Suspension AutoPower cage ?
6th Gear
Joined: Aug 2004
Posts: 1,629
Likes: 7
From: Pipe Creek, Texas
Not all roll bars have the same design. Nathan brought up a point about air curtain deployment and from the air curtains I’ve seen after inflation, as long as there is enough room for the B pillar trim to move forward a little more than an inch and the headliner is allowed drop about three inches at the edges, there is enough room for the air curtain. The curtain also has a strap at the B pillar line so the main hoop will not be much more of a barrier. The Autopower’s rear braces will keep the rear curtain section from inflating outwards, but then there should be no passengers in the rear of the cabin anyway, if there is a bar in the car.
In Built-By-Bones design, there is plenty of room for curtain deployment.
If you want to be competitive in auto-x, a bar will slow you down and there is a very low risk of roll-over, plus, auto-x speeds will not likely create a situation where the OEM design might be compromised. I’m all for augmented safety on the street and as long as there is no compromise of the outstanding air bag system, I think a bar is ok.
In Built-By-Bones design, there is plenty of room for curtain deployment.
If you want to be competitive in auto-x, a bar will slow you down and there is a very low risk of roll-over, plus, auto-x speeds will not likely create a situation where the OEM design might be compromised. I’m all for augmented safety on the street and as long as there is no compromise of the outstanding air bag system, I think a bar is ok.
It looks to me like the rear braces of the Bones bar are clamped to the main hoop. I'm not sure how strong that connection would be. I don't believe that clamp arrangement would pass muster with an SCCA tech inspector. Got any close up pictures of that connection?
6th Gear
Joined: Aug 2004
Posts: 1,629
Likes: 7
From: Pipe Creek, Texas
Actually, longer braces are at a better advantage than shorter braces. Keep in mind this is a street application with access as a consideration. Diagonal and cross bracing are options if track use was intended. Here is a picture of onasled’s former sport model (non-straight rear braces) with the optional cross bracing which can be welded options (recommended for door-to-door racing), and in reality if you are going to do door-to-door racing you should have a halo arrangement and every thing should be welded with at least six anchor points.
I’m not against the AutoPower or any one else’s approach, but since you mentioned the brace insertions; don’t they (AP) have two bolts as fasteners?
There is a great deal of MINI specific engineering involved in the B-B-B design and every other bolt-in bar I’ve seen makes me appreciate it more. If you were to see the base plates and the main hoop’s base reinforcement compared to the “other” brands you would be singing a different tune.
I’m not against the AutoPower or any one else’s approach, but since you mentioned the brace insertions; don’t they (AP) have two bolts as fasteners?
There is a great deal of MINI specific engineering involved in the B-B-B design and every other bolt-in bar I’ve seen makes me appreciate it more. If you were to see the base plates and the main hoop’s base reinforcement compared to the “other” brands you would be singing a different tune.
Peace Keeper
Joined: Dec 2006
Posts: 2,747
Likes: 1
From: Defiance, Ohio
Ok, now I can see where you are coming from. And Yes, that cage is exactly what I would be looking for from them. Very Nice looking products, just did not know what to really think about them. Maybe I will do a comparison between the two and decide which to use in the end.
2nd Gear
Joined: Jul 2003
Posts: 122
Likes: 0
From: Redstone Canyon, near Masonville
Keith pointed me to this thread. I have not read the entire thread, so bear with me if I repeat some info.
Keith's bar is strictly for the street, and access was a concern for him, that is why there is no diagonal or X-bracing. We do offer bolt in additions that brace the main hoop, and serve as anchor points for the shoulder harness'.
Remember that cages and roll bars are as unique as the drivers who need them.
Some people just want a secure place to attach a harness, some people want some additional security for track or HPDE days, some people need to comply with sanctioning body rules and will choose a bolt in cage, some people want (and can afford) a cage with all the bells and whistles.
For a driver going wheel to wheel, or door to door, I would recommend a bolt in cage at the very minimum, and a fully welded 6 or 8 point cage if they can afford it. I still struggle to comprehend how some drivers will spend $3K or $4K on go-fast mods, but they baulk at spending half that on adequate safety equipment.
