Experienced go kart builder needed

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Hey you guys,I want to build an off road kart for my son. It is going to be a small one maybe powered for a 6.5 HP engine. However, I am having trouble designing a real simple front and rear suspension system. I bought some plans, but I think I made a mistake this is a mayor work. I just want a beautiful project that we can build together. Any experience, help, info about adding a good simple suspension system that any of you can share with me I would really appreciate it.Thank youAlfredo
Reply:Sounds like major----if you are going to include a suspension system.. Most carts that small don't have one. Just muscle, bones and iron against the elements.  I guess the front could be two small A arms with a small coil on top of each. The back is tougher. First thing that comes to mid is a mono-shock like a quad, but then there will be engine mounting issues.Boy I dunno."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Suspension will also add a fair bit of weight, might be pushing a 6.5HP engine a bit. If you run good sized ATV/baloon tires, the ride won't be that back without suspension if you keep the tires aired down bit.
Reply:Alfredo,Sounds like a fun project.  My brother and a friend salvaged a part of a frame, a tired 10 hp Cushman engine and any other junk we could get our hands on to build one when we were in our early teens.  It took us all summer to get it together and running but it was great fun to build and ride.  Looking back on it the engineering was horrible, we didn't have access to a welder and everything was bolted together as best we could.  We saved and bought air filled kart tires for the rear but the fronts were solid with no suspension.  Rode it in parking lots and in the dirt.  Rattled and shook like heck but we didn't care..I've "graduated" to a sand rail (a go kart for big kids), have a nice garage with lots of tools and welders and we're having a good time with it all.  Whenever I'm looking to fix or improve something on the buggy I look to some of the commercial designs or other folks work.  Can't always adapt it to my needs but it usually gets me to thinking in the right direction.Check into the Yerf-Dog web site (www.yerf-dog.com) for some great kart ideas.  They've got everything from a basic no suspension lightweight to a sturdy looking full suspension almost sand rail type kart.  Their 6.5 hp model (#3203) is a two seater, has basic full suspension and weighs in at 300#.  The front suspension are simple single swing axels with a small coilover shocks.  The front wheels are going to tilt from the outside edge to the inside as the suspension cycles up and down (like an old VW or Corvair rear end) but ain't going 100 mph in the thing so what the heck.  The rear suspension is similar to what Sandy was proposing.  They mount the whole rear axel, engine and drive train on a separate rectangular frame.  That frame is connected to the main frame behind the seat with a pivot so it can swing up and down.  They put another couple of coilover shocks from the rear frame to the main frame and away you go.I've never driven any of these so I can't comment on how they ride but they do look like fun.On the web site they not only have decent pictures of all the models they also have manuals including detailed illustrated parts breakdowns showing all the frame components, etc.  The one for the #3203 is about as close to a build plan as you could get ;^)Good luck, if you do check out the Yerf-Dog web site let me know what you think.  If I didn't already have a sand rail, quad, motorcycles, etc. to keep me busy in the shop I think I'd try to build one :-)TinkerCentury 135GS, ThermalArc 250GTS
Reply:You might also check out this site:http://www.sae.org/students/minibajaus.htmI was involved with this for a year.  They are basically the same thing as the higher end models shown on Yerf-dog, but with more suspension travel.  You might call some local universities with auto-tech or mechanical engineering programs to see if they participate and if you can see some old designs.  I'd also call the teams that have won for several years and ask if they can send you some pictures for a donation (since many of these programs rely on donations to stay afloat).  With a 8-10 hp Briggs you can go 30-45 mph with enough power to climb most any hill.  These are also really safe, I don't remember any stories of injuries due to their strict building rules.  Operator mis-judgement does happen occasionally though.An easier route and probably for about the same money you could get a honda odyssey, (the ATV, not the automobile). And for something a little bigger, look into a honda Pilot (also an ATV).  Here's a good place to start.http://members.aol.com/dunepilot/links.htmlI had a go cart growing up and now I'm looking to get a odyssey or pilot to give my kids the same experience only safer and more fun.As for the suspensions, I agree with the other about the front. As for the rear, we had good luck with a salvaged ATV swing arm, and mounted the engine above it, not on the are itself.  This link illustrates it better than my words can.http://www.geocities.com/Baja/Dunes/...uspension.htmlIf your looking for a good place to start with a frame you might check this:http://odysseysalvage.com/index.htmlThis might be the best, because they are so fun, your likely to do what we did in Mini Baja, we'd get the car ready about 4-6 weeks before the competition and test it (run it ragged) 'til it broke, weld it back stronger than before (or change the design) and then take it out for 'testing' again.  .   So your son can be in a safe vehicle (notice all the mini-baja racers have 5 pt harnesses, wrist straps, and  full-face helmets) and then when he breaks something, you can teach him how to repair it so it will be stronger and safer.
Reply:Hi All,I am real interested in this thread, as I am planning on building something like y'all are describing. Here are some old shots of a buddy in his oddesy, Yes they are a blast to ride. I found that the lack of rear suspension made for a wild ride at a lower and saver speed, More adreniline & less blood. Attached Images
Reply:Anothe shot of the Oddesey. Attached Images