roll cage?

[trenton davis]

I'm thinking about making a roll cage and was wondering if anyone had some tips for me.

 

[J_Walker]

yeah. get a bigger engine. cause its gonna weigh your cart down at least x2 the current frame weight.

and make sure to make triangles, NEVER ENOUGH TRIANGLES!

 

[trenton davis]

so if i have a 6.5 predator now what should i get for it thats more. and also you said triangles what do you mean by that ?

 

[Poboy kartman]

yeah. get a bigger engine. cause its gonna weigh your cart down at least x2 the current frame weight.

and make sure to make triangles, NEVER ENOUGH TRIANGLES!

Not really....there's a lot more to a frame ....maybe add another third....and we're not talking NHRA 200mph chrome moly stuff here...A copy of what's on my Manco should suffice and I'll bet it weighs less than 50 lbs....

 

[crazykart]

First tell us this, driver weight, current kart weight (ballpark is fine) rear tire size, and current gear ratio, CC or TC?

Your current set up may be able to handle a simple cage.

Triangles as in try to design it with as many triangle shapes between the bars as possible because in the event of a crash/roll over it will help distribute the weight/force out and away from the impact point(s), at the same time providing superior strength at those points.

BUT a full cage is probably not needed. At the very least you want something to protect YOU from serious injury/death, and maybe even allow the kart to self upright back onto its wheels.

Put some pics up of your current kart.

I have an idea that would probably add 20-30 pounds, 40 at the very most dependig in your kart, that will both save your life, and your wallet.

 

[OzFab]

#1 tip, BEND, DON'T CUT & WELD!

 

[trenton davis]

right now with nothing on it as in motor or tires or anything it weighs maybe 50 pounds and I'm about 180, I'm putting 15 inch mud tires on the back and 12 inch mud tires on the front it has a 45 tooth sprocket on the axel and 10 tooth sprocket. the frame now is essentially a big motorized steer able rectangle. i need some kind of cage because i found myself almost sliding off the edges of the kart when turning.

 

[crazykart]

Ok, first off, 10 and 45 tooth.... thats not gonna work (45 tooth, where in the world lol) you have a 4.5:1 ratio... get ready to burn up that clutch. I woukd reccomend a 60 tooth sprocket if not 72. Give you at least a 6:1 ratio.

I retract everything except for this: get a seatbelt if you want to keep from sliding out of your seat, not a 50-60 pound cage that does nothing if you go flying out of, or into it.

That kart should never go into any situation where you would need any sort of cage...

But again what do I know.

 

[trenton davis]

i have a 62 tooth but its bent. could it be bent back? but for the cage itself i should just do like the cage over the seat? i've seen stuff like that and i just never thought it would protect as much as like a full cage. like if i roll it where would it roll onto? but as for the stability of the cart it is not stable but i got a bunch of square tubing to basically remake the floor panel like put reinforcement bars across every few inches then rivet a new piece of sheet metal on top to make a new bottom that will be stronger and make it more sturdy to support the sides and cage that will be welded on it so i can go off roading and not worry about it snapping in half or rolling on top of me if i hit something.

 

[Denny]

Crazycart that cage will get him killed or worse! Do not build anything like that! A simple hoop behind the rear seat with bars from the top of the hoop one on each side to the front and rear of the cart would be much better and a bar across the hoop at 2" below shoulder height. Gussets and diagonals added in are you're friends. To figure hoop height mount the seat you are going to use sit in the seat with your helmet on have a friend set a straight edge from the top of you're helmet to the ground just in front of the cart frame where it ends in the front. Carry the line to where the hoop will be placed behind you. This will safely get you into the ballpark. You will end up with a 6 point cage at least, more if you split the long bars which I would. Remember any part of your body that is outside of the cage in a rollover will get broken off or mangled beyond use. have fun and be safe.

Denny

 

[landuse]

Throw away the 45 tooth. It is useless for you. Like crazykart says, you should get a minimum of a 72T sprocket in my opinion. If you putting on 15" tyres, you are going to need the extra torque that gearing lower will provide

Personally i would not do a cage over the seat like crazykart drew. That design would fold at the first sign of a crash

 

[trenton davis]

so should i do something like this but beefed up a little more so it will be a bit stronger? like add a second hoop around the the seat and some posts between some of those just so they are more stable. and be able to protect me better. also could i bow the cage out like bend it outside the edge of the frame to add more room so nothing there would be nothing sticking out incase of a roll over. and get a larger sprocket.

 

[trenton davis]

so basically i will have the bars running to the front of the kart in one way shape or form. at that point i could run them to the back to just so theres a little more support. i just need something that will be built like a tank but also be relatively quick in a race.

 

[Denny]

I am well versed in roll cage construction having built more than a few for drag cars as well as stock cars. What you drew would fold like a cheap suit I don't care where you put it. Hmmmmmmmm. The area you are referring to in the picture is for driver containment. It's purpose is to keep the driver from moving about all over violently in a high speed roll over. It is what is referred to as a funny car cage. It is built into a properly designed cage.

Denny

 

[crazykart]

i need some kind of cage because i found myself almost sliding off the edges of the kart when turning.

Hence the containment design...

Roll cage to keep you sliding off, and possibly protect your head

But hey what do I know huh?

 

[trenton davis]

so maby a modified version of this built to fit my frame set up

 

[Denny]

That is a good start but it needs some diagonal pieces to keep it from folding up. Remember the strongest geometric shape is a triangle. If you push at any one of the three points it will not collapse, take that Mr. Circle or Mr. Square/Rectangle.

Denny

 

[trenton davis]

so i could do a design like that but just add a few more bars in there for maximum stability. is there any rule of thumb when testing it without just going out and rolling it and hoping it saves you.

 

[Denny]

No bars ending in space (like the down bar behind the drivers seat in your picture) continue that bar down to the bottom frame rail. No long spans without a triangle, try to keep all 3 sides the same length. Gusset all Joints and triangulate all bends.

Denny

 

[jandj]

As to belts - Cage, belts.
No cage, no belts.
If the problem is sliding off the seat while cornering the simplest solution is get a racing type seat with sides high enough to keep you from moving around.
You could also go to a vintage Dart type seat with higher side pads and a jewel pad in front.