Dave Barrett
Registered user
Engineer said:
I tend to agree with you here, which is why my belief is that it's more likely to be a regulation issue than design for design's sake.
Servo Failures: DRIVERS' PERCEPTION OF SECONDARY BRAKING SYSTEMS
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I tend to agree with you here, which is why my belief is that it's more likely to be a regulation issue than design for design's sake.
Will ABS become compulsory?
Discussions are already under way.
http://www.unece.org/trans/doc/2003/wp29/TRANS-WP29-AC3-03e.doc
Do we really need to be 'looked after' by 'big brother'?
Will
Discussions are already under way.
http://www.unece.org/trans/doc/2003/wp29/TRANS-WP29-AC3-03e.doc
Do we really need to be 'looked after' by 'big brother'?
Will
Dave Barrett
Registered user
bigkuri said:
I'm very happy with my servo brakes, thank you very much. Stopping a fully laden 270kg (unladen) bike when pulling off autobahn slip roads from speeds that would get you jailed in the UK has never been so easy.
Having got used to them (and especially after the last brake fluid change), I think there's plenty of feel.
bigkuri said: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?
My guess is that the master cylinder must be different. If it had the same operation and power as the non-servo version, the ABS would come-in as soon as you breathed near the lever. I guess if you bypassed the servo, you'd have little more than the "residual" braking force left. Those people with servo brakes will know what that is like (with the ignition switched off). For non-servo brake owners - try stopping the car without the engine running for a demo, but please don't try this on a public road or anywhere you might actually have to stop.....
Dave Barrett said:
My point, Dave, is that I can say exactly the same for my non-servo brakes - where's the gain?
Mike
Dave Barrett
Registered user
Mike, I've owned both versions of the 1150GS - with and without servo ABS. I can honestly say that the braking performance, especially from high speed, is far superior on the servo version - no question about that.
Having said that, I also agree with you that I never questioned the performance of the pre-servo version, which was still damned good.
I don't now how old you are Mike, but did you ever drive any old cars without servo brakes? At the time, no-one questioned brake performance or brake effort.
To sum up: I think it's called progress or something...
Having said that, I also agree with you that I never questioned the performance of the pre-servo version, which was still damned good.
I don't now how old you are Mike, but did you ever drive any old cars without servo brakes? At the time, no-one questioned brake performance or brake effort.
To sum up: I think it's called progress or something...
I'll call it progress when I see some Dave...
Mike
Mike
bigkuri
Guest
Dave Barrett said:
Don't think so? Residual braking is only the way it is as you are manually pumping through the "redundant" servo and abs unit. What I'm meaning is bypassing the servo which mean a direct link from handgrip to brake - no in-betweens. The servo and abs would not be a factor.
[email protected]
Guest
Progress...
Progress is, when BMW will invent brakes without servos.
We know from the Article in DIE WELT (12/18/04) they do.
This is called progress! The other is called BMW BS!
OH
Progress is, when BMW will invent brakes without servos.
We know from the Article in DIE WELT (12/18/04) they do.
This is called progress! The other is called BMW BS!
OH
Horrific new failure reported?
I was horrified to read this on Advrider:
http://www.advrider.com/forums/showthread.php?t=65182
BMW just don't care! (oops I'll have set him off again)
I was horrified to read this on Advrider:
http://www.advrider.com/forums/showthread.php?t=65182
BMW just don't care! (oops I'll have set him off again)
laughingBob
Guest
Re: Horrific new failure reported?
Could this be why I saw an Adv with spotlights from the old Wembley stadium on his bike in Aylesbury on Sunday? God knows what they were doing to the fuel economy of his bike. They must have been at least 10" in diameter!
John Armstrong said:I was horrified to read this on Advrider:
http://www.advrider.com/forums/showthread.php?t=65182
BMW just don't care! (oops I'll have set him off again)
Could this be why I saw an Adv with spotlights from the old Wembley stadium on his bike in Aylesbury on Sunday? God knows what they were doing to the fuel economy of his bike. They must have been at least 10" in diameter!
Mouse
Registered user
Just as an aside, a friend of mine had a headlamp problem on his Honda many years ago - something shorted out and the lamp went out, resulting in him crashing into a car (it was night).
Honda paid him a few grand compensation for that. For years he had the remains of the frame mounted on a trophy plaque on his living room wall
Honda paid him a few grand compensation for that. For years he had the remains of the frame mounted on a trophy plaque on his living room wall
Re: Re: Horrific new failure reported?
The headlamp on my Ducati has never failed - so perhaps BMW should fit Ducati headlamps instead of the unreliable ones they are currently using ;-)
The headlamp on my Ducati has never failed - so perhaps BMW should fit Ducati headlamps instead of the unreliable ones they are currently using ;-)
[email protected]
Guest
significant engineering developments
I do have a question about the long term recommendations of the MIRA Report, requiring significant engineering developments.
"Technologies such as electro-hydraulic braking will become available on more vehicles although it may be many years before their widespread adoption."
What the hell does that mean? Do they suggest to use electro-hydraulic brakes?
OH
I do have a question about the long term recommendations of the MIRA Report, requiring significant engineering developments.
"Technologies such as electro-hydraulic braking will become available on more vehicles although it may be many years before their widespread adoption."
What the hell does that mean? Do they suggest to use electro-hydraulic brakes?
OH
Re: significant engineering developments
I do not think that they mean anything - it is just an observation.
As a professional Engineer their findings do not surprise me.
[email][email protected][/email] said:
I do not think that they mean anything - it is just an observation.
As a professional Engineer their findings do not surprise me.
ELIMINATOR
Registered user
Look guys, this is not conjecture. MY GS1150 INTEGRAL ABS has had two servos replaced. The first one would run when the front brakes were applied gently then released.and not go off. But although the servo was running brakes were not being applied.
5 weeks later the servo failed just after leaving my house, braking power greatly diminshed. Just to rub salt into the wound, the ABS lights came on after I had stopped.
Both were done under warrantee,FORTUNATELY.
5 weeks later the servo failed just after leaving my house, braking power greatly diminshed. Just to rub salt into the wound, the ABS lights came on after I had stopped.
Both were done under warrantee,FORTUNATELY.
Mouse
Registered user
I think so, if the tester knew to pull the lever hard enough. Two people on this board have independently confirmed that servo failure doesn't affect braking distance.
[email protected]
Guest
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
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
Mouse said:
DOH!
If the servo failure does not affect braking distance then why bother fitting one? 'Normal' good quality non-servo brakes can stop a bike very effectively with only moderate pressure on the lever.
Re: deceleration is different
Have to agree with oprah on this one - it is the sudden, unexpected change in braking performance that is potentially dangerous.
It is essential to have complete confidence in the brakes on a motorcyle - the rider should not have to be 'worrying' if the brakes are going to work as expected when they are required - particularly in an emgergency.
I have no idea if there is a real problem or not with BMW Servo/ABS brakes. I have only read the comments in these forums - I have no hard evidence whatsoever; but if there is the slightest doubt then BMW MUST investigate as a matter of urgency and be totally open with the results. Have they done this?
[email][email protected][/email] said:
Have to agree with oprah on this one - it is the sudden, unexpected change in braking performance that is potentially dangerous.
It is essential to have complete confidence in the brakes on a motorcyle - the rider should not have to be 'worrying' if the brakes are going to work as expected when they are required - particularly in an emgergency.
I have no idea if there is a real problem or not with BMW Servo/ABS brakes. I have only read the comments in these forums - I have no hard evidence whatsoever; but if there is the slightest doubt then BMW MUST investigate as a matter of urgency and be totally open with the results. Have they done this?
