Inertia Reel Seat Belts
What started out as a nice little Saturday job of replacing the original static belts with Inertia Reel units as fitted to the Federal cars turned into something slightly more unsettling, and of course, far longer than the planned Saturday morning.
The plan was to buy some units, modify the reel mounting plates in similar fashion as Lotus had done, and then simply pop them in place. Simple.
"An hour at most, you put the kettle on love, I'll be back before you know it.
Except when it came to taking out the old belts, something didn't seem right.
I'm quick on such things, and when the sill mounted bolts first creaked and then sheared as I tried to remove the old belts, I figured something might just be amiss.
And so it turned out, the anchor plates inside the fibreglass sills on both sides of the car had been doing their bit to increase the car's performance by adding lightness over the last 40 years or so.
An Optimistic Seatbelt Anchor
Old and New Anchor Plates
And very enthusiastically as well. As you can see from the photo not only has most of the steel evapourated, but also the bolts and rivets have taken their leave as well.
Hence the weekend was spent measuring and making new plates, which are quite simple constructions but still take time to make & paint, especially if you're following the "trial and error" school of design.
I used 1/16" mild steel plate but of course stainless would be much nicer even if it is something that you hopefully won't be seeing any time soon.
The top of the plate is held in with small bolts, I used M6 bolts with large washers to spread the loading.
At the bottom the lower sill is riveted together and several of these had to be drilled out in order to get the new anchor plates in place.
So yet again the job grew and I ended up removing all the old rivets (not too hard as it turned out) and replacing them with M5 stainless dome allen bolts. It takes far longer but looks and feels a more secure job.
Anchor plates installed
Inertia reel installed using original Mounts
And finally, two days later, we get to the "one hour job".
The static belts fitted to the UK cars only had a single bolt fitting and I retained this as the principle mount, but also drilled the firewall lower down to fit a secondary bolt in the same fashion that Lotus did on the Federal Export cars.
This did involve dismantling the inertia reel mechanisms and welding a longer and stronger backing plate on the frame, but after the fuss so far, it's only a ten minute job.
Well, almost.
Ok, ten "Lotus" minutes.....
BUT - after all that it really was worth the effort. None of that "having to move the belts to get in the car" or "have to release the belt to get to the handbrake" deal that I've put up with for far too long as it now seems.