2008 abs frustration

[eaglemike]

Background - new to thr forum, traded in a R12R and R12RT on a new K12LT a few weeks ago.

Situation causing me to lose religion:
If I hit a bump with the brakes engaged, the brakes totally fail for several feet, with the bike freewheeling. It seems to happen worse when the front brakes are used fairly hard, and something upsets the rear wheel - the brakes totally go away!!!! I never anything close to this happen with the RT or the RR bike. This is scaring the you-know-what out of me. I did have it back to the dealer, and got the "well, there weren't any fault codes, and it's probably because your rear tire had 48lbs or air in it." I'm scared to ride the bike in traffic at this point..

Anyone else ever run into (pun intended) this???

TIA!

all the best,

Mike

[ArthurKnowles]

Well the 48 lbs. in the rear sounds correct. Most people run 42/48 (F/R). The frewheeling sounds like an ABS interruption. It can happen anytime you hit a bump with the brakes engaged and your tire goes in the air. Your ABS thinks the wheel locked up and will engage to prevent the lockup so you can maintain directional control.

I'd suggest putting it to the test and driving it out to a parking lot and making some braking runs at higher speeds (stagered) and higher braking forces to get a feel for how the ABS works and see if it's just your inexperiance with the K1200LT's servo assisted brakes and ABS that made it seem like a problem occured, or if an ABS/brake problem actually did occur.

[eaglemike]

I actually had two (2!) R1200Rt's - a 2005 and a 2006 (story below). Both of these had servo-assisted brakes. I never had an experience like the scares I've had with these brakes. When the ABS engages under these conditions, it takes a couple of seconds before I have brakes again. It might be only a second, or just less than a second - but that's a long time to have zero brakes.

all the best,

Mike

My silver 2005 RT was backed into and knocked over by an uninsured and unlicensed driver. I traded it and the insurance check on a red 2006, hoping that would be more visible.

[JimH]

...If I hit a bump with the brakes engaged, the brakes totally fail for several feet, with the bike freewheeling. ...Anyone else ever run into (pun intended) this??? Yes. I just wait until the brakes resume normal function, but it does make my head bob a bit... :D

[kellenbenz]

This is one that has not been discussed much on here, but is real. I had an experience with a triple bump segment that was spaced just right to keep the wheel up. I just about rear ended the car in front of me and I actually dropped the bike.(slow lay down on the left side) It can certainly put you in the panic mode. I think it is more prevalent in the integrated abs than my older 2000LT.

Ron

[mccodavj]

I have a 2008 LT and have experienced the same sudden loss of brakes. It has always been when I've hit a bump and the ABS has decided that I've lost traction. However the brakes are back on and working before I figure out what's happenning. It has happenned about 3 times in 9k miles - none when it has caused me serious concern.

I also have a 2004 K1200RS with the same servo assist ABS system. In 54K miles it may have happenned 2 times. Perhaps the 2008 system is a little more sensitive - I'm certainly not riding any harder on the LT than the RS.

[eaglemike]

I just took the bike back to the dealer. To repeat - this situation is scaring the you-know-what out of me. The dealership owner is also an LT rider. He's going to test ride it. He's also confirmed the servo-assisted brake system is pretty much the same as my prior RT's. He mentioned they had one do this a few years ago.

I'll try to explain again - when the ABS "thinks" it needs to "activate," it doesn't allow any pressure back into the system after I'm back on even pavement where there is traction - the bike acts like it's in neutral, brakes not applied. It seems to be unable to sense there is traction again.

I've felt the abs activate in the other bikes before, just for maybe a foot or so. As an example: when the streets are wet, and I'm braking up to a stop sign, crossing the painted word "stop." I can feel the abs activate ever-so-briefly. I did this as a test when I first got the 2005 RT. So - (I think) I know how it's supposed to work and feel.

IMHO, my bike is not safe until it's fixed. The stopping distance is FAR longer than it would be in a non-abs bike. Yes, I've heard all the pro and con abs arguments. Riding since 1972, 7th beemer.

all the best,

Mike

[focussvt]

I made the nearly same move off a 2005 RT onto an 08 LT and had the brakes do the same thing. One clear difference is that the on the RT the rear brake is independent of the front when using the pedal. The front grip engages both. On the LT I have never received a clear answer on just how the brakes are interlocked. On the GW (according to my brother the pedal engages the rear brake and only one caliper on the front, and the grip engages all the brakes.) How does this work on the LT?

Where I live the roads are such a mess in many places and road construction so prevalent I think I am riding the worlds biggest dual sport. So out of habit I use the pedal and grip. What I have had happen is I hit the bump for a split second the brakes release then when reengaging for a panic stop I have increased the pressure on both grip and pedal that the rear wheel locks up for a split second and I perceived normal ABS operation. I do not like this but I have not found myself thinking it unsafe.

What did the dealer find?

[eaglemike]

The dealer replaced the ABS modulator, and the front master cylinder. The brakes now have a less "wooden" feel. The ABS does activate easier than either of my R12RT's, and does not recover as quickly. This part is disappointing - I wish there was not as much distance traveled as there is without brakes after the ABS activates and the system recovers. I'm sure it's not a huge distance - but it's not as good as my RT's were - and yes, they were the 2005 and 2006 with the servo-assisted brakes.

Bottom line the brakes a better, but I don't know if they are totally right yet. I'm going to continue to be concerned about his for a while, and test the brakes, when and where it's safe. The dealer has offered to let me test ride the 2009 in stock to see if it's the same as my bike currently acts.

I can only say good things about BMW and the local dealer, San Diego BMW Motorcycles.

all the best,

Mike

[ArthurKnowles]

I can only say good things about BMW and the local dealer, San Diego BMW Motorcycles.

You and me both! SD BMW has truely been good to me (as a customer) and I honestly appreciate their commitment to service.

I'd suggest taking them up on the '09 model and see if it does behave the same way. I bought my '06 from them and can't say I've experianced the problems you have had with the brakes/ABS. Maybe I should go test mine out a bit more and see how it works out.

[Houston07LT]

My 2007 has done this several times. Scared the piss out of me the first time and I was in heavy traffic. I thought I had hit an oil slick.