Welcome back folks,
This post looks at the work undertaken to replace the ghastly functional yet robust plastic tank designed by a team of Yamaha motorcycle engineers with a much older rust filled one from a completely different bike…Because I think it will look better!
My idea for this build has always been to keep the originality of the bike, such as the colour, but give it a retro touch. Like it could have come out the factory that way (damaged stock). One of the key ways to change the look of the bike is by changing the fuel tank. Sometimes this can be a fairly straightforward task, but the shape of the original tank is very different from the retro tanks that I have used as inspiration and the mounting points on the TT600 mean that this is a slightly bigger task.
Firstly I had to find a tank that would fit. There are plenty of options that have been tried and tested but in reality, it’s about personal preference as to what you think looks best and suits the riding you plan on doing (hahaha.. riding, I plan on putting this thing in my lounge when it’s finished and staring at every night). Too big a tank and the bike may look bulky, too small and you may have a very limited range and your bike looks all skinny and weird.
I quickly tried my XS750 tank I had lying around (it wasn’t going back on that bike anytime soon), but quickly decided that this was a bit too bulky and top heavy.
For me, I settled on a Honda CB360 tank, I had seen a few scramblers with this tank and always thought it had a nice teardrop shape, which reminded me of my own daily tears…Luckily I spotted one for sale on Instagram and bought it straight away, thanks woodgates motorcyles. The tank was in good condition, apart from a bit of rust (shitloads) on the inside but was perfect for this project.
Depending on your ability and confidence, most tanks can be made to fit. If you are good with sheet metal and a welder (unlike me) you can cut and modify the tank to change the look further. Luckily this tank fitted nicely over the top tube of the frame. The challenge here was to modify the frame to allow the tank to sit nicely and not get twatted by the forks everytime I turned a corner. See below for :
In order to check this clearance out properly, I had to fire up Mr Grinder (not the app) to remove some of the parts of the frame. A lot of the mounting points for the original frame we no longer required.
The three-axis need to be considered when fitting the tank. Picture this in relation to sitting on a bike with the tank in front of you:
- North/south – How far forward the tank sits needs to be worked out. You do not want the forks hitting the frame if the bike is on full lock, like the video explains. If this is the case but you like where the tank is sitting, you may have to modify the tank by removing a few scallops. A bit ambitious for my build but I was tempted. I just moved my tank back as close as it could be without hitting the forks
- East/west – the tank needs to sit parallel and straight on the frame. You don’t want it lopsided, because that would look dogshit
- Vertical – When you look at the tank from the side of the bike, it needs to follow the line of the frame. I created a post showing the frame loop and the line I wanted to follow. Ideally, this should follow the same lin
Once these above points are considered, it’s time to start marking on the bike where mounts will need to be added. The tank has a couple of mounting points itself. Two at the front and one at the back.
I had to line up (eyeball) where I think these would go on my frame and add corresponding mounting points….When you are hamfisted like me this stage was a complete and utter pain in the tits.
It must have been all the WD40 I had inhaled which caused the rusty cogs in my head decided to move for a split second and give me a bright idea. The tank mounting points at the front are C-shaped, and mate with a rubber bush on the original bike, Honda CB360, holding it to the frame. I picked up a set of rubber bushes online and used these to help me mark out where I think the tank should be. This part really is just trial and error until you are happy.
Because the frame is narrower than the original bike (probably), the edge of the tank didn’t mate up nicely with the frame:
I decided the best way to use the bushings was to but a bolt through the conveniently placed hole and weld a captive nut onto the frame. This would ensure the frame would sit tight at the front.
This was another fiddly job as I had to mark out the hole for the frame using the tank as a reference point. I think when I do this again, I would reuse my pikey plum line and be a bit smarter with my measuring…you will see why later on (**Spoiler – I’M A DUMBASS).
Once the holes were drilled, I welded the captive nut on the frame. This job was OK. I was able to hold the nut tight to the frame by threading a bolt through the hole and adding another nut to the back.
During welding I started to see pink elephants…not because of the LSD I took before going to the garage (I find this really focuses the mind), but because of the zinc galvanised steel bolts giving off a toxic gas when you weld them. Duly noted, turns out they aren’t joking when they say try to use a ventilated area. I also now have a workaround for this. If you set the bolts in a citric acid solution (mixed with water) and leave for 30 mins, the zinc will fall off the nuts and you won’t die when you weld.
Ah what’s the old saying, measure twice drill once, measure twice drill once…shit… I should have probably measured again *facepalm*. When I went to screw in my mounting points, I couldn’t help notice that they weren’t quite even…not sure I took a picture I was a tad embarrassed.
This wasn’t hugely noticeable when the tank was mounted, but I wasn’t happy…Mr Grinder to the rescue again. I cut off the bolt and measured off the other side. Like I said this was a fiddly job, and if I was to do it again iI would measure differently, using a plumb line and reference points on the frame…live and learn!
Ok, onto the back end (hey hey). there was no mounting point on the back end where the frame met the tank, so I had to make one. This was quite fun, I even had the helpful assistance of a similarly hamfisted friend. Simply, I had to make a bridge that I could bolt the tank to without ruining the line of the bike.
I had some 3mm thick sheet steel lying around which would do the job. I would like to say we got hugely scientific with the measuring but getting the angle and final fit was more trial and error. Welding the mount on required some gentle massaging from Mr grinder to get it to sit right on the frame.
Once in place, the final piece was to fix the tank to the mount. The tank will need to be removed from time to time (when the engine more than likely shits itself after my rebuild), so I went with the captive nut option again. I welded the nut onto the mount, and I was good to go. The tank is mounted. Success.
This was an enjoyable part of the build. I think a lot of people wanting to do their own build may see this as a stumbling block (I certainly did), so hopefully, this gives a better idea of how I went about it. Again there are probably quite a few ways to do this but this one worked for me and was straight forward enough with the basic garage tools.
The next post will look at the steps taken to remove the rust and other 38 years worth of shit which somehow decided to set up home in my tank…
To be continued,