Gear question ... more techincal really ... Denier thickness

Message

bmgibben · Fri Apr 06, 2007 11:47 am

I'm going to slightly-hijack this post. The original poster mentioned he is now using Sliders Kevlar jeans. When I start purchasing gear for my bike, I was planning on either those, or more probably, a pair of Draggin Jeans (kevlar). Probably also planning to opt for their jeans knee armor (knox made I believe).

I know that pure thick denim isnt as good as most textiles, but with the kevlar and knee pads, does anyone think this will not be adequate protection? Thanks!

ninja79 · #12 Unread post by **ninja79** » Fri Apr 06, 2007 11:59 am

bmgibben wrote: I know that pure thick denim isnt as good as most textiles, but with the kevlar and knee pads, does anyone think this will not be adequate protection? Thanks!

It will be better than regular jeans but worse than polyester mesh.

jonnythan · Fri Apr 06, 2007 12:32 pm

ninja79 wrote:
bmgibben wrote: I know that pure thick denim isnt as good as most textiles, but with the kevlar and knee pads, does anyone think this will not be adequate protection? Thanks!
It will be better than regular jeans but worse than polyester mesh.

I disagree completely.

The Kevlar lining under this Denim is really thick, and it is going to *kill* polyester cloth in an abrasion test. Polyester mesh wouldn't stand a chance.

Look at the PDF linked above. Motoport's test showed 500 denier polyester getting 180 cycles before failure.. but Kevlar getting 1800. Polyester isn't even as abrasion resistant as ballistic nylon, much less Cordura. We don't use polyester sheaths on caving ropes for *that one specific reason* even though polyester offers lots of other advantages.

ninja79 · #14 Unread post by **ninja79** » Fri Apr 06, 2007 1:53 pm

jonnythan wrote: I disagree completely.
Look at the PDF linked above. Motoport's test showed 500 denier polyester getting 180 cycles before failure.. but Kevlar getting 1800. Polyester isn't even as abrasion resistant as ballistic nylon, much less Cordura. We don't use polyester sheaths on caving ropes for *that one specific reason* even though polyester offers lots of other advantages.

*which kevlar*? Motoport's "stretch kevlar" is a blend of kevlar, cordura, and lycra. It gets the tensile strength from kevlar fibres, and abrasion resistance from cordura. Notice that, according to the same table, 1000 denier cordura has almost the same abrasion resistance. Pure kevlar is very strong (i.e. hard to rip it apart) but not very abrasion resistant.

Kevlar fibers in dragging jeans and such reinforce them so that they will not shred immediately upon impact (as regular jeans do), however, once you are down and sliding, the only thing that separates you from the pavement is a thin layer of cotton.

edit: I am rather skeptical of Motoport's numbers, considering that I have yet to see any non-leather outfit being used in professional racing. I am almost positive that their "stretch kevlar blend" is actually Shoeller Keprotec, which is used in low-impact areas on many leather jackets/pants. I own motoport "kevlar" overpants (which I still believe are one of the best overpants on the market) but I'm sticking with my leather jacket.

jonnythan · Fri Apr 06, 2007 2:28 pm

ninja79 wrote:Kevlar fibers in dragging jeans and such reinforce them so that they will not shred immediately upon impact (as regular jeans do), however, once you are down and sliding, the only thing that separates you from the pavement is a thin layer of cotton.

edit: I am rather skeptical of Motoport's numbers, considering that I have yet to see any non-leather outfit being used in professional racing. I am almost positive that their "stretch kevlar blend" is actually Shoeller Keprotec, which is used in low-impact areas on many leather jackets/pants. I own motoport "kevlar" overpants (which I still believe are one of the best overpants on the market) but I'm sticking with my leather jacket.

You do know that Draggin Jeans have a separate layer of thick, stretchy Kevlar + nylon blend?

Obviously leather is better, but no polyester mesh is going to come close to the durability of the Kevlar that lines Draggin Jeans.

ninja79 · #16 Unread post by **ninja79** » Fri Apr 06, 2007 3:05 pm

jonnythan wrote: You do know that Draggin Jeans have a separate layer of thick, stretchy Kevlar + nylon blend?

Obviously leather is better, but no polyester mesh is going to come close to the durability of the Kevlar that lines Draggin Jeans.

You mean the entire pants are lined with "kevlar"? Why even bother with denim?

bmgibben · #17 Unread post by **bmgibben** » Fri Apr 06, 2007 3:05 pm

I almost completely unworried about the kevlar holding up in a slide. The maker of Draggin Jeans lab tested during development by being dragged behind a truck on pavement, sitting on the ground in them. So I would assume in the high kevlar areas it has at least a decent chance of holding up. My worry is more the rest of the denim (thick as it is) holding up in the areas other than the seat and knee.
The thing I am worried most about is the impact. The knox knee armor should do its job there, but what about the most crucial joint south of the navel? The pelvis? Ive done very little research on the armor provided by pants, just recently thinking about them, but how dangerous is it not having armor protecting the side of the hip from impact forces? Is this a rare occurance in a crash, or does most of the pant armor just not have this? Is it only some of that specialty armor that has protection for this? Or is it not deemed as important in a crash? Thanks for all the input.

Sev · #18 Unread post by **Sev** » Fri Apr 06, 2007 3:22 pm

The thing that worries me is the stitching letting go.

As for hip protection, I'm fairly certain racing leathers don't even have any besides being leather.

mgdavis · #19 Unread post by **mgdavis** » Fri Apr 06, 2007 3:48 pm

I have pants which have removable hip pads. They make me look very broad through the waist, but should work well if I ever go down. Mine are discontinued Tourmaster's, IIRC.

jonnythan · Fri Apr 06, 2007 4:39 pm

ninja79 wrote:
jonnythan wrote: You do know that Draggin Jeans have a separate layer of thick, stretchy Kevlar + nylon blend?

Obviously leather is better, but no polyester mesh is going to come close to the durability of the Kevlar that lines Draggin Jeans.
You mean the entire pants are lined with "kevlar"? Why even bother with denim?

Not the entire pants. The butt/hips area and a large patch over the knees are lined with a thick woven Kevlar blend.

http://www.dragginjeans.com.au/products ... arJean.htm

Apparently these guys did a "drag a guy on his butt at 140kph for 300 meters on asphalt" test. The denim obviously wore through but the kevlar lining did not. This is good stuff. Unarmored, of course.