Mounting Seat belts AND four point harness at the same time?

[Spency747]

Hi all,
I’ve just bought my first Caterham (270R) and as part of the deal I asked the dealer to remove the four point belts and replace with standard inertia reel belts as 99.5% of my driving will be on the road.
Now I’ve kept the harnesses (just in case I sell in the future) but rather than lose them in some long forgotten cupboard I was wondering if they could be fitted in addition to the inertia belts (but stowed behind the seats) until required for some future track day?
If anyone has done it could you let me know, and specifically if longer bolts/spacers are required for the lap belt connections.
Many thanks,
Richard

[Mort7]

Why go for inertia reel over a 4-point harness? Most people go the other way. Not sure I'd feel secure without a harness.

I originally had inertia reel. The belt, inertia mechanism and anchor point are still in place, and live behind the seat, but the stalk and buckle were removed by Caterham to accommodate the harness. They currently live in the garage.

I think each belt would need separate anchor points.

[Spency747]

It’s all about convenience, I’ve previously lived with harnesses and they are great on the track but a chore (just my opinion) on a day to day basis.
I’ve also got to give rides to my kids and belts are just so much easier when swapping passengers.

[trunnie]

I bought my 275SV with harnesses and it came with inertia reel belts as well. Possibly because it may be a requirement to have inertia reel belts in France. I find that the odd passenger prefers the inertia reel belts, but I use the harnesses and haven't got around to taking out the inertia reel belts. Not sure what the fitting is however (and may not be the same as in an S3).

[Spency747]

Hi Trunnie,
Thanks fo the reply, my car is an SV too.
Looking at my car it looks like there is a (now unused) threaded hole on each side of the transmission tunnel which is no doubt for one side of the lap strap, the only uncertainty is the other (outboard) side which I’m assuming uses the same mounting hole as the inertia belt mounting.
If you could have a look at yours (you might need to slide the seat) to confirm that would be a great help.
Cheers 👍

[snapper seven]

I have both inertia reel and four point harnesses fitted - 1994 S3 car. They both share the same mounts. I did use the same bolts but I am currently re-building the car so will be double checking the thread length to ensure I still have enough.
Interesting what the OP says. When I bought my car, it only had inertia reel and I never felt safe with just those belts. It felt like I was always about to fall out of the car.
Only time I have used the inertia belts is to secure bulky items in the passenger seat (no...not my wife ;-) ) or in addition to the harnesses when taking kids out.

Cheers
SS

[trunnie]

Hi,

I've checked and indeed the lap belt shares the same fixing on the transmission tunnel as the inertia reel belt, with a very long bolt. I asked the dealer to add the harness and they took it literally. I've also got a light on the dash for seatbelt not being connected, but it's never come on, presumably because the dealer disconnected the electrical connector underneath the seat to the inertia reel belt. I'll probably connect it when its control technique time (French MOT)

Trunnie

[MBBlat]

I've got both fitted to mine - built it with inertial reels, fitted 4 point harness soon afterwards
Caterham Harnesses by MBBlat, on Flickr

Rarely use the inertial reel except for very short journeys as it doesn't feel at all secure compared to the harness.

[Spency747]

Thanks to all have contributed, looks like the only issue is checking the bolt lengths.

Edited by Spency747 on Thursday 13th February 10:17

[Spency747]

Typically I’ve just seen this:
https://www.pistonheads.com/gassing/topic.asp?h=0&...
And now I’m not sure that 4 point belts are a good idea at all?

[dhutch]

Spency747 said:

Typically I’ve just seen this:
https://www.pistonheads.com/gassing/topic.asp?h=0&...
And now I’m not sure that 4 point belts are a good idea at all?

Always hard to know, and always possible add more safety to a car.

However, rightly or wrongly, my current understanding is that if you ensure the lap belts are well tightened and the top straps not overtightened, the risk of submarining in a 4 point belt should be manageable. Presumably no worse than the submarining risk of a 3 point belt, with less risk of coming out of the top.

I don't know. But it is also certainly very true the with our cars and or grp seats, it is very easy to end up with the lap belts in sufficiently tightened, with the tendency to to then overtighten the top belts and end up with the buckle nearer you belly button than your crotch. I have 4 points, which are not reverse-tighten, and you do have to work to ensure correct fit. Often getting out of the seat to adjust.

Interested in others thoughts.

Daniel

[chriskd]

I've had my Caterham for about 4 months.It had 4 point harnesses and inertia seat belts already fitted. I've been using the 4 point harnesses but have not done much mileage due to weather.

I do find them very annoying. Time-consuming to adjust properly and they don't allow you to lean forward or twist around when negotiating difficult junctions.

Maybe it's just me but I've decide to try the inertia belts for a while. The harnesses just tuck behind the seatbacks so are available any time if or when I have a change of mind.

[BertBert]

dhutch said:

Interested in others thoughts.

Daniel

The problem is that harnesses work when they are done up tight. If you don't do them tight, the wheel is very close to your chest and head.

But many people drive with them loose so they can move and look around more easily.

Anyone racing wouldn't dream of having their harnesses loose.

Bert

[Spency747]

I don’t suppose “Wheeler Dealers” Mike Brewer would be glad of how he has adjusted his harness in the event of a shunt!


I’m not knocking him personally of course, he’s a genuinely nice chap, but I do see the odd person wearing theirs in a similar manner.
Risky business

[dhutch]

Spency747 said:

I don’t suppose “Wheeler Dealers” Mike Brewer would be glad of how he has adjusted his harness in the event of a shunt!

Ouch!

I agree they take an amount of adjusting, and prevent you reaching for things in the passenger footwell or whatever, but assuming you are happy to have that compromise, and adjust them correctly, if they then work that is the main thing for me.

Wouldn't be so easy for a car used daily, or by a range of people, but as with most of our cars I use it frequently enough the faff is acceptable as long as it keeps me safe, even when using it multiple days a week in summer. Life is a compromise, I have a rac-style hoop, not a cage, forinsance.

However if a when a 4-point is adjusted right, its as good for submarining as a 3-point (and presumably better for not going sideways out at the top) then that answers the question for me.

Obviously also somewhat depends on the seat and posture I guess.

Daniel

[framerateuk]

I replaced my quite worn Caterham harnesses with 6 point Titon harnesses a few years ago.

It's no more faff really and once they're attached properly you don't really notice the additional straps.

I don't think I'd like to drive a 7 with a normal seatbelt. Although perhaps with a CG Lock or similar it may be tolerable.

[badger748]

Spency - I went thru the same thought process with my 310s - harnesses are a faff - and they do detract from the "get in and go" nature of a more conventional sports car. However, a Caterham is very exposed and an inertia belt simply cannot handle the energy of a high speed crash.You have too much exposed bits - including roll bars.
I did all the research you did, spoke to a lot of people, saw some examples of crash aftermaths from open cars with inertia belts. I concluded, NO WAY would i drive the Seven without harnesses. I often have my partner or my son with me, the risk is just too great. Take the extra minute, fiddle with the harnesses but do so in the knowledge that you are a bit safer.Plus the time you are doing this will be well spent letting the peaky Sigma engine warm up!