TR3 roll cage

[Greg_Blake]

Does anybody have a good drawing or picture(s) of a roll cage for a vintage race TR3?

Thanks,

Greg

 

[aeronca65t]

There are a couple on this page, but some are more of the "forward diagonal" type of cage...not many *true* cages in TR-3s. ( https://64.23.28.109/tr3/index.html ).

Here's one...he certainly makes "the 2 inch helmet-clearance rules".:

 

[Deleted member 3577]

Bill bought that car new! /ubbthreads/images/graemlins/yesnod.gif

haven't seen him for a few months.
He didn't retire did he?

 

[JerryB]

Greg:

Very first thing to do is look at the rules of the club you will be racing with.

Usually all the vintage groups actually requre is a main hoop and suitable bracing....whatever that means.

What you really need in designing a cage is to look at the SCCA GCR for tube size requirements and basic design. 1.5" x .095" ERW will do it as those cars are about 1800 #.

The same goes for a low front hoop and main hoop design.

Unless you are bend and weld conversant you will want to find a good fabricator....'good' being the operative word here.

Good luck.

 

[Greg_Blake]

I want to run with CVAR. What has me concerned in the '72 rule book is the front hoop. It says that the front hoop has to be equal to or above the top of the steering wheel. In a TR3, this would not be practical, unless you build a full cage as in the picture you have posted. Now, lokng at the pictures on FOT and CVA, I see that not many racers follow this front hoop rule. So what rules are followed and what rules are bent?

Anyone know a goof fabricator in Austin TX?

Thanks,

Greg

 

[MGB12]

No front hoop is required by CVAR. " ROLL BARS/CAGES: All race cars must have a roll bar or roll cage that was, at a minimum original to the time of the car's manufacture and/or meet 1972 SCCA General Competition Rules. Post 1972 cars must have roIl-over protection, current with their organization's requirements, as long as they exceed CVAR rules and regulations. No race cars are allowed to participate in any CVAR race event without approved rollover protection" If you got you 1972 GCR from SCCA, their safety rules may have been updated.

That being said, make sure it all is safe. Look at potental loading to the bar(s) in all planes. Also be sure that the top of the roll bar is at least 2" above the top of the helmet of any potental drivers. Door bars will stiffen the car and add safety. CVAR has stated they intend to start taking a closer look at roll bars.

 

[Twosheds]

I like this one. The new owner put it in my old car. It is not welded to the frame, but bolts to the frame where the body attaches. And into the wheel arch, which is very strong. You can barely see part of the front hoop.

 

[Greg_Blake]

great picture. Do you have one of the front hoop under the dash?

 

[Twosheds]

You can just see the vertical part in this one. I can ask the new owner for more photos if you're interested. The front hoop would be hard to photograph, though.

 

[Monkeywrench]

Here is a picture of a typical rollbar set up for a vintage car. This one is for a Triumph TR4 (picture taken from www.tonydrews.com).

 

[Greg_Blake]

Thanks for all of the ideas. I met a guy today, he wleded my spider gears, who has been building cages for 15+ years. The TR will be visiting his shop once I get it rolling again. I'll post some pictures once it is done.

Greg