Sportster Bobber Tank Modifications
Life's a bitch... Thank God there's Harleys...
1973 Sportster Peanut Style Fuel Tank
The standard peanut fuel tank of our 1973 Harley Sportster did match the overall Bobber design we had in our head, so L&T decided to re-use it.
This is how our 1973 Harley XLH Sportster looked like in April 2008, before L&T stripped her down.
As you can see, the Sportster gas tank sat right on top of the Ironhead engine cylinder heads, and the top frame member runs halfway through the fuel tank.
Here's a closer look of the upper tubular of the frame running through the tunnel in the Sportster fuel tank.
Elevating the Gas Tank
For a more extreme Bobber look, L&T wanted the Sportster gas tank to sit higher on the frame.
We wanted to go from here:
Bottom of Sportster tank below the upper frame member.
To here:
Bottom of Bobber gas tank on top of the upper frame member.
So, some modifications were required.
Sportster Gas Tank Modifications
In more or less chronological order:
As you may have noticed from the pictures at the top, there was quite a bit of old paint and filler on the original gas tank, which had to come off.
That was not so easy, this is how far T got after two hours chipping away carefully with hammer and chisel...
To elevate the Sportster tank we ground off the forward support brackets and fixed new ones to the bottom of the tank.
Who needs a seat? We got wheelz!
Here L is welding a closure plate on the tunnel gap of our 1973 Harley Sportster gas tank.
Meanwhile, T - angel on his shoulder - is drilling some holes in the upper tubular of the frame to fit the bolts of the repositioned Bobber gas tank.
This is what we were trying to achieve.
And here she is!
This mock-up gives a fair impression of the geometry of our Bobber.
Note the 20" Nash Midget Gimp Hangers!
April 2009
To be continued...
Ironhead Engine Assembly Steps:
- Step 1 - Engine Case Assembly
- Step 2 - Oil Pump
- Step 3 - Cam Gears and Cover
- Step 4 - Installation of Primary Chain and Sprocket Wheels
- Step 5 - Fixing of the Compensating Sprocket
- Step 6 - Clutch Unit: Parts Cleaning and Preparations
- Step 7 - Clutch Release Disc: Installation Using Spring Compression Tool
- Step 8 - Startmotor: Cleaning and Inspection
- Step 9 - Startmotor and Bendix: Install and Test
- Step 10 - Primary Cover Back in Place
- Step 11 - Main Shaft Rollerbearing
- Step 12 - Oil Seal and Sprocket


Jan's 1976 Zundapp GTS50 Moped
Frans and his 1970 Jaguar XJ 4.2