Braking Was : Best way to travel 5 miles to a train station?

What is the 0-60mph time of your bike? Bet you can quote the figure
'measured' in a magazine test. Let me guess - 2.8 seconds. Near enough?
Perhaps the figures are really derived by the test rider after going into a
trance and studying a few chicken bones.

 

Indeed. God forbid that we should actually try and _prevent_ accidents in
this country. Far better to follow the old "Blood on the tarmac" system eh?

Jon

 

I'm sure that when I learned to drive, the figure for stopping from 70mph
was 315ft. Maybe they have revised the figures, or maybe I've misremembered.

 

TROLL!!!! Run for your lives it's a troll!

Not a very good one though.

You do seem to be having some problems so let's give it another go shall we.
Good brakes doth not mean good stopping! If I put your brakes on my race
bike with it's 23mm wide tyres do you seriously believe that it would stop
better? Think carefully before you answer this question.

Jon

 

misremembered.

Think about it! (well, the HC figures include a time to do this anyway...)

cheers,
clive

 

I'm happy for you. Really, I am. But the laws of physics apply even to
those who are too ignorant to understand them.

James

 

DavidR says...

When I approach a roundabout I'm too busy thinking about whether I
should do a rolling stoppie up to the line or whether I should do a full
knee down all the way round it. I don't have time to work out the
coefficient of fricton of my brakes and how it affects the working
temperature of my tyres. Physics is great when you're sat behind a desk,
but it means **** all when your steaming into a roundabout. Seat of the
pants and years of experience is what counts there.

I'm bored with you now and I can't bear to think that your getting your
geeky little kicks by replying to me. You still haven't been able to
dispute my statement that the the NSL we have in the UK is hopelessly
outdated, but you did try to distract everyone away from the subject for
a while. Nice attempt, but not good enough. You carry on sticking to
speed limits, I'll carry on breaking them.

 

Maybe you should be thinking 'What if' and slow down to a speed which
would minimise injurues if...

As you are NOW! You CAN'T defy the basic laws of physics, however
arrogant, ignorant or clever you happen to be!

Yebbut you've not gathered any facts to back up your weak argument.

Who says we're not bored? We've been entirely unable to show anything to
you. You seem to be entrenched in a view which defies basic reason.

One poster tried to point out that the human body was just as soft and
squishy as when the NSL was introduced. Several posters have tried to
point out why brakes *can't* be improved beyond certain constraints. You
have not listened, preferring to counter reasoned argument with
arrogant, unsupportable statements.

We'll continue to think some speedophiles are homicidal maniacs who are
best avoided, derided and abhorred.

Those of us who have known people killed by motorcyclists might have
stronger views.

 

Because that's the highest figure the Canadians whose study of
motorcycle braking was quoted earlier in the thread were able to
achieve with experienced riders on real modern sports bikes equipped
with state of the art telemetry under real conditions.

So if you can point to a study - a proper study with real telemetry, not
down-the-pub boasting - which did better, post away.

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

;; 'I think we should trust our president in every decision
;; that he makes and we should just support that'
;; Britney Spears of George W Bush, CNN 04:09:03

 

Ah, but you see, there are those who don't believe you and won't believe
you till you can come up with something that's objective not subjective.

Hence the measuring tape, since the point in question is not how hard
you can brake by feel, but how long a distance it takes to actually come
to a stop...

 

You can think what you like. The fact remains that a motorcycle
driven by a speedophile is considerably less dangerous to "the general
public" than a car driven by a speedophile (and, while we're at it,
spotty teens, myopic pensioners and harried salespersons). So if your
issue is road safety (which is entirely laudable and noble) then I'd
politely suggest that you target your avoidance, derision and
abhorrence more effectively.

Well, that's unfortunate. However, it's a massive minority.
Motorcycling deaths are mostly caused by a car driver's actions.
Where a motorcyclist kills himself/herself through recklessness, they
rarely take anyone else with them.

 

If said biker had not been doing ridiculous speeds he wouldn't have had
to alter his speed - I was doing 65 and there was a long enough gap
behind that I pulled out in to.

On a three lane motorway.

The car I was then following was doing - 70mph (it was fairly busy). If
the gap hadn't been sufficient I wouldn't have pulled out - but I accept
that on a motorway there will always been slight alterations of speed
needed, and I don't think the idea that consideration means never
requiring another to alter speed or path is valid. He had plenty of
time to do that, even at the speed he was approaching - I wouldn't have
pulled out otherwise - but he left it to the last minute then on with
all the play acting.

