Suspension Geometry for our builds


That's a really great find! Especially this advice:

"… don’t install a roll bar so close to the driver’s or passenger’s head … that they hit it in an impact … UNLESS you are ALWAYS going to wear a helmet … including on the street. Guys have died from moderate wrecks on city streets, when their unprotected head hit the roll bar and split their head open. In those type of typical auto wrecks, they would have been better off to have no roll bar. Please don’t use this as an excuse to not have one. Just install it with this in mind.

NHRA requires the roll bar to be within 6” of the driver’s helmet. My rule of thumb is make sure the roll bar is 5” from the primary driver’s head with no helmet on, which should work out to 4” from the driver’s head with a helmet on. Most 5-point harnesses … if cinched really tight (as in uncomfortable at first) … allow about 2” of driver movement in hard wrecks. (I know from in-car video.) 4”-5” distance between human heads and steel tubing “should” keep the driver & passenger’s heads from hitting the roll bar, yet still be close enough for the roll bar to provide driver protection in a roll over."