Anyone know a good machinist?

[Fiskadoro]

Originally Posted by sasha

Actualy you dont need so much to balance the shaft as to make sure its perfectly stright. When I had my own auto shop one of the guys had a K5 blazer. With 48in tires on it. He twisted some shafts and broke both front and rear ends. Every time he send for a shaft to be build they never lasted as the welds sucked. Yes we send them to the best shops that everyone seems to rave about. Talked to a a very old timer that used to build race cars in the 50s. He said as long as the shaft is stright you dont need to balance it as its diameter is too small. For the next build we got front and rear ends off a 3 ton chevy truck. We needed 4 guys just to get each one off the delivery truck. Found a pipe where both ends of the shaft would fit snag. cut a window in it. Using an arc welder we welded both ends togher. Joel been driving that K5 for 7 years now with out a single problem. Heck he span the tires from stand still. Jim i seen some pics you posted of the welds you done. Trust me you would do a 10 times better job then any shop would.

Thanks for the great feedback. I appreciate your confidence. I may do it myself, but everything seems tough until you actually do it kind of thing.

The shaft on the beemer is solid about a half inch in diameter. I have some 1/8 walled tubing with almost the same ID. I figure I could cut the shaft take down the shaft diameter a tiny bit on each end so it sleeves into the tubing perfectly tight then weld it and true the welds down for balance on my lathe.

This is actually a common modification. Here's some pics from a guy who did this on his GS.









His top one initially failed because he did not have clearance for the sleeve but I made my swingarm a different way and should not have the same problem.



Most guys who do this are trying to get added ground clearance on their Offroad dual sport bikes that see a lot of abuse. I'm just doing it for length on what will essentually a road bike, but since I'm adding so much more length then is standard 317mm vrs the more normal 35mm to 50mm I'm pretty concerned that it get's done right.


You almost got me inspired. I guess the bottom line is to do it spin it to make sure it's true and if it works it works. If it fails or vibrates I could just pull it and do it again.


Jim