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Author Topic: How to install crotch strap on 6 point belts?
Alberto M Goncalves
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Year : 1990
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I ordered the G-Force 6 point belts from Saferacer:
http://www.saferacer.com/g-force-pro-6pt-camlock-harness.html?productid=953
and also ordered a pair of Eye Bolts thinking they would be necessary for the crotch strap:
http://www.saferacer.com/g-force-eye-bolt-20mm.html?productid=882

Now, I'm scratching my head trying to figure out how this stuff all works together.

How do you normally attach the lower straps? Do you use eye bolts or do you just attach to a regular bolt through the floor board with appropriate 3" backing washers?

Thanks.

Greg Arsenault Verified Driver
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quote:
Originally posted by Alberto M Goncalves:
I ordered the G-Force 6 point belts from Saferacer:
http://www.saferacer.com/g-force-pro-6pt-camlock-harness.html?productid=953
and also ordered a pair of Eye Bolts thinking they would be necessary for the crotch strap:
http://www.saferacer.com/g-force-eye-bolt-20mm.html?productid=882

Now, I'm scratching my head trying to figure out how this stuff all works together.

How do you normally attach the lower straps? Do you use eye bolts or do you just attach to a regular bolt through the floor board with appropriate 3" backing washers?

Thanks.

The belts as picuted are bolt-in. The eye bolts are used for clip-in belts. It is important to install the bolt-in plates in the correct orientation with respect to the load. Bolting them flat to the floor is not correct, they should be loaded in double shear meaning the load is inline with the belt. A good view is here: http://www.stockcarracing.com/howto/scrp_0603_racing_seatbelt_installation/photo_07.html

Recommend changing the ends to clip-in using something like this: http://www.saferacer.com/g-force-snap-hook.html?productid=881

Then you can install the eye-bolts perpendicular to the floor with proper bracing and backing and clip in the anti-sub belts. You can also do the same for the lap belts.

The angle the belts make from their attachment points is also important. This document has some real good mouting information and discusses angles, etc.: http://www.schrothracing.com/sdocs/2009_Competition_Instructions.pdf

Qik Nip Verified Driver Made Donation to Website Series Champ
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Alberto:
You should be able to use somewhat longer bolts installed in the factory lap belt mounts with each of those two bolts passing through that side's lap belts and the sub belt. That way the sub belts will pass under each thigh and up through your croutch to the buckle. Make sense?
Rick

--------------------
Fortune Cookie Racing SM 60
Directions for use: Race, Rumple, Repair ... Repeat!

Alberto M Goncalves
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Year : 1990
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Thanks Greg. What you said makes sense but I find it odd that they sell the belts with the sub strap using those bolt in plates.


Rick - Yes it makes sense but your recommendation is contrary to the recommendations that Schroth makes...

wheel Verified Driver Made Donation to Website
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Personally, I wouldn't mount the sub straps as far back as attaching them where the lap belts attach. I don't think that is really the approved way to mount them.
wheel

d mathias Verified Driver Made Donation to Website
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Wouldn't it depend on whether you use the 'sit-on' layout or the 'through the seat' style?

Jay Flath
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I just did this on my car. I used a Schroth Profi 2 belt and followed their guidelines. Sub straps should be installed at a 20 degree angle back from the hole through the seat. they should be mounted 2-3" apart from the centerline on the hole in the seat.

http://www.schrothracing.com/docs/Schroth_Installation_Checklist.pdf

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d,
All I have ever used, or seen used, is the through the seat type. I did about 40 annual inspections last year and did not see any 'sit-on' belts. The through the seat type is the only type with which I am familiar.
wheel

Alberto M Goncalves
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Year : 1990
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Just tried to call Saferacer to get some clarity on this. Nobody there seemed to have much of an idea on how to actually install this stuff. They definitely don't know anything about "double shear"... They did say that they typically use "Snap Hooks" with Eye Bolts. Link to part:

http://www.saferacer.com/g-force-snap-hook.html?productid=881

I wish they would have told me that when they told me to order and use eye bolts. Would have saved me money in shipping and time...

I'm not happy right now...

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quote:
Originally posted by wheel:
d,
I did about 40 annual inspections last year and did not see any 'sit-on' belts. The through the seat type is the only type with which I am familiar.
wheel

Wheel:
My sub belts (Simpson) are actually a "V" configuration - with a single latch that engages the buckle.(That way the same buckle works for a five or six point rig).

The two attached ends of the V sub pass through the same seat side entry points as the lap belts but lay on the seat. When I sit down on them, the end which forms the V comes under and up through my legs to attach to the buckle.

The direction of force (at the mounts) is identical to the lap belts but the angle of the sub belts is actually lower from that of the lap belts since those belts pass over my legs rather than under them.

My preference for the "sit on" installation is that the sub holds you in place from the get go. If you pass the sub belt through the bottom hole in the seat, your body needs to shift considerably forward to be restrained by it. With the sit on mode, you are strapped much more securely in place - even at rest.
Rick

--------------------
Fortune Cookie Racing SM 60
Directions for use: Race, Rumple, Repair ... Repeat!

