littlephil
Member
hello all, i'm thinking of fitting 4 point safety harnesses to my exxey and was wondering how and where to mount them?
Cheers Phil
Cheers Phil
Technical 4 point harness
- Thread starter littlephil
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Technical 4 point harness
Phil,
the harnesses mount in 2 different ways. The first way is to clip onto eyebolts, the second way is to bolt them straight down. The lower belts can fix to the seat belt mounts on the floor, the top 2 will need bolt holes drilling into the bulkhead behind the seat.
The harnesses themselves come with different clip mechanisms. You can get a normal seat belt type clip of an aircraft type one.
In my car i used to have a clip in type harness fitted to eyebolts which let me use the normal seat belt as well.
Pm'd you as well.
the harnesses mount in 2 different ways. The first way is to clip onto eyebolts, the second way is to bolt them straight down. The lower belts can fix to the seat belt mounts on the floor, the top 2 will need bolt holes drilling into the bulkhead behind the seat.
The harnesses themselves come with different clip mechanisms. You can get a normal seat belt type clip of an aircraft type one.
In my car i used to have a clip in type harness fitted to eyebolts which let me use the normal seat belt as well.
Pm'd you as well.
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jimbro1000
Established member
The eye-bolts you buy should come with a threaded reinforcing plate. If you fit the belt to the bulkhead (and there really isn't anywhere else you can fit them on an X1/9) then it is vital you reinforce the metal. The bulkhead is pathetically flimsy. Ideally the bolts should be fitted into the shelf above the bulkhead not into the bulkhead itself as the harness must put a shear force on the bolt in order for it to be safe and the straps should go backwards at approximately 90 degrees to the level of your shoulder.
littlephil
Member
hi all,
Jimbro, you mean the bit where the speakers are? To fit the reinforced plates on the passenger side i'd have to drop the fuel tank wouldn't i?
also, just double checking 4 point harnesses are road legal aren't they?
Cheers for the pm ratty, i'll have a think.
Phil
Jimbro, you mean the bit where the speakers are? To fit the reinforced plates on the passenger side i'd have to drop the fuel tank wouldn't i?
also, just double checking 4 point harnesses are road legal aren't they?
Cheers for the pm ratty, i'll have a think.
Phil
jimbro1000
Established member
http://www.demon-tweeks.co.uk/Perfo...olts_Plates/Willans_Stress_Plate/1695/0/14794This is the stress plate i used.
Jimbro, are you sying that the eyebolts should be put in the shelf pointing upwards. this would mean that in an accident the bolt won't pull out equally. It should pull evenly on all threads.
As i last went in an X1/9 in 1994 i can't remember what the first bulkhead is like. Is it feasible to go through the spare wheel well to the main bulkhead?
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jimbro1000
Established member
The eye bolts should be fitted vertically, with the eye at the top, the belt should be tensioned so that the force acts perpendicular to the length of the bolt. This way the strength of the bolt is the core. If you load the force in parallel with the length of the bolt the strength is only in the thread of the bolt.
Been hunting around on the internet for something that shows the lengths and angles that the harnesses are designed for and sadly most of the resource has disappeared - even the old MSA Blue Book seems to have become inaccessible and missing the vital information - but I did find this Users Guide Racing Harness.pdf which covers most of the points. It may be specific to a single brand but the key information is the same for all of the different harnesses I've ever worked with.
Been hunting around on the internet for something that shows the lengths and angles that the harnesses are designed for and sadly most of the resource has disappeared - even the old MSA Blue Book seems to have become inaccessible and missing the vital information - but I did find this Users Guide Racing Harness.pdf which covers most of the points. It may be specific to a single brand but the key information is the same for all of the different harnesses I've ever worked with.
littlephil
Member
whats the best way to mount the plates? I would prefer to fit them from the underside of the shelf and seam welded, but i think i'll struggle at the top of the fuel tank. can the plates be bolted in?
Also, is the thread of the eye bolt standard or will i have to get a special ones for where the original mounts are for the hip strap?
Cheers all
Also, is the thread of the eye bolt standard or will i have to get a special ones for where the original mounts are for the hip strap?
Cheers all
standard as far as i know.
jimbro1000
Established member
They definitely use the same thread and pitch size as your original seatbelt mountings - a very useful detail!
The reinforcing plates should come with a smaller threaded hole that you can use to screw the plate into position without the harness attached and to stop it wandering off when you remove the eye bolt. It should always be on the reverse of the metal you are mounting through even if welded in.
The reinforcing plates should come with a smaller threaded hole that you can use to screw the plate into position without the harness attached and to stop it wandering off when you remove the eye bolt. It should always be on the reverse of the metal you are mounting through even if welded in.
Stanley Searra
New member
I have a 4 point harness in my car Bottom harness are in U-Bolts my top are in my roll cage.. Why you want to fit Harness?
