Servo Failures: DRIVERS' PERCEPTION OF SECONDARY BRAKING SYSTEMS

[bigkuri]

Re: deceleration is different

sorry - this is really not possible.

The maximum deceleration of the servo-brake ist different of the maximum deceleraton of the brake when the servos are switched off.

Because of the different maximum deceleration the servo failure indeed does affect braking distance!

Tests under realistic condition with both maximum deceleration of (1) servos and (2) no servos withe the integral brake showed the extension of braking distances.

But this is not the problem, and this is legal at all! The problem is, that in case of the failure you are surprised and may think that you might have no brakes at all.

And – of course you suddenly have no ABS, but you were used to ABS. Keep that in mind.

Sorry, but the statement "servo failure doesn't affect braking distance" is wrong! If - theoretically - this were true, what the are servos about?

OH

OH, I think that you are confusing the statement and circumstance here. IF you are aware of the servo failure, and grip those brakes in a death-fear induced tension, the braking performance will be pretty much exactly that of if they were working. Mechanically and hydraulically you are just making up for having to push additional fluid around and through the valve mechanisms that make up ABS and servos.
I think that your point is if the servo failure is not expected. Then you'd be in s**t with the usual servo-induced 1/2 finger braking ability.

 

[Mouse]

I stand by what I said about braking distances - I have tested it personally. But I agree totally that the "surprise factor" may well impair braking in a genuine emergency.

 

[Spout]

The biggest suprise for the tester of TBM Magazine (after his servo stopped) was when the servo sudenly started working again!
Would definitely need the ABS then!

 

[Mouse]

That would be quite a surprise

 

[[email protected]]

Truth is not the same as democratic majority

Truth is not the same as democratic majority

 

[Chris G]

I am not too keen on the servo system, but if it is here to stay , why don't they make it split circuit like on a cage so that at least you would have one wheel braking correctly if there is a system failure of some kind

 

[mikeh501]

Guess well will be seeing more of OH now hes banned from Advrider

 

[[email protected]]

state attorney?

Guess well will be seeing more of OH now hes banned from Advrider

nope. you won't.

and – they banned my because I am an asshole. that's okay with me.

today some dude wrote in public in germany tho the state attorney in public: http://www.freemof.de/forum/viewtopic.php?t=16351

OH

 

[mikeh501]

I am not too keen on the servo system, but if it is here to stay , why don't they make it split circuit like on a cage so that at least you would have one wheel braking correctly if there is a system failure of some kind

Thought it was

 

[[email protected]]

• Driver training to give controlled safe experience of brake failure modes

The consequences of no training at all were emphasized by MIRA.

I recently mentioned at ten motorcycle training camps in germany to test BMW motorbike riders with the different brake failure modes.

But at least I do know that most of the riders did not activate ABS on their bikes at all. What does that mean? They won't pull immediately and steadily the lever until the bike stops. Think of the implications what ABS is worth for most of the riders.

OH

 

[[email protected]]

empirical evidence that training is necessary

And – there is also empirical evidence in the press that training with the different brake failure modes is indeed necessary.

http://driving.timesonline.co.uk/article/0,,12389-1345663,00.html

"When I tested the Montauk I crashed it into a fence. Kevin Ash, who writes for Motorcycle News, crashed another BMW with the same brakes into a wall. In both instances the power braking didn’t respond."

OH

 

[[email protected]]

ATTACK ON BMW INTEGRAL ABS

German Motorbike Magazine "TOURENFAHRER"

TOURENFAHRER Nr. 2 /2005. page 72 – 76

"Attacke auf BMW-Integral-ABS"

5 pages article with interview of press officer!


http://www.tourenfahrer.de/


OH

 

[Shurv]

I am SOOOOOOOO pleased my GS has NOT got either a servo or ABS. I simply rely on my 2 pinkies for all the braking I shall ever need.

 

[[email protected]]

You can get the issue here:

REINER H. NITSCHKE Verlags-GmbH
Eifelring 28
53879 Euskirchen
- GERMANY -

Phone. +49 2251 65046 0
Fax: +49 2251 65046 99
E-Mail: [email protected]

German Motorbike Magazine "TOURENFAHRER"

Cover Story: "BMW ABS: REALLY DANGEROUS?"

TOURENFAHRER No. 2 /2005. page 72 – 76

Full Story: "ATTACK ON BMW INTEGRAL ABS"

5 pages article with interview of press officer Mr. Stoffregen!

