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Tue Nov 29, 2022 5:59 pm

So on my tube frame buggy I'm considering removing the overhead tubes on both sides. Looking over the car I don't think this will affect the structure or anything, I think the strength of the car is in the bottom tubing. I don't see this being any different than the pan type fiberglass body buggies. I plan on keeping the one bar similar to the "roll bar" on the fiberglass type cars and of course the bar around the windshield. I guess my question is do you think that this will affect the strength or rigidity of the frame? I'm thinking that it won't but what do I know. I should add that this is not an off-road car, it's street legal and it gets a couple hundred miles a year being easily driven.

Tue Nov 29, 2022 8:45 pm

Yes it will absolutely effect the strength and rigidity of the frame. In your case where you are not beating the crap out of it… maybe it’s not a big deal. The car is still going to be at least as strong as a fibreglass Manx style street Buggy without a cage. I run one like that. It will definitely leave the center of the car weaker though.

I have been thinking about moving both overhead tubes to the center to get more head clearance. A double one in the center will not be quite as strong but still better strength wise than taking them completely out.

Just a thought.

Tue Nov 29, 2022 9:01 pm

Absolutely, massively affects the stiffness of a cage/car - that's why convertibles end up heavy 'cause they add 50kgs of reinforcement in the sills and things to get the stiffness back.

Will it matter for a road car just cruising? Maybe not, depends on the frame.

Wed Nov 30, 2022 4:54 am

My Manx copy as I said before, doesn't have a roll cage or roll bar and I like the clean simple nostalgic look. However having driven it for many miles on the street I am fully aware of how much this car flexes. I will be adding front and rear sway bars in an effort to tighten up its handling in the corners but I also realize that it may not change anything because of how the body twists over the bumps now. It really needs a cage but I am reluctant to do that because cages look ugly (especially if you make them tall enough to clear your head!), make access to the car much more difficult and render the rear seat useless.

I don't run this Buggy off road and can't imagine doing so as the end result without a cage would be a lot of cracked fiberglass.

If you do cut off those tubes it would be interesting to see if the frame would sag enough so that they would not fit back in. That totally depends on the wall thickness of the tubes the frame is made of but I would expect that even if it didn't sag a bit right away that after you ran it for a summer and rechecked you would find it has sagged some.

The other thing to consider is if you ever hit something hard on the front, with the drive train weight behind and passenger weight at the weak point the frame will fold in the middle. The floor will go down and the sides out. I am confident my Manx copy will fold like this.

Again, with light use all may be good, just be aware that those tubes are structural.

Wed Nov 30, 2022 4:58 am

I wouldn't be afraid to modify the cage, just make sure to triangulate especially where there's long tubes at close angles. You don't want it to fold up on you. Be smart about it.

Sat Dec 03, 2022 8:20 am

It may not effect the rigidity of the lower portion of the frame but it will definitely effect how easily the windshield frame will collapse down on you if you happen to roll or hit anything at that level , ie rear ending a truck or anything that sits higher than the nose of your buggy.
Having put 4 vehicles on their roofs , i can tell you first hand that in that moment you are praying the roof is strong enough to hold up. I would never do anything to weaken a roof structure, period. I also wont ride around in a convertible or a Manx either ( no offense oprn or to anyone who owns one ) i do like them but without a cage they dont offer anymore protection than a cardboard box. Can you imagine getting T boned while driving a Manx? Nooo thanks

Sat Dec 03, 2022 3:14 pm

BFB, I can assume then that you have never, will never ride a motorcycle, quad or snowmobile? I have ridden and will continue to ride all 3 of them.

I am well aware that my Manx copy is no safer than any of the above and I operate it with that in mind. Just my personal level of acceptance of risk.

Sun Dec 04, 2022 9:23 am

oprn wrote: BFB, I can assume then that you have never, will never ride a motorcycle, quad or snowmobile? I have ridden and will continue to ride all 3 of them.

I am well aware that my Manx copy is no safer than any of the above and I operate it with that in mind. Just my personal level of acceptance of risk.

