Vintage minibike classifieds and ebay..Any clue where to shop for them?...ones I'm finding on Amazon are all the bigger hollow stem bolt like a traditional motorcycle
Just modded my sons suspension...........heres what I did:
An XR50 stock rear shock lines up and bolts right on with the stock hardware after pushing out the bushings in each "eye" (end) of the shock and replacing with new 1/4 x 5/8 x 3/4 bushings from ACE hardware ($2.99 ea). This raises the rear about 2" and gives a much softer/smoother ride with more travel. I had one laying around from other builds Ive done but the stockers are cheap on ebay (or any other pitbike shock).
For the forks.......
Theres a hole in the bottom of the forks where you can put a VERY LONG allen head tool (I had to make one using a hex apex and welding to a long metal rod with a nut welded on the other end) Remove these 2 bolts and the 2 bolts on top of the forks to disassemble. The white nylon bushing that keeps the inner fork tube stable can be compressed using small screwdrivers to pry it out after you pull the fork tubes out. Replace the bolt you just removed with a longer bolt (length depends on how much longer you want it to be/how long your new springs are) I had to make my own bolt as my local stores didnt have anything long enough in the correct thread. (I simply cut a bolt in half and welded in a metal rod to make it longer) You will find a rubber tube inside the spring in the forks when you disassemble. You dont need it. I cut this (1/4" length) and put it under the head of the new bolt to keep the bolt from slamming on the rebound of the fork. (thats the banging noise you hear on your stock forks. Older dirtbikes with spring forks used a rebound spring in this place....you could do that too. Make sure to account for this added length when choosing/building a new bolt) I cleaned/greased up everything and then reassembled using a longer spring I got from ACE. I dont know what the stock spring rate is but I bought the closest thing I could find in the same diameter/spring rate & length I wanted. ($2.99 ea) Put it all back together and you end up with the forks balancing out the rear end for ride height. The new seat height is 27". (Not sure what stock was) This made the bike waaaaay more fun. Even just riding around in the grass, you dont feel any of the little bumps etc..... With the added leverage, stoppies become easy. Super cheap mod!!
I also had a KX60 rear brake lever laying around so I fabbed up a bracket and cable to add a rear foot brake for it. Welded on some metal to widen the footpegs and sharpened them up. Hit me up if you have questions.