Thread: ORGS build up
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Old 04-03-2010, 11:01 AM   #13
x3300 OP
Joined: Mar 2005
Location: San Jose, CA
Oddometer: 170
Fitting Tanks

Given the will, there is a savage way!

I've been pushing to get all the frame welding done so I can move on to other things. I added two gussets to the shock mount to give it a better connection to the frame.

A big box arrived by air freight from Germany.

I really liked having the big tank on the PD. I've done 1000 mile days with it where I just needed to fill-up a few times. A big tank is really nice when you go off into the mountains for a day or two and don't need to carry extra cans. I'll have this big tank for trips, and use the R65 tank for local riding.

I got the more expensive nylon tank that can be painted. I figured it would be a better investment, as I can repaint it when it gets scratched-up or when I want to change the color scheme.

I made up this pattern in the lower right for the front tank mount bracket.

I don't have a photo of the unmounted bracket. I fabricated it out of 1/8" flat stock and drilled a big hole in it.

I used a piece of welding rod and a bubble level to align the two brackets on the frame, then tacked the brackets.

The welded brackets look a little flimsy. I'll add another support running from the inside of the down tube to the bracket, but I don't have any stock of that size. I'm thinking 1/8 x 1/2 will work good. Here's how it looks with the tank.

For the rear mount I made up these bungs with a M8 x 1.25 threaded hole.

I bolted the bungs up to the tank to get the alignment for welding.

As seen in the photo, the tank mounting tangs are not quite even. I thought the reason for the difference was that the two gussets were not aligned, but after welding I checked it and it was the tank. I should have done the check before welding it up. I can fix the tank by shaving some material off the the one side, or gluing a spacer on the other. I can fix the frame by either welding a washer on the low side, or grinding the high side.

I used some thin sheet aluminum to make a heat shield between the bung and the nylon tank, but the tank got hot enough for the nylon to melt a little when I did the tack weld. After welding up the bung I chased the threads with a tap.

As I mentioned in an earlier post, I got this black R65 tank off ebay. I really like the shape.

I like the lines of the tank and this GS long seat.

The R65 tank is longer than the HPN tank so I made up this adapter plate. Whenever I want to use the R65 tank I'll need to bolt on this adapter.

The R65 uses a hanging swing type of mount in the rear, but there was just no way to get that working with this modified GS frame, so I took the old mounting hardware off the tank and made up a new mounting plate from 1/16" flat stock that will bolt to the frame adapter plate. Here I have the new mounting plate clamped to the tank and ready for tack welding.

Once, when I was a kid, I was working on the tank of my Hodaka Super Rat and the fumes in the tank ignited. It was a minor explosion, but scared the hell out of me. Since then every time I work on a gas tank with heat I do this check.

Here's the plate tacked to the back of the tank.

Here is the modified tank bolted to the adapter plate. I just have some spacers that were handy in there to check the fit. I'm thinking to make another smaller set of M6 bungs to weld to the adapter plate.

The fitted R65 tank.


x3300 screwed with this post 07-29-2010 at 06:46 PM Reason: Fix broken URL.
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