Rollcage

[dickdixon1]

Had a trip to check over the Davrian the other day to work out the work needed. One thing that has always bothered me is the rollcage - the original roll hoop has been cut and a previous owner fitted a full rollcage. But the main upright brace has been canted to follow the line of the seat and bonded in. Would anyone else be concerned that this has taken the main strength out of it? I'm thinking I will have to remove and re-establish the original...

Line of cage highlighted in red -

Rollcage.jpg (99.03 KiB) Viewed 7043 times

(along with Fulvia rearscreen!)

On the positive there are not many pieces missing - require wheels, waterpump, radiator and dizzy.

Just need to finish the wardrobe, dining table/chairs and sideboard before I'm allowed to bring it down

[dickdixon1]

Having read the MSA regs 'Structure consisting of a near vertical frame or hoop located across the vehicle just behind the front seats.'

I'm pretty sure this isn't a safe rollcage and would buckle - not that I am thinking of building it for racing and complying with MSA but I am more risk averse than I was 20 years ago and want a bit of security around me, but means more work when I start it

[gtm4honda]

Email me I had to make sure my cage was ok before it was given an MSA rally logbook.
All the best Dean.

[Hal Mercier]

What Mk car is this in?

I ask because my Mk7 has no roll hoop, (which is odd as I thought they ALL had hoops bonded in at birth) and Tim, (I think) said that they had a single hoop which as you say, slopes to follow the seat back.

I'd really like to see how a mk7 hoop is normally fitted, and how the diagonal braces go in, as the position of the rear screen makes fitting one like in the Mk4 impossible.

[dickdixon1]

Hal,
Here is the best image I could find of how the brace attaches.

As you can see the original roll hoop has been chopped and the new cage fitted at forward and down the line of the seat.

There is no door bar or spreader so I still remain sceptical of whether this provides enough structural rigidity in compression, but I will look at it properly when I get it down.

The brace also looks like it is just slotted into a larger tube - can't see any evidence of welding.

cheers

Dick

[Hal Mercier]

What model is the car? I think fitting the FIA hoop is fairly straightforward apart from on the Mk 7 with the rear window curving in to touch centrally just behind the seats.

Fittting the two rear support bars is ok, they just go inside the buttress line, but the diagonal? You couldn't fit it to the rear support legs, it'd have to go on the front hoop and I don't think that's allowed, is it?

Has anyone got some pix of a Mk 7 with FIA rollbar, cage, whatever?

[dickdixon1]

Hal, this is on a Mk6 and now I have it down with me it frustrates me even more. It is not properly attached to give any sort of protection, along with not being welded but sleeved connections and will all have to come out. Just working out in my mind whether I take the roof off to replace the original first and then take the existing out. Not sure whether have to apply steel body principles to maintain shape and rigidity. Alternatively whether it will be easy enough in situ. Got to finish hall redecoration first so have thinking time! Might need a second opinion Mark/ Nugget so we need to catch up at some point.

[Hal Mercier]

Dick, At the time I fitted the bar in the Mk 4, Tim had just done the very first fitment of an FIA hoop and back braces without removing the roof.

At Tim's shop I took photos of John Wheeler's car which was the first, and mine was the second. What you need to do is cut 3" wide slots out of the seat rear bulkhead level with the main hoop legs, then the welded up hoop and braces unit is inserted and rocked into position, finally bolted and bonded in.

It's got to be much easier bonding up the bulkhead than the roof!

[dickdixon1]

My preference was always not to remove.

Are you able to share those pics (or pre digital !)?

[Hal Mercier]

I'm doing a computer search but haven't located them yet!

Will post when I've found them....alternatively, I can whip the seats out of Dolores, and photograph the 'scars' where I boned the cut-out sections of bulkhead back in....

No sign of the John Wheeler pix for the moment.

Here's the Mk 4 with seat shell removed...the repair patches are a fair bit larger than the actual cut-out part, which wasn't a lot wider than the diameter of the hoop tubes. I seem to recall we inserted the hoop without the foot plates on the vertical hoop, and welded them in in situ (with the rear window out of course.)

It might be possible to insert it with the footplates on the main hoop but you'd need wider slots.



The actual cut-out was a lot narrower than the inner line of the tape shown here, I recall not much more than the tube diameter.
It probably followed the outer 'fold line' you can see here of the edge of the seat recess. As you can see the slots aren't very deep..about 15cm.



Welded in situ...



I think the rear brace plates were welded to the tubes before fitting, probably when bought from Tim..Best check fitting method with Tim, he's done a few since 2001 I think.