Ever hear the expression: “The cobbler’s kids have no shoes”? The more I work in the custom bike world, the more I find this to be true, ask any builder and I think you’ll get a chuckle and nod if you mention this idiom. When your entire day, week, month is dedicated to building awesome creations for your customers, it’s hard to find time at the end of the day to make something cool for yourself.
This spring, I happened upon an ad on craigslist for a 1977 CB750F for a price I really couldn’t ignore. I already had one mind you, but that one is my daily rider, “old reliable”, “grocery getter”, you get the idea, and it was not to be molested in any way which would take it off the road for any amount of time! I quickly bought this bike, justifying the extra CB750 in the garage by telling anyone concerned that “for the price I got it, I could just resell it come summer for at least twice what I paid”. Though this may have been the case, the truth was I just needed something I could play with for myself, I had my rider, so I could just go nuts on this one.
Rather than do a “full teardown” build, I decided to point in a direction with this bike, I wanted something fast, I wanted something fun, ergonomics was in, cosmetics was out, I didn’t want to shell out tons of bucks to do it either. Fortunately my day job happens to be building custom bikes and parts, so as far as the fabrication and machine work went, I could do all that myself. This formula turns out to work really well if you’re okay with spending a lot of time working on something.
The first thing I went about on this one was to replace the front end and brakes, I never liked the feel of damper rod forks on my other 750, and the old disc brakes weren’t all that confidence inspiring either. I happened upon another craigslist find of a ZZR1200 front end, wheels, fairly new tires and both sets of brakes for about what new tires would cost, so I jumped on that. I had a feeling I’d be up for some fabrication to make everything work, but I really didn’t have any idea as to the extent. Since the front end didn’t come with trees, I got to designing some of my own. I didn’t like the idea of converting ZZR trees to the CB750 frame because newer bikes use less rake and less offset to get the same trail, putting a low offset triple on a high rake frame like the CB750 would result in a bike requiring heavy wining and dining before even suggesting flipping into a turn, so that just wouldn’t do. I fired up the Bridgeport and started carving up some aluminum that would mate the new forks to the old frame and maintain the same trail. This took some figuring out on the computer, but after a little head scratching I was able to come up with a design that did it, machining the parts took about a day, by the end I was walking around ankle deep in aluminum chips.
With the front end done, the rear wheel was looking lonely, so I set about attempting to shoehorn it into the swingarm. As can be expected, it was nowhere close to fitting, between being too wide and nothing else lining up, it just wasn’t going to work. I’ll spare you the carnage, but after another 20 hours of designing, welding and machining, I had an alloy swingarm and modified sprocket carrier that would put the wheel exactly where it needed to be. This, of course, made apparent the fact that the oil tank was the wrong shape to accommodate a reinforced swingarm like the one I had just made. Again, nitty-gritty aside, I built a new oil tank.
With all that work behind me, I finally had a bike that was ride-able, ugly as hell, but rideable. Of course, ride-able and enjoy-able are two different things. With the stock seat and tank, there was just no way to ride this thing the way it wanted to be ridden, it was like having a trailer hitch on a Porsche. I figured changing up the seat and ditching the stock pegs would help for sure, and being not too shabby at fiberglass, I decided that would be the quickest route to a nice seat, after a few days I had something workable. The pegs were knocked out on the Bridgeport and Rockwell lathe, along with the levers welded together with stainless tube, all told about 3 hours of work, ugly as hell but definitely what I needed, good grip, folding, and in the right place.
The tank, on the other hand, was another story.
Riding this bike with the proper bars, foot controls and seat made the tank feel like it was trying to perform some kind of operation on me which I would rather avoid. Fire up the torch! The tank I designed really only had three requirements, I needed at least 4 gallons, it had to fit me, and if possible, I would like to shave some lbs. off the stock weight. After another few days of pounding aluminum, I had something that didn’t leak. At this point in the late summer, having put only a handful of miles on this beast, that’s really all I was hoping for… hold gas, no leak, good. While doing the tank, I also got the bug up my nethers to build a quarter fairing, not sure why, but I had a spare windscreen from a build years ago and decided somehow that this bike should be it’s new home. Fortunately the fairing didn’t take all that long so I told myself it was well worth the extra time.
Long story short, new (old junk) flatslide carbs, sandbent exhaust and *some tuning, this turned out to be a fun bike to ride, tucking into the fairing and opening the throttle is quite the experience indeed. I was initially surprised at how even a primitive fairing like mine would shed so much wind resistance. The high speed stability of the bike is also quite satisfying, my daily CB750 at high speed almost feels like a sneeze would topple her into an unrecoverable tank slapper, but with the newer suspension and rubber, along with a slightly stiffened frame, at speed, it’s almost boring. Fortunately maintaining the stock geometry keeps this bike fairly nimble for diving into corners.
On the note of new ideas, I’ve begun putting together a CB750 parts engine for this bike, I’ve become a little bored with the stock engine performance i.e. I’m not at all scared of this bike. Using the Bridgeport and a nice old Lisle hone, along with some Yankee ingenuity, I’m cobbling together a 900cc mill out of the CB750 husk and some other “junk”. I’ll keep you all posted!
*hours on top of countless hours of frustration and smelling like gasoline