Harness Fitting

[Jig]

This must have been discussed before but I cannot find any threads. Is there a safe way to fit a harness whilst retaining the inertia reel seat belts?

obviously the shoulder straps are ok, but the lap belts are a challenge. The inboard side appears to have a 2nd threaded hole (current metric SV chassis) - can I use this? The outer side only has a single threaded boss? Is it safe to use an eye bolt to secure the seatbelt and then clip the harness to it?

i prefer to use standard seatbelts for road use which will be most of my driving but want the option. Only other way I can think of doing this is to physically bolt the harness in whenever I want to use it. A bit of a pain but I suppose I could do that. 

[pugwash]

Why not just ditch the inertias and use the harness all the time?  I have an SV with 4 point harness and while it might take a few more seconds to put on than the inertia’s it is very easy to live with. 

[Paul Richards]

Use longer bolts (7/16 unf) and fasten both belts to the same one using appropriate spacers. 

[MADMALC]

Why use inferior safety equipment when you have the choice. Having had a big accident I must almost insist that you do not use the inertia belts. You would be better fitting the the lap belts to make the harnesses six point fitting. It is my belief that they are the reason we survived relatively unscathed. End of sermon..

 

[robjjones]

Jig, I've got both fitted. I've added a set of Triton harnesses to my inertia reels by using the method Paul suggests above. I thought I'd not bother with the harness when nipping out for a quick run, but in reality only ever use the harnesses. This isn't safety based. With their fastenings, these isn't anywhere for them to go when I am in the seat.

I'd imagined clipping them together behind the seat, but no. For road driving, I don't believe they are any more or less safe than the inertias, if correctly adjusted. If not correctly adjusted, they are considerably less safe, so they do mean a few extra seconds every time you drive. On the track, harnesses are a must. Unless you are tracking the car then, I'd think long and hard about the convenience of the inertias.

Of course, having harnesses does also add to the theatre of taking a drive, they do feel a bit special, and passengers love them, so there is that to consider too.

In terms of fitting, when re-using the existing fittings you just need to be careful about the length of bolts used for the outer lower fixing points. Too long, and they will punch through the outer skin. I measured the length of the bolt I removed, added the spacer length and bought a couple of suitable UNF bolts. I think mine were 7/16" and 1.5" threaded section, but yours might be different. 

[Paul Richards]

All seat belt fittings are all 7/16 UNF. 

[Jig]

Thanks for the comments chaps. Anyone have a good supplier for the spacers?

[Jonathan Kay]

I had some "top hat" spacers made when I replaced my factory harness with one from Titon with thicker plates. I'd guess they couldn't take two plates, but if you let me know the combined thickness I'll check.

(I couldn't find a commercial supplier.)

Jonathan

[Jig]

Thanks Jonathan

I do have access to a lathe so I may end up making some spacers if I cannot buy anything off the shelf.

Cheers, Jig.

[bjw]

I'm not sure exactly what you're looking for, but ebay item 292462596324 is a 12.5mm high seat belt collar spacer, with a 9mm long reduced diameter section. <link>

Cheers

.

[Jig]

Great spot - so 'collar spacer' is the magic phrase. All seems to be one eBay vendor who has cleared a seatbelt factory! I'll contact him with my dimensions and see what he has available. Cheers.