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braking shudder normal?

4K views 23 replies 10 participants last post by  Juan 
G
#1 ·
So occasionally, under moderately hard braking, just before the bike stops, the front end will shudder. Sometimes hard enough to make the bars vibrate up and down a hole inch. It only happens right before I stop, like the last 4-6 feet or so before the stop. Doesn't happen every time, but fairly consistantly, if you brake hard all the way to a stop.
I checked the disks, by spinning on a front stand and examining the rotors by eye, and with a straigt edge achhross sections of the rotor. Looks flat to me. (Couldn't find a way to mount my dial caliper, or I would have properly measured the runout.) But it would seem strange for this to be a wapage thing, as I don't feel any pulsing, and this only happens sometimes.
So I called the dealer, who proclaimed this shudder is common on the monster. (He called it chatter, but I tend to use that term for tire/road effects, so I am saying shudder, FWIW). He said sometimes new pads and cleaning the retaining pins helps.
Any comments? Is this a well known monster issue? If so, I just won't brake anymore.... ;-)

My plan is to clean the front rotors, throw in a new set of SBS pads, and to make sure the front end is all alligned (the 'loosen the tripple clamp and axle and bounce it out" method) and double check the streering head bearings.
But again, is this a known issue?
C
 
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G
#2 ·
experienced the same condition with my s4. i'd go ahead and work through the steps you're already considering just for verification, but it may in fact be slightly warped rotors, in which case, it's warranty time ;)
 
#3 ·
I've read that this is a problem for the new Multistrada, but I don't remember hearing about it on the Monsters, and I've been following the Monster List for quite a few years now.

The one problem the standard forks does have is that the rebound damping is too strong relative to the compression damping and spring rate, so on bumps the forks will compress down and can bottom out. My forks are currently at Aftershocks in Palo Alto getting revalved so that this isn't a problem. You might want to look into stiffer springs or more preload to reduce the problem.
 
G
#4 ·
Is this the same Mr. Nelson I remember from a hundred years ago who used to ride a... Hmmm I'm thinking an 851?

Good advice on the preload etc, I'll put a zip tie on there and see whats up.

Carl
(slowduck with new M900S)
(Still has his 92 750SS and 66 Mach 1 ;-)

Any other shudderers out there?
 
#5 ·
Is this the same Mr. Nelson I remember from a hundred years ago who used to ride a... Hmmm I'm thinking an 851?
Nope, I've never owned an 851, but I hope to get an 888 someday.

As for putting a ziptie on your fork leg, all that will do is indicate that the fork bottoms about an inch from where it looks like it ought to be able to compress to. They're good for setting sag, but it's hard to determine from them if you've really bottomed the fork or not.
 
G
#6 ·
Actually, I can bottom the forks once, note the location, and then see if it shudders without bottoming. Should be fairly straight forward. Just a half dozen runs up and down the street. ;-).

C
 
#8 ·
I experience the exact same thing every now and then - in the final few feet of a hard stop. I have also felt a sort of clunking shudder in the rear. It was a very strange sensation - it almost felt as if the rear caliper was moving or the chain was doing something funny. I have felt a similar rear effect on downhill mountain bikes (also with disc brakes) under heavy rear braking, where the braking forces would cause the rear suspension to "hop". It's a rather unsettling feeling and I'd like to know if there is a way to eliminate it.
 
G
#10 ·
WPF- Great article that you linked: thanks!

And it seems I'm not the only one out there with this... so I will consider it a 'normal' bug, but will still try and fix it ;-)
I'll report back on my success or failure...
 
G
#14 ·
I experience the exact same thing on mine. I had the dealer check and the rotors were well within normal tolerances. He told me not to worry about it for now, but if gets worse and becomes a problem to try the steps you have already mentioned.
 
#15 ·
Slowduck, what year and mileage on your M900?

I haven't experienced a front brake shudder...yet(?).

Particularly distressing dealer responses; " So I called the dealer, who proclaimed this shudder is common on the monster." and "He told me not to worry about it for now, ....". Dumb@$$es (dealers, not you guys), leaking batteries on S4's are common too, that doesn't make it right or OK or not worth worrying about.:mad:

Slowduck, If you can stand it, change just one thing at a time to find out what eliminates it. It's really tough to do when your bike isn't working right and you want to fix it, but it's informative. Try doing the free stuff first, like checking the steering head bearings and making sure the fork assembly is happily in line.

As far as the rear is concerned, the behavior that iamic referred to..
Since I have what is now a reasonably effective rear brake, I have experienced occasional rear wheel hop under trail braking in a corner. As in, "F@<K this corner is tighter than it looked, gotta scrub off some speed!". Really not fun, as I've got to let off the rear brake to let the suspension settle down while squeezing more front brake and using up pavement that I'd rather not.

I've seen some early Monsters with a full floating caliper bracket, with the tension rod hooked to the bottom of the crankcase. It's a technically superior arrangement compared to attaching it to the swingarm, but more complicated. I had considered doing it just because it's The Right Thing. More serious about it now since I've got enough rear brake to actually slow the bike down a little.
 
