I was experimenting today with ways of mounting a window net on the lower bar of nASScar door bars and I came up with this. It's legal according to the GCR which requires mounting to the cage, no plastic, and no elastic. I'm going to beef up the D-ring if I decide to keep it this way, but otherwise what do you think? I have more pics if it's hard to see.

 

Travis,
I guess that technically it is legal. I don't think it is safe though. You need the net to be solid not stretchy. Instead of the sping, I used some ss cable. Ditch the band & weld on a tab with a hole. I used a small quicklink (link with a threaded gate) so that it can be removed if wanted.

BTW, I copied this idea from others pics on the old thead on window nets.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicrr &raquo;</TD></TR><TR><TD CLASS="quote">Travis,
I guess that technically it is legal. I don't think it is safe though. You need the net to be solid not stretchy. Instead of the sping, I used some ss cable. Ditch the band & weld on a tab with a hole. I used a small quicklink (link with a threaded gate) so that it can be removed if wanted.

BTW, I copied this idea from others pics on the old thead on window nets.</TD></TR></TABLE>

Well, it's hard to tell from the pic, but I don't think the net could stand to be under much more tension. When clipped in place at the top it's solid. I saw the pics on the other thread and I may end up copying one of those ideas myself, but I figured I would give this a try. If I like it, the hardware will be replaced.

Are you guys able to get good tension on the net with a static lower mount?

 

I was actually refering to the spring. From the pics, I believe that it would be able to stretch given a decent load.

I have almost too much tension on my net with current setup. It is a mother to get the top in. BTW, I went to this 'new to me' style because my old setup just took too long to get out of in a real emergency.

 

personally, if i was an inspector, i would fail you. the springs may look like they are holding, heck they might even be really stiff, but its not really going to be effective during a major collision where g forces are all over the place. i suggest you rethink the whole design.

it also wont pass the NASA requirement that the whole netting must drop down in a quick release.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">personally, if i was an inspector, i would fail you. the springs may look like they are holding, heck they might even be really stiff, but its not really going to be effective during a major collision where g forces are all over the place. i suggest you rethink the whole design.

it also wont pass the NASA requirement that the whole netting must drop down in a quick release. </TD></TR></TABLE>

Fair enough. Looks like I may go back to a solid connection.

Quick question about the NASA requirement. Could you explain? How would this (or this...with the spring replaced by a solid chain/cable) not meet the requirement?

 

If you have a quick release type mechanism up top, it will pass.

From the NASA CCR.

15.9 Window Nets
Window nets shall be used on the driver’s side window. The net shall be installed with a quick release mechanism at the top front mount so as to allow the window net to fall toward the floor of the vehicle when released. Fasteners must be metal and must be attached to the roll cage, and not the door or body. Drilling holes in the roll cage to mount the window net is strictly prohibited unless properly “bushed” (not recommended). No plastic ties or Bungee (type) cords allowed. The net must carry a label indicating an SFI Spec 27.1 approval.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicrr &raquo;</TD></TR><TR><TD CLASS="quote">If you have a quick release type mechanism up top, it will pass.

From the NASA CCR.

15.9 Window Nets
Window nets shall be used on the driver’s side window. The net shall be installed with a quick release mechanism at the top front mount so as to allow the window net to fall toward the floor of the vehicle when released. Fasteners must be metal and must be attached to the roll cage, and not the door or body. Drilling holes in the roll cage to mount the window net is strictly prohibited unless properly “bushed” (not recommended). No plastic ties or Bungee (type) cords allowed. The net must carry a label indicating an SFI Spec 27.1 approval.</TD></TR></TABLE>

Thanks for the text! I meet all of those requirements with this design, safe or not. I didn't post a pic of the top mount, but it has a quick release front mount and it drops down and out of the way when released. Really the only difference between this and the standard design is the use of a very stiff spring in place of a static chain/cable. I was hoping to get a little extra tension.

