46 replies to this topic

[sschassis]

To Clerify a few things, I have yet to build extra light roll cages. The lightest cage I have ever built was made from 1 1/2 .095 wall tubing . Most of our roll cages since 2011 were made from .120 wall and .105 wall tubing. If you would like heavier we would build it for you, safty is our #1 concern.The bar that bent on the 25 car was  around 4 feet away from the driver and in no way did any of the cage bend around the driver, offset cages do not even have that part of the cage.  As for the car that rolled the roll cage was not built buy me or in my shop. Last, my buisness name is SS chassis and Supply

[Schwarty28s]

That is how bad rumors get started, I heard that same rumor going around the pits all weekend and heard from reliable sources that it had nothing to do with an ss chassis...people need to get facts straight.

[Walt Wimer]

Right Bob!!   I heard the same thing, but just kept it to myself and did not repeat it!!

 

GOOD RACING!!!

 

Walt

[march66]

was told by a medic that the cage did NOT fail but they cut the door bars and top of the cage to get him out!  was a big guy and went  out the top with a lot of help. maybe someone close with the 81s can clear this up?

[GOTTI]

It was a tragic accident! Id be more than willing to bet seat and belts werent fitted right. But somehow thats s&s chassis fault for a car he didnt build. Some peoples stupidity is beyond belief

[racer777]

Again. Tech. Too many death traps on the racetrack weekly. Honestly I think it's time tracks focus more on racers safety. Face it. Alot of the racers mentality is that it won't happen to me. Wrong. Sooner or later you will be in a bad wreck. But racers would rather spend $1,000 on extra horsepower than $750 on a Hans. Make this stuff mandatory.and tech the damn cars. We are our worst enemy.

[RmiT]

Again. Tech. Too many death traps on the racetrack weekly. Honestly I think it's time tracks focus more on racers safety. Face it. Alot of the racers mentality is that it won't happen to me. Wrong. Sooner or later you will be in a bad wreck. But racers would rather spend $1,000 on extra horsepower than $750 on a Hans. Make this stuff mandatory.and tech the damn cars. We are our worst enemy.

AMEN

[jo73]

For anyone to make any statements after a driver is injured is ridiculous. Did someone see a S & S decal on the car and automatically start the rumor. As it was noted S&S CHASSIS AND SUPPLY. Maybe people should respect the guys family and keep there mouths closed for another time. Because this surely wasn't the time to start this.

[Mike Clark]

Just wanted to clear something up about impact forces. The equation for impact force is F=(1/2 x m x v²)/s. Where F=force, m=mass, v=velocity, and s=amount of crush on car.

 

So lets assume all of the cars we test have a crush of s=.5 ft.

 

Late Model 2350 lbs, and an average speed of 85 mph

Stock Car 3050 lbs, and an average speed of 75 mph

 

Late Model: F=(1/2 x 2350 lb x 85 mph(or 125 ft/s)²)/.5 ft = 3.67 x 10 ⁷ ft lbs/s²

 

Stock Car: F=(1/2 x 3050 lb x 75 mph(or 110 ft/s)²/.5 ft = 3.69 x 10 ⁷ ft lbs/s²

 

So as you can see the force of impact is basically the weight of the car multiplied by the speed, which in the example above the forces are very similar.

Also there are many things to consider in roll cage design: using correct triangulation the placement of much lighter bars can be much stronger then heaver bars.

Also you have to consider welded seam tubing verses DOM verses Chromoly. Chromoly being much stronger alloy then standard alloys.

 

You must also consider that bigger diameter tubing is much stronger, for example: 1.750" diameter by .065" wall thickness has a section modulus of .139 and 1.500" diameter by .095" wall thickness has a section modulus of .138. As shown they are almost identical in terms of strength.

 

Therefore there are several things to consider when a tech guy looks at a roll cage and tries to determine its safety, it would be virtually impossible without knowing what material was used and its thickness, let alone having a full understanding in roll cage design. That is where the big name chassis builders use CAD and Finite Element Analysis to determine actual strengths. But for that stock car guy who builds his own chassis they just needs to research a little and learn a few basic principles to build a safe roll cage. 

