Mr. Sandman
04-19-2007, 05:58 PM
After way too many years of riding my 250R with nothing but brute strength to keep the front end down on launches while hill shooting the dunes, I finally decided to extend my swing arm. Now, I like to wheelie as much as the next guy, but ever since I bolted my 310 kit on a few years ago, the unwanted wheelies had gotten ridiculous. So….after reading up on extended swingers both brand new and stretched stockers, I decided to undertake the project myself. After all, how hard can it really be? I only wanted 4 more inches but didn't want to spend a fortune to get it.
I decided not to cut up my original but shinier than stock swing arm so I bought a thrashed one on ebay. A little measuring here and little measuring there and I broke out the hacksaw. Fifteen minutes later, the swing arm was in two pieces. A little more measuring to see what size steel I needed and I found out that the Japanese in their infinite wisdom used a size of rectangular tubing that cannot be found at my local steel supplier. With an O.D. of 1 3/16” x 2 3/8” there was only one thing I could do to make it work, look clean when finished, and still be plenty strong. So, I bought another swing arm on ebay to use a sacrificial steel supply.
One thing I noticed about most stretched stockers is that they didn't have clean lines due to the weird angles that were left after they were welded up. Because the swing arm gets narrower as it gets longer, the extensions have to be angled out to meet up with the pieces of tube left on the carrier. Now I’m sure there are other ways to go about it, but I decided the easiest way would be to cut the dog bone mount yoke right down the middle. By doing it this way, I was able to spread the tubes apart, insert a 5/16” spacer to make the narrowed end wider, keeping everything straight without any weird angles and not affect the pivot point where it bolts up to the frame. Going this route on anything longer than a 4" extension would probably not work as the pivot wants to bind on the swing arm bolt. But, a problem with doing it this way is that the dog bone mount tabs are also 5/16” further apart as well, so some new filler tabs were made up to weld into place to get the correct dimensions back. The semi-trick particle board extensions were made up first to make sure everything lines up as planned. Now it's time to start cutting up the sacrificial swinger. More to follow as things progress.
I decided not to cut up my original but shinier than stock swing arm so I bought a thrashed one on ebay. A little measuring here and little measuring there and I broke out the hacksaw. Fifteen minutes later, the swing arm was in two pieces. A little more measuring to see what size steel I needed and I found out that the Japanese in their infinite wisdom used a size of rectangular tubing that cannot be found at my local steel supplier. With an O.D. of 1 3/16” x 2 3/8” there was only one thing I could do to make it work, look clean when finished, and still be plenty strong. So, I bought another swing arm on ebay to use a sacrificial steel supply.
One thing I noticed about most stretched stockers is that they didn't have clean lines due to the weird angles that were left after they were welded up. Because the swing arm gets narrower as it gets longer, the extensions have to be angled out to meet up with the pieces of tube left on the carrier. Now I’m sure there are other ways to go about it, but I decided the easiest way would be to cut the dog bone mount yoke right down the middle. By doing it this way, I was able to spread the tubes apart, insert a 5/16” spacer to make the narrowed end wider, keeping everything straight without any weird angles and not affect the pivot point where it bolts up to the frame. Going this route on anything longer than a 4" extension would probably not work as the pivot wants to bind on the swing arm bolt. But, a problem with doing it this way is that the dog bone mount tabs are also 5/16” further apart as well, so some new filler tabs were made up to weld into place to get the correct dimensions back. The semi-trick particle board extensions were made up first to make sure everything lines up as planned. Now it's time to start cutting up the sacrificial swinger. More to follow as things progress.