Michael:
Sorry to jump in on this, but this question went around the list a
while ago.
A roll bar will only protect a person if their body stays within the
limited area defined by the height and shape of the hoop. In a race car the
body is strapped securely to a seat and the head is protected by a helmet.
The race course is carefully managed to reduce the possibility of intrusion
into this protected area during a crash. Haybales, tires, armco etc.
For street use a roll bar is going to give limited protection in the
case of a roll over. To fit under a soft top, the bar tends to be low.
Stock seat belts do not hold the body firmly in the seat, and the head is
not protected if it impacts the bar. Luckily unlike an SUV (I couldn't help
myself) it is difficult to roll a sports car. Unfortunately the kind of
impact that involves a rollover tends to also involve lumpy bits that can
intrude into the area protected by the bar.
Roll bars do provide some side intrusion protection, so there is an
added element of safety in the more prevalent case of a T bone accident by
some idiot that did not see you.
All in all, installing a roll bar in a street car is a very personal
decision. The likelyhood that a rollbar in a street car will save your life
IMVHO is small. Once a sports car starts to roll, the fates have you in
their grasp. See Barneys pictures of Dick Criswell's fatal crash. A roll
bar would not have helped Dick. Driving skill and good seat belts are the
best way to stay safe.
As to the initial question. All of the commercially available roll
bars if installed correctly will keep the car off your head in the event of
a rollover on a solid surface. The question is, what were you doing rolling
over on a solid surface :)
Kelvin.
Who has a roll bar in his MGB GT, and Vintage race car. But does not plan
to put one in his MGB V8 street car.
> -----Original Message-----
> From: Michael Torrusio [mailto:mtorrusi@maine.rr.com]
> Sent: Wednesday, March 29, 2000 3:56 PM
> To: Eric
> Cc: MG CHAT LIST
> Subject: Roll bars
> Importance: High
>
>
> Eric;
> Does this mean that the of-the-shelf roll bars won't do a
> good job if we
> roll over during standard driving? (Assuming there is such a
> thing as a
> standard rollover. And, if one gets a custom made roll
> bar,what's your
> protection if you bring it down to half size as you mentioned
> you would do
> for regular driving. And, lastly, there seems to be a bit of
> talk in this
> group about racing. How do I find out about it? I'm in
> Portland ME. And
> someone mentioned pylon racing. Any info about this?
> Thanks.
> --
> Michael Torrusio, Jr.
> USCG Master
> Seven Seas Yacht Delivery
> 443 253-0200
>
> ----------
> >From: Eric <eric@erickson.on.net>
> >To: Michael Torrusio <mtorrusi@maine.rr.com>
> >Subject: Re: Bodily Dimensions
> >Date: Wed, Mar 29, 2000, 10:10 PM
> >
>
> > Michael Torrusio wrote:
> >>
> >> Question:
> >> We are going to get a roll bar for our 71B. Is there any
> reason why
> >> you are having one built rather than getting one through say, Moss?
> >
> >> >
> >> > I have a person who is building me a rollbar (yes,
> finally) and he
> >> > would like to get materials and some construction happening
> >> > before this weekend when I can give him my car for a few
> hours for
> >> > the final fitting.
> >> >
> >
> >
> > Michael,
> >
> > Yep, it is a racing thing. The main reason is because I
> want the top of
> > my head to stay where it is and because I race my car and our rules
> > state that the rollbar needs to be more than 50mm above the driver's
> > head (to stop you losing the top of your head or breaking
> your neck if
> > you turn turtle).
> >
> > Most 'off the shelf' rollbars don't conform to this -
> especially if you
> > are wearing a helmet.
> >
> > The other requirements are that there needs to be a diagonal
> > crossmember, or a "tranverse tube between a top corner of the main
> > rollbar and a lower mounting point on the other side of the
> rollbar",
> > plus, for further strength I will have two "backstays".
> >
> > As you see... not the usual "off the shelf" rollbar and one
> which will
> > probably prevent me from putting the roof up (unless I can find some
> > ingenious modification to either the roof/frame or rollbar
> which fits
> > all requirements). I can make the rollbar (half cage)
> 'removable' to
> > return it to a 'roofed' vehicle for 'normal' driving.
> >
> >
> > Eric
> > '68MGB MkII
>
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