There is nothing wrong with an Autopower cage, or any of their products, provided they are correctly installed. Autopower offers very good value for money, and I cannot compete with their pricing. To call an Autopower cage a death cage is just ignorant. Some safety gear is better than none at all, but you need to be cognisant that adding race track related safety equipment to your daily driver, may actually compromise some of the safety features of the Mini during normal road use. Air bag deployment is one concern. If you have a roll bar in your car, I strongly recommend that you do not carry passengers in the rear seat, if you are t-boned by another car, you risk that your passengers will come into contact with the bar, or rear bracing.
Likewise, if you have a fully caged car, and drive it on the street. There is a chance that your head may make contact with the upper halo if you are involved in an accident. And the FIA/SFI padding will not cushion the blow (you are using the "hard" padding right? not the pool noodle stuff).
The chances of anything like this happening, is pretty small and remote, but it is a real possibility. if we had unlimited budgets, and could afford a dedicated race car, then this is not an issue, but in the real world we are all financially constrained in some way.
As far as those clamps are concerned, my own 2003 Cooper S had a roll bar, that passed tech for SCCA Club Trials, with two of those clamps as shown on Keith's bar. The bar was removed and replaced with a full cage (bolt in) with the rear braces attached to the hoop with those clamps and passed NASA tech. A friend of mine, who is a licensed tech inspector for the SCCA has examined the cage and would have no problem passing it.
The cage was also examined by Pete Taylor (Taylor engineering, and the winner of SSC in a Mini the last two years. Pete also builds the roll cages for many of the front runners in the SCCA, as well as the cages in the Dodge Neons that ran in SCCA Rally) at the Mini Cooper Challenge event in Las Vegas in 2006, and he had no problem with those clamps. I would happily discuss those clamps with any inspector who thinks they may be unsafe.
I have also used those clamps for roll hoops for cars that run at Bandimere and they have passed NHRA tech. Those clamps were originally designed and built for roll cages for off road vehicles. I have personally examined a Jeep wrangler that rolled 4 times in Moab, and while the roll cage tube bent in a number of places, none (yup, none) of the clamps showed any sort of failure.
We have tested a number of those clamps to destructive failure, and the clamps have always held up fine. The tube the clamp attaches to will bend or kink, and in certain cases, the tube welded to the clamp will fail. The tube fails right next to the HAZ (heat affected zone) next to the weld on the clamp.
The only potential area of concern, playing devils advocate, would be that in a particularly violent impact, the clamp may slip on the tube,IF not installed correctly. Highly unlikely, but possible. You could always put a bead of weld next to the clamp to prevent this (but if you have the ability to do this, I am going to recommend that you use a weld in cage, not the bolt in style)
Personally I see the safety ladder as follows with regard to bars and cages
- stock Mini, no cage or roll bar
- Roll bar with rear bracing, ( $300 to $800)
- Roll bar with rear bracing, diagonal or X brace within main hoop, shoulder harness bar ($500 to $1000)
- Bolt in cage, 4 point, then 6 point, then 8 point. ($400 to $1500)
- Weld in cage (like an Autopower, that you fit and weld) ($600 to $2000)
- Custom cage welded in, with NASCAR style door bars. ($1500 to $3500)
- Custom cage built to FIA rally specs, in my opinion the best cage possible, ($3500 to $5000)
Some important things to look for in a cage
- tubing. Make sure the tube in the cage is DOM, drawn over mandrel. Do not buy a cage with ERW or HREW tube (welded seam tube). Most sanctioning bodies do not accept this tube any longer (not sure about NHRA)
- tubing size. The bigger the diameter, the stronger the tube, and the thinner the tube wall can be. Bigger also equals heavier though. At a bare minimum you should be looking for tubing that is 1.5" in dia. and 0.120" wall thickness. I would recommend that the main hoop, the halo, and the side hoops are 1.75"x 0.095". Bracing tubes should at the minimum be 1.5" x 0.095". Some gussets and smaller bars can be 1.25" x 0.095"
- While Chromolly is nice (and $$$) it is important to check that the cage has been "normalized" if it has been tig welded. Welding puts a lot of heat into the metal, and this changes the structure of the metal on a microscopic level. This hardens the metal and makes it brittle, and failures usually occur on the edge of the HAZ. A good cage builder will normalize the cage by heating each weld joint with an oxy-acetylene flame until cherry red, and then let it air cool.
