Seat runner re-enforcement for live axle 7

[Gridgway]

I am contemplating replacing the bench seat in my crossflow 7 with seats of some sort on runners.  For this I think I should have the re-enforcement channels that should go under the floor where the runners will be.

Can anyone advise where these go, what the likely dimensions are, what they are made of (aluminium I assume), how thick they are and how they are rivetted on please?

A pic or two would be very helpful.

Thanks Graham

[Golf Juliet Tango]

Hi Graham

They certainly are aluminium. Does this picture help?

This particular set are destined for my 21 but those on my Seven are the same

[Golf Juliet Tango]

Alignment at the back.

[Jonathan Kay]

Graham

There's a fair bit of discussion in the archives on how to inject the load somewhere stronger than the sheet floor. For example: https://www.caterhamlotus7.club/comment/2126931#comment-2126931 and following posts.

Jonathan

[Nigel Riches]

When I fitted the individual seats to my 1982 car I cut some 6mm ply board to the same outline as the seat well, if you see what I mean, this will spread the load across the floor area, similar to the original seat squab.

I measured the centres at front and rear of the seats, you may need to cut the rear seat rail step up section if it is present, this is for use with later chassis, which have a tube across for mounting the seat rail, drilled holes through the chassis tube in front of the original seat position, a larger hole at the top, and smaller at the bottom so I could introduce a spacer to stop crushing the chassis tube, drilled the rear of the seat rails to accept Hank nuts on the upper side, I subsequently had these tack welded in place, as I didn't like the idea of just relying on the peened over, swaged installation of these in a position inaccessible when the seat is in place.

I used 8mm bolts and nuts, some large washer to spread the load, especially at the front, bolting to the chassis tube., if you use this idea you will also need 6mm spacers between the seat rails and the front chassis tube, as the seat is obviously raised by this dimension.

It wasn't particularly difficult to achieve, and it didn't incur the disdain of the picky inspector bloke when I had to have it all eyeballed, but that maybe because a 1982 car predates a lot of the requirements.  

Have fun, and these seats are lot more comfy the old padded park bench.

Regards.

Nigel.

[Wrightpayne]

I helped Tazio fit a cut down tillet (cracked through the belt holes) in his XF. Being a S/A, he was able to retain the bench seat backrest and also the seat squab on the passenger side.

Our approach was similar to Nigel's, however, we cut a piece of 2mm ally to sit inside to spread the load then modified a couple of used dedion floor braces to fit the underside.

We spent a lot of time carefully positioning the seat to mark the main bolt holes in the floor for drilling, then bolted up the additional floor and strengtheners to drill and rivet in place. The initial positioning is critical to ensure the seat goes backwards and forwards easily without jamming into the tunnel or side.

Hope that makes sense.

Ian

[Gridgway]

Thanks all, that's really helpful and lots of food for thought.  I'm in many minds of which way to go.  I would like a tillet or similar on the driver's side (and there's a pair for sale), but that won't be very helpful for Mrs R as she may not be comfortable in it with er child bearing hips!  I am a short arse too so could probably get away with leaving the seat back in place.  But a tillet one side and bench on the other is pretty yucky.  Also taller drivers won't be able to get the tillet back far enough.

I'll need to change the harnesses too I would think as I can't see how you'd get to the lap adjuster outside the seat (as it were).  Maybe that's a non-problem

Perhaps I should re-think the basic problem.  With the bench seat in I am far too far away from the pedals and the wheel.  The few times I've driven it (before starting my winter refurb project) I had a very fat cushion!

A much simpler solution is just to pour a seat back insert in expanding foam and see how I get on.

[Tazio]

As Ian ( Wrightpayne) said, as I am a short arse I couldn't easily reach the pedals so we put this cut down Tillett in, it's a very comfy place to be, left the original seat back in so I could take a passenger.  Only criticism is I'd like to sit a little lower but as I cannot put a lowered floor in the only solution would be a bag seat.  Alan

[Gridgway]

Does look like it works well!  I'll go and measure Mrs R's hips and see if she'll actually fit in a Tillet!

[Jonathan Kay]

[Gridgway]

BTW are those the narrow harnesses that need a HANS?

[Tazio]

No idea, why would they?, they simply replaced a set of Caterham branded original 37 year old belts as a like for like replacement.

[Gridgway]

Because they are designed #only# to be used with a HANS.  They are 2" straps from what I can see.  For just on-shoulder use they need to be 3" wide.

[Tazio]

Strange, as I'm pretty sure I have boxes of old caterham branded harneses that are only 2 inches wide in the loft....every day is a school day .

[7 wonders of the world]

AFAIK all the old CC ones were 3x3,

The schroth have a reduce shoulder strap to fit in the HANS as prevously mentioned, ideally if not running HANS you need 3" shoulder straps with 2" laps as these locate on your pelvis better with 2" crutch too.

In a shunt 2" are lkely to give your shoulders some grief, we both had a fair amount of bruising even with 3" ones after ours.

Love the cut down seat... looks like someone has put a child seat in the car.......   

 

 

[Tazio]

Neil, you can ..................expletives deleted lol, it was either that or blocks on the pedals!