You will notice in the first picture that the axle has chewed up the cardboard where it meets the wheel. The wheel fell off shortly after this picture was taken. One of the things that can cause this is using a low density paper board like ".5 inch honeycomb paper board" for the wheels. This type of cardboard is thick and light weight and reduces the number of laminations that a team has to glue together, but it does NOT stand up to sidewall wear. For making laminated wheels, I recommend using thin strong cardboard or paper board. Another good idea is to use some material to form a protective axle sleeve between the rolling axle and the cardboard.

Finally, you should avoid trying to glue the axle to the wheels so they turn together. If you want the axle and wheels to turn together then consider using some form of spoke laminated in between the cardboard laminations. Below are a couple examples of internal spoke wheels.

One quick note of caution. Do not use a thermal plastic (melts when it gets hot) for either the axle or for an axle sleeve. The photo below shows the melted axle sleeve of a vehicle that was on its way to a course record when its plastic axle sleeve melt around the axle which effectively stopped the vehicle.

Another tricky area that results in many vehicle failures is the drive mechanism. One of the most common problems for all drive types is using a material for the axle or pedals that is not strong enough to withstand the forces placed on them during the race. Many teams have tried using PVC pedal systems and most have had the plastic fracture during the race. There are a few teams who have had success with this design, but they are the minority. Another material that has caused problems when used in the pedal assembly is wood. It's not that wood is inherently a bad choice, but many teams have had problems when using it. The photos below show some of the vehicles that have faced this problem. You will note that many teams try to go on even after this critical breakdown.

Another problem that has occurred enough times to make it worth mentioning is when teams built metal pedals and axles, but during the manufacturing process they softened the metal. This allowed it to deform under the forces applied during the race. One team faced this problem when they decided to use a normal bicycle pedal and gear assembly. The part was to heavy so they used a hand grinder to narrow the pedal arms. The heat from grinding softened the cast metal so that during the race it quickly bent. Below is a picture taken while the team was building their vehicle. They did not realize it at the time, but this was the moment their plans went wrong.

Finally, the last thing I want to talk about is indirect drive systems. This is a drive assembly where the pedals drive a belt or chain which in turn drives one or more wheels. This type of design has the potential to produce the fastest speeds, but and that is a big BUT, they are also the hardest to incorporate into a paper vehicle and most vehicles that have tried to use this design have not even completed the race. So if you think that this is the way to go, I strongly recommend that you leave LOTS of time for testing and fixing your design. Rework time is more critical for this type of vehicle than any other. If your vehicle can't finish the race it won't matter how fast it might have been.

I hope that this page provides you with some helpful information and that your vehicle goes on to run a strong race.

Below you will find links to some of the team build photos of previous winners. It is notable that both the 1999 and 2000 winners were simple wheel chair designs.