I'm in the process of getting a GS 1150 adv and have come accross some with abs and some without. I have been told that the ABS is expensive to fix and if it breaks in the middle of nowhere it may be a problem. I plan to go from Durban to Daresalam in mid December and will be doing further missions in the SADAC countries so the local BMW agent will not be on hand. How do those currently with the GS 1150 find the weight? I have been riding a Africa Twin which I love but, is getting a bit old. I also see that in 2005 they brought out a special release but could not find what was so special about it. Any info would be great. Cheers

As far as the bike goes, the 1150GS ADV is a pretty heavy bike but very able bike if you can handle the weight. I just finish a 1200 miles weekend with some long stretch of sandy road 2 up fully loaded and riding those road was fairly easy. Now regarding the ABS , you are right and if it does break down you are in big sh....but I love mine and on my 1200 fully loaded 2 up the ABS saved my butt during a creasy breaking on a slippery road , I never met anyone with broken ABS yet.

Good luck.

I may be wrong, but as far as I know your brake won't break in case the ABS goes bananas. You'll just lose your ABS (and brake assist since they're somehow connected) but you will still be able to brake. But like I said, don't take me for granted cause I might be plain wrong.

My ex-girlfriend had an R1150R and we've actually suffered a complete brake breakdown once. It was covered on warranty so we got it fixed, but most important is this: even though the ABS and brake assist broke, the brake itself was still working. It was just a bit harder to brake.

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I'm well out of date with BMW's but they have to my knowledge used variations on three systems over the years.

The R1100 type system is a basic hydraulic ABS. It consists of a block of solenoids and a pump that hold pressure in a wheel that's in deep slip, release pressure in a wheel that's gone deeper into slip and pumps the excess fluid back to the reservoir. If anything fails the red light comes on and you revert back to a non-ABS system. This can lock the wheels, so providing you ride it like a non-ABS bike you have 100% of the brake potential available. This system has blink code diagnostics (you bridge two pins with a lamp) and can be repaired with nothing more complex than a multimeter and speed bleeder (the valve blocks can be a swine to bleed).

The later ABS system is similar to the above but has a CAN link. Rather than a lot of wires it gets and sends information via a network of two wires and an alpha-numeric code. Again, failure should only leave you with an annoying red light and a fully functioning non-ABS brake system. Diagnostically the CAN bit needs a PC to work out what bit is saying the wrong thing.

What you should be scared of on an overland bike is the power brake system fitted to some K bikes. This uses the pump to assist the brakes. No pump and you drop to the legal minimum for emergency braking. Imagine a ton of K1200LT with the braking power of an Enfield due to a blown fuse. Diagnostically it's a CAN system, so sometimes you'll find the fuse and fix it, other times you need the PC to find it's the CD player that's shutting down the brakes by yelling "CAN error".

There is a lot of guff about ABS. BMW have ripped owners off for probably millions over the years for a "reset". This consists of grounding a pin to clear the error memory and keying the ignition to make the system self test. I've heard them charge £200 for this five minute job. To earn that sort of hourly rate, most people need to work laying down or be very good at kicking a ball!

Don't be scared of ABS, it's a mature, useful technology and on something like an R1150GS should really be only part of a bigger picture of mid to high technology. A busted engine ECU or security system issue, now that'll ruin your day. If it scares you, you'd better get that Enfield as it's the only way to avoid modern electrics.

Feel free to tell me I have a rather twisted view on this. I developed truck ABS and EBS systems for almost 15 years and owned R1100's with the BMW system for five of those. The basic BMW system could be so much better, but it's crudeness does add a little toughness compared to some of the other corners BMW cut.

I'd get the bike in the right condition at the right price, ABS or not unless you'll ride in heavy traffic in bad weather as part of a daily commute.

Andy

Early 1150 Adventures with ABS had normal hydraulics. If the ABS pump fails (it can happen, valves get stuck in the pump itself, happened on my girlfriends 1150GS), then the ABS does not work but your braking is unaffected.

Later 1150's with ABS have brakes with electronic servo assistance (also known as "power brakes" by some). Basically for the same amount of braking, you need to apply less pressure on the brake lever or pedal. If the ABS pump fails on such a bike, then you're left with (approximately 40%) residual braking, not ideal on a loaded overland bike on a steep descent.

Easy way to check what's fitted: turn the ignition on, leave the engine off & squeeze the brake lever. If you hear an electronic whining sound similar to the fuel pump priming itself, then the bike's got the servo or power brakes.

