Handbook Insert for bikes with ABS Brakes

  • Thread starter Thread starter Starman
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Sorry guys, but it would appear that some skill is still required to ride a bike

Yup What I said. :thumb
 
I've had the letter too, though not booked the bike in for the free 'inspection' yet... What is that going to tell me? "It is working just fine sir, off you go" is what I expect.

What I want to know is how much power:
(1) the servo assistance motor sucks during use?
(2) is being sucked up by the lights?
(3) is required to keep the engine, ignition and local area network going?
(4) is necessary to charge the battery after a cold weather start?
(5) is being used to warm my hands?
(6) being output by the alternator on a normal basis...

Importantly, in the case of (4), how long does it take to re-charge the battery... For a garaged vehicle, it has been very sluggish at starting during this cold spell and I would not put it down to the oil.

Clearly, if (1) to (5) inclusive is greater than (6) then the result is a deteriorating battery condition... In that case, I want to know what muppet designed the system and what the remaining chumps working for the manufacturers are going to do about it... :spitfire

Has anyone done the maths for me??
 
I can say that the battery does charge during 'normal' use i.e. ride it once a day for a decent amount. Leave it around in a cold garage without riding it and you could well be stuffed, particularly if you have an alarm fitted. Don't forget that cold starting is a double edged sword - not only is the oil thick, but the battery is unable to deliver the same amount of power than at a higher temp.

The 12GS needs a maintenance battery charger if left for more than a few days - simple.
 
Pukmeister said:
The way I read this is:

"Sorry everyone, but we have unfortunately over-servo'd the brakes on our bikes so they stop really well in normal use. Grabbing a handfull however will definitely lock up your front wheel, causing the ABS to release and reapply, by which time you will be half a mile further down the road than normal and in need of fresh underwear." :D



Pukmeister - you're the man ! That is exactly what BMW should have written.
Nice One :thumb

Martin
54 GS12
 
I went trail riding on my GS yesterday, and over the course of 60 miles I must have stalled the bike (and thus restarted it) at least 20 times, probably more. Yes I'm that good :D

Never once did the starter fail to turn. And trail riding is probably much harder on the brakes (and thus the servos) than road riding.

As for the above, we can fill in some figures:

What I want to know is how much power:

(1) the servo assistance motor sucks during use?

Dont know.

(2) is being sucked up by the lights?

55 watts, unless you have full beam on.

(3) is required to keep the engine, ignition and local area network going?

Again don't know, but the ignition will take the most, but no more than any comparable bike.

(4) is necessary to charge the battery after a cold weather start?

I never have.

(5) is being used to warm my hands?

Whatever the grips are rated at, maybe 20 watts?

(6) being output by the alternator on a normal basis...

600 watts, presumably at optimum engine speed.
 
OK - The way I read the insert is as follows: "During rider safety training... the battery is put under heavy load by the ABS control actions, but... is not being recharged as practically no riding is being done... this... situation... can bring th ABS up to its technical limits in which its... function is no longer fulfilled" - and the rider ends up no servo ABS...

It goes on to say "ride... over sufficient distance to recharge the battery afer a maximum of five braking exercises... switch off consumers such as... grip heating" etc. etc.

To me, the implication of this are (1) that if the battery is in a low state, for whatever reason, the servo ABS is not going to function properly (2) braking with servo and ABS control functions takes more out of the system than the alternator can put back, hence the drain on the battery.

Someone tell me why I'm wrong, please, as such a design totally sucks...
 
Chisurz said:
OK - The way I read the insert is as follows: "During rider safety training... the battery is put under heavy load by the ABS control actions, but... is not being recharged as practically no riding is being done... this... situation... can bring th ABS up to its technical limits in which its... function is no longer fulfilled" - and the rider ends up no servo ABS...

It goes on to say "ride... over sufficient distance to recharge the battery afer a maximum of five braking exercises... switch off consumers such as... grip heating" etc. etc.

To me, the implication of this are (1) that if the battery is in a low state, for whatever reason, the servo ABS is not going to function properly (2) braking with servo and ABS control functions takes more out of the system than the alternator can put back, hence the drain on the battery.

Someone tell me why I'm wrong, please, as such a design totally sucks...


You are not wrong - this is what happens af far as I can see. However it doesn't bother me too much as I chose the non-abs version for precisely these reasons! This issue has been known about for ages, but BMW have only just around to telling everybody.

Although to be fair, in practice your not going to do lots of emergency stops in quick succession, so it is highly unlikey to be an issue in the 'real world'.
 
Engineers - thanks - looks like mine won't have servo-ABS at some point either, so we'll be in the same situation!!

I can accept that this specific situation is unlikely, although someone using the machine for lots of short journeys in an area where they need to use the brakes a lot, including at standstill, could presumably be at risk of system failure... The design muppets clearly don't use the bike systems they knock together in real-life situations

So, I'm still no closer to understanding the performance parameters and limits of the design...

Any more offers?
 
Chisurz said:
The design muppets clearly don't use the bike systems they knock together in real-life situations
So for the five years that EVO-brakes have been around neither the design muppets nor any of the customers have been using the bikes in real-life situations? Well that would of course explain why we havent heard of the extreme unsafety with these brakes during all the previous years.

But those real-life situations running up and down a straight and doing extreme brakings without ever riding enough to have the battery recharged sounds pretty boring to me. I guess I'll just stick to using the bike in my ordinary non-real-life way, where the servo-brakes don't have problems... :mmmm
 
I got the same insert for my K1200RS manual the other day.

