Fitting harnesses

[JKJ]

My '91 dedion supersprint was fitted with recoil seatbelts as standard. How difficult would is it to replace these with 4 point harnesses? I imagine that fitting the harnesses is relativly easy, but where do the parts of the recoil belts lurk and how easy are they to get at?

 

 

 

 

[CHRIS CLARK]

Yes it is easy to fit the harnesses (depending on seat type; but thats a long story).I have fitted the 5/6 point ones & have left the existing cross over diagonal one in place.

The reason for this is if you ever get caught in a downpour & have to fit the roof its a lot easier to climb in and use them than the full harnesses! If further info req. e-mail me 'Caterham7man@aol.com

[Pierson Broome]

Fitting a harness is straightforward, as you say - all 7's have the mounting points for harnesses already in place, welded directly into the chassis. There are two shoulder mounting points underneath the rigid metal strengthening strip which runs through the front edge of the boot cover - you need to drill through this strip (be careful - the tolerances are a bit tight) and bolt the shoulder straps through the boot cover and strip.

 

Then there are two more mounting points per side at the back of the cockpit behind the seats. You'll have to remove the seats to get at these (unless you've got very long, very, very thin arms...), but once visible, simply attach the lap-straps using the harnesses' own bolts, washers and spinners.

 

Although I've never had to remove an inertia reel belt set, I believe that the bottom links probably use these same mounting points. The top points sit on the outside of chassis close to the roll-bar uprights and simply remain uncovered once removed.

 

One final point - I'd strongly recommend the fitting of a 6-point rather than 4-point if you're going to use the car on the track - more comfortable and much, much safer. A 4-point harness can ride up in the event of a frontal impact and the lap straps cut into the abdomen if you 'submarine' down into the cockpit without the crotch/crutch 5th/6th straps in place.

 

Pierson

 

pierson.broome@bt.com

[S33VEN]

I thought that with a six point, you had to sit on the crotch strap assy?

OK for the track but not my idea of fun when driving to Spa!

Anyone know how to get round this issue. I would really like to add the crotch straps, but am reluctant at present.

 

thanks

 

Tony Stattersfield

[Pierson Broome]

For touring, I have to confess that I've taken to wearing just the 4-points, & leaving the 5/6 straps off. I have individual seats (not bench) and simply sit on the 5/6 straps after they pass through the gap between the squab and the seat back - not uncomfortable at all.

 

On the track, I've recently taken to using a light-weight race seat instead, and the 5/6 strap(s) pass up from underneath through a hole in the bottom of the seat.

 

This is using Caterham's own badged Luke harnesses - other systems such as Willans sometimes use a 'proper' self-tensioning coupling rather than the 5-point tangs and buckle of the Luke, whereby the crotch straps have a system of passing webbing through the lap straps. Either way, I don't find it uncomfortable to sit on the straps if I have/want to, though as I said, I do often now leave them off and simply tuck them behind the seat.

 

Pierson

[Peter Carmichael]

When fitting the 6-points to the same mountings as the 4-point lower mounts, how long a bolt do you need, what spec and where do you get them?

[Pierson Broome]

Ah-ha, Can Of Worms about to be opened...

 

I mounted my 5/6 points onto the same mounting points as the lap straps with a Luke bolt (OK - 2 Luke bolts for the pedants out there...) obtained from Luke themselves - slightly longer but I can't state how long. Same tensile constuction as the original, just longer.

 

The Can Of Worms pertains to the discussion as to whether to use the existing mounts and double up or use seperate mounting points, perhaps in the chassis rail which runs towards the back of the cockpit and under the seat. I've a feeling that if driving competitively, you now need to mount them seperately - couldn't really say, though.

 

Where do the Caterham race cars mount the 5/6 points, I wonder?

 

Pierson

[Wallbanger]

My car, and others that I know in the GoldArts classes use the standard mount points for both the lap and crotch straps. Can speak for RoadSports or Superlights thou.

[Andrew Russell]

I'm not a rocket scientist but surely it is safe to use the same mounting brackets for either 4 or 6 point harnesses....the loading should remain the same, being the mass of the driver's body....it is simply being absorbed by a different number of restraint straps.

 

I use the Caterham/Luke harness with the six point strap passed up between the seat back and squab.....not at all uncomfortable either in use or to sit upon.

 

I would certainly recommend their use for enthusiastic driving as they do prevent any submarining, and allow you to really tighten yourself in. Really feel at one with the car!

 

Andrew.

[Peter Carmichael]

I don't think the issue is with 6 points mounted in this manner being less safe than the 4 points, but in that they may not achieve the increase in safety hoped for with the extra points of attachment. Indeed, attached in this manner the harnesses still only meet the car at four points .

 

The prevention of submarining is a good safety feature. I know that driving on track with 4-point harnesses I have sometimes felt the need for better attachment - coming into Woodcote at Goodwood is one example where I was actively leaning slightly at the waist before applying the brakes to prevent submarining. Even without extra mounting points, the anti-submarining will be achieved. However, the belts will not provide much more security in a total inversion without further mounting points.

 

I am sure the Blue Book has lots to say on the subject.

[SJL]

I have just been fitting the luke 4 point harnesses to my roadsport and am trying to keep the inertia belts for convenience - question is that the lower strap bolts now stick out too much for the seat to go right back - I tried reducing the shim thicknesses but don't want to remove them entirely (they allow the buckle ends to rotate) - does anyone have any experience with this one please ?

 

Also I need to punch some holes in the boot cover to pass top strap bolts thru - whats the best way for a neat job ?

 

 

[CHRIS CLARK]

I use the six point harness with the crotch belt fitted to the lower fittings (As PC would say, a four point fixing). I turned the spacer on a lathe and then cut the amount down by a bit at a time to give the required rotation + adequate clearance to slide the seat. I also have the original lap & diagonal still in place on the same fixings too so I know it WILL all fit!!!

[SJL]

Yes - have just spent all night cutting the bushes down to size such that harness and inertia belts fits together - its a tight squeeze with those seats though - took two goes of seat out and seat in (on each side)