LOST CAUSE

Bobbing the Yamaha Venture
 
Believe it or not, there are at least two people on the planet crazy enough to try this! Click here to see some examples...
 
Start with one 1983 Yamaha XVZ1200 Full Dresser Such as this beauty here...This is Tim Kloppenerg's. Click HERE for the full article on Tim's ride.

 I wasn't bright enough to photograph mine and it wasn't in this good a shape. It only cost us $500, all the plastics were cracked, and it was a prime candidate for "bobbing". We rented a trailer and picked the bike up in Virginia on our way to visit our families in Philadelphia. I should have known we were in trouble when the gas filler cover blew away within the first few hundred feet. 

 
Strip every possible creature comfort off the steel chassis...Including that front fender. This is Tim's photo, I had a picture of my stripped frame, but lost it. I stripped the frame while we were in Philly. The bike had everything, including a trailer hitch!. Since I ride motorcycles and not tractors, that hitch was the first item in the junk heap. Looking at Tim's bike, it never occurred to me to keep the rear seat frame and reuse it. It got thrown away with everything else. 

 
This is Lost Cause, my version of the "chop".

Looking at it, I guess I could not have used that seat frame after all. It would have taken the bike in a completely different direction. The tank is handbuilt from 16GA mild steel in a technique I would call "force welding". The curves were formed by tack welding the side and top as I bent the metal to fit the adjacent side. Parts were cut on a table saw with a metal cutting blade.

Although it was reasonably successful, the tank has one major flaw. It won't hold gasoline. My welding skills aren't quite up to par when it comes to creating a seamless joint.

The fender is a trailer fender from another bobber project, purchased on E-Bay for less than $10. The seat pan was hand formed using 16GA steel and a ballpeen hammer. The seat itself is made from pigskin leather (way cheaper). It was soaked in warm water, stretched over the foam and then riveted to the seat pan.

There is also a cardboard pattern for an intake / air box visible under the tank. It will also be "force welded" out of 16GA.  It's drooping because it got wet. Hopefully the steel version will hold up better.

The trees were loosened and the bike lowered on the forks. I also took the  handle bars apart and reversed the pieces so they would extend back to the seat.

The green paint is a test. I painted the bike different color on each side to get an idea of what I wanted. The other side is metal flake black and probably a better idea, but I'm partial to this green. The engine is painted with Buick engine paint and some black header paint.

 The "bob" didn't start this way however, it went through a few design changes before it got to this final shape.

 

 
This is the first incarnation of the bike. Originally intended as a "rat bike" there were no plans for fenders and other niceties. You can see the "seat" is just fastened to the frame. The tank is cut from an air tank, the cheap ones you can get at Walmart. You can see the other half on the ground at the lower right.

While it probably would have been a lot of fun, I doubt it would get far once I passed my first police cruiser. About the only part retained from this version are the exhaust pipes. They're cut from a set of Hooker headers I bought on E-Bay for my long gone '76 Oldsmobile.

 
This is a mock up of the next phase. All the tin you see here (aside from the rear fender) are actually cardboard patterns. You can see that the early seat bracket was quite different. It was cut from the top of a cheap Chinese made hand truck. I had to scrap it, because the steel was really low quality thin wall tubing. It broke.

The intake / air box was carried over to the "final" design. I managed to make the bottom out of a square of 16GA mild steel. The four holes for the carbs were cut with a hole saw.

Fabricating the steel parts was easier than I thought it might be. I was able to make everything with the table saw and a metal cutting blade. It made for some great fireworks after dark. Took me months to clean up all the metal shavings around the saw. I swept up a mound several inches tall. I'm still finding pieces whenever I sweep the garage.