The ABS option is becoming more common in owners of new Monsters... time to start collecting info into a thread.
What is ABS?Well we've gotta start somewhere.
ABS (Antilock Braking System) aims to keep wheels from locking up. The most efficient way of braking is increasing the friction force of the brake pad to the rotor; if a wheel's rotation is arrested the braking force comes from the friction of rubber vs. road which is not nearly as efficient.
Ducati's ABS system is described in the manual as
"Antilock braking system with separate action, controlled by Hall-effect sensors mounted on both wheels and pulse wheel readings: option available to disable ABS."When it says "separate action" it means this: The brakes are connected the same way as any standard system (Master cylinder -> line -> slave/caliper) BUT the ABS system connects into the line between the Master and the Slave cylinders and creates a second pseudo-slave cylinder. When the ABS system is activated the ABS solenoid releases hydraulic pressure from the line, releasing the pressure from the pads/rotor and allowing the wheel to move freely. It does not and can not apply brake pressure.
Each wheel has a pulse wheel mounted to it. There are sensors looking at the pulse wheel and measuring the wheel speed. If a wheel's rotation is arrested before the other wheel, the ABS for that wheel is engaged and the brake pressure is released in pulses (like a car). The ABS should act fast enough (each sensor system looking at the other wheel's system) that it prevents the possibility of both wheels halted at the same time before the vehicle has stopped... but luckily I haven't tested that.
Can I change the front/rear sprocket?YES YOU CAN!!!
QuoteThank you for contacting Ducati North America.
Changing the final drive sprocket will not have any ill-effects on the ABS system of your motorcycle. Below is an excerpt from a Ducati Service Manual that explains the operating principle of the Ducati ABS. As you will read, the ABS does not use engine speed as part of its calculations.
“The Ducati ABS brake system manages the front and rear brakes separately. A pulse generator (phonic wheel), with a ring of slots, is fixed onto each wheel. On the left caliper mounting bracket of the front fork and on the rear brake caliper holder plate are HALL effect sensors which detect the full sections and voids on the phonic wheel as the vehicle moves, providing and instantaneous wheel speed reading. These sensors transmit the data to the ABS control unit, which contains software implementing a specific control algorithm developed by Ducati. The software compares the average speed of the vehicle against the instantaneous wheel speed values to determine the degree of skidding. If the pressure applied to the caliper by the rider causes the control limits to be exceeded, the control unit intervenes in the braking circuit relative to the wheel for which incipient lockup is detected. The ABS modulates the caliper pressure with a system of solenoid valves that initially prevents any further increase in hydraulic pressure (EV valve closed), and then reduces pressure (AV valve opened). The AV valve is opened in a series of pulses (with less than 10 milliseconds between successive pulses), to reduce pressure in steps. When the wheel begins to rotate again in response to the diminished braking force applied and the wheel speed reaches the reference value, the AV release valve is closed. Simultaneously, the EV inlet valve is reopened, restoring normal operation of the brake system. The ABS control unit can monitor and modulate brake force accordingly in the three following different conditions: dry road surface (high grip), wet or greasy road surface (poor grip) and uneven road surface. ABS functionality is disabled at vehicle speeds lower than 5 km/h.â€
We hope this addresses your concerns.
Regards,
Customer Service
DUCATI North America
10443 Bandley Drive
Cupertino, CA 95014
www.ducatiusa.com (//http://) (//http://)
Tel: (408) 253-0499 x4411
Fax: (408)253-4099
Apparently the word from Ducati is "no".
QuoteThank you for contacting Ducati North America.
The ABS system uses both speed and RPM in its computations, two things directly affected by changes made to the gearing ratio. The ECU that governs the ABS system is programmed to work with the stock gearing on the bike only.
We hope this provides you with the information you were after.
Regards,
Customer Service
10443 Bandley Drive
Cupertino, CA 95014
Phone: 408.253.0499
I disagree. I say YES since I've been running ABS with a 14T (from 15T) since I got my bike and the ABS has worked just fine.
I'm no Ducati engineer but I've got some thoughts on why the final-drive gearing doesn't matter to the ABS system. Ducati NA says the ABS system is dependent on knowing the wheel speeds (sensed from what Ducati calls 'pulse wheels' mounted near the rotor) AND the engine RPM. So we can assume that the computer is watching the engine speed and the wheel speed and calculating what the two should be, and if there's a difference then the ABS system kicks in. BUT here are my problems with that being the case:
A) The front wheel ABS system can't be correlated in any way with the engine speed (RPM) because it is not connected to the engine. One can imagine a situation in which the rear wheel is turning much faster than the front wheel... *ahem* wheelie? The manual that accompanies the 1100S ABS says that "A prolonged wheelie may disable the ABS."
