The thing is, I wanted to check the steering rather more carefully, and perhaps change the routing of the column a soupçon. In order to do that, I needed to check how it fitted under the bodywork. The problem is, I had to do lots of faffing around to get the central portion to fit over the cage; for example to allow the front hoops of the cage to stick through the bodywork, and also to allow the steering column to poke through the front of the central bodywork section. You can see both of these in the photo on the right.

The problem was, even to get the bodywork down here I needed to fit the rear portion around the cage’s rear hoop. I always knew this was going to be tricky as I’ve got the long wheelbase version of the chassis, which is 60mm longer at the rear. The problem is, the bodywork isn’t. Longer, that is. That meant that the rear section of the bodywork was pretty much in the same position as the rear hoop and that wasn’t going to work.

I discussed this with Jeremy right at the start and the original plan had been to split the bodywork around the rear of the central tub area where the shape is essentially a 2D curve. That means that it can be put back together with a 60mm spacer of some form without messing about with the shape. I had originally intended to leave this until a lot later in the process. However, as I was doing the steering it seemed more and more as if I was going to have to cut the poor girl in half right now.

So, I did. Not without a considerable bout of loin-girding though.

The end result is shown in the photo, although the rear bit is just resting there at a jaunty angle hence the variable gap. The plan now is to seal this up with a strip of aluminium, riveted in place with the gap maintained at 60mm. Once I come to finishing off the bodywork, I will put some release film under the aluminium and layup some gel and CSM on the inside to extend the bodywork. Using the film should get a pretty good finish on the outside (it’s shiny stuff that doesn’t stick to resin at all) without resorting to excessive application of elbow grease, a commodity in short supply around here.

I’m hoping that with the aluminium attached the bodywork will be a bit more robust; at the moment it’s rather floppy because the two sides are no longer attached at the rear. What’s more, I’m hoping that I’ll be able to remove it from the cage without any further surgery. That was, after all, the reason for making the cage backstays removable.

However, I’ve been waiting so long I decided to just work around the problem which I think I can. I certainly shan’t be putting any business their way in the future though.

Still, at least I could get going on this now. First thing was to fit the diagonal to the rear hoop and weld that to the chassis. So, I tacked things together and tacked the hoop to the chassis after cutting the bottom of the legs so that it would all end up vertical when it was fixed to the non-horizontal plates on the chassis. However, with it in position I realised that it could easily be too far forward in that there might not be room for a crash pad behind my helmet. So, I fixed a bit of hardboard to the hoop and checked how much clearance there was; in fact I videoed myself as it’s really quite difficult to work out how much clearance there is around your helmet when you’re wearing it!

That testing showed that the hoop was indeed too far forward and I had to move it back to the position that you can see in this photo. The problem with this, if you look at the bottom of the hoop, is that the legs are no longer above the chassis.

So, I had to extend the hard mounting points on the chassis which I did by welding in a chunk of box section in as shown in the photo, and then extending the plate I’d already welded to the top of the chassis.

With that done the hoop seemed to be fine, although the upcoming problem is working out how to attach the harnesses to the car. I’ve always known this was going to be an issue but I’ve never worked out what to do about it. There’s really two possibilities. One is to weld an additional horizontal harness bar into the cage over which the harnesses will loop before going to the chassis mounts. (This is what I did on the Fury when fitting the HANS device.) The second is also to weld an  additional tube into the cage, but to use that directly for attaching the harness to. Any suggestions gratefully received.

Anyway, with all that sorted I welded the diagonal properly into the hoop and welded the hoop to the chassis.

Then I had a nice cup of tea.

Next up was the backstays. As I’ve mentioned I wanted to make these removable. So, I turned some lumps of steel so that I could weld a pre-made insert into the end of the tubing into which I could mount a rod end. The joints I’m using are actually rather more expensive that the ones I normally use. They’re rated at about twice the maximum radial load that a normal cheapie joint is rated at. I decided I wanted to do this properly, you see.

