From: pae@teal.csn.org (Phil Earnhardt)
Newsgroups: rec.skate
Subject: Re: ROLLER-BRAKE Survey Results & Continued...
Date: 21 Dec 92 20:52:26 GMT
Distribution: rec
Organization: Colorado SuperNet, Inc.

In article <1992Dec17.023657.16553@vax5.cit.cornell.edu> pl3x@vax5.cit.cornell.edu writes:
>To generalize, the responses seem to be favorable for the developement of a
>new brake system, but most seem to feel gthat the current methods available
>are enough.

It really depends on how your marketing types market it. If they say that
current braking systems are categorically unsatisfactory, then you can
count on a negative reaction from skilled skaters.

I request that you exercise great care in the language that you use to
market such a devide.

>Put simply, same stopping geometry as pads(rear pad) but with ABS - anti-lock
>braking.

Now, this is an interesting analogy! Did you know that ABS is *not* the
most efficient means of stopping a car? Threshold braking -- applying braking
force to the threshold of the surface's limit of traction -- is the most
efficient means of stopping. On all surfaces.

It does take great skill to perform threshold braking. Instructors at the Ford
Ice Driving School in Steamboat Springs, CO, can do it, but they don't teach
it in their intro courses. I'd guess after a couple of weeks' worth of driving
on their ice'n'snow track that you could begin to learn how to do it.

One other comment about ABS: I'd be happier of *everybody* took a half-day ice
driving course than if *everybody* had ABS. We'd be better off if everyone
knew the limits of their vehicles and drove accordingly -- if they drove in
such a way that they didn't *need* to use the stopping power of an ABS. After
all, it doesn't do you a whole heck of a lot of good if *you* can stop but the
driver behind you can't. ABS won't help if you're not alert.

>Having ridden the prototypes myself, it really is similar to stopping with
>ABS in a car to skidding in one without. Control is maintained since the
>braking "wheel" does not skid. 

...which implies that control is *not* maintained when using traditional
brakes on in-lines. Woe unto your venture if you start emitting marketing
statements which utters "facts" like this.

Did you answer the question I asked before: is any of your team highly skilled
in traditional braking? Have you seen the "triangle" method that we describe
in the FAQ?  This method gives you stability when stopping; it's the
breakthrough technique in braking technology.

Also, have you used polyurethane brakes? They have a different "grab" than
earlier brakes. I believe it connects and releases at a much higher frequency
than other brakes...

>4. any distinct perfomance parameters a brake must exceed to be worthy of
>purchase? Someone mentioned on a repost that a 1ft per MPH was doable with
>pads. Someone else claimed a 6ft stop from 25MPH.

1ft/mph would be mightily good. 2ft/mph would be quite acceptable. Skaters
will have to have quite good fore/aft balance to keep from falling at even the
lower deceleration.

I'm also interested in your heat dissipation properties. Will your device fail
on, say, a 2000-foot descent (7%+ grade) for a 200lb+ skater? I don't know if
you have any such trails in the East; this is part of the terrain on the bike
path over Vail Pass from Copper Mountain to Vail.

If you're interested in a volunteer, I'd be more than willing to test your
device on The Pass. I would attach a boring-but-functional brake on my other
boot. And it may be April/May before the path is clear...

>Todd Stiers

--phil
Newsgroups: rec.skate