading for a dual carriage way and would have certainly had a career ending high side.
Rarely use it, usually at junctions to hold the bike still or healed over too gain a little control. You acknowledge this was self-inflicted & I agree the proximity of the reservoir & exhaust is a tad silly. Or at least have a heat shield ducati!!
Ha Ha.....done that twice now, last time stranded me on a roundabout in the middle lane, could not move my multi. It does state the adjustment in the handbook though
If you had a lockup I suspect you had adjusted your MC piston to the wrong position. There is a port in there that releases fluid and if you adjust too deep that is obstructed. I will cause what you describe. I know of a fatality from someone doing the same thing on their front with the wrong length plunger an on aftermarket lever. From years of off road racing I know that when you overheat a brake system the fluid will boil and that results in no brake, not a lockup. Sounds like yours started to expand, had no where to go and caused the pistons to push out causing your lockup. Important to not block that internal port. Generally that pushrod should just barely engage the piston of the MC.
Should read : Beware rear brake lockup if you’ve fucked around with adjusting the free play and don’t know WTF you’re doing
You are right with the handbook but I think it is a bit light on detail given the potential result. I had left more than the minimum travel quoted. Perhaps recommending the procedure is carried out when the cat is hot might negate some of the effects of expansion?
Take a thin nose pair of pliers and a 10mm spanner and find a long straight road, this is the best way to achieve adjustment, that's what I did.
Thanks I was not aware of the port you mention - what is its function? I thought I had been generous with travel post the pedal stop position but the result suggests otherwise.
Thanks - I will make sure adjustment is made when the cat is hot also. Additionally I will use verniers to see if I can take some measurements for reference.
The port is the usual inlet hole in the master cylinder. When the plunger/piston is fully out (i.e. not applied) the inlet hole is uncovered to allow fluid into the master cylinder / air out (or at least it would allow air out if the master cylinder was the other way up !). Once you start to apply pressure it gets covered over as the fluid is compressed and forced out of the outlet. If you adjust the slack out and it has compressed the piston a bit, that results in what you experienced. I did this too on my 2010 multi. The solution is to bleed the brake properly, then it doesn't have so much soggy compression to start with. There was also a guy making heat shields to go behind the master cylinder. Not sure it made much difference (still got mine fitted) but worth a search for if you think this is affecting it. Oh, and get a cat bypass pipe, that removes a major heat source. (nice excuse to need a full system )
Not sure if this applies to the 1200 or not BUT on the 1260 there are two adjustments for the rear brake pedal. The stop screw that also activates the brake light switch and also the pushrod on the slave cylinder can be adjusted as well. This allows you to get the pedal further down if needed and is in the 1260 manual.
I can only surmise that I didn’t adjust the pushrod sufficiently relative to the pedal position despite the travel feeling ok when cold. Heat is significant looking at the threads above
Posting a picture for those who don,t know how a master cylinder works. See the pointer to (bypass port). If you adjust your pedal or brake lever too much you will push the piston too far. This will cover the return hole stopping fluid returning to master cylinder when it expands due to heat. Hope this helps. I know many of you already know this. But many do not.
