Kart Building Tips
Provided by Peter Bowden, our founding Kart Scrutineer
Building your first kart is often perceived as a daunting task. Don’t panic, when all is said and done it only has to manage two (or possibly three) runs on a 750 metre course! Bearing that in mind, it also has to cope with a couple of quick(ish) corners, a heavy braking area at the end of the course and then be strong enough to allow up to nine other karts to be towed behind yours! So what are some of the ‘tricks of the trade’ that we’ve learnt over the years?
Karts come in all shapes and sizes (within our Technical Regulations of course!) and the primary ‘donor’ items have included push bikes, a piano, ride on lawn mowers and kid’s pedal karts, to name a few. Push bike based karts are chosen by many. Hopefully you can get hold of a ‘donor’ bike from friends, neighbours and the like. Don’t try the local Civil Amenity Site; I did and was told that nothing which enters the site can be taken away, even when I said I wanted to recycle an old bike! I’m sure it used to be called a recycling centre! Oh well.
Wheels are one of the more difficult parts to get hold of. Bike wheels, as used by most competitors, are plentiful. Do bear in mind though that bike wheels aren’t designed to operate with high ‘side loads’, something they rarely experience when being used as originally expected i.e. on a bicycle! So if you are using bike wheels, think of the likely end weight of your kart. Remember, mountain bike wheels are designed to cope with a load of maybe 60-80 Kg in a vertical direction. Your creation may carry three team members (75 kg each?) plus the weight of the kart itself and increased side loads have seen many mountain bike wheels fail. They have been used by many competitors but be wary! BMX wheels are a stronger option and are freely available. Again they are not designed to take high side loads but they are considerably more robust than ‘normal’ pushbike wheels. Another option is to get hold of some wheels designed for use on workshop trolleys and the like.
Very important! Your kart has to be fitted with efficient brakes. Be cautious with the use of brakes sourced from a child’s bike; they’re not strong enough. The problem is that the brake levers are designed for little hands and don’t offer a great deal of leverage or overall ‘travel’ because a kid has small hands. You may be tempted to use a kid's bike brakes but substitute the levers for the adult version. Don’t! The callipers will simply bend or worse still, break! Adult bike brakes work well but please don’t scrimp on the fitting of brakes. Other people have cobbled up a braking system using moped / scooter / motorcycle brakes. These have proved to work well.
This is probably the most daunting task as not many of us have access to welding equipment. Help is at hand. Tom Webb of The Forge Motor Company (07854370870 firstname.lastname@example.org) can help at very reasonable rates. Once you have an idea of what your welding requirements are, get in touch with Tom direct. For a really in depth insight into building a kart go to scottishcarties.org.uk and look in the 'resources' tab. Very best of luck and remember, it’s not such a daunting task, it’s only got to go down a 750 metre track twice (or possibly three times)!