Web bridge question

[NMSbowhunter]

I built a Wraptor 2 panel saddle a year or so back and I really like it. I have the bridge made from tubular webbing. It is routed through some heavy duty steel "triglides?" I bought from Eastern Woods. I think they are 4000 pound rated. I have the tag ends doubled over and sewed so they won't back out and I also sewed the web below the tag end to the bridge itself. There is the question that has been nagging at me a little lately.

Am I correct in saying that sewing webbing weakens it? I believe that is true. My concern, and it may be unfounded, is that the sewing through the actual bridge going to be an issue or not? Would it be better to route it back through the triglide like shown in the second picture and then sew the tag back onto itself so it can't back out. That way no actual weight bearing webbing is sewn through.

Thoughts?

 

[krub6b]

My limited understanding of sewing materials is that when strength is a concern using a ball point needle minimizes strength lost due to the needle "rolling" the existing threads out of the way as opposed to cutting existing threads like a sharp point needle might. I assume that this is the process used to make climbing slings and the like out of tubular webbing

 

[Vorsteg]

as opposed to sewing, what about tying an overhand knot in the end, instead?

 

[Brocky]

I built a Wraptor 2 panel saddle a year or so back and I really like it. I have the bridge made from tubular webbing. It is routed through some heavy duty steel "triglides?" I bought from Eastern Woods. I think they are 4000 pound rated. I have the tag ends doubled over and sewed so they won't back out and I also sewed the web below the tag end to the bridge itself. There is the question that has been nagging at me a little lately.

Am I correct in saying that sewing webbing weakens it? I believe that is true. My concern, and it may be unfounded, is that the sewing through the actual bridge going to be an issue or not? Would it be better to route it back through the triglide like shown in the second picture and then sew the tag back onto itself so it can't back out. That way no actual weight bearing webbing is sewn through.

Thoughts?

The sewing you have won’t weaken it, the thread has only passed through the webbing, not disturbing it much.

 

[NMSbowhunter]

The sewing you have won’t weaken it, the thread has only passed through the webbing, not disturbing it much.

Thanks! To ease my mind, I went ahead and replaced the webbing bridge with one where I routed it as normal but instead of sewing it back to itself, I fed it back through the buckle again and then doubled over and sewed the tag end so there is no way it can back out.

 

[Fl Canopy Stalker]

The way that you did it by sewing the ends over so that it doesn’t back out will not weaken it enough to cause any concern at all. At most you are talking 5 to 7% reduction in strength and it’s at a point in the webbing where no weight is actually being held (the ends). Also keep in mind that a bridge is a two points of contact loop style connection, not an end to end straight pull so each end is only seeing half the load. Aka it’s plenty strong that way… . Folding it back over the triglide makes it harder to adjust.

 

[NMSbowhunter]

How I had it configured in the first picture above was what had me concerned where the sewing went through the actual weight bearing portion of the webbing ahead of the D rings. I got to thinking I might have cut a lot of fibers by sewing it there and it might just rip through or let the webbing snap. I have since changed it by routing the loop back through the buckle and sewing a tag end on so it can't back out. Once I get the length right, I never adjust the bridge length. I based the new bridge length on the old one.

That's good to know about the weight distribution of force. That makes sense.

 

[Fl Canopy Stalker]

How I had it configured in the first picture above was what had me concerned where the sewing went through the actual weight bearing portion of the webbing ahead of the D rings. I got to thinking I might have cut a lot of fibers by sewing it there and it might just rip through or let the webbing snap. I have since changed it by routing the loop back through the buckle and sewing a tag end on so it can't back out. Once I get the length right, I never adjust the bridge length. I based the new bridge length on the old one.

That's good to know about the weight distribution of force. That makes sense.

I just noticed that you also sew it back to the main piece. Either way the tri glide are holding the bulk of the weight your stitching was just keeping it from going back towards the triglide so it was still safe. It wasn’t enough stitching to compromise the webbing by much at all. Think about bartacks and how many passes of thread they create in webbing and even then they don’t weaken it by more than 15%. For reference 15% of 4000lbs webbing is still about 3400 lbs which is plenty strong especially since it’s splitting the load in loop configuration.

 

[NMSbowhunter]

as opposed to sewing, what about tying an overhand knot in the end, instead?

That would be one way to do it and I have done just that with a web lineman's belt I put on a rock harness, but for this application I wanted something neat and tidy. Routing the webbing through a heavy duty steel triglide did that for me.

 

[Weldabeast]

The sewing is overkill anyway....once u got those buckles doubled over webbing not moving. I made a reference mark on the webbing and years later with lots of climbing/sitting time it hasn't moved on my old saddle