There is that saying about all work and no play, well it's a pretty good saying to follow! Over the past few years here on this blog I have shared with you a few different hobbies I like to mess around with including R/C cars, SCUBA diving, and other fun stuff. Well over the past 10 months I have taken up a hobby that has a bit more speed to it.
Here is a quick video of me partaking in my new hobby this past weekend:
That is a 2012 CRGRoad Rebel Shifter Kart. It's motor is a 1999 Honda CR125 dirt bike motor that is basically a 125cc two-stroke motor with a 6-speed gearbox. It is capable of accelerating from 0-60 in under 4 seconds, and has a top speed of just over 100MPH, all while sitting just an inch off the ground! On the tracks we run on, it's also capable of hitting as much as 2.5 G's in turns, both positive and negative G's. Stopping, or slowing down the kart for the turns is handled by a front and rear brake system that has is bias adjustable, and uses ceramic brake discs for better braking under extreme brake loads.
Since it's a two-stroke motor it runs on a 32:1 mix of oil and 100 octane gas. Here in Nevada you can purchase 100 octane gas at the pump for the low cost of $6.50 a gallon. A gallon of mixed fuel is usually good for about half a day at the track. The power is transferred to the rear wheels via a chain, and there is no differential meaning that in order to get around a corner, the chassis has to be set up in a way that will allow for the inside rear tire to lift off the ground so the kart can turn more efficiently. There is no suspension, so the design of the frame is such that it will flex and twist to achieve the needed changes to get around a turn as fast as possible.
The kart also has a data acquisition system that records a number of channels including, motor temps, lap times, and rpms, and it also has a gps system that is uses to map out the track you are on, provide gps measured speed, and also the G loads via an on board accelerometer.
Here is a sample track map generated from the system. The yellow lines represent the path the kart took and that data was then imported into Google Earth and overlaid automatically based on the gps coordinates:
Here are a few pictures of the kart itself:
And yes, the kart is designed in SolidWorks! Along with probably most of the add-on parts!