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Mon May 07, 2007 2:17 pm

give some more pics, different angles of the upper shock mount. we can probably come up with a way to brace it. thats alot of leverage on those welds as it is now.

Tue May 08, 2007 6:54 am

I've never built shock mounts before, but I am a mechanical engineer.
If you gusset the top portion of the bracket back onto the frame like this:

you'll be in much better shape. That, and always avoid sharp corners (like you have now, top and bottom). Adding a small fillet can reduce the probability that a part will brake by as much as 2 or 3 times. If you give me an hour or two, I might be able to do a simple stress analysis on your mount, show you how much it will take.

Tue May 08, 2007 9:57 am

Ok... so I played around with your shock mounts, just for fun. I guessed at the dimensions, but I think they're close enough for the point I'm trying to make.

all studies have a 5000 lb upward force applied. I've also assumed that you're using 2" DOM, 1/8" wall, and have perfect welds. The little arrow shows where the material begins to fail.

This first pic is your design, more or less:

Notice that there are significant portions of your mounts that are almost 2x above the acceptable stress limit.

Now, adding the gussets:

Portions of the material still fail, but the amount of material failing is much less, and the peak stress level is much less.

Finally, adding the appropriate fillets (round edges) to everything brings the stresses below failure, again for 5000lbs:

Your welding may be in question as well, if you don't grind the edge of the plate to be welded at an angle, so as to allow complete penetration, you can again reduce these numbers by a factor of as much as 3.

Tue May 15, 2007 5:39 am

SpazMo - Thanks for the research. That is a cool program you have at your fingertips. I will look into adding the gusset. For now it is rolling so I can get it to Arizona next month. Knowing me, if the gussets look like crap when done I will probably cut them off and do it right....

Mon Jun 04, 2007 9:57 pm

First off I'm new to building Baja's. I have always wanted one I just have always had Drag racing cars instead. But now I have aquirred a 1974 Super Bettle. Which me and Kids can not wait to get started on. Our build plans are alot like what you are building. :?: My First and most important question is what Tubing size did you use for the main rails of your chassis and also what tubing sizes are you using through out your build for the cage and shock mounts. Please give me the OD and wall thickness. My issue is I'm only used to NHRA rules for cage tubing and it seams like overkill for a Baja. Please keep the build updates coming.

Mon Jun 04, 2007 10:29 pm

Ditch the super or be prepared for a whole lot of work that you could spare yourself by buying a standard beetle.

Tue Jun 05, 2007 6:45 pm

Really what would be the advantage of starting out with a Standard Bug. I would end up cutting off the Ball joint front end anyway and swaping in a link pin. So I might as well cut up a Super B and save a Standard for someone else to make a street car out of. Besides When I saw this Super Baja sitting next to this guys pole barn, it was crying to be saved and turned into something great.........

so would 1 1/2" x .095 DOM tubing be stong enough for the chassis and cage. Also thought about using 1" .095 DOM tubing for all the "X" bracing. Would this work or would .125 wall be better? Or should I go up on the tubing diameter?

Tue Jun 05, 2007 7:15 pm

Super "B" wrote:
so would 1 1/2" x .095 DOM tubing be stong enough for the chassis and cage. Also thought about using 1" .095 DOM tubing for all the "X" bracing. Would this work or would .125 wall be better? Or should I go up on the tubing diameter?

Use 1.5" .095. If it's for play I guess 1" for the X's might be ok, but really consider using larger dia. tubing all around. I would even consider using 1.75" for the main roll bar.

My cage is being built out of 1.75" .095 for the main roll bar, half lats, windshield bar, knee bar, and sill bars. My X bars in the main roll bar are 1.5", and I'm using a V design to brace the roof plane and back stays all out of 1.5".

Tue Jun 05, 2007 7:29 pm

Most roll cages for bajas are 1.5 x .095 or .120 steel tubing. 1.75 would seem a little overkill and much added weight.
I dont know if its that simple cutting off the front of a super because the front clip is not the same as a balljoint, dont know if it will accept a linkpin beam, I just looked at some pics and where it meet the pan looks alot different.

Tue Jun 05, 2007 7:32 pm

Nicksan wrote: Most roll cages for bajas are 1.5 x .095 or .120 steel tubing. 1.75 would seem a little overkill and much added weight.

I'm building my cage to current FIA rules required by my sanctioning body. 1.5" was the norm up until 2006.

Tue Jun 05, 2007 7:53 pm

markhuebbe wrote: Nicksan wrote: Most roll cages for bajas are 1.5 x .095 or .120 steel tubing. 1.75 would seem a little overkill and much added weight.

I'm building my cage to current FIA rules required by my sanctioning body. 1.5" was the norm up until 2006.

Oh, didnt know that, Thanks for the info.

Tue Jun 05, 2007 8:57 pm

[markhubbe wrote:]My cage is being built out of 1.75" .095 for the main roll bar, half lats, windshield bar, knee bar, and sill bars. My X bars in the main roll bar are 1.5", and I'm using a V design to brace the roof plane and back stays all out of 1.5".[/quote]

Thank you for the info on your cage tubing size. That really helps me. Any one else have any input on the tube size to use for DOM tubing?

