Roll Bars in Street Cars
- Category: Safety & Driving
By Bruce Baker, Bud Osbourne, Victor Wild, and Barry Lee Brisco
Roll bars installed in 356s that are only driven on the street, while looking undeniably cool, do raise the question of occupant safety, but perhaps not in the obvious way. Yes, they can prevent the roof from collapsing onto the occupants in a rollover accident, but they can also inflict lethal head injuries in more typical accidents (like rear enders), since they are located close to the occupants heads and 356 seats are very low compared to modern cars.
On race cars, helmets and roll bar padding are mandatory, protecting the skull from injury. But when was the last time you saw a 356 driver wearing a helmet for daily driving in his roll bar-equipped vintage Porsche?
What follows is taken from a discussion initiated on 356Talk, with additional comments by veteran 356er and racer Bruce Baker. It is a cautionary tale for those who have roll bars installed in their "street only" 356s. This article is not about how to safely mount roll bars, safe roll bar design, or roll bar racing regulations, it is simply about the use of roll bars in 356s that are primarily used for street driving only.
Please keep in mind that the photos shown on this page are only examples of roll bars in 356s, they are not meant to illustrate recommended methods of mounting or racing approved styles. [Barry Lee Brisco]
Victor Wild — Real World Wrecks and 356 Roll Bars
In a real car wreck the head makes incredible and violent excursions off axis from it's natural position. This means that if you do not have a helmet on a roll bar is very likely to crush your skull. It's just physics. Have you ever noted roll bar shaped dents in a helmet after a racing crash?
Unfortunately the roof pillars of a 356 are pretty insubstantial. A roll bar placed far enough aft to be out of head range would be pretty low [Ed: and probably not be very effective in a rollover accident].
Bud Osbourne — Roll Bars in Street 356s Are Not a Good Idea
Over the years, I've seen a lot of "boy racer" roll bars, mounted in various sports cars, and I've always thought the same thing that Victor has: not a smart idea, for a street driven car, in which the occupants are not wearing helmets. Some may have noticed the padding, on roll bars, in race cars. This is required (I know, from 1st hand experience, that SCCA is very fussy about roll bar padding) by SCCA and others, because, even with a helmet on, a roll bar is capable of busting your head, in an accident.
Moral of the story: Roll bars, in "street" cars, are not a good idea, unless you can be sure that your head CANNOT come into contact with them, under any circumstances. In a car as small as our 356s, it would be pretty much impossible to locate a roll bar that your head could not contact, during a violent crash. Padding, of a sufficient amount to protect the un-helmeted head, would add so much bulk to the roll bar that it could hamper visibility, and look a bit silly, to boot.
Bruce Baker — Original 356 Roll Bars Require Helmets and High Seats
First, "modern" convertibles like my wife's VW Cabrio have lightly padded roll bars, but seats with integrated headrests. Obviously, automakers feel that the risk of striking your head is outweighed (to coin a phrase) by the car coming to rest ON you should it turn over.
My crash in my Speedster was oblique and not in the fore/aft design for the "expected" dynamics, thus I struck my helmeted head on the padded brace that went from the top center of the hoop to the front right of the passenger side, shattering my helmet and giving me a severe concussion BUT, along with a "horse collar," keeping me from getting a broken neck. Another positive trade-off, as I'm able to write this now.
I have constructed and installed a few rollbars in customer open cars for their protection in a roll-over and for use as a proper attachment point for three-point seat belts for "street" use. If the construction maximizes the interior space when the top is up (a Speedster is difficult to work within but possible), it is similar (if padded) to the "modern cars" like the Cabrio, the TT convertible, the Boxster, etc. The key is to understand the forces of sudden stops and have a head restraint on the seat or the bar. Then the fore-and-aft action is covered and the lateral is minimized.
I was in CA in the early '80s and went to a Time Trial, I believe at Laguna Seca. I watched a C Coupe roll. The roof never caved in. Dented, yes, but not crushed. Stronger than anyone expected.
In the '60s, I was hillclimbing in PA in a Speedster. Many a car would roll. Whether open or closed, a rollbar was newly mandated. Those were cars that were righted, the oil checked, and then driven away.
I was Grid Chief at Watkins Glen for the 50th anniversary of racing there. In the rear of the huge grid for the all-MG Collier Cup was the only old T-series MG without a rollbar. I asked Denver Cornett, the aging driver, what he would do if it rolled. He replied that he had rolled the same car there in Milliken's Corner in the first or second race on the streets and roads surrounding the Glen in '48 or '49 and all he did was "duck under the cowl." I laughingly asked him to demonstrate that feat 50 years later and he replied "Can't! Gotta wear this seat belt now."
Think about that.
The design of safety equipment in an automobile is a blend and balance of an unpredictable list of "what-ifs." It always comes down to a worst-case scenario and luck. What we have learned is that in design and construction, the original optional rollbars in a 356 are better as visual static curiosities than practical devices. If it's really needed, you better be lucky, as they are downright dangerous without proper bracing, padding and a strong headrest. That's a case of "better nothing than something" instead of "better something than nothing."
Actually, the headrest function is the key ingredient.
Below, Bruce Baker "in good company" at Watkins Glen