DIY Suspension Pics and Advice

You need a good lathe, bridgeport type mill helps also and either a good TIG welder or good MIG welder and a power hacksaw comes in handy. Material of choice is chrome moly.

Here is where I buy all my moly tubing and flat and 60061 T6 aluminum tubing and sheet, carbon fiber, fiberglass, kevlar, polyester resins, epoxy's, etc.

http://www.aircraftspruce.com/

Here is a skid kind of what your talking about I built, weighs 33 lbs with a Alternative Impact front arm and my chrome moly rear arm, taske off on a Yami arm, and similar to what Timbersled did. Rear axle is my own two wheel inside design. Used the small tip of rails wheels (anti stab) on the inside up by the front arm also. Don't have time right now to look up all the numbers but with moly I like to be at least 50 tom 70 thou on the wall. Years ago I made a real light weight front arm out of moly and had fatigue cracks near welds. I think if you go with real thin wall its best to have it annealed and reheat treated.

Just call up Aircraft Spruce and have them send you a catalog, has pages of tubing dimensions with OD,ID, weight per ft etc. The dimensions you end with to a great extent dpend on shaft sizes, one tube needing to go inside another or mating to another etc.

Oh yeah forgot you do need the Bridgeport or a real good drill press to fish mouth the tubes for a perfect fit. Porting motor and carbides helps also for perfect fitting and finishing. If you don't already have all the above equipment far cheaper to just the buy the TimberSled suspension.

Good Luck

My mod TNT longtrack weighs 450 full wet.

I have stops on the rear arm to limit travel and use wire tie wrap on shock tubes as indicator for how much of the travel is being used. I made a full scale paper doll mockup of the whole skid and front and rear arms out of mat board with stick pins for bulletin board for moving pivot points to figure approximate locations of elements of suspension arms and shock locations.

Few years ago built a rear arm like the Fabcraft with a scissors and never even tried it on the sled because with it just bolted in the rails it never felt like it would work. I even rebuilt the lower scissors a couple times with different dimensions. This latest one works pretty good and started by going to local yami dealer with a tape measure in mm and caliper and doing as much measuring as possible.

Good Luck

I have no limits on the rear arm for fully extended. Skis as far as I know have no limits for fully extended on any sleds. Drag racers will tie the front ends down for aerodynamics. Fully compressed and bottomed out would be real bad on shocks and can break suspension parts. The front arm of my skid still has a limiter strap for tuning.

Good Luck

Now I know what your talking about. I did it a bit different than Timbersled. I have a bolt in between the arms that pulls the upper arm down towards the lower for less weight transfer. My lower arms slide inside the upper arms also. Thats not really a limit arm for the shock extension travel. If you have more travel on that arm then the sled should pull the skis higher. When its completely compressed the rear arm is linked to the front and the two arms are working like a parallelogram with no give in them like a rear arm with a scissors. The rear arm picks up the added spring rate of the front arm making it very hard for the rear of the tunnel to go down and the front of the sled to come up at the skis.

Good Luck