ArVeeNiner

ArVeeNiner

Well Known Member
Hey all:

OK, I'm officially getting started with installing my roll bar on my slider. There are a couple of things left unsaid in Van's instructions. I think I have figured out the reasoning behind some of them but it bothers me that they don't come right out and say what I'm thinking so I need to bounce it off y'all.

1-The instructions state that the pilot drills need to go through both the "upper surface of F-721B and the lower flange of F-721B". After quite a bit of head scratching, I'm thinking the holes in the lower flange simply enables you match drill up into the roll bar. Once the pilot holes are drilled in the roll bar, the holes in the lower flange are no longer used for anything, except for perhaps a future cup holder installation. Am I right?

2-The instructions state after modification of the C-668 spacers, you end up with a foward left, aft left, forward right, and aft right spacer yet they only show two spacers, a forward and an aft, in the details. It seems to me that, along with the spacers shown in the views on DWG 42, you have to make mirror images of these as well.

3-The drawing states that the roll bar attachment bolt holes should be as close to the longeron as possible. This is another one of those Van's high pucker factor moments! You drill a pilot hole which has to be opened up and that bigger hole needs to be as close as possible to the longeron. If you get too close, you can nick, or worse yet, drill into the longeron. What is a good method of drilling these holes without damaging the virtually invisible longeron? Yea, I know there are dimensions on the drawing but I've been burned before carefully measuring out holes only to have them be in the wrong places...just like everybody else's.

PS: Man, I never thought that I'd be eventually working on the roll bar when I got that first kit many years ago. This part of the build seemed so far away but here I am. Very cool!
 
Last edited:
roll bar

1. There's only 2 holes per side on the roll bar flange.
2. Yes, you need 2 spacers per side.

Study the section view carefully to get a better mental picture. I struggled with the roll bar fore-aft location. I never did see a real dimension on the prints.

You'll need super glue, tape, and a bent wrench to get the nuts on the bolts.

Steve
 
Question #1

Yes - the holes thru the lower flange are just for pilot drilling / alignment.

I needed to bend my roll bar a bit to get it to fit. Be prepared with some big nylon come-a-long straps, and a big friend!


Be careful - this makes for a pretty big spring!

IMG_1273.jpg


IMG_1267.jpg
 
Last edited:
Read the prints carefully ! Dimensions are there.

Kelly, I found the instructions a little confusing as well but the prints are really pretty clear. Read them with a highlighter several times. You got the answers to 1 and 2 above so here is just a comment on 3 about the bolt spacing.

There is a critical dimension on the plans which gives the clearance between the outside edge of the roll bar and the outside edge of the fuse. I think it is something like a 1/4 inch (check to be sure). If you have that correct, and drill in the center of the flange, I "think" the edge distance takes care of itself. The plans also show specifically where to position the roll bar front to back.

I can also tell you those bolts are tough to get nuts on and would be impossible if they were really close to the longeron.

Just a hint on the bolts and spacers,... you can glue them (spacers, washers, and nut) together with a thin skin of RTV. Then start the bolt by hand until it is snug and then worry about getting a wrench or socket on it.

Use castle nuts for all the fitting and only torque real nuts on during the final install.

Hope this helps!

Bill S
7a finishing
 
Bar overlap - inside edge is not flush!

Kelly, you may also find that if you fit the roll bar correctly to the outside edge dimension, it overlaps the inside edge and is not flush.

No problem, just trim that back with a file later but be sure the outside edge dimensions are correct.

Bill S
 
Thanks

Thanks for all the responses. I have everything laid out but now I have to wait my obligatory waiting period before I commit to cutting metal. :eek: Depending how our Christmas light installation (on the house and tree, not on the plane) goes this week, I should have thought about it long enough to literally pull the trigger by weeks end.
 
Last edited:
ArVeeNiner said:
1-The instructions state that the pilot drills need to go through both the "upper surface of F-721B and the lower flange of F-721B". After quite a bit of head scratching, I'm thinking the holes in the lower flange simply enables you match drill up into the roll bar. Once the pilot holes are drilled in the roll bar, the holes in the lower flange are no longer used for anything, except for perhaps a future cup holder installation. Am I right?

3-The drawing states that the roll bar attachment bolt holes should be as close to the longeron as possible. This is another one of those Van's high pucker factor moments! You drill a pilot hole which has to be opened up and that bigger hole needs to be as close as possible to the longeron. If you get too close, you can nick, or worse yet, drill into the longeron. What is a good method of drilling these holes without damaging the virtually invisible longeron? Yea, I know there are dimensions on the drawing but I've been burned before carefully measuring out hole only to have them be in the wrong places...just like everybody else's.
Click to expand...
Questions 1 and 3 are directly related to each other. To make sure your hole ends up in the right place, just measure over from the vertex of the longeron .75" + half the diameter of the bolt. By drilling through the aft deck first with a 3/32" bit, you can then place the roll bar in position, insert a long 3/32 drill bit from the bottom up, and twist it a couple times to mark the hole position on the roll bar base. Pull the roll bar off, drill it 3/32 separately, then you can drill from the top all the way down through the roll bar and deck at the same time with the full size bit. If in doubt or if it makes you feel better, give yourself an extra 1/32 when measuring over from the vertex of the longeron.

Hope this helps. Good luck.
 
You must log in or register to reply here.