 

My thoughts and prayers to the Henry Family. 

[Crusty1]

Just wanted to clear something up about impact forces. The equation for impact force is F=(1/2 x m x v²)/s. Where F=force, m=mass, v=velocity, and s=amount of crush on car.
 
So lets assume all of the cars we test have a crush of s=.5 ft.
 
Late Model 2350 lbs, and an average speed of 85 mph
Stock Car 3050 lbs, and an average speed of 75 mph
 
Late Model: F=(1/2 x 2350 lb x 85 mph(or 125 ft/s)²)/.5 ft = 3.67 x 10 ⁷ ft lbs/s²
 
Stock Car: F=(1/2 x 3050 lb x 75 mph(or 110 ft/s)²/.5 ft = 3.69 x 10 ⁷ ft lbs/s²
 
So as you can see the force of impact is basically the weight of the car multiplied by the speed, which in the example above the forces are very similar.
Also there are many things to consider in roll cage design: using correct triangulation the placement of much lighter bars can be much stronger then heaver bars.
Also you have to consider welded seam tubing verses DOM verses Chromoly. Chromoly being much stronger alloy then standard alloys.
 
You must also consider that bigger diameter tubing is much stronger, for example: 1.750" diameter by .065" wall thickness has a section modulus of .139 and 1.500" diameter by .095" wall thickness has a section modulus of .138. As shown they are almost identical in terms of strength.
 
Therefore there are several things to consider when a tech guy looks at a roll cage and tries to determine its safety, it would be virtually impossible without knowing what material was used and its thickness, let alone having a full understanding in roll cage design. That is where the big name chassis builders use CAD and Finite Element Analysis to determine actual strengths. But for that stock car guy who builds his own chassis they just needs to research a little and learn a few basic principles to build a safe roll cage. 
 
My thoughts and prayers to the Henry Family.

Well said from top to bottom!
It sounds like we have a new chassis tech person!
Thanks for the input.

[yenko1]

lernerville is to worried about motors  to check a rollcage

[714d]

I don't know if it's changed recently, but Lernerville is the ONLY track that has checked dates on belts and mounting of other safety equipment in the cars I've helped over the years. Every track needs to step up in that category

[racer777]

I've been to plenty of tracks that never even looked to see if the car had seat belts. Let alone mounted properly. Alot of ppl do some dumb half assed shit. Most of it goes unchecked and uncorrected until something bad happens.

[Hatorade]

I do agree that tracks need to check for safety belts, devices etc. However, the thickness and safety of the cage are dependent upon the builder. I highly doubt that a chassis builder wants his name associated with a tragic incident such as this one. IMO they would be ludicrous to skimp. It is not worth jeopardizing your safety for $500.

[The Legend]

People buy containment seats and then bolt them to the 0.080 aluminum floor all the time. I absolutely crush the wall at lernerville and there isn't many straight pipes left on the car and my seat never moved and I went to the gym the next day just fine. The car is absolute trash but I was fine. Saftey needs to be taken seriously

[old man d]

Legend, a friend of mine went and saw you crash. He told you took one hell of a hit and walked away. Was glad to hear you where ok. I think all track techs should mandate a better safety guide line such as Belts, Seats, Cages and Welds. Cars that don"t pass go back on the trailer. Just my take.

[ramsey31]

I love seeing the blind bat who welds beside the seam rather than over it.  A few of those cars floating around

[Racefan68x]

tracks need to worry less about the back gate income and more about safety of the racers. but that will probably never happen.jmo

[bhhracing]

racing is a business, unless the track makes money off parts, they would have to spend more money to hire qualified techs and such, you know that aint happening.

[bigracer25k]

We all know racing is not the most safest sport but that is the chances that we as racers take. No one is to blame for this tragic accident. I think that it's a shame to try and put blame on anyone.