Franken90 - A 90cc crime against nature


Way back in April I was ever so pleased when I struck a deal with my dad's cousin: I'd take the assorted 90cc Hondas from his back yard, and in return I'd throw together a Honda 90 paddock basher.

Unfortunately for me, he insisted on a CT90 with telescopic forks and a dual-range gearbox...


Here's Frankenbike. Due to the paucity of some parts it has been cobbled together from at least 6 different bikes. I've still got a bash plate, air filter and carry rack to bolt on.

The handlebars are off some kind of Suzuki trailie - this way I got a rotary throttle instead of the old-fashioned Honda "slide-in-a-trough" unit (I know that some of you out there know what I'm talking about!)

The forks and triple clamps were removed from a CT90K0 from the junk pile (not original fitment on that, either!) The exhaust is off a CT90K0. The front wheel is off that CT90 that was in the shed in the top pic. The rear shocks and centrestand are C90 units.

I didn't need to use any parts of this particular CT90K0...

...because it's pretty much this rusty all over. 20+ years lying in the open will do that.

The K0 was the first CT90, and had leading-link rather than telescopic forks. They don't work quite as well, but they don't wear out as quickly either.


I used the front wheel off this CT90. I would have used the whole bike, except that it's forks, motor, chain and rear shocks are all seized.

My CD90. It's the next project in line after Franken90 leaves the shed, I'll be putting a Chinese 125cc motor in it and making it my Wintersun 2008 mount.

As you can see, CT90K0 mufflers have slightly different bends in the header pipe as compred with all other CT90 motorbikes.

Usable kickstands were one of those things in short supply. Rebuildable carburettors and unrusty non-bent intake valves were also a bit uncommon. The footpegs are once again CT90K0 parts.

Costs so far

  • CT90 motor (ALL the others were beyond repair from 20 years in the weather) $50
  • O/S piston kit (piston, rings, gudgeon pin, circlips) $27
  • Brake cable (used) $10
  • Drive chain $25
  • Cylinder rebore & hone $75
  • Battery $15
  • Kill switch $3
  • Fork oil $5

    Yeah I know, it's WAY more than the bike is worth, but I'm also getting to be a lot better at rebuilding motors than I used to be.


    Home Page