Simone Sorio is Energy’s “super preparer”, a specialist with immense expertise in high-profile kart racing. With maniacal attention for even the smallest detail of chassis fine-tuning, Sorio explains and illustrates some simple, but fundamental tricks of the trade that will help you get the most from your kart.
There are tons of checks to do! I could make a huge list. One, for instance, is the position of the three axle bearings: they need to be perfectly aligned for the axle to work in optimal fashion and to minimize friction. This is what you have to do: you block the two side bearings at the correct height, then insert the axle through the three bearings, making sure it slides nicely. The third bearing will get automatically aligned to the other two, because the axle will set it in position. You can then proceed to bolt this third bearing too. In the absence of the bolt keyways, its internal ring should spin freely [see the video to the side]. This should be the case also and especially when the engine and chain are mounted.
When you purchase a new chassis, it comes with the bearings already aligned; but when a chassis is used, it’s better to check, since the bearing cages may be worn out or you may have off-set the alignment during set-up modifications.
In my opinion, it’s fundamental, even if not everyone does it - in the sense that many people only do it on the front tires, while it should be done on all four. If you don’t balance all four tires, they will wear out in a non-uniform manner, with an obvious impact on performance, not to mention annoying vibrations at high speeds. This said, balancing must be done properly. Say you have a tire that is particularly off-balance and you need to add 30 or more grams: instead of sticking the weights in a line along the inside rim of the tire, you want to stack them one over the other on the exact balancing point. In addition, as you noticed, I said the inside rim of the tire: I recommend applying your weights here, rather than on the outside perimeter, one, to protect them from impact and, two, because it’s more effective, since tires tend to wear out more on the inside.
Never handle disc brakes with your bare hands or with dirty gloves. If you happen to do so, immediately clean them off with a dedicated product. Why? Because besides causing the metal surface to oxidize, dirt and moisture can corrupt the friction finish, with consequences on braking action.