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I certainly understand the concept, I just have never seen belts installed that way.
wheel

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That surprizes me Mr. Wheel. My understanding is that routing the belts through the "sub-belt hole" in the seat defeats the advantages of the 6-point belt. I installed my belts in the manner Rick described.

Also, what Rick said, many seats the hole in the bottom is too far forward for a 6-point belt.

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The debate rages on. I have seen many where the holes in the seat are moved back a bit, but none where the driver sits on the sub straps, coming from way back.
wheel

FastM3 Verified Driver
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http://www.hmsmotorsport.com/store/schroth-competition-belts/profi/profi-ii

Read it

Study it

Sub belts are supposed to hold the lap belt down sow you don't submarine. The Lap belt is supposed to stop you from going forward. If the Sub belt stops you from going forward guess what gets removed in the process.

The sit on belts are for formula cars.

Good Luck. Contact HMS Motorsports (No connection to me) with any questions on belt installation. They do Schroth belts for NASCAR.

--------------------
Phil
Silver 38 SM/ITA

Alberto M Goncalves
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quote:
Originally posted by FastM3:
http://www.hmsmotorsport.com/store/schroth-competition-belts/profi/profi-ii

Read it

Study it

Sub belts are supposed to hold the lap belt down sow you don't submarine. The Lap belt is supposed to stop you from going forward. If the Sub belt stops you from going forward guess what gets removed in the process.

The sit on belts are for formula cars.

Good Luck. Contact HMS Motorsports (No connection to me) with any questions on belt installation. They do Schroth belts for NASCAR.

Thanks for the link. I had considered getting the Schroth but when I called Saferacer to try and learn the difference between the two, the only thing they could comment on was price.

Now that I see that link and have the G-Force in my hands and notice the differences in how the End Fittings are mounted and that they include slip on fittings and eye bolts, washers etc, I would have gone with it.

I'm disappointed in Saferacer right now.

Jay Flath
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Profi 2 is a great belt. That is what I ran when I had an E36 M3 track car and its the same belt I am using in my SM. Schroth belts are excellent quality. I wont use anything but for my safety. Also using the Schroth center and window nets as well.

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quote:
Originally posted by FastM3:
http://www.hmsmotorsport.com/store/schroth-competition-belts/profi/profi-ii


Sub belts are supposed to hold the lap belt down sow you don't submarine. The Lap belt is supposed to stop you from going forward. If the Sub belt stops you from going forward guess what gets removed in the process.


Phil:
First, thankls for the link. The Schroth instructions are the best I've ever seen. I heartily recommend everyone taking a look. (I've printed it out).

As for the function of the sub belt, I fully agree. At issue is the positioning of the sub so that it can do it's job (i.e. keeping the lap belt positioned on your pelvis). A sub that is too far forward may not accomplish that since the occupant can already be submarining before the sub comes into play.

By using the sit-on method, and by properly adjusting them so that they are working in tandem with the lab belt, the "early" tension on the lap belts in a frontal incident prevents them from shifting above the hard point of the pelvis. Alternatively, a too forward (or too loose) sub belt may not accomplish that task.
Rick

--------------------
Fortune Cookie Racing SM 60
Directions for use: Race, Rumple, Repair ... Repeat!

Alberto M Goncalves
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Year : 1990
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quote:
Originally posted by Jay Flath:
Profi 2 is a great belt. That is what I ran when I had an E36 M3 track car and its the same belt I am using in my SM. Schroth belts are excellent quality. I wont use anything but for my safety. Also using the Schroth center and window nets as well.

Yeah, NOW I can understand why people spend the extra $$ on it. I searched a lot of past discussions where people said that they preferred the Schroth but nobody said why. Now I am starting to understand why....

- the snap in hooks are correct for use in a Miata making it easier to mount. Otherwise, you would/should bend the fixed bolt-in bracket that is standard on the G-Force so it is in-line with belt routing (double shear) or buy the extra snap in ends to swap out at extra cost.

- the snap in hooks are built/sewn into the belts so much easier to install and adjust once in the car

-the Schroth belts includes all the extra hardware - end bolts etc.


I just returned the G Force belts to Saferacer and bought the Schroth belts. A bit happier now. They were easy to work with.

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I have used the Safecraft 6 point belts for 2 years and have used them in a "sit-on" installation as recommended by Safecraft. You will find out that there is a reason that the Safecraft and Schroth belts are used by more of the top NASCAR, ALMS, and Rolex teams than any of the other brands out there. I just sent my Safecraft belts back for the free re-webbing and they are also upgrading the hardware for me at no charge. The quality of the adjusters and hardware makes a huge difference in the wear and fit of the belts. My belts are a 2" hybrid system which I use with my HANS.

--------------------
Paul McLester

   

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