TRM Bolt-in Roll Bar pictures

[dinanm3atl]

In the "cage game" one persons better is another persons crap. There really is more than 1 way to do a cage and be safe. It seems though that one person will argue that their way is right to the death. Go figure :)

[matt]

You probably think nascar bars are awesome, don't you halston?

:p

[dinanm3atl]

Yup, exactly what I posted.

[matt]

Don't be so serious all the time. It's not good for you.

[dinanm3atl]

Ask Ken... I think I am the least serious person you will find ;)

[Elephant]

In the "cage game" one persons better is another persons crap. There really is more than 1 way to do a cage and be safe. It seems though that one person will argue that their way is right to the death. Go figure :)

That fo sho. Although personally I've looked at hundreds of cars and there are probably only a handful that I would consider unsafe, probably many that exhibit poor practices. Rather I am more amazed at the wide range of quality of workmanship. Even a basic 6 point cage welded in (sorry, I do consider bolt in unsafe for the most part) is going to generally be pretty safe. At some point it's simply diminishing returns, you can only get so much more safety out of it by improving the design.

And of course price. That, at least it seems to be which makes sense, is highly geographical. All I can say is I'm glad I'm living in the midwest where it seems I'm getting way more than I'm paying for!

Cheers.

[brodee]

One thing to think about with this bar is it doesn't appear you can run a rear seat with it. Although I will never have anyone in my back seat I have to leave it in to be class compliant in STX and I believe other classes are the same way. That means this bar would be off the table for me.

Then again if I was just doing auto-x I wouldn't bother with a bar at all, any stiffness gained is negated by the added weight. But since I will do DE's with the car also I wanted the security of a bar and the best mount points for my harnesses.

The rest of the design on yours looks great. I like the idea the rear plates are pre-bent. That was the biggest pain in the ass with my Kirk bar was getting the rear plates and the opposing plates curved correctly to fit right.

[matt]

I think we could fit a rear seat in with it with a little cutting. The harness bar is not as far back or low as it looks.

[z31maniac]

One thing to think about with this bar is it doesn't appear you can run a rear seat with it. Although I will never have anyone in my back seat I have to leave it in to be class compliant in STX and I believe other classes are the same way. That means this bar would be off the table for me.

+1

[brodee]

Can those of you that know the difference explain to me why the welded bar is so much better? Mine has fairly large plates and opposing plates on the opposite side of the metal with the 4 bolts going through the plate, the floor, then the other plate. To me for this to fail in a roll over it would need to tear out as much or more floor than if the plate was welded in. I could understand if it was just bolts in the floor without the opposing plates, are most bolt-in bars made that way?

[JGood]

Can those of you that know the difference explain to me why the welded bar is so much better? Mine has fairly large plates and opposing plates on the opposite side of the metal with the 4 bolts going through the plate, the floor, then the other plate. To me for this to fail in a roll over it would need to tear out as much or more floor than if the plate was welded in. I could understand if it was just bolts in the floor without the opposing plates, are most bolt-in bars made that way?

I think the idea is that in an impact, it could punch through the floorboard like a cookie cutter.

[z31maniac]

I think the idea is that in an impact, it could punch through the floorboard like a cookie cutter.

And I think his question is, that why would a bolt in bar do this, but not a welded in bar.

[matt]

Even a basic 6 point cage welded in (sorry, I do consider bolt in unsafe for the most part) is going to generally be pretty safe.

How are you going to weld a roll cage into a McLaren F1? :mrgreen:

I would say that bolt in cages are not unsafe just because they bolt in, they are unsafe because (in general) they are poorly designed and constructed.

Take the two extremes: Would you rather have a crappy fitting bolt in cage welded into your car (with all the bolt in tubes welded also), or would you rather have a custom, excellent fitting, no-bolted-together tubes cage installed, but with each base plate only bolted to the unibody? Luckily, nobody has to make that choice, but I know which I would go for.

Crap is crap whether it bolts in or is welded. Crap designs can also be installed with incredible craftsmanship, but that's a whole different issue.

[brodee]

And I think his question is, that why would a bolt in bar do this, but not a welded in bar.

Exactly

[Elephant]

Can those of you that know the difference explain to me why the welded bar is so much better? Mine has fairly large plates and opposing plates on the opposite side of the metal with the 4 bolts going through the plate, the floor, then the other plate. To me for this to fail in a roll over it would need to tear out as much or more floor than if the plate was welded in. I could understand if it was just bolts in the floor without the opposing plates, are most bolt-in bars made that way?

A welded bar is joined metal to metal at the molecular level. A good metal to metal joint is always going to be stronger than typical bolted joints. The strength of bolted joints really comes mostly from the bolts holding it together.

Even in a roll over the forces put through the cage are not strictly axial, there are shear forces too. Bolts are not going to be as strong in shear as a welded connection.

As the chassis is used (IE driving) those bolted connections will loosen up slightly. Enough for you to notice? Maybe, maybe not. But a welded connection will not loosen with exception to metal fatigue failure. And if that was going to happen with a welded connection it most certainly would happen, and likely worse, to a bolted connection.

It is possible to get a good solid bolted connnection. But a quality welded connection will always be better. Honestly for a roll bar, it's not as big of a deal to bolt vs weld, it's much more important in a cage. Personally, I will always weld unless there is a specific reason not to.

Cheers.