Also here is a link to a member on here who put a link pin in a super. Just looks like a lot of cutting and welding but isn't that half of the fun.. :D

http://www.thesamba.com/vw/forum/viewtopic.phpt=130980&highlight=super

Tue Jun 05, 2007 9:11 pm

i did it, the only real way is to fully cage the car and mount the beam off of that. otherwise, i'm pretty sure you would be cutting the pan past the firewall, and fabbing a new one.

as for tubing size, how do you plan on using the car? do you have a bender, what dies do you have? 1.5 is fine for a play car with a roof. my next chassis will be 1.75 with 1.25 braces

Tue Jun 05, 2007 9:27 pm

You did a great job on that. It has given me lots of Ideas on how to do mine and show everyone you can baja a Super, just like you did. The car will be for Play. But we like to play hard..(If it's not broke your not driving it hard enough). Reason I asking about the tube size is I was going to buy a bender and dies next week. Looking at the JD2 model 3 bender. I was thinking of doing my cage and front end just like this build by Adrenaline Junky. Anyone know what tubing size he is using?

Wed Jun 06, 2007 12:03 am

I just ordered a tubing bender with a 1.75" die last week from asheville machinery (http://www.tubetek.net/). It comes with a extended handle for leverage, and a drilled plate so you can make your own pedestal. It was only $475 including shipping. I plan on using 1.75 to build a full cage, including front and rear bumpers, and an exocage.

Thu Jun 07, 2007 1:47 pm

mybugsucks wrote: I just ordered a tubing bender with a 1.75" die last week from asheville machinery (http://www.tubetek.net/). It comes with a extended handle for leverage, and a drilled plate so you can make your own pedestal. It was only $475 including shipping. I plan on using 1.75 to build a full cage, including front and rear bumpers, and an exocage.
I don't mean to bum you out, BUT, I am returning mine to Tubetek.

I got the 1.5" x 4.5"R die and it kinked both .095" and .120" wall mild steel, BIG TIME! The .120" wall tubing dia. was 1.502" to start and when finished it had kinked both inside and outside to a dia. of 1.360".
This is crap. I've used JD2 benders for the last 15 years and never had a visible kink. Sure, you could feel the start of a bend, but not see it like this!
The guy didn't have an explanation, so he sent me a 1.5" x 6"R die to try out. Same thing, just not as bad - 1.415".
Both dies severely kink the inside and leave a flat outside, as well as a step on the outside.

I have been going back and forth with him since February, sometimes taking 4-5 weeks to get a hold of him. No email or phone replies. I even used other peoples phones thinking he was avoiding my number on caller ID.

So, it get's boxed up tomorrow and sent back for a full refund. I could have bought the Harbor Freight PIPE Bender if I wanted bends like that :shock:

I really hope you have better luck.

Thu Jun 07, 2007 3:29 pm

I'm using 1.5 in .095 wall for most of it. Slipped in a little .120 wall in where I thought I needed it. I also have a stick of 1 in .120 wall that I will use for the front hoops and some X bracing. Getting ready to move to Arizona, so I haven't had time to work on it. Although I did tell the movers they could roll it into their trailer........ So you know what I'm doing this weekend if I can find the thing under all the packing material and boxes :D The movers are coming next Friday :shock:

Did get me new Nankang 7.00X15 yesterday. Damn that was crazy. They went up $20 a piece from Vee Dub Parts Unlimited. So I went this route, $164 shipped for the pair. http://www.thesamba.com/vw/classifieds/detail.php?id=450076

Thu Jun 07, 2007 8:49 pm

Thanks for the info on the tubing size you used. Good luck on the move and please keep us updated on the progress of your build when you get back to working on it. You have really help me with some ideas I can not wait to but into my project

Thu Jul 05, 2007 10:23 am

Well this post took a little longer than I expected. Kind of like working on the Baja. It always takes longer than you think.....

I took a couple days before I moved and fabricated enough of the front end to get it rolling. Had to, it was going to AZ on a car hauler so it needed to be rolling. Lucky for me everything fit well and the fabrication went smooth. I installed a complete 6in over front end from Steve at Tweeds Design. For anyone wondering, he is very helpful and answers the phone everytime I call. Top notch service there!!!! Here's a few shots, because I know a lot of you like pics :)

Not sure what I'm doing with that tunnel yet, so I thought I'd rather leave it then wished I had it later. I'll cut it when I get to that point.

Installed up some Gearone 2 piston disc brakes up front. These are also a very nice kit and bolted right up.

Front end completed

Rolled out of the garage

Like I said, I only had time to get it rolling. There is a lot more cross bracing that will be welded in. I had to stop here anyway, my 1/2 drill went up in smoke so I has to make the last couple notchs with a 3/8 drill motor. That was a treat :shock:

Anyway, I'm here in AZ now. Looking forward to meeting some of the locals. It was 116 degrees yesterday, but it was a dry heat :lol:

Thu Jul 05, 2007 10:33 am

Congrads on getting it rolling. It looks great. One question did you go with the 4" longer tweed arms and the 3 drop spindle?