Tikt Roll cage/Bar
Thread Starter
Super Member
Joined: Jul 2019
Posts: 679
Likes: 262
AMG GT R Pro
Tikt Roll cage/Bar
Anyone know have this? Or know anyone who does? Bolt in? Any cutting or modification?
https://www.tikt.de/de/performance-p...-fuer-amg-gt-r
Might have to be the guinea pig here...
https://www.tikt.de/de/performance-p...-fuer-amg-gt-r
Might have to be the guinea pig here...
Member
Joined: Aug 2016
Posts: 139
Likes: 79
From: Redondo Beach
20 E450 Luxury
I do not know these cars, but I suspect the built in AMG GT roll bar is plenty strong?
I will make two observations. In Germany, ADAC is the controlling organization for motorsport, as such they approve motorsports safety devices. A group called TÜV authorizes any modifications to road cars. The simple question is it ADAC or at least TÜV approved as a replacement safety device? I see no reference on that page, a good first clue. From an engineering standpoint, safety cage and safety bars are made out of deformable, but extremely strong metal. The Carbon Fiber piece as depicted, will just shatter when its yield strength is exceeded, a good second clue. The saving of 6.6 Kg over a deformable, and therefore more robust factory designed piece is pretty expensive hamburger.
There were carbon fiber/titanium strut tower bars on the SUBAEU WRX STI versions in the 1990's. A beautiful piece, JIS approved. They were very strong, certainly plenty strong for road cars. But, we found that they would snap in two when used in a fully caged, even much stiffer Group N rally car. So, we went to a bolt-in, metal cross piece. It did did not shatter when stressed.
I will make two observations. In Germany, ADAC is the controlling organization for motorsport, as such they approve motorsports safety devices. A group called TÜV authorizes any modifications to road cars. The simple question is it ADAC or at least TÜV approved as a replacement safety device? I see no reference on that page, a good first clue. From an engineering standpoint, safety cage and safety bars are made out of deformable, but extremely strong metal. The Carbon Fiber piece as depicted, will just shatter when its yield strength is exceeded, a good second clue. The saving of 6.6 Kg over a deformable, and therefore more robust factory designed piece is pretty expensive hamburger.
There were carbon fiber/titanium strut tower bars on the SUBAEU WRX STI versions in the 1990's. A beautiful piece, JIS approved. They were very strong, certainly plenty strong for road cars. But, we found that they would snap in two when used in a fully caged, even much stiffer Group N rally car. So, we went to a bolt-in, metal cross piece. It did did not shatter when stressed.
Last edited by Mike__S; Jul 5, 2020 at 05:49 PM.
Thread Starter
Super Member
Joined: Jul 2019
Posts: 679
Likes: 262
AMG GT R Pro
I do not know these cars, but I suspect the built in AMG GT roll bar is plenty strong?
I will make two observations. In Germany, ADAC is the controlling organization for motorsport, as such they approve motorsports safety devices. A group called TÜV authorizes any modifications to road cars. The simple question is it ADAC or at least TÜV approved as a replacement safety device? I see no reference on that page, a good first clue. From an engineering standpoint, safety cage and safety bars are made out of deformable, but extremely strong metal. The Carbon Fiber piece as depicted, will just shatter when its yield strength is exceeded, a good second clue. The saving of 6.6 Kg over a deformable, and therefore more robust factory designed piece is pretty expensive hamburger.
There were carbon fiber/titanium strut tower bars on the SUBAEU WRX STI versions in the 1990's. A beautiful piece, JIS approved. They were very strong, certainly plenty strong for road cars. But, we found that they would snap in two when used in a fully caged, even much stiffer Group N rally car. So, we went to a bolt-in, metal cross piece. It did did not shatter when stressed.
I will make two observations. In Germany, ADAC is the controlling organization for motorsport, as such they approve motorsports safety devices. A group called TÜV authorizes any modifications to road cars. The simple question is it ADAC or at least TÜV approved as a replacement safety device? I see no reference on that page, a good first clue. From an engineering standpoint, safety cage and safety bars are made out of deformable, but extremely strong metal. The Carbon Fiber piece as depicted, will just shatter when its yield strength is exceeded, a good second clue. The saving of 6.6 Kg over a deformable, and therefore more robust factory designed piece is pretty expensive hamburger.
