Re: BMW brakes in the news

["Steve Makohin" <wateredg@xxxxxxxxxxxx>]

Hello John,

John Dancoe <jdan@xxxxxxxx>


> Steve Makohin relayed some interesting & plausible ideas about expecting a
> power-assisted-brake machine to keep working while coasting; likewise the
> probability of mistranslation from the German. Thanks for distilling the 
> big
> list which I surely don't have time for.
>
> Steve also wrote:
>
>>With respect to John Dancoe's ABS observations, yes, BMW bike ABS responds
>>suboptimally under some real-world conditions [SNIP]
>
> [SNIP] replaces an excellent description of the syndrome, and it was good 
> to
> hear my speculation about its nature described accurately and
> authoritatively.
>
> Steve, I could not have said it better myself--and I've tried and 
> apparently
> failed many times!
>
> I don't consider myself a brake god, but I do feel I'm competent and I've 
> been
> riding long enough to "know what I like".
>
> Yes, I know I'm exposing myself to greater risk in general while possibly
> reducing it in one very specific scenario. But I can't deny the fact that 
> over
> the course of several years of riding with ABS, the only truly terrifying
> experiences I had were in that scenario. It is entirely possible that if I
> lived anywhere but Michigan, I never would have encountered it...however, 
> I do
> live in a notoriously-potholed locale, and as a result this happened with
> sufficient frequency to cause my dissatisfaction.
>
> I bought ABS with enthusiasm and I feel I gave it a fair shake. Comments 
> about
> "where to draw the line of acceptable risk" apply.
>
> Again, my own peculiarities notwithstanding, kudos to BMW for a 
> demonstrated
> ethic of striving to make motorcycling safer.

Your description of a "notoriously-potholed locale" is precisely the type of 
surface that makes bike ABS break out in a sweat. I can't say that I blame 
you, as much as I am a supporter of bike ABS. In your case, while riding in 
that "notoriously-potholed locale", choosing to be without bike ABS seems to 
be the lesser of two evils.

It seems that it would make sense to have an ABS-defeat switch on a 
motorcycle, such as the kind they have on dual-sport bikes. One that would 
have to be turned off after each engine start would ensure that the rider 
always made the decision to turn ABS off as opposed to forgetting it in the 
OFF position.

For riders who want to turn ABS off without such a switch, you may be able 
to do so by exploiting one of BMW's design constraints which requires that 
you turn on the ignition key and pause while the ABS computer boots and 
resets. To prevent the ABS computer from booting and working, and thereby 
deactivating ABS on startup, try pressing and holding the starter button 
with the ignition OFF, and then turning the ignition switch to the RUN 
position. The ABS computer will experience a voltage drop as the starter 
motor cranks your engine, and if it has insufficient voltage, it will fault 
out and the ABS will be inoperable. I found this worked on my '00 R1100S, 
but I have not tried it since I first got it.

- -Steve 

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