Rpm rollbar

[Ghmpin]

Anybody use the 4 pt rpm rollbar? They have a chromoly variant that seems to be quite light! Looking for a e92 w/ sunroof.

Looking for feedback, and how easy the installation was?

Thanks

[M3SQRD]

I would not use this rollbar if you’re looking to improve roll over safety. The main hoop diagonal cross bar (upper corner of the driver’s side to bottom corner on the passenger’s side) should be in the plane of the main hoop. Its purpose is to split the main hoop into two “triangles” so the main hoop + diagonal cross bar act like a truss structure (external applied load is reacted as tension and compression in all legs of the main hoop-diagonal bar). The out-of-plane diagonal bar will allow the main hoop to deform in-plane. If you actually rolled your car, this rollbar would not provide the proper structural load path (strength) and stiffness to protect you. As for looks, this one looks just as bad as the Studio RSR Tesseract rollbar. The Pinnacle T45 rollbar and JP Marketing harnesses bar appear to be the best bolt-in rollbar options. However, I wish there were better pictures of the Pinnicale bar’s mounting points with the chassis.

[gh0stE92M3]

The pinnacle cage mounts to the or mounting points for the GTS cage inside the cabin. In the rear they replace the triangle plate on each side and tie it together with a horizontal bar.

When you remove the rear seats and lift the carpet you’ll see the mounting points, you have to drill a little bit to have access to be able to bolt it all in. But it’s the same as the gts roll bar.

[M3SQRD]

Originally Posted by gh0stE92M3

The pinnacle cage mounts to the or mounting points for the GTS cage inside the cabin. In the rear they replace the triangle plate on each side and tie it together with a horizontal bar.

When you remove the rear seats and lift the carpet you’ll see the mounting points, you have to drill a little bit to have access to be able to bolt it all in. But it’s the same as the gts roll bar.

Thanks. I still haven’t found a good picture showing the rear down and cross bar mounting points (found a good picture of the f8x rollbar rear four-bolt mount). One picture shows the lower single bolt but it sits far down from where all of the bars meet. The large vertical offset with a relatively thin and long single bolt mounting tab isn’t structurally efficient in reacting in-plane loads and it also bends right before where the bolt is located (bolt hole is angled upward). You mentioned a triangle, does that mean there are two fasteners on the rear upper mounting locations?

[gh0stE92M3]

Originally Posted by M3SQRD

Thanks. I still haven’t found a good picture showing the rear down and cross bar mounting points (found a good picture of the f8x rollbar rear four-bolt mount). One picture shows the lower single bolt but it sits far down from where all of the bars meet. The large vertical offset with a relatively thin and long single bolt mounting tab isn’t structurally efficient in reacting in-plane loads and it also bends right before where the bolt is located (bolt hole is angled upward). You mentioned a triangle, does that mean there are two fasteners on the rear upper mounting locations?

Look at the picture circled in yellow, it’s a plate that replaces the stock one and mounts in the same location which ties both sides together. You have to remove your rear trunk liner to be able to access this area. You’ll see the plate it replaces if you pop you liner off a little.

Edit: I found a picture of another company that makes roll bars for the e92 chassis he’s out in the uk as well and has a very similar design. Gosling racing he also has a seat delete kit you can purchase separate. But the picture clearly shows where it would be mounted in the rear.

[M3SQRD]

Originally Posted by gh0stE92M3

Look at the picture circled in yellow, it’s a plate that replaces the stock one and mounts in the same location which ties both sides together. You have to remove your rear trunk liner to be able to access this area. You’ll see the plate it replaces if you pop you liner off a little.

Does the upper leg have one or two bolt holes? Nevertheless, the thickness of the plate is going to bend out of plane if a normal forces is pulling the plate to the right in the picture. The mounting plate is not stiff enough out of plane to transfer the normal load-lateral bending moment to the mounting points. In a rollover, one side will be in compression and the other side in tension. That plate cannot support the loads generated during a rollover.

[gh0stE92M3]

Originally Posted by M3SQRD

Does the upper leg have one or two bolt holes? Nevertheless, the thickness of the plate is going to bend out of plane if a normal forces is pulling the plate to the right in the picture. The mounting plate is not stiff enough out of plane to transfer the normal load-lateral bending moment to the mounting points. In a rollover, one side will be in compression and the other side in tension. That plate cannot support the loads generated during a rollover.

It’s the same as the stock mounting point. I’m not sure what the thickness of that plate is. You should reach out to pinnacle or gosling and see what the thickness they use and the logic behind their design.


I do understand your reasoning that during a roll over things are gonna be under tensions. But I feel like not many bolt in rollbars would hold up to a severe roll over. The only safe bet would be if the bars are welded in.

But as far as mounting locations being located in oem mounting points I think is better than other rollbars on the market as they’re structurally more sound than drilling into your floor and adding plates.