Ducati Monster Forum

Just on my way back to work from lunch. I was approaching a green light and had the throttle on heavy because I knew it was going to flip yellow. Well, it flipped way to fast and I would have ran a red light so I had to brake hard. Applied both front and rear brake, although I grabbed quite a bit of front brake instead of progressively applying. Front wheel started to hop and chatter. I was too concerned about stopping to think of letting go of the front brake and re-applying, not sure if it would have helped but I think thats what I learned back in MSF lol. Anyone ever have this happen to you? Kind of rattled me, never had the bike act like that. Never went too hot into a red light before either  [roll]

What bike/suspension?

Over stiff rebound/compression settings can cause chatter and reduce brake effect.

I recently picked up a KTM - the recommended 'sport' settings for the suspension were WAY to harsh and translated into the front brake as or less effecive than the rear. Softening the settings has greatly improved the ride quality and brake effect.

BUT - before you go messing with settings (if you can) you need to understand the effects. So don't rush into twiddling knobs. Also, you may just have dealt with something totally unrelated to suspension. In that section of road right before a stop, the road has a lot more oil, grease crap on it - Take a good look at an older road and you'll see a dark section right before an intersection.

It's quite possible that you went from a section of higher traction, to lower and at that point your pressure on the brakes was more than the available traction, so you wheel was skipping and grabbing - like squeaking chalk on a chalk board.

And generally, unless there's some car/truck that I'm confident will end up, up my tail pipe I avoid blasting through yellows as intersections are always messy pavement.

If you have ABS brakes, you might have just experienced that. The other thing also is the road itself, if it even has the slightest imperfection (bump) it would cause the hop because you front suspension might already be at full compression.

I've got a 96 m900...so no adjustable susp. Probably was the road. Although the shocks were modified by the po. I don't know what all was done but I've never had a problem

Or we could change our riding style and try not to race the light. If you have to stop, you have to stop.

Touché

Thought of this video when I read the title. Keep an eye on the rear in the slow mo.

Ducati Monster Motorcycle Crash - May 13, 2012 (http://www.youtube.com/watch?v=ZBgrVI0Dyto&list=UUvtfT-xYX4Q-jC2Mbsk3OUA&index=10&feature=plcp#)

Rear wheel hop is that case and the OPs are rather different than front wheel. In both cases the rider is hard on the brakes, transferring a lot of the weight of the bike to the front wheel increasing it's traction, and decreasing it in the rear.

Though that S4Rs shock could probably use some adjustment for sure. But rear wheel hop and front wheel hop under hard braking is different.

I think the wheel hop was caused by not progressing so the tires didn't have time to compress as well. Should try to let go just enough of the brake to stop it and get back on it again. I know what it's like to emergency brake and you rarely have time to check for cars coming behind you but that would what I'd be more worried about.

Have the forks ever been serviced or is that original oil in there?  If it's more than about 2 years and 20,000 miles old it's piss water and you're not getting the dampening you should from the forks.

Same goes for the rear shock.

The fronts I know were done before my purchase of the bike around 10-12k miles. I'm around 20k now. The rear I have no clue what so ever. I should look into that.
sorry for the late responses, apparently I didnt subscribe to my own thread!  [laugh]

My bike does that, slowing down after the long straights on the track.
I have too much oil in the forks, as a result of an attempt to reduce the bottoming dive effect of too little damping.
Not a good solution, but worth a try - I thought. (yes, I'm fixing the hydraulics)
Instead of bottoming out, it's jumping on oil and that makes trail braking exciting too.
The point of my story is to suggest that the previous owner might have done something similar...

I was reading somewhere that the original reason the guy had such massive rear wheel hop was because the engine locked up.

if it locked up - it magically unlocked as it's shown running after the crash. Now he might have gone down too many gears and locked up the rear that way... But if you skip to :53 the engine's a runnin after the crash.

Yeah, I get a little front wheel chatter when I've done something stupid. misjudged the corner, misjudged the road surface, gotten the entry speed wrong (or all of the above).

Sometimes I feel like Rossi and sometimes I feel like Stoner when I get that uneasy chattering out of the front wheel except without any of their skill and none of their bravery either. Another difference is that they're not getting front end chatter because they're doing something silly.  Nevertheless, it results from much the same condition; i.e. pushing your bike right up to the limits of traction coupled with a less than perfect handling bike.

Using maximum braking performance on the street is not good for your long term health.  I advise against it on a regular habit.

The guy in the video looks like he just panicked running into the corner.  Banged down through the gears too fast and started it hopping, but look at his body positioning and his inside foot coming off the peg.  That is the proper technique for a super tight u-turn or 10 mph turn, not for a corner.  If he had just leaned inside he would have been fine.

Oh yeah he totally panicked. It appears that he hand gone down too far in the gear box before the camera gets on it, and instead of getting on the gas/ slipping the clutch some to allow get the wheel rotation speed in line with the bike velocity he gives up and tries to ride a bike that's telling him get the F off.

he hand't even entered the turn that gets a number of folks before he crashed it

The guy on the S4R made me very sad to see such a beautiful bike riden by someone who has no business riding a motorcycle.  That is a perfect example of how not to use your brakes, throttle, clutch, handlebars, turn signals, footpegs, headlight, rear veiw mirrors, horn, or any other control input on a motorcyle.  He didn't even ATTEMPT to make that turn.  He should have just gunned it and gone sailing over the guard rail out into space.  At least he was wearing a helment.

[laugh] [clap]
I think "When in doubt, power out" is quite appropriate...

I feel like everyone is flying off the handle with all of these theories. To me it sounds like your rotors and pads are slightly "too worn".

My S4RS is getting to that point right now where a hard panic stop will cause some "chattering". I have the suspension set up perfectly and the bike is a dream. Still does this with worn rotors and pads. If you were "hopping" your front wheel (from the road surface, shitty suspension, bottomed out forks, etc) you would have crashed.

Too much rebound damping

I think the tire was telling you, "I'm about to slide". Fortunately for you, you stopped before the tire broke loose.