There were carbon fiber/titanium strut tower bars on the SUBAEU WRX STI versions in the 1990's. A beautiful piece, JIS approved. They were very strong, certainly plenty strong for road cars. But, we found that they would snap in two when used in a fully caged, even much stiffer Group N rally car. So, we went to a bolt-in, metal cross piece. It did did not shatter when stressed.
Only reason I’m looking is the GTR in North America don’t come with roll cages.
ill look elsewhere then carbon fibre though.
thanks for the info!
Junior Member
Joined: Feb 2019
Posts: 36
Likes: 46
From: Belgrade, Serbia
GTR
I do not know these cars, but I suspect the built in AMG GT roll bar is plenty strong?
I will make two observations. In Germany, ADAC is the controlling organization for motorsport, as such they approve motorsports safety devices. A group called TÜV authorizes any modifications to road cars. The simple question is it ADAC or at least TÜV approved as a replacement safety device? I see no reference on that page, a good first clue. From an engineering standpoint, safety cage and safety bars are made out of deformable, but extremely strong metal. The Carbon Fiber piece as depicted, will just shatter when its yield strength is exceeded, a good second clue. The saving of 6.6 Kg over a deformable, and therefore more robust factory designed piece is pretty expensive hamburger.
There were carbon fiber/titanium strut tower bars on the SUBAEU WRX STI versions in the 1990's. A beautiful piece, JIS approved. They were very strong, certainly plenty strong for road cars. But, we found that they would snap in two when used in a fully caged, even much stiffer Group N rally car. So, we went to a bolt-in, metal cross piece. It did did not shatter when stressed.
I will make two observations. In Germany, ADAC is the controlling organization for motorsport, as such they approve motorsports safety devices. A group called TÜV authorizes any modifications to road cars. The simple question is it ADAC or at least TÜV approved as a replacement safety device? I see no reference on that page, a good first clue. From an engineering standpoint, safety cage and safety bars are made out of deformable, but extremely strong metal. The Carbon Fiber piece as depicted, will just shatter when its yield strength is exceeded, a good second clue. The saving of 6.6 Kg over a deformable, and therefore more robust factory designed piece is pretty expensive hamburger.
There were carbon fiber/titanium strut tower bars on the SUBAEU WRX STI versions in the 1990's. A beautiful piece, JIS approved. They were very strong, certainly plenty strong for road cars. But, we found that they would snap in two when used in a fully caged, even much stiffer Group N rally car. So, we went to a bolt-in, metal cross piece. It did did not shatter when stressed.
Rear section is actually hybrid, so what You see on the outside is carbon layer for aesthetics and inside structure is combination of aramid braids and unidirectional carbon fiber. Compression force capacity is ~30% higher compared to matching component made in 25CrMo4 (40x2 sides, 35x1.8 harness bar and 30x1.5 diagonals) Tensile strength however is much higher in composite and that is what we are looking for in the rear cage section. Aramid fibers make it practically impossible to shatter or tear apart two broken pieces.
Member
Joined: Aug 2016
Posts: 139
Likes: 79
From: Redondo Beach
20 E450 Luxury
Correct, carbon/polymer structures do not shatter, they shred. Catastrophically.
The focus needs to be on this concept of deformability as the preferred failure mode. Deformability is a good thing, because is tied into energy absorption. Energy that is not passed onto the occupants. That absorption of energy in a crash is what road car design is all about. They are very much deformable structures by design, the trick being where to make them strong and where (and how) to make them absorb energy.
Carbon/Kevelar bits are inherently attractive simply for being thought strong, but more to the point, high tech and exclusive. Their effectiveness cannot be disputed in case of a complete, integrated carbon/kevlar structure such as used in F1, Indy car monocoque shell or LM endurance chassis. However, it is a different design paradigm. Everything is kevlar and carbon fiber to save mass and provide torsional rigidity to the chassis. These structures can sustain pretty massive, make that huge impacts, but these huge loads are imparted directly on the driver. In contrast, and no bonus safety feature, road cars use deformable metal crumple zones (and airbags) by design that are reinforced by robust, high tensile strength steel sections as and where needed.