G
#16 ·
The rotors are only 100 miles old, the previous owner had them replaced, thinking this might be the issue, under warrantee. Since then, a year ago, he only rode 100 miles. Total mileage, 2800. It's a 'like new' bike.
Had a fun night in the garage! I fit brand new SBS street pads, cleaned the rotors (nothing violent, just a good wipe down with alcohol.) You can still see the honing scratches on the disc, so I didn't want to go whacko cleaning with scotchbite or anything like that.
I also double checked the preload, compression and rebound dampening: all at factory settings. (I will eventually set the sag for me, but need a helper for that).
Then I did the bounce out routine, aligning the front fork. Torques everything back to spec.
So tomorrow I bed in the pads. 10 hard stops from about 60mph. Let the brakes cool completely. 10 more hard stops. Let cool again.
And then we will see how it is... ;-)

On those who commented about not accepting any strange behavior like shuddering... I understand where your comments are coming from. But I am a long time Ducati owner. This is my 4th. Actually, I sold my 996S last week, more than paying for this one. And there is a Mach 1 and a 750SS in my gargage still. With Ducati, the reality is that you aren't buying an 'appliance'. It's a lower volume product made in Italy. Sometimes products escape the factory with known issues, that are never completely resolved, any you must live with it. Thats why I surveyed this excellent forum about this issue! And interestingly, it appears a good sampling of people see the same thing. If you don't have it, good for you! And I will give a solid try at fixing mine. But, from experience, I don't expect a Ducati to be an appliance, and sometimes a little stangeness just comes allong with Ducati ownership. FWIW, my advice is to learn to accept it as something that comes allong with the package. Otherwise, rocker flaking, cracked frames, loose swingarm pivots, burned out regulators will make you nuts, and drive you back to a h*nda!
C
 
#17 ·
I experience something similar very rarely. One very noticeable aspect is the slapping noise it makes and a kind of rapid bumping along. To me, all of the instances involved coming to a full stop, and fairly suddenly but from average speed. I also suspect some road roughness is involved. It almost feels like a locked wheel hovering over a series of bumps with not enough grip for a stoppie. This leads me to think that it's about cold brakes, and the slaps coming from the forks bottoming out over successive bumps.
 
#18 ·
To continue on my post about cold brakes. My father, who has built many custom race bikes for forty years, a machinist and has worked as a certified mechanic for many different motorcycle manufactures, concluded that with the large diameter dual rotor brakes on modern bikes, initial warm-up is a problem and can cause chatter when cold and hardly used riding in town.

If everything is within spec and you haven't glazed the pads too bad, I would try riding/dragging the pads during initial take off to heat them up, then bed them in with a good hard thrashing in the twisties.

My $.02

*BTW, I'm just explaining what cured my braking problems on my scooter that had 265 demo miles on it when I bought it.
 
#19 ·
Howie is correct. Brake shudder is not normal. I had my 6000 service done over the w-end. The mechanic that took care of my bike went for a test drieve and came back to tell me about the brake shudder. I told him tha I had reported that before, ever since it was new, and was told that it will go away when I replace the pads. Well he did not think that that was wright so he took the bike back in and check the rotors, only to find that the left rotor was slightly bent. My dealer will check with DUCATI to see if this can be cover by the guaranty, (I Hope they do) any way the left rotor needs to be replace. It is a safty issue.
 
#20 ·
What dealer did you take yours to Juan? I'm taking mine to Munroe for the 6k tomorrow and I'd like to ask them about it. If you were also at Munroe, they may notice a pattern and be more willing to take some time to look into it.
 
G
#21 ·
Hey, if your rotor is warped or coned, it should definitely be replaced! Warped rotors are unacceptable. Just be aware that there are other possible causes for shudder. And typically, warpage can be felt as a pulsation in the lever, as opposed to a front end vibration. The article posted by WPF is excellent on this issue.
http://www.stoptech.com/whitepapers/warped_rotors_myth.htm
Frankly, given my recent experience with dealers... I'd go to the shop, and watch him measure the runout on the disc. If I had the tools I would have done this myself. Would be an interesting learning experience, regardless!
But it sounds like lots of peole have this shudder... And I bet we don't all have warped discs.
I also wouldn't wait for new pads if you think thats it. They are cheap and only take about 10 minutes to install. It's cleaning the disc that's hard.
Please let us know how your disc measure up!
C
 
#22 ·
I noticed the same thing with my Monster (M750d, 2001). The brakes do not shudder at high speeds but do sometimes just before coming to a stop. The patern I have noticed is that the brakes are worse when the bike is dirty. After I wash the bike the problem goes away. So my conclusion is that it is dirt (dust maybe) on the rotors that is causing the problem. I now keep the rotors clean and have not had a problem since. The dealer could never find the problem, but oddly enough it was always gone when I picked it up (they cleaned the bike!).

So before you try anymore work on the issue, see if a good wash of the rotor will solve the problem.

jl
 
#23 ·
As pointed out in the original post, another thing that will cause the bike to shudder as it comes to a stop is the triple clamps being loose in the head tube or the bearings being bad.

Typically you can check/feel this by sitting on the bike, holding the front brake on and rocking the bike back and forth. If it's loose, you should feel the bars move slightly in your hands.

You might try loosening all of the upper tripleclamp bolts, including the pinch bolt that clamps the upper to the stem, and re-torqueing the stem bolt just for good measure.

HTH,
--Fillmore
 
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