Featured photo for Greeley Grand Prix

Greeley Grand Prix

My former co-worker Ken was racing in the Greeley Grand Prix this weekend, so I went to check out the qualifying rounds. There were lots of ultra-low frames on 10-inch tires (and that’s the outside diameter) making lots of noise and enormously big heads sticking out of them. Oh wait, I mean normal-sized heads in ultra-small race cars, also known as go-karts. I never saw Ken but learned a lot about these vehicles. A few facts about them:

  • Some weigh only 175 lbs., or less than half of most motorcycles (and many drivers!)
  • Engines typically were one-cylinder two-stroke engines running pump gas and putting out 28 or more horsepower.
  • Some go-karts had one gear; others had sequential transmissions with as many as six. (Those go-karts were referred to by the announcer as “shifter-karts.”)
  • They can accelerate from 0-60 in ~3.5 seconds!
  • Top speed is said to be about 135 mph!
  • They can pull ~2-3g on the skidpad!
  • These performance numbers, aside from the top speed, are better than any street car and on par with Formula 1 race cars.
  • A racer who usually raced Porsches, Vipers, or Corvettes would practice in his shifter-kart, then race in his Viper which would subsequently feel very slow in comparison.
  • Go-karts are like bicycles in that they usually don’t have suspension.
  • Go-karts generally cost $5500 new or $3000 used according to a guy I talked with.

It was fun watching these little cars in action, and I’m sure even more fun to drive. That said, I’ve concluded I don’t really have a great interest in picking up go-karting as a hobby. Go-karts are limited to the track, and just don’t have the same aura to me as a sports car. Or a motorcycle. So for racing, I think I’ll stick with running and time-trialing instead.

I had problems finding the park, but when there, no problem finding the go-karts due to their noise!  Here's a shifter-kart on a straightaway.
The official event vehicle was a Mini Cooper S convertible -- i.e., the car Britney Spears has.  According to the race announcer this is the closest you'll get to a street-legal mini-kart.  Well, Caterham will probably disagree...
A go-kart approaching a hairpin.
Go-karts through the hairpin.
A single-gear (non-shifter) go-kart was on a jack, so of course I went to look at it.  The owner told me his go-kart weighs only ~175 lbs!
You can see the single gear hear along with the drivechain.  The hub encases a centrifugal clutch that automatically engages when the engine is about 1400 rpm.
This offset disc brake (in the rear) is the only brake on the car.  Some go-karts have brakes on all four corners.
The trip computer in the steering wheel can display split times, current speed (when used with a wheel sensor), etc.  The gas tank is under the steering wheel.
A carnival was going on simultaneously at the park.
The Hooters Hummer H2 was here!  So were a few Hooters girls (sorry, no pics).
The Greeley Grand Prix was at the Island Grove Park, which was huge.