Yes I absolutely have, all three and also lawn mowers, go carts, three wheelers ( one of which was raced out Honda 250R that’ll do 75mph stock and i wrecked it wound out in 4th hauling ass across a golf course ) 6 wheelers, both jeeps and old 60’s fj40 land cruisers with soft tops. Ive driven vehicles that the roofs were cut off of and doors and misc body parts / panels removed… i could go on & on, Ive been in close to 20 accidents, 4 of which i put the vehicles on there roofs. I’ve done auto body repair for over 30 years on cars, semi’s, and motor cycles and have seen many vehicle ppl have died in and many that you wouldn’t believe ppl lived through. So, you know what they say about assuming something…
Also, your point is pretty much moot anyhow. Of the three you listed trying to justify the saftey of your Manx only one is driven on the streets, unless you live in an artic area where snowmobiles are the accepted means of transportation, and comparing the safety of your Manx to a motorcycle only reinforces my point. It’s known that its not IF a motorcyclist is involved in an accident it’s WHEN. And yes i am also well experienced in that area too as I’ve worked on motorcycles for the local HA and several other clubs.
My original comment was just stating that’s how i see driving a Manx on the roads, in traffic. No different than “your personal level of risk acceptance “ so really no need for you to make assumptions about me and try to make a “ my dick is bigger than yours” type comment. I know your hung up on front brakes but have no qualms about putting your grandkids in porch swing you bolted to your buggy without any saftey harnesses. so our views of saftey is so far apart it’s ridiculous and we shouldn’t even discuss it

Sun Dec 04, 2022 4:55 pm

Wow! :shock: Here is a fellow with an axe to grind!

Sun Dec 04, 2022 7:05 pm

His user name in a previous life was dick head.

Sun Dec 04, 2022 8:42 pm

I wish him no harm.

The OP has not replied so any further discussion is likely pointless.

Mon Dec 05, 2022 4:13 pm

Nope, still reading. I think I'm going to whack them out and redo them so I have more clearance. The bar on my side is maybe 1.5" from the top on my noggin and that's the reason why I want to do something. My tubes are 1.5" and some are .065 wall , some around .080 wall and some are .125 wall. Should make for easy welding at least.

Mon Dec 05, 2022 4:33 pm

I ended up redoing my hoops 3"-4" higher. After I made them 3"-4"wider. I'd swear some of these things are made for a guy under 5'8" and a buck fifty or less.

Mon Dec 05, 2022 4:41 pm

Yea, I'm 5'11" and around 190. I fit in it pretty good but I bang again it every now and again. I think I'm going to look at an "X" configuration, I'll lay it out and see how it looks and will fit.

Mon Dec 05, 2022 8:04 pm

Nowhere near my head.

Mon Dec 05, 2022 11:51 pm

I am 6' 1" and with glass buckets with no seat foam and my hair touches the bars. I am going to move both to the center and put gussets at the ends of them.

Tue Dec 06, 2022 5:57 am

SCORE International says 3" minimum helmet to cage clearance. I have seen other sanctioning bodies for drag racing for example that specify a maximum as well for bars going front-to-rear, saying no MORE than 6", which seems somewhat reasonable to consider as well, I can get on board with the general concept that a cage maybe wouldn't protect you as well if you were a little dude down inside a giant cavern of a cage.

On my Chenowth rebuild I took the opportunity to go from .095" wall to .~3/16" wall on the two very important top tubes.

Tue Dec 06, 2022 1:21 pm

I like it!

Sat Dec 17, 2022 12:19 pm

oprn wrote: Wow! :shock: Here is a fellow with an axe to grind!
No, that’s on you, dont do something dumb like make assumptions about me and turn my comment into something personal and then not expect me to reply accordingly.

Sun Dec 18, 2022 11:03 am

oprn wrote: BFB, I can assume then that you have never, will never ride a motorcycle, quad or snowmobile? I have ridden and will continue to ride all 3 of them.
I am well aware that my Manx copy is no safer than any of the above and I operate it with that in mind. Just my personal level of acceptance of risk.

What do motorcycles, quads and snowmobiles have to do with not wanting to ride around in a Manx? Are motorcycles, snowmobiles and quads some kind of bravery test? I don't like the cold so that leaves out snowmobiles but I do ride Jet Skis. Do they count? What about an undersea "Tow Bug"? Or a powered para-sail?

I ride or fly all of those things but I don't like riding around in any kind of convertible because they're dangerous! So what?