 

you can buy the net attachment kit from ioport, but its just some cheesy assortment of 2 rods (which is not long enough to span across the whole lower section), end pieces, a spring, and mounting tabs to the cage. if it fits altogether, its not a bad deal, the spring suffices as a quick release which is loaded against the mounting tab so once you free that end, it pushes the other end out of the tab and thus drops. i guess its kinda hard to explain.

when i bought it, i guess i didnt really understand how it was all supposed to work, plus i had to get another rod (btw, youll be failed if you use an aluminum rod, they tested mine by grasping it and yanking it out, and sure enough it bent, imagine how well it would hold up in a real accident) so i wasnt so impressed with the kit at first. but since i had designed mine to be bottom loaded, i recently bought this kit from RW and welded the locking tab to the top. now it all pretty much falls apart when released, which is the objective i suppose.
http://www.racerwholesale.com/...F-WM1

sorry no pics, im halfway across the world from my car at the moment...

oh, just noticed from the pics you DID buy the ioport kit! and it sounds like youre smarter than i for figuring out how to make it a quick release.

 

btw, just hardmount the mount with the spring to the top of the sidebar of the cage. it looks to be jsut an inch or so away.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">you can buy the net attachment kit from ioport, but its just some cheesy assortment of 2 rods (which is not long enough to span across the whole lower section), end pieces, a spring, and mounting tabs to the cage. if it fits altogether, its not a bad deal, the spring suffices as a quick release which is loaded against the mounting tab so once you free that end, it pushes the other end out of the tab and thus drops. i guess its kinda hard to explain.
</TD></TR></TABLE>

Actually, that's what I used. I/O Port says that the quick release should go on the bottom and that the upper rod should should be permanently attached to the halo. I knew that this wasn't right so I used the quick release hardware and the shorter rod on the top. Then I cut the longer rod to length and permanently (well, not quick release that is) attached it to the main hoop (back) and lower door bar (front). I believe the rods are steel.

So the question remains, is a stiff spring an unsafe replacement for a fixed length chain, assuming all other parts are equal?

 

Here are the upper mounts, FYI.

This is the spring loaded rear:



and this is the quick release front (hard to see how it goes together, but the rod extends about 1" into the tab where you can't see it):



Sorry for the huge pictures, but I'm working with a new computer and I don't have any photo editing software installed yet.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">btw, just hardmount the mount with the spring to the top of the sidebar of the cage. it looks to be jsut an inch or so away. </TD></TR></TABLE>

Yes, the upper bar is about an inch away. The only reason I mounted it on the lower bar is to allow it all to drop way out of the way when released from above.

 

well, since i had to get an extra long lower rod to span across the whole door i just used the extra length of the rod as my tension and attached the mount a little lower than it it needed to be. then i cut the mounting tab open on the bottom side, so i just push down and out, while the tnesion pushes up, instead of having to pull it out. youre probably betterto utilize the closer top doorbar as i mentioned above since its only an inch or two away, but i dont have nascar doorbars and it have ot look like the way you set it up currently.

 

Actually the GCR shows mounting tabs welded both top and bottom. That is how mine was done and it is very tight this way. Keep this in mind while rethinking your install-the size of the net can be whatever is commercially available (M&R makes custom sizes-hint) to cover the window opening. Just my 2cents

 

i did mine in the same manner.. But I used a few links of chain!

 

I usually do about the same as shown on the red car but use a lengths of cloth strapping like old seat belt to make a flexible but strong lower forward attachment point. I always prefer to make my net unlatch at the top so a down net drops into the area of the seat and door bars. Some leave it hard attached at the top but that means the net in the open position will either hang down or must be flipped up on the roof and scratch your paint.

Travis, the idea of the spring is good to keep tension on the net when installed but it needs some rod, chain, belting, etc. to be a stronger mount that can't get any longer with force. I size the length of the belting so the net just goes into tension when latched in place.