B) One can easily imagine that in MOST cases involving the ABS system (ie: emergency braking) the clutch lever would be pulled in to the bar... negating the relevance of engine speed once again in the majority of ABS-needed situations.
C) (the stretch) Okay let's assume for a minute that Ducati engineers are smarter than me (I tend to live my riding life by that belief btw) and that the engine speed does matter to the ABS system in correlation to the wheel speed... Compared to the 15/39 stock ratio, going to a 14/39 ratio will make your wheel speed LESS at a given RPM than it would be at stock. So the ABS says "Wait a second, that wheel is moving slower than it should be... but it's not stopped, so we're not doing a wheelie... and I'm assuming we're not in neutral since the front wheel is spinning at the same speed... so I should get that wheel to speed up... Huh... that's kinda not my job... oh well *shrug*"Nope. But you'll be glad its there when you need it.
The only things that are noticeably different are: the inclusion of the pulse wheels with the rotors on the wheels, and the ABS Light which comes on when you start the bike and doesn't go away until you have gone above 10mph at least once [rudimentary system check].
What if it becomes mandatory to have ABS?!!
It seems that all companies with ABS equipped bikes are also adding a way to turn it off if so desired by the rider. Who knows if that will be allowed in the distant future, but for the time being: you can turn it off! Ducati has included the option to turn it off in the same menu as where you set the clock. There's also always the option of a prolonged wheelie [moto].
So what about "Not for ABS" warnings on aftermarket mods??Well from what I've come to understand is that no one is yet quite sure how the ABS system effects non-stock components. But that is not to say that anyone knows how ABS will effect the stock components either... don't OVER use the system is what I've been told.
Aftermarket levers will say "Not for ABS" because they don't want to be liable for your master cylinder busting from the pulsating hydraulic pressure of ABS. Some people say that even the stock levers will have problems eventually with ABS, but no one knows yet. I am using aftermarket levers with no problems so far. I also am using Rizoma rear-sets which requires two custom (lengthened) brake lines for the rear brake due to the ABS system (Note also that bleeding the ABS brake lines is quite a process that I'm not clear about).
BUT if you get a new ECU, be sure it is meant FOR ABS!!
Okay, that's it for now... work in progress... share your thoughts/questions!
better you than me going against Ducati on the sprocket question though.
the rest [thumbsup]
Rumor-mill can finally sleep quietly tonight... Official word from Ducati is that changing the final-drive ratio has no effect on ABS!!!
So go out and pop on those 14T sprockets my safely-braking friends!
Quote from: Raux on September 07, 2010, 07:40:09 PM
posting the email? curious how it contradicts the other.
Woops, I meant to say I updated the first post striking out the old email (which said "Don't change anything!") and replaced it with the new email (which says "Go ahead!") .
Quote from: Amlethae on September 08, 2010, 02:47:27 AM
Woops, I meant to say I updated the first post striking out the old email (which said "Don't change anything!") and replaced it with the new email (which says "Go ahead!") .
Which email is correct? [evil]
Quote from: humorless dp on September 08, 2010, 03:57:00 PM
Which email is correct? [evil]
[laugh] Well I'll trust the longer, more detailed one that actually explains the ABS system... therefore I choose to believe "Changing the final drive sprocket will not have any ill-effects on the ABS system" ;D
Quote from: Amlethae on September 08, 2010, 04:13:50 PM
[laugh] Well I'll trust the longer, more detailed one that actually explains the ABS system... therefore I choose to believe "Changing the final drive sprocket will not have any ill-effects on the ABS system" ;D
As long as you like the answer it doesn't matter? [laugh]
I'd agree that the one that quotes the shop manual makes more sense.
Quote from: Dr. D on September 10, 2010, 01:26:46 AM
???
I don't understand the lever issue. I have owned several BMW motorcycles with ABS and I have changed the levers with no problem. Heck, on my current one, a K1200GT, I had a dealership install the aftermarket levers along with some other work. The levers had no "OK for ABS" statement with them. As long as the levers fit, there should not be a problem.
I feel the same way... I can't imagine there being any issues with it... the word I heard on the street is that aftermarket levers could hurt the master cylinder if the ABS release/reapply modulation is stifled or over-pressured by some crazy insane new lever... but again I think that's so highly unlikely that all the "Not for ABS" is only there to cover people's asses in court if something does happen.