Does anybody know if MCN is planning to write a report? Is there any recent isssue that deals with BMW ABS Brakes?

OH

 

[richie]

All these world-wide dicussions on servo's - why cannot unhappy owners simply buy some new brakes lines and bypass the whole lot? I know that this would also get rid of ABS, but if some are so concerned about it, then why not?

Could then either remove the ABS/servo unit and lines, or potentially even just disconnect and blank off the input/output lines.

Have looked at this myself in passing interest - and from a thread in AdvRider it should be possible to do. As far as I can tell all the master cylinder pistons are the same, likewise the other "manual" braking components.

The result should be pure simply manual brakes?

Kind of a good idea but a shame to lose the ABS IMHO...

I've said this before but my 11 year old GS with ABS has brilliant brakes (even now after so much time) and it seems outragous that B*W had to fit servos....

 

[[email protected]]

case is not closed

There are some errors in the article of TOURENFAHRER. One is, that the case is not closed by german authorities (KBA). They are still investigating.

Contact:

Präsident Ekhard Zinke
Kraftfahrt-Bundesamt
Fördestraße 16
24944 Flensburg
Telefon: +49 (4 61) 3 16-0

[email protected]

 

[[email protected]]

authority / department UK

Hello,

these guys of you that suffered servo failure and do know the impact of this event, and those guys of you that experienced the intermittent fault of the brakes on bumpy roads, and those of you that experienced other phenomenons should immediately contact:

VOSA

They keep records of accidents and vehicle complaints. If the issues indicate a problem then they can discuss the matter with BMW and suggest a recall campaign. But it's all done under a code of practice.

I hope my contribution was helpful to you.

OH

 

[John Armstrong]

Re: authority / department UK

I hope my contribution was helpful to you.

OH

No. Just what ABS system currently on production vehicles can hope to modulate the brakes according to the bumpiness of the road? No I can't either unless you know of a system that includes active suspension inputs, and now we are talking expensive and complicated.

You don't just happen to make such a system?

 

[[email protected]]

Re: Re: authority / department UK

Just what ABS system currently on production vehicles can hope to modulate the brakes according to the bumpiness of the road?

My english is bad, sorry. I am talking about system specific behavior (you don't get that on ANY other ABS on motorbikes, only on motorbikes from BMW with I-ABS III Brakes)

Have a look, you might get the picture:

From MOTORRAD Magazine, Germany (Translation)

"... the brake distances of the R1200GS vary greatly. Once she comes to a tandstill at 53 meters; next time she needs 65 meters.
Clearly the GS shows a problem that was already there in previous tests with Boxers-models on third-grade roads. In such circumstances, they show a great loss of braking power.
This symptom is reproducable at the "sawtooth stretch". With speeds between 60 and 70 km/h, the front wheel turns with a high slip, the back wheel starts chattering and eventually signals a standstill. At that moment, the front brak opens unusual long, the motorcycle runs without being braked for meters.
If that would happen in a corner, it could be dangerous."

You might get the article in the German Motorbike-Magazine:

Cover Story: "BMW ABS: REALLY DANGEROUS?"

TOURENFAHRER No. 2 /2005. page 72 – 76

Full Story: "ATTACK ON BMW INTEGRAL ABS"


Everything is explained there. I am waiting for the publication in UK and USA magazines. I am wondering why they were not reporting in the past. Well? I don't know.

OH

 

[[email protected]]

VOSA

... should immediately contact:

VOSA

They keep records of accidents and vehicle complaints. If the issues indicate a problem then they can discuss the matter with BMW and suggest a recall campaign. But it's all done under a code of practice.

Please feel free to contact the Vehicle Safety Defects Branch at VOSA. The head of branch is Mr. Sweeting, but I won't post his details here. But - he is personally informed by DoT!

The Text and Interview in the magazine in TOURENFAHRER is in German language. But I like to translate an important part of this interview:

To summarize, and according to the BMW interview, there has been a detection of 21 irregular functions (personally I do know more!). Furthermore there where hundred of cases of (the computer) logging some incident which went undetected by the rider or, where noted by the rider but 'Not' logged by the computer. This is what BMW admits. And the truly declare, that they will not make any further specific statement.

Now, think of brake failures – that may be not logged in the computer! Think of the implications.

This here is a report of a citizen of the United Kingdom: http://www.ixat.net/ViewSummaries.asp?ID=845. Please, have a look at it and read it totally. This man was frightened to death, and I know his feelings. I do have collected much more reports, more than you can read, really, it’s a work of month!

OH