Used chassis - how to choose the right one for you, saving a bit of money.

1 WHY CHOOSE A USED KART

It doesn’t always make sense to buy a new chassis, especially when you’re new to the world of karting. If you’re careful, you can often find used karts in excellent condition that are fine when starting out and, in addition, can save you quite a bit of money. Later on, once you have gained more experience, you will no doubt have the opportunity to buy a new chassis.
However, there are many elements to consider and analyse when choosing the right used kart. Let’s see what they are.

2 THE CHASSIS MUST BE STRAIGHT

Aside from any easily visible cracks or damage, for a chassis to work and perform properly the main thing to check is that it is straight. Obviously, it is difficult for a kart driver, especially a beginner, to have (and carry around) a basis for comparison. Nevertheless, there are other simpler and more practical, as well as very effective, ways of telling whether a chassis is bent and, if so, to what extent. Please remember that if they are not too bent, chassis can be straightened and become perfectly usable.
You way to check is to run four chains of equal length to the two ends of the rear axle and the two front stub axles. Once this has been done, insert another axle in the chains “hanging” on the axle and one on those “hanging” on the stub axles. Then, looking at the kart from behind, you can see whether the two axles are in line (meaning that the chassis is straight) or not.

3 SIGNS OF WEAR THAT NEED TO BE CHECKED

All karts suffer wear in the lower part of the frame’s tubes, because on turns it is inevitable that they often touch the kerbs, which rub against the metal pipes and cause them to wear. The points most affected on a chassis and which therefore need to be checked carefully are the transversal front tube on which the nose is mounted and, above all, the longitudinal tubes that link the front and rear ends. If the points of wear on the lower part of the tubes are relatively ample, say about a centimetre wide, it means that the chassis is quite worn out and that needs to be taken into account when deciding whether or not to buy.

4 WATCH OUT FOR CRACKS

Speaking of used karts, it is evident that the prolonged use of a frame can result in the formation of cracks. Therefore, you need to check carefully if there are any and where they are. While cracks on the seat support tubes is a problem that can be solved by welding, cracks on the axle bearing housings are far more serious. Even with excellent welding, the problem often reoccurs, reopening small cracks between the tip of the weld and where the unwelded tube begins. In particular, you need to check the tubes on which the engine-side housings are welded and which, due to the vibrations, tend to be subjected to greater stress.

5 ACCESSORIES

Another key aspect is the braking system, to avoid having to immediately have work done on a kart and shoulder extra costs for spare parts. The test you need to carry out is to brake hard and try to sense if the pedal gives way and, therefore, if there is air in the system. This situation can nevertheless be resolved by bleeding, but there may be more serious problems. For example, if oil leaks from pumps and clamps appear when the brake pedal is pressed as hard as possible for a long time, that would indicate the need to replace the system’s rubber pistons. In the worst cases, it may mean that the seat of the pistons is scored and, therefore, needs to be corrected or replaced.

The next step is to check the axle bearings, which are always placed under stress: after freeing the axle, turn the rear wheels and you should hear a uniform noise. If the noise is too loud, it may mean that the ball bearings or the cage are damaged or worn. The steering must rotate effortlessly and you need to check that there is no excessive play concerning the uniball. Lastly, do the same for the front hub bearings as you did for those of the axle: when turning the front wheels, the rotation must be free and almost noise-free.

HOW TO... CHOOSING THE RIGHT USED CHASSIS