I then welded some mounting to the cage and the end result is shown in the photo.

So, that meant that the back end of the roll cage was all done, and a view of the whole rear end is also shown.

I now had to fit the front hoop. First thing, though was to again check that there was sufficient clearance when I was wearing my helmet. So, I cut the base of the hoop at the correct angle for mounting it to the chassis (although I don’t yet have the hard points in the chassis) and held it in position with, errm, two G-cramps and a length of ½” tubing held in place with gaffer tape. Luckly, the tubing is CFS so it should be strong enough.

With that done I again videoed myself climbing in and checking this. You should think yourselves luckily that I’m not showing you any of this riveting video. The conclusion was that it seemed to be fine.

So, the next job is to put the hard points in the chassis and weld the front hoop in place. Then I need to do the roof bars.

The problem with all this is that the cage is horribly heavy. The regulations have changed and the whole thing is much heavier than the equivalent cage I have on the Fury. Oh well, I suppose there’s not much I can do about that…

Finally, the dampers have moved on a bit. I’m now being promised these at the end of January which will be OK for me; I’m getting more and more convinced that I’ll need to start the new season using the Fury, to be honest so it’s a good job that I haven’t sold it. To tease you a bit, though, here’s the latest rendering of the damper and reservoir!

As you can see, it fits in pretty well. In fact, the CAD model seems to have predicted how it will fit exactly which is nice to know. Also, with the diff at this position, and with the largest sprockets that I’ve got fitted, the chain seems to be clear of the diff mountings and the chain guard around the drive sprocket. Admittedly, it’s not far from the latter, but hopefully OK.

The main issue now is how to retain the bottom of the frame around the diff. There seem to be two ways of doing this. The first is shown in the CAD model and uses a couple of plates with  slots cut into them into which the bottom bolts on the triangular support plates fit. That will require two more laser/water cut plates though, and positioning the plates might be a bit tricky. Mind you, from what I can see of the current position of everything, a little bit of inaccuracy on this is probably no great problem.

The alternative is just to use a couple of turnbuckle like things, perhaps just lengths of studding really, to restrain the bottom corners of the triangles to the engine frame. In fact, I could even use turnbuckles that were arranged in a slight (plan form) triangle so as to locate the bottom of the diff laterally. That’s essentially what’s done on the Radical that I showed you the photograph of in the same post. It has the advantage of ease of manufacture and, perhaps, slightly easier adjustability.

While musing about this, I’ve pressed on with a few other things. You may remember that in an earlier post, I mentioned that the front lower damper mounts were really too low and wouldn’t allow enough droop in the front suspension. I did spend a while talking to Jeremy about this and he suggested that he could make some different front rockers. However, I thought I’d just do what I said and space the damper mounts up slightly which, as you can see from the photo, I’ve now done. This second set of holes is 30mm above the normal ones, which are themselves raised 25mm above the “standard” ones because of the lowered chassis on this car.

I’m now just about at the point where I’ve finished all the various bits of welding to be done to the chassis. The main thing left is the roll cage. The parts for this are currently  languishing in Fedex’s depot up the road in Huntingdon and I’m going to go and pick them up tomorrow. Or, perhaps I’ll just get them to deliver them while I’m actually in.

I’m planning on just welding the roll cage to the car directly, not bothing with making it removeable as I’ve done before. In order to do so it seems sensible to beef up the mounting points with some chunkier lumps of steel. So, I’ve started this off by welding some 3mm thick plates where the main roll hoop will mount. Also, you may remember that I’m planning on making the rear diagonal stays removeable so as to ease fitting of the bodywork. So, I’ve welded some attachments for the lower end of these stays to the rear of the chassis. The intension is to use a ½” rod end at each of the removeable stay so as to make fitting the stay straightforward. This at least means that the positioning of this attachment isn’t fantastically critical. This is something else, though, that will need a bit more welding when I can turn the chassis upside-down, hopefully in a week or so.

You can see these two hard-points, the ones on the left of the chassis, in this photo.