All of the white Special Edition 1150 Adventures came with servo brakes as standard.

All 1200's up to October 2006 build date have servo brakes, after that BMW reverted to non-servo brakes.

Note: I've heard that extra care may be needed when pushing the caliper pistons back in to the caliper body on servo braked bikes to allow fitment of new, thicker pads? Not sure if this only applies to 1200's?

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Hey Andy,

Thanks for the info, it seems a well tested technlogy. I actually started riding an Enfield Bullet for 9 months in India as my first bike so I guess you can see where my aprehention comes from. Pulled most bits of and replaced them over the trip and no electrics indeed.

The other question I had with regard to the brakes is about the split between the front and back breaks. When pulling the front brake the back brake opperates to, the split depending on the speed. Is this driven by the ABS or something seperate?

Cheers

Technically, it's something different, the latter dubbed "Integral Brake Assist" by BMW. It is possible though that once again, just like with the servo brake (which is what I was referring to as brake assist, some call it brake boost, whatever), BMW has linked two components that do not belong together. For example on my R1200GS Adv. ABS and ASC are linked even though they're not dependent on each other. Still, if I disable one, I automatically disable the other.

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"Life is not a journey to the grave with the intention of arriving safely in one pretty and well preserved piece, but to skid across the line broadside, thoroughly used up, worn out, leaking oil, shouting GERONIMO!"

ABS & ASC are linked because the ASC (Automatic Stability Control or Traction Control) utilises the ABS wheel speed sensors to determine if the rear wheel is rotating faster than the front wheel i.e. the wheel's lost traction & is spinning up. Note that you can't have ASC on a non-ABS BMW.

Separating the two would entail two sensors per wheel on an ABS/ASC bike, adding unnecessary cost & complication.

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ABS is a simple brake override function, it retains the two circuits we all know but adds the ability for the system to hold or reduce pressure in each circuit independently. The only link is via the control loop. The system needs a vehicle speed for comparison to calculate the slip rate of the wheels. As there are only two wheels, one of course has a big effect on the other when ABS starts to take control. ABS can only hold or release a brake, it can't apply one and it knows one wheel braking should effect both. The software includes factors such as a wheelie/stoppie detection where one wheel locks instantly as the brake is applied, which is one of the reasons why the result can feel crude compared to a car with 4 wheel speed sensors and no risk of doing a stoppie.

Linked brakes such as Moto Guzzi used were a simple change, the circuit split was just different, 1 front and 1 front/rear. This aids ABS as it's impossible for the rider to demand a 0-100% front-rear brake split, the rear then trying to lock up and the ABS having to sort it out. One rear brake locked or trying to lock of course makes for a really long stop compared to front and rear working together down the optimum slip curve.

I am not that familiar with the BMW integral thing. As there is ASR (known as traction assist, it isn't, but that's another story) it has the ability to control the engine (within limits) and apply at least the rear brake. It would be logical to then add an ESC software function which would act in a similar way to a linked system and let the electronics decide on a minimum front;rear split. This function will be limited to a low percentage of braking as there is a risk it could apply in error and the bike would need to be controllable if it did.

Brake assist is the designers weapon against bad drivers. It's a delay factor so that when the driver stomps on the brake and makes the ABS cycle, but then gets terrified by the pulsation through the pedal and lets his foot off so he can watch life (or the alternative) in slow motion while going "Hu?" and looking at his feet , the system assumes the driver is a muppet and keeps braking until another control is used. On a bike, this again must be limited and will cut off once the system detects a demand from the throttle or the clutch.

Hardware wise, this is just a third solenoid (for brakes on) in each circuit. The complex bit is the decisions in the software for when to fire that solenoid. The fact that ASR, ESC and EBA need information from the clutch, engine and dashboard is why we have CAN and PC diagnostics. They are very very reliable, but when something breaks there is no fixing it with baleing wire, you need a PC that can tell you what info is missing or unbelievable. I won't be getting any of this until the bike OEM will sell me the diagnostic software. This has happened on cars with OBD2, but I think BMW are still ducking and diving on the bikes.

In practice, once you get used to simply holding the brakes, ignoring the clicking and chuffing the system should just take care of itself, but it is a different experience to those Bullets.

Andy

ASC/ASR stops you falling off by spinning the back wheel, stops you spraying dirt over passers by and might, if backing off the throttle is the right thing to do, get/keep you moving.

TC decides the best way to get you moving and helps you do it.

I'm a pedant I know

Andy