- Bolt in cages. make sure all the hardware and fasteners are a minimum of grade 5 (preferably grade 8). Make sure all your base plates have backing plates of adequate size, and at least 3/16" thick, preferably 1/4". Weld in cages should have minimum 1/8" mounting plates and should be perimeter welded.
- Santion body rules. Make sure you have read and understand the rules pertaining to your car and santioning body. Take a copy of these to your cage builder, and make sure he understands them. Ask to see examples of his work. Don't ask a NHRA cage builder to build a cage legal for Rally America. (I would not have a problem if a rally cage builder built a cage for a drag car though)
-weight. bolt in is going to be heavier, and marginally less stiff, than a weld in cage
- tube bends. The radius of the tube bend needs to be at least 3 times the diameter of the tube. There should be no visible evidence of kinking or crimping of tube. Your cage builder should be using a mandrel bender, not an exhaust tube bender, or a harbor freight conduit bender.
We no longer sell our sportbars through ebay, mostly because I have been so busy with cages this season, I could not keep up with demand. I currently have a 3 month waiting list for cage work, and rely strictly on word of mouth advertising from local racers for work.
I hope that answers most of your questions. please PM me if you wish to discuss this further, I do not look at NAM too often.
many thanks
Grant "Bones" Barclay
Built-By-Bones Inc.
Keith's bar is strictly for the street, and access was a concern for him, that is why there is no diagonal or X-bracing. We do offer bolt in additions that brace the main hoop, and serve as anchor points for the shoulder harness'.
Remember that cages and roll bars are as unique as the drivers who need them.
Some people just want a secure place to attach a harness, some people want some additional security for track or HPDE days, some people need to comply with sanctioning body rules and will choose a bolt in cage, some people want (and can afford) a cage with all the bells and whistles.
For a driver going wheel to wheel, or door to door, I would recommend a bolt in cage at the very minimum, and a fully welded 6 or 8 point cage if they can afford it. I still struggle to comprehend how some drivers will spend $3K or $4K on go-fast mods, but they baulk at spending half that on adequate safety equipment.
There is nothing wrong with an Autopower cage, or any of their products, provided they are correctly installed. Autopower offers very good value for money, and I cannot compete with their pricing. To call an Autopower cage a death cage is just ignorant. Some safety gear is better than none at all, but you need to be cognisant that adding race track related safety equipment to your daily driver, may actually compromise some of the safety features of the Mini during normal road use. Air bag deployment is one concern. If you have a roll bar in your car, I strongly recommend that you do not carry passengers in the rear seat, if you are t-boned by another car, you risk that your passengers will come into contact with the bar, or rear bracing.
Likewise, if you have a fully caged car, and drive it on the street. There is a chance that your head may make contact with the upper halo if you are involved in an accident. And the FIA/SFI padding will not cushion the blow (you are using the "hard" padding right? not the pool noodle stuff).
The chances of anything like this happening, is pretty small and remote, but it is a real possibility. if we had unlimited budgets, and could afford a dedicated race car, then this is not an issue, but in the real world we are all financially constrained in some way.
As far as those clamps are concerned, my own 2003 Cooper S had a roll bar, that passed tech for SCCA Club Trials, with two of those clamps as shown on Keith's bar. The bar was removed and replaced with a full cage (bolt in) with the rear braces attached to the hoop with those clamps and passed NASA tech. A friend of mine, who is a licensed tech inspector for the SCCA has examined the cage and would have no problem passing it.
The cage was also examined by Pete Taylor (Taylor engineering, and the winner of SSC in a Mini the last two years. Pete also builds the roll cages for many of the front runners in the SCCA, as well as the cages in the Dodge Neons that ran in SCCA Rally) at the Mini Cooper Challenge event in Las Vegas in 2006, and he had no problem with those clamps. I would happily discuss those clamps with any inspector who thinks they may be unsafe.
