Rear suspension hinge conversation

[J.Bourne]

I see in most pictures people have custom built hinges for their articulating rear suspension. Basically consisting of a custom built bracket on both sides of the frame that connects via a bolt or something of the kind. What I'm thinking about using is an actualy butt hinge. Something very sturdy of course with a 3/8" pin. I was thinking about using four of them along the frame backside to increase strength. So has anyone ever done this or heard about doing this? I'm curious to know if it will work out well, provide great pivoting ability, but most importantly STRENGTH. Here is a pic so you know what I"m talking about. Oh, on a side note, I did speak with a "hinge engineer" and he thought it would work ok if I went with the larger guage steel and larger pin IE: 3/8" pin. He said the weakest point on the hinge is where the "tooth" had been rolled over to create the barrel that the pin rides in. He said you can weld it shut to increase strength as well. Let me hear your ideas. Thanks.

 

[Leftythenub]

I tend to agree with you engineer. If you do use this idea, definitely weld the loops.

 

[700 efi guy]

I'd use bushings, and maybe even a grease nipple.

 

[newrider3]

You don't necessarily want hinges, you either want a tube with quality bushings, and tabs on the frame, or you want to use rod ends (heim joints), and tabs on the frame.

 

[J.Bourne]

You don't necessarily want hinges, you either want a tube with quality bushings, and tabs on the frame, or you want to use rod ends (heim joints), and tabs on the frame.

What do you think the downfall of using heavy duty stainless hinges would be? Lack of lubrication was one thing I was considering. I thought it could be ok though if I pulled the pin and greased it really well. Also, spray lube goes a long way and can be applied daily if need be. Thing is, I have these heavy duty hinges, (free) so I thought they could be a nice addition. Very clean and simple looking, yet 'possibly' quite effective.

 

[sideways]

You don't necessarily want hinges, you either want a tube with quality bushings, and tabs on the frame, or you want to use rod ends (heim joints), and tabs on the frame.

This is exactly how it should be done. Other ways aren't ever as satisfactory.

Thanks

Hayden

 

[J.Bourne]

This is exactly how it should be done. Other ways aren't ever as satisfactory.

Thanks

Hayden

What about flange mounted bearings instead of bushings? Does anyone see a problem with this? In theory this should be a better application because it reduces wear where a bushing would be.

 

[sideways]

What about flange mounted bearings instead of bushings? Does anyone see a problem with this? In theory this should be a better application because it reduces wear where a bushing would be.

Bearings don't like sudden high load hits, especially when not turning ,they will end up notchy quite quickly, not to mention the extra expense.

Thanks

Hayden

 

[J.Bourne]

Bearings don't like sudden high load hits, especially when not turning ,they will end up notchy quite quickly, not to mention the extra expense.

Thanks

Hayden

That's a good point. I've read that a huge problem with articulating suspensions is the under engineered "tabs" that link the rear end to the frame. So I think I will take the actual square tubing I'm building the frame with and cut out 3" sections and use these as tabs. This way their a bit sturdier and I can drill straight through and install flanged bushing on both sides of the tube. I'll make two tabs on the left side of the frame and 2 tabs on the left side of the rear end. So a total of 8 bushings and use a 3/4" shaft through these so their extra strong. I'll repeat the same process on the right side of the kart to make two super heavy duty hinge points. Does this sound legit then? I'll try and build them tomorrow and post pictures of them over the weekend.

 

[Doc Sprocket]

Yeah, I'm pretty much on board with everybody else, here. Deep-six the door hinge thing, and fab something using steel tube and bushings. Cross-drill the tube for a zerk fitting, and you're home free. A little lube now and then, and it'll live forever. 3/4" is probably overkill. As long as it's well built, 1/2" should survive armageddon.

 

[newrider3]

The issue with using a hinge would be slop, and wear. You would quickly ovalize the holes or wear out the pin. Also, there would be a ton of slop and play from the beginning, door hinges aren't precision engineered by any stretch.

 

[r97]

whats wrong with some nice 1/4" flat bar? its not like its at all expensive. if you really want you can brace it a bit. also if you ask me 3/8" sounds a bit thin