His attitude stunk. Bit like those who seem to think that if having
bike headlights on during the day makes you more visible, having them on
full beam means you're twice as visible. No, it just manages to dazzle
drivers (yes, even in the daytime, unless it's bright and sunny) - and
I'd like to know just how many bikers really want a driver that's just
been dazzled - unless you actually WANT them drifting into your path?

As a cyclist I know full well how unobservant cars can be (and
motorbikes, for that matter) when it comes to push bikes and motorbikes
- I've seen it all too often, I don't need to ride a motorbike to know
what it's like. But the attitude from a lot of motorcyclists that *all*
car drivers are unobservant twats just tends to alienate the drivers who
*do* look out for bikers and their safety. Do you *really* want to make
that sort of attitude self-fulfilling and turn every single car driver
into one that couldn't give a shit about the motorbikes, cos they're (to
put it bluntly) all a bunch of arrogant wankers?

I get a lot more thankyous from motorcyclists than I get experiences
like the above. That tends to make me think that I drive well around
them - and having racked up substantially more than 10k miles a year for
the last 8 years or so I've seen a lot of bikers in my time. The
majority of them are fine, but there does seem to be a subset of bikers
who are just plain rude, arrogant, and abusive arseholes, and who are
probably exactly the sort of personality type that shouldn't be allowed
on the roads at all.

 

Come on, most of us can tell that. The issue is whether he can
understand what 1g translates to in terms of distance covered during
deceleration.

Furthermore, it's worse than that (he's dead, Jim) since in real life
you can't just switch on your maximum braking force instantaneously; so
his braking distance is somewhat greater than your calculations imply.

 

If you think this makes you experienced, you are mistaken.

 

It's a two-wheeled strategy I see. I've never ridden a motorised bike
but do thousands of miles a year on unmotorised ones and this is my
credo, too - and has served me very well.

(To be fair, when learning to drive my instructor's first bit of advice
was along very similar lines - assume everyone else on the road is out
to get you and is about to do the exact opposite of what you expect and
what their signals and whatnot are telling you; you'll be fine.)

 

Bit like car drivers, and lets be honest, the whole of humanity.

 

You're either being really clever, humourous or thick - I can't decide.

Champ's question was:
"Please explain how a motorcycle travelling at 150mph endangers anyone apart
from the rider."

You appear to have completely failed to answer this question.

Just the question mind you - no adding in "but it might be outside a school"
etc etc.

 

Yeah ban motorcycles.
And cars.
And trains.
And planes.
And pavements.
And houses.
And food.

And... bicycles - they kill people too.

 

Funny that. Because my experience shows there to be a subset of cagers
who aren't just plain rude, arrogant, inattentive, careless and abusive
arseholes, and who are probably exactly the sort of personality type
that should be allowed on the roads.

No, I don't have any figures to back that up.

Soy.

 

I suspect that a lot of the confusion in this debate has been around the
relationship between stopping TIME and stopping DISTANCE. See here:

http://phors.locost7.info/phors11.htm

Stopping TIME varies linearly, i.e. twice the speed needs approximately
twice the time to come to a stop. On the other hand, stopping distance
varies as the square of the speed i.e twice the speed = 4 times the stopping
DISTANCE. For example, the stopping distance for an Enzo Ferrari is given
as 109 feet from 60 mph. However from 80mph the distance increaes to 188
feet. An increase of 33% in speed has resulted in an increase of 72% in
stopping distance. In other words, it may be possible to stop more quickly
than a slower vehicle with less efficient brakes but still travel much
further whilst doing so. This can deceive drivers into thinking that their
better stopping times actually equal better stopping distances - it ain't
necessarily so

Stopping from 150mph takes a MINIMUM of about about 740 feet in a modern
high performance car (very close to the 754 feet distance calculated in the
link posted above) . See here:

http://www.nsxprime.com/FAQ/Media/magazines/cd9808.htm

There is no reason to believe that any motorcycle would substantially
improve on this

The highway code, based somewhere near the stopping times of that legendary
Mark 1 Cortina (it was actually done with a Ford Anglia in 1968) gives 315
feet as the stopping distance from 70 mph. So it looks like the stopping
DISTANCE from 150 mph (about 750 feet), even with the best conceivable
braking system, will still be more than double that of the Mark 1 Cortina
from 70 mph. All that would be needed to disprove this proposition would be
for you or anyone else to brake to a stop from 150 mph in less than 315
feet - so get out from behind your desk, put the 'seat of your pants' on a
fast bike and show us that its possible - frankly you would be NOT be able
to to stop from 150 mph in under TWICE the distance of that crappy old Ford
Anglia/ Mark 1 Cortina takes at 70 mph.