I have also used those clamps for roll hoops for cars that run at Bandimere and they have passed NHRA tech. Those clamps were originally designed and built for roll cages for off road vehicles. I have personally examined a Jeep wrangler that rolled 4 times in Moab, and while the roll cage tube bent in a number of places, none (yup, none) of the clamps showed any sort of failure.
We have tested a number of those clamps to destructive failure, and the clamps have always held up fine. The tube the clamp attaches to will bend or kink, and in certain cases, the tube welded to the clamp will fail. The tube fails right next to the HAZ (heat affected zone) next to the weld on the clamp.
The only potential area of concern, playing devils advocate, would be that in a particularly violent impact, the clamp may slip on the tube,IF not installed correctly. Highly unlikely, but possible. You could always put a bead of weld next to the clamp to prevent this (but if you have the ability to do this, I am going to recommend that you use a weld in cage, not the bolt in style)
Personally I see the safety ladder as follows with regard to bars and cages
- stock Mini, no cage or roll bar
- Roll bar with rear bracing, ( $300 to $800)
- Roll bar with rear bracing, diagonal or X brace within main hoop, shoulder harness bar ($500 to $1000)
- Bolt in cage, 4 point, then 6 point, then 8 point. ($400 to $1500)
- Weld in cage (like an Autopower, that you fit and weld) ($600 to $2000)
- Custom cage welded in, with NASCAR style door bars. ($1500 to $3500)
- Custom cage built to FIA rally specs, in my opinion the best cage possible, ($3500 to $5000)
Some important things to look for in a cage
- tubing. Make sure the tube in the cage is DOM, drawn over mandrel. Do not buy a cage with ERW or HREW tube (welded seam tube). Most sanctioning bodies do not accept this tube any longer (not sure about NHRA)
- tubing size. The bigger the diameter, the stronger the tube, and the thinner the tube wall can be. Bigger also equals heavier though. At a bare minimum you should be looking for tubing that is 1.5" in dia. and 0.120" wall thickness. I would recommend that the main hoop, the halo, and the side hoops are 1.75"x 0.095". Bracing tubes should at the minimum be 1.5" x 0.095". Some gussets and smaller bars can be 1.25" x 0.095"
- While Chromolly is nice (and $$$) it is important to check that the cage has been "normalized" if it has been tig welded. Welding puts a lot of heat into the metal, and this changes the structure of the metal on a microscopic level. This hardens the metal and makes it brittle, and failures usually occur on the edge of the HAZ. A good cage builder will normalize the cage by heating each weld joint with an oxy-acetylene flame until cherry red, and then let it air cool.
- Bolt in cages. make sure all the hardware and fasteners are a minimum of grade 5 (preferably grade 8). Make sure all your base plates have backing plates of adequate size, and at least 3/16" thick, preferably 1/4". Weld in cages should have minimum 1/8" mounting plates and should be perimeter welded.
- Santion body rules. Make sure you have read and understand the rules pertaining to your car and santioning body. Take a copy of these to your cage builder, and make sure he understands them. Ask to see examples of his work. Don't ask a NHRA cage builder to build a cage legal for Rally America. (I would not have a problem if a rally cage builder built a cage for a drag car though)
-weight. bolt in is going to be heavier, and marginally less stiff, than a weld in cage
- tube bends. The radius of the tube bend needs to be at least 3 times the diameter of the tube. There should be no visible evidence of kinking or crimping of tube. Your cage builder should be using a mandrel bender, not an exhaust tube bender, or a harbor freight conduit bender.
We no longer sell our sportbars through ebay, mostly because I have been so busy with cages this season, I could not keep up with demand. I currently have a 3 month waiting list for cage work, and rely strictly on word of mouth advertising from local racers for work.
I hope that answers most of your questions. please PM me if you wish to discuss this further, I do not look at NAM too often.
many thanks
Grant "Bones" Barclay
Built-By-Bones Inc.
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