I've had to use my ABS (rarely) a number of times due to idiots in cars who shouldn't be on the road (usually in wet conditions too) - but never more than once in a day. As a result (and due to regular servicing and maintanence) I've never had an issue. I'm sure I'd be having a break if I had to use it properly more than once in the same day!

But then I'm always commuting, on asphalt roads, and the majority of the time on motorways - my battery is nearly fully charged the entire time as I'm an all-weather, all-year biker.

Your milage _will_ vary for any number of reasons such as if you are off-road, riding for 'fun' in areas you don't know or even only ride once or twice a week. BMW have to cater for both extremes of types of riders (occasional vs full time) with their documentation, hence the booklet. It's all about reducing the possiblity of being successfully sued due to not informing the rider imo.

One thing that people haven't mentioned is that whilst ABS helps a lot in slippery conditions, it does help considerably in dry as well - well trained/experienced riders 'may' be able to stop faster than somebody with ABS on a similar non-ABS bike in any type of weather, but the vast majority of riders are not well trained and don't tend to have a wealth of experience in emergency braking (same as car drivers!) - and hence either lock their wheels up (causing a slide usually) or don't apply enough brakes thereby stopping in either the same distance as somebody with ABS or even a larger distance. Throw some painted road markings in the equation and I'll keep to wanting ABS on my bike... If I was doing off-road stuff as a mainstay, I'm sure I'd change that opinion - gravel roads + ABS as an example means ABS is more dangerous!
 
Brake Failure

With regards to the MCN article of this Wednesday (21 December) I would also confirm contrary to the suggestion of the article "the brake failures" occurred during an extensive demonstration period and not whilst riders were training with the machines. The alleged battery failure was not a technical failure rather than the battery becoming discharged from the repeated operation of the ABS pump over a short time period. This article has been very misleading to the public and we have received many telephone calls from customers who have taken delivery of brand new motorcycles who will not have received a letter.
 
Starman said:
I
All very well, however one paragraph seems a bit scary:
'In emergency braking as it is often taught, in which the brake pressure is generated as quickly as possible and with all possible force, the dynamic load distribution cannot follow the increasing deceleration and the braking force cannot be completely transferred to the road. The ABS has to intervene to ensure that the front wheel does not lock up; this reduces the brake pressure and the braking distance is extended' !!!!

It just means that if you snatch at the brakes ( without allowing weight transfer to front wheel) you will lock the front wheel so the ABS will operate. increasing both the braking distance and your life span!

Just ride the bike properly, and then, when you have a bad day, the ABS will take care of you.

Shep :bounce1
 
Chisurz said:
Engineers - thanks - looks like mine won't have servo-ABS at some point either, so we'll be in the same situation!!

I can accept that this specific situation is unlikely, although someone using the machine for lots of short journeys in an area where they need to use the brakes a lot, including at standstill, could presumably be at risk of system failure... The design muppets clearly don't use the bike systems they knock together in real-life situations

So, I'm still no closer to understanding the performance parameters and limits of the design...

Any more offers?

OK- my reading of this goes something like this.

Find a short straight bit of road with no traffic - ride along at lets say 20mph, do any emergency stop by braking as hard as you possibly can so the ABS operates - IF YOU HAVE A NON-ABS BIKE DON'T DO THIS!! DOH!

Keep repeating this procedure over and over and over again and some more! - if you do this often enough then BMW say that the battery may discharge (the servos are electrically driven) far enough for the servos/abs system to not operate properly.

I believe that residual braking should still work OK but the servo/abs system won't until the battery has recharged to a sufficient level.

The battery will recharge when the bike is ridden normally for a period of time - the problem will only ever happen if you do lots and lots and lots of emergency stops, one after the other without a break.

DISCLAIMER - This is just my reading of the situation - if you try doing this and fall off don't blame me!!!!
 
As you so eloquently put it Keba:

" BMW have to cater for both extremes of types of riders (occasional vs full time) with their documentation"

They should also design the SYSTEM to cater, as well as the documentation.

Imagine if aircraft designers didn't cater for every probable/possible eventuality when designing flight controls etc. Planes would be falling out of the sky occasinally as the Pilots experienced the failure mechanisms the designers forgot about.

I count myself lucky that;

a) I have an Optimate and use it regularly
b) Motorcycles don't fall out of the sky if their systems fail. They may fail to stop in sufficient time/distance however.

Just because ABS failure is unlikely in normal use, doesn't mean that this issue should be brushed aside IMHO. I haven't experienced ABS failure myself yet (touch wood) but somebody somewhere might, and thats not acceptable.
 
I just hope Dr.ABS doesn't read this thread - there's enough bo**ocks being talked here already :)
 
Pukmeister said:
Just because ABS failure is unlikely in normal use, doesn't mean that this issue should be brushed aside IMHO. I haven't experienced ABS failure myself yet (touch wood) but somebody somewhere might, and thats not acceptable.

If the ABS fails, a red light starts blinking. If you don't maintain your battery, the ABS won't work correctly.

The insert covers both of these issues (well, the first is already explained in the manual). Not paying attention to the flashing red light and/or not maintaining your battery is now _not_ considered normal use once you have the insert.

Failure to read the manual (or failing to acquire one if you didn't get one with a second hand bike - or failing to ensure that BMW know you know own a second hand bike in the first place so that you get the updates) is not grounds for a defense if you have an accident due to improper riding behaviour.

They covered themselves quite well really ;)
 


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