EvilCartman

iTrader: (1)

Ordered up a set of bolt in belts for the up coming jungle gym in the car and have a delima. From the looks of things the easy way of doing this since the shoulder belts are so long would be to drape them over the one crossbar and run them to a lower bar. Some loops would be added on the top crossbar so they don't slide side to side then anchor them to the bottom crossbar. Think I have seen this done before but forget where. Thoughts? Return and get wrap arounds like this set? (summit BOB-30298-19-06) Here's the one I have now (summit BOB-30298-18-06), zero adjustment for the length of the shoulder straps other than the short pull down when you snap in.

AlkyIROC

I just mount mine to the crossbar and cut off the excess belt.

EvilCartman

iTrader: (1)

There is no way to adjust the length from the mounting tab to the pull down adjuster, it's a fixed length, the hardware is stitched in. Only way to make it adjustable is to cut the mounting plate out of the stitched end loop and buy a couple of those slotted plates that come with the wrap around style.

gcpoland

iTrader: (18)

Shoulder belts must be mounted 1"-4" below shoulder height. If they are mounted any lower, spinal compression can occur. DO NOT cut belts. DO NOT change mounting hardware. A good set of belts come with general instructions.

You are better off with street belts then improperly mounted 5 point sets.

EvilCartman

iTrader: (1)

Ugh... I KNOW about the shoulder mount height, that is why that upper crossbar is going to be in place with stops to keep the belts from sliding sideways. The angle wouldn't be any different than if it were mounted to the crossbar itself. The anchor point is the only thing changed which would be a near straight pull between the upper and lower crossbar.

gcpoland

iTrader: (18)

I guess your not understanding the set up. The anchor point for the shoulder belts can be no more than 1-4 inches below the shoulder. You shouldn't run them over a bar and down. It has nothing to do with the angle or stops to keep them from sliding. (Which is an extremely bad idea, because they cause bunching and can create a failure point) It is a stretch issue. The length of belt from your shoulder height down is a CRITICAL mount point for the system.

In the end it is up to you. You can mount them correctly and be as safe as possible or mount them however you like and take your chances. The good belt companies have very specific instructions on how to mount their systems. If you call or send them pics, they will also tell you where the weak points in your set up are. I personally recommend G-Force or Willans as companies who know restraint systems.

gcpoland

iTrader: (18)

Taken from G-Forcenstall instructions:


Proper Installation is Important.The effectiveness of a restraint assembly is also influenced by attachment techniques.The principal precaution for installing the mounting hardware to the vehicle is to minimize bending stress in the fitting. This is achieved by making sure the belts pull from a straight angle against the hardware. The assembly should be installed so that the straps do not rub against any surface that can cause the webbing to fray. The anchoring mechanisms should also be periodically checked so that they don’t become loose or weakened.Proper installation of the restraint assembly also means achieving the correct fit to the driver. Belts should be as short as possible to reduce stretching for better control of occupant movement.The attachment points must provide the optimum geometry to minimize movementof the belts. Lap belts perform best when they act at an angle between 45° and 55°relative to the longitudinal axis of the vehicle as illustrated in part A of Figure 2. This angle permits the lap belt to react to the upward pull of the shoulder harness. A sys-tem installed with a shallow belt angle, as shown in part B of Figure 2, permits the shoulder harness to pull the lap belt up off the pelvic area and into the abdominal region with the likelihood ofinjury to internal organs.The end attachments of the shoulder harness must also be installed at appropriate angles. The ideal position is anywhere between 5° below and 30° above the driver’sshoulder, as seen in part Cof Figure 2.If the upper attachmentpoint falls significantlybelow the driver's shoulder,then a spinal compression injury is likely to occur. In an accident situation, the shoulder belts pull down and back on the torso as they resist the forward motion of the driver. The resultant restraint force compresses the spinal col-umn and will add to the stresses in the spine already caused by the force of the crash impact.On the other hand, if the trailing ends of the harness are too far above the shoulder(greater than 30°), then two problems can occur. First, tension in the shoulder har-ness is increased and undue stress is applied to the harness and its structural attach-ments. Second, excessive angle will cause excessive motion. If the harness belts are too far above the shoulder, they will provide little resistance to forward motion of the dri-ver’s upper torso. The result is impact with the steering wheel and the possibility of neck injury. The shoulder straps should also be 3-6” apart behind the driver's neck toprevent slippage off the shoulders.The reliability of a restraint system is greatly affected by the way it is installed. It is imperative to follow the installation instructions provided by the seat belt manufac-turer. Also, the necessity of replacing or rewebbing seat belts every two years canno tbe more important.As cars become more advanced and consequently go faster, everything possible mus tbe done to make the racing experience safe as well as fun. Failure to do so can cause serious injury, or worse. If there is anything that can be learned from the sport of racing, it’s that anything is possible, and taking the attitude that “it won’t happen to me” is risky, because it does happen.
ExcessiveAcceptableRangeABCReprinted from SFI Foundation/Jennifer M. BowdenFIGURE 1FIGURE 2

EvilCartman

iTrader: (1)

Finally a clear answer, thank you. I'll be returning these belts and getting a wrap around style.

patricklav

iTrader: (7)

Sorry for bringing up an old thread but figured i would, as opposed to starting a new one.

How did you mount the shoulder straps to the cross bar?

AlkyIROC

Depends on the type of straps you use.

If the straps just wrap around the bar, you need to use something to keep them in place so they don't slide back and forth along the bar. Some 1/4" round stock bent at both ends and welded to the crossbar for the straps to wrap through will work fine.

My current belts use a tab so I have another tab welded to the crosstube for the belt tab to bolt to. I use 1/2" bolts for all the belt mounts.

patricklav

iTrader: (7)

The belts I bought have a tab with a bolt hole in it. They work well when bolting to the factory lap belt hole locations as well as the center belt that connects to the floor. The shoulder belts are very long and have the same tab with a bolt but I wasnt sure what I would be bolting it to. Your idea of welding. Tab tk the crossbar and using that to bolt up to makes a lot of sense and I think I will try it.
Would it be safe to bolt the the shoulder belt tab to the rear seat belt location? The rear seats have been removed so there's nothing in the way.

Thanks for your time.

AlkyIROC

Probably won't work or pass a tech inspection. The much lower mounting location won't hold you in the seat. The shoulder belt mounting position needs to be roughly straight back so if your body moves forward, the belts hold you in.

If you're going to weld tabs onto the crossbar, it's better to weld them pointing backwards away from the seat but in the line of pull so the bolt would have to shear.

patricklav

iTrader: (7)

Makes sense. Do you have a pic of your harness, as well as the weld location for the tab, by any chance?

thanks again.

AlkyIROC

I could take a picture of the tabs tonight but my seatbelts are out of the car right now. My belts are expired and I haven't picked up a new set yet.

I run 6 point belts. Each shoulder strap has it's own tab. My seat is bolted to tube framework that's welded to the cage so the seat isn't attached to the floor. On both sides of the framework are the lap belt tabs. The crotch straps go to either side and also attach to the lap belt tabs. My belts have 6 straps but only use 4 mounting points.

AlkyIROC

Car is a little dirty but here's a pic of my shoulder strap tabs welded to the crossbar. Those tabs are angled but are in a direct pull with my shoulder straps.

You can also see how the back of the seat is attached to the crossbar. There's a plate welded to the post and the seat is bolted to the plate.