Thread: ORGS build up
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Old 04-03-2010, 12:01 PM   #13
x3300 OP
geoff
 
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.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/shock-mount-gusset.jpg

A big box arrived by air freight from Germany.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/big-box.jpg

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/big-box-open.jpg

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/big-box-unwrapped.jpg

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.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/big-tank-concept.jpg

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

http://stuff.gotdns.org/bike/orgs-build-up/gusset-design/hpn-tank-mount.jpg

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.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/big-tank-mount-align.jpg

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/big-tank-mount-tacked.jpg

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/big-tank-mount-welded.jpg

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.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/big-tank-mount-done.jpg

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

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/big-tank-bungs.jpg

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.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/bung-setting.jpg

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.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/chasing-bung.jpg

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

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/r65-tank.jpg

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

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/r65-tank-seat-lines.jpg

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.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/r65-adapter.jpg

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.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/r65-clamp-up.jpg

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.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/flame-check.jpg

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

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/r65-tacked.jpg

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.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/r65-mounted.jpg

The fitted R65 tank.

http://stuff.gotdns.org/bike/orgs-build-up/08-fitting-tanks/r65-fitted.jpg

-x3300

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