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Discussion Starter #1
Re: [EVDL] * Re: Throttle cut-off

dale henderson wrote:

> that's the thought i had "two types... if the rider
> doesn't maintain some action" if the bike could
> respond to some action that should not happen in a
> burn out, maybe a butt switch? i think most people
> raise their weight off the bike for a burn out
> [right?], if the bike measured some sudden weight or
> inertia it would shut off, or maybe just sensor
> [button?] in the seat: you sit down the bike shuts
> off. of course that option will need to be turned off
> when not doing burn outs.

I suspect that designing hardware specific to enhancing the safety of
brakestands being performed elsewhere than on the dragstrip is more
effort than is warranted given that the bike's mission is drag racing
and the additional interlocks, etc. would quite possibly interfere with
reliable operation on the strip.

I think the solution for public displays may be as simple as ensuring
that there is adequate clear space in front of any waterbox to allow
safely stopping the bike should it launch.

I haven't had the pleasure of doing a brakestand on a bike of this HP,
but my experience with other bikes is that the rider stands, applies the
front brake, and leans on the handlebars which compresses the front
forks and transfers some weight off the rear wheel just as the throttle
is rolled on. During the brakestand the front forks remain compressed,
so a switch that cuts off the controller if the forks extend normally
could also work, however, like any of the other approaches, it would
just be one more bit of wiring that could interfere with the bike's
normal operation at the strip.

Cheers,

Roger.

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Discussion Starter #2
Re: [EVDL] * Re: Throttle cut-off

Roger Stockton wrote:

> I suspect that designing hardware specific to enhancing the safety of
> brakestands being performed elsewhere than on the dragstrip is more
> effort than is warranted given that the bike's mission is drag racing
> and the additional interlocks, etc. would quite possibly interfere
> with
> reliable operation on the strip.

I agree.

> I think the solution for public displays may be as simple as ensuring
> that there is adequate clear space in front of any waterbox to allow
> safely stopping the bike should it launch.

I agree but...

That is not as easy as it sounds. In fact Bill did provide enough
distance in front that no bystanders appeared to be in danger and
Bill almost stopped the bike. How much power, how much traction, how
fast a reaction time equals how much distance? Not an easy call.

My understanding is that EV drag bikes have a mechanical disconnect
attached to the pilot (with that kind of power "pilot" seems more
appropriate than "rider".) Perhaps that should be attached a short
distance behind the bike, instead of to the rider, for exhibition
stunts. Then the power would have been cut after only a few feet of
the launch making it easier to stop in time. Plus, its just a reuse
of an existing safety system and not something new that may interfere
with proper track performance.

One can be sure that Bill is thinking about safety systems again.
Hey, I thought I had my EV buggy handled too, until I found out I
couldn't reach the dash while backing up! (and that safety gap is
being addressed) I'd enjoy hearing Bill's input on the subject
(beyond "me no pilot" :) That kind of power and no serious harm - he
clearly knows what he is doing.

Paul

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Discussion Starter #3
Re: [EVDL] * Re: Throttle cut-off

I'm inclined to say that one thing we did learn from Bill's experience is
that precautions weren't quite adequate. Property damage happened.
Is the bike licensed and insured for street riding? That is what it
ended up being, a ride, not a non-moving exhibition. A downside to
the press coverage is that if we want to be able to do exhibition
burnouts anywhere but at the strip, I think we need to be prepared to
explain what has been done to prevent a recurrance. Once can be
seen as a miscalculation. To do another exhibition without improved
safety precautions would generally be perceived as carelessness, if
not illegal.

Personally, I'd say that if you don't want to run safety equipment
beyond what is required for the controlled and insured conditions at
the strip, then the only place the bike should be doing burnouts is at
the strip. If we don't police this ourselves, we may not like it when
some safety zealot starts making mandates.

If a safety device is thought to be too unreliable on the strip
(which suggests to me that it's too unreliable to be a safety device),
then disconnect it when racing. But if the bike is going to be used
for public exhibitions and at the strip, then safety around the general
public should be priority one in my opinion.

----- Original Message -----
From: "Paul" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Monday, September 17, 2007 6:55 PM
Subject: Re: [EVDL] * Re: Throttle cut-off


>
Roger Stockton wrote:
>
>> I suspect that designing hardware specific to enhancing the safety of
>> brakestands being performed elsewhere than on the dragstrip is more
>> effort than is warranted given that the bike's mission is drag racing
>> and the additional interlocks, etc. would quite possibly interfere
>> with
>> reliable operation on the strip.
>
> I agree.
>
>> I think the solution for public displays may be as simple as ensuring
>> that there is adequate clear space in front of any waterbox to allow
>> safely stopping the bike should it launch.
>
> I agree but...
>
> That is not as easy as it sounds. In fact Bill did provide enough
> distance in front that no bystanders appeared to be in danger and
> Bill almost stopped the bike. How much power, how much traction, how
> fast a reaction time equals how much distance? Not an easy call.
>
> My understanding is that EV drag bikes have a mechanical disconnect
> attached to the pilot (with that kind of power "pilot" seems more
> appropriate than "rider".) Perhaps that should be attached a short
> distance behind the bike, instead of to the rider, for exhibition
> stunts. Then the power would have been cut after only a few feet of
> the launch making it easier to stop in time. Plus, its just a reuse
> of an existing safety system and not something new that may interfere
> with proper track performance.
>
> One can be sure that Bill is thinking about safety systems again.
> Hey, I thought I had my EV buggy handled too, until I found out I
> couldn't reach the dash while backing up! (and that safety gap is
> being addressed) I'd enjoy hearing Bill's input on the subject
> (beyond "me no pilot" :) That kind of power and no serious harm - he
> clearly knows what he is doing.
>
> Paul
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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