I will still prefer a deformable failure mode tubing materials. Bracing a deformable roll bar by materials of similar strength and failure mode vs some hybrid combination of dissimilar strength materials would have to undergo a finite element simulation to prove my point that what we want are controlled deformation failure modes. And, we use this deformation concept as a way to absorb energy before it gets into the driver's body. One only need to view Petter Solberg's 2004 Baumholder crash
(minute 27:45) to appreciate a fully integrated high tensile strength steel cage system. A thirty percent increase in tensile strength and a poor failure mode is not what we would have wanted to see in this violent crash.
A 30% greater tensile strength number pales in force calculations. Force = (0.5 * m * v^2) ÷ d. That velocity squared bit (v^2) implies that we have a steel tubing that bends in a 200kph impact and a carbon/Kevlar bar that shreds on 230kph impact for its 30% greater tensile strength. Those are the choices when impact forces are in play. The carbon/kevlar piece is toast, it is has failed and not longer contributes any strength to the structure. This failure may possibly lead to other pieces failing. In contrast, the high tensile steel tube deforms, it bends, continuing to absorb significant force. With good design (and welding) it will absorb more energy without catastrophic failure well past its nominal tensile strength yield point. A hybrid steel/carbon kevlar tube design does not have this "beyond yield strength" structural integrity. This has been my point all along. Think NASCAR and rally car safety, closer cousins to track day risks.
My view is that failure mode and total system design integration are the key criteria, Solberg's car registered an impact of 30g, co-driver Phil Mills required hip surgery, but recovered well. It was a lucky day.
The focus needs to be on this concept of deformability as the preferred failure mode. Deformability is a good thing, because is tied into energy absorption. Energy that is not passed onto the occupants. That absorption of energy in a crash is what road car design is all about. They are very much deformable structures by design, the trick being where to make them strong and where (and how) to make them absorb energy.
Carbon/Kevelar bits are inherently attractive simply for being thought strong, but more to the point, high tech and exclusive. Their effectiveness cannot be disputed in case of a complete, integrated carbon/kevlar structure such as used in F1, Indy car monocoque shell or LM endurance chassis. However, it is a different design paradigm. Everything is kevlar and carbon fiber to save mass and provide torsional rigidity to the chassis. These structures can sustain pretty massive, make that huge impacts, but these huge loads are imparted directly on the driver. In contrast, and no bonus safety feature, road cars use deformable metal crumple zones (and airbags) by design that are reinforced by robust, high tensile strength steel sections as and where needed.
I will still prefer a deformable failure mode tubing materials. Bracing a deformable roll bar by materials of similar strength and failure mode vs some hybrid combination of dissimilar strength materials would have to undergo a finite element simulation to prove my point that what we want are controlled deformation failure modes. And, we use this deformation concept as a way to absorb energy before it gets into the driver's body. One only need to view Petter Solberg's 2004 Baumholder crash
A 30% greater tensile strength number pales in force calculations. Force = (0.5 * m * v^2) ÷ d. That velocity squared bit (v^2) implies that we have a steel tubing that bends in a 200kph impact and a carbon/Kevlar bar that shreds on 230kph impact for its 30% greater tensile strength. Those are the choices when impact forces are in play. The carbon/kevlar piece is toast, it is has failed and not longer contributes any strength to the structure. This failure may possibly lead to other pieces failing. In contrast, the high tensile steel tube deforms, it bends, continuing to absorb significant force. With good design (and welding) it will absorb more energy without catastrophic failure well past its nominal tensile strength yield point. A hybrid steel/carbon kevlar tube design does not have this "beyond yield strength" structural integrity. This has been my point all along. Think NASCAR and rally car safety, closer cousins to track day risks.
My view is that failure mode and total system design integration are the key criteria, Solberg's car registered an impact of 30g, co-driver Phil Mills required hip surgery, but recovered well. It was a lucky day.
Last edited by Mike__S; Jul 12, 2020 at 09:21 PM.
