View Full Version : K12rs Bumps, brakes, and clutch

06-17-2004, 08:17 PM
Greetings K12 gurus,
I have a 99 K12RS with 45K mi.
Since I have owned it, (20K mi) I have experienced this phenomenon, and I know for sure it's not just my imagination.... please explain:

When coming to an abrupt stop, while grabbing clutch and front brake (+/- rear brake) AND hitting a bump (pothole or lane bots) with the front wheel... I am sure that the clutch (dis)engages, ever so briefly, and the bike will lunge forward.
I thought at first that it might be the ABS, somehow activating briefly, and releasing brake, but it definitely seems powered.
These situations are usually when I am traveling faster than I should be, like when lane splitting gets a little hairy, and so it is particularly distressing.

Anyone have an answer? The dealer looked at me like I had been smoking something.

06-17-2004, 08:40 PM
It's your ABS. My R bikes will do that on occasion too.

06-18-2004, 02:53 PM
I agree with Kbasa:

the bump or hole is causing a change in the amount of pressure the brakes are applying the pad, causing (what wants to be) a quick lockup.

The ABS is jumping in very quickly.

When you clear the bump/hole, the amount of force you're applying to the brake is the same as what it was before the bump/hole and all feels normal again.

I've felt it many times to the extent that if I see a small hole or rough spot ahead of me while coming to a stop, I'll release the brakes and coast through it and then reapply the brakes.

06-18-2004, 03:31 PM
Thank you both for your thoughts...
ABS was my first impression, but it seems to occur with both front and rear brakes applied. maybe I am imagining that part. the ABS is not linked to oscillate both wheels on and off at the same time, is it? In other words, will the ABS "unbrake" the back wheel when only the front is sliding?
A Bit Slow

06-18-2004, 05:47 PM
On the K12s I couldn't say--perhaps someone else can answer.

On my K100, the ABS only interrupts the pressure you're applying to the locking brake. If you've clamped down on the lever, the computer pulses the brake when it detects a lock. As soon as you release the lever, it can't help you.

Galne Dansken
06-25-2004, 12:27 AM
Originally posted by kjenne
... In other words, will the ABS "unbrake" the back wheel when only the front is sliding?

Most likely will this happend. You have estimated +90% of your braking power on the frontwheel - so, when the ABS starts in the front - and instantly release the brakes - will a load of pressure go the rear and the tire will most likely loose it??s grip - and you have the ABS there as well..

My K12 is a year 2000 - and I feel while the ABS is in functio that the release-time is quite long.. I know that when I brake hard from 120 km/h, then is my brake length about 5-10 meters longer on a dry road (do??t talk about when it??s weat..)