Apply to Enter

If you and your friends/co-workers can collect sponsorship money, build a kart and then race it down a steep hill then why not enter?  You’ll have a great time and in the process raise money for Thames Valley Air Ambulance or your chosen charity.

In this section there is advice and guidance on How to Build a Kart, Top Tips for Fundraising and the all important Rules and Regulations.

If you are new to Soapbox racing, don’t worry. We’ll assign you a mentor to provide help & guidance if required.

Registration opens 1st January 2020

Kart Building Tips

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 800 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 half a dozen other karts to be towed behind yours!

So what are some of the ‘tricks of the trade’ that we’ve learnt over the years?

Sourcing Parts

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.

AA Metal Recycling in Burghfield have kindly offered to provide parts for free that may help your kart build. Simply take a copy of your entrance conformation email to their site at Burghfield bridge, opposite the Cunning Man pub.

Reading Bicycle Kitchen have also said they can help.


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 up to two 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 calipers 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. Try asking at local garages or some small engineering companies in the area, they may be willing to help with your requirements for a small fee.

The team at Pratley and Sons have offered very favorable rates and assistance with your metal working needs! They are next door to AA Metal Recycling so you don’t have far to go with your metal work!

For a really in depth insight into building a kart go to 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 800 metre track twice (or possibly three times)!

Building Tips Credited to:
Peter Bowden
Cookham Dean
Gravity Grand Prix Chief Scrutineer

Fundraising Info

The Box Kart Bash is intended to be a family fun day for the benefit of local community. It is held before the summer holidays so that it gives families and individuals a project throughout the spring and longer days, and allows schools and other groups to work on their karts before the summer holidays.

The popularity and fun of the event means that it’s a great platform to raise money for good causes. This year we have a target of £20,000 – Remember it’s all done for charity. All of us involved in running it are volunteers.

We have set a target to raise £200 for each team that participates. If you have four people in your team, that is £50 each.

We believe this is easily achievable and expect most of you will raise much more for your nominated charity.

You can help to reach this target in three easy ways:


Download and print our Sponsorship Form then get your friends, family, neighbours, teachers, work colleagues, your boss, the postman to write down the amount they will sponsor you or your team for taking part in the event.
Create a unique fundraising page which you can send to everyone who wants to sponsor you.  Just follow these simple steps:

  1. Go to and click on ‘Start Fund Raising’
  2. ‘Login’ if you already have a JustGiving Account, otherwise ‘Sign Up’ for one.
  3. Search for the charity you want to support.
  4. For ‘What you are doing’  click on ‘Organised Event’ and Search for ‘Burghfield Box Kart Bash’.
  5. Agree to the Terms and Conditions and ‘Create Your Page’
  6. Personalise your page by entering the requested information. Remember your target should be at least £200
  7. Add you page to the Box Kart team page by going to and clicking on ‘join the team’
  8. Your page is now complete. Share it with all your Facebook friends and email contacts!


Sell or buy a programme page – An ad costs only £100 per page (£50 half page). Thousands will see it!

Corporate/Business support

Find a kart sponsor – Get a company to sponsor your kart. For £50 corporate entries can have their own banner displayed along the Course and be mentioned by the event commentator throughout the afternoon. It is also a fun day for your supporters. Entering a kart can also be a good team building exercise and you can even raise money by selling space on your kart or helmet.

Rules and Regulations


These Rules and Regulations apply to all entries; they have been designed for your safety and the safety of others around you. They enable us to run the event effectively for the maximum benefit of all, so please ensure that you read them carefully and comply with the details.

If you have any comments or concerns please contact us at

A copy of the  DRAFT rules can also be downloaded from here.

The Course

This year’s course is still being finalised. Expect a length of around 850m and a drop of 40m. Karts can be expected to reach high speeds, safety is paramount at this event and we expect you to be mindful of your safety, and that of the crowd.

Your kart must have efficient brakes and excessive ballast must not be carried. As the design and weight of karts will be highly variable, what is deemed as excessive ballast will be determined by our scrutineer (please refer to Technical Design Criteria Note 4). You must therefore agree with our chief kart scrutineer  the amount of ballast allowable for your kart before the final build is submitted for scrutineering.

Our decision will be final.

Prize Categories

  • Spirit of the event – This prize will be awarded by the organisers to the team which in their opinion best reflects the fun and sporting nature of the event
  • Fastest single time on the day 1st 2nd 3rd
  • Best engineered kart 1st 2nd 3rd
  • Best novelty kart 1st 2nd 3rd
  • Most money raised

No team can win more than one prize (even though they may deserve it) with the exception of any additional prize resulting from the timed trials.

As this is primarily a charity event, teams will only be eligible for prizes upon reaching their fundraising target (£200 minimum for a charity of your choice)

The Rules

Every team must read and accept the Rules in full.

  1. A team will consist of a maximum of four persons; up to two in the kart and two pushers.
  2. Pushing, by up to two team members, will be allowed from the start to a line approximately 5m from the start. Any infringement will preclude the team from the fastest time awards.
  3. Participants must be over 14 years old and every team member must sign the Indemnity Form. Anyone under 18 years old must have signed consent from a parent.
  4. All karts must attend for scrutineering and photography two weeks prior to the event. This will be at 10.00 a.m. on Saturday June 6th. Any actions to make karts fit for racing will be listed.  Karts deemed not safe on race day final checks will not be allowed to race.
  5. The Organisers reserve the right to refuse entry by any team, at any time, and for any reason.
  6. No head first driving. Once seated, drivers and passenger must remain seated.
  7. Numbers provided at registration must be prominently displayed on the front of each kart.
  8. Teams with a good idea for a novelty kart may apply for exemptions to the rules and the design criteria.
  9. The officials’ time is final, even if it’s incorrect.
  10. There are expected to be two timed runs down the course.  The second run may be limited to the fastest karts, depending on timings of the day.
  11. Run One: Show the hill who is boss!
  12. Run Two: The finals for the fastest karts.
  13. After Run One all karts will be towed back up Hermits Hill from the Hatch to the start line. Once Karts have finished Run One race marshals will direct them to the tow hitch-up area. The tow will commence once the last kart has completed its run. It is anticipated that there will be up to 6 towing vehicles and karts will be towed in groups of up to 6.
  14. After the Gravity Grand Prix all entrants should remain for prize giving on the Hatch.
  15. All Kart occupants MUST wear helmets
  16. Every member of the team MUST walk the course during the driver’s briefing.  Non-attendance will see the disqualification of the Kart from the event
  17. It is recommended that drivers and passengers should wear appropriate gloves. Clothing must be capable of withstanding a spill on tarmac or concrete. No bare limbs please. Be reminded that it is your body travelling at ~30mph – potential contact with tarmac and immovable objects will probably hurt and you may wish to consider this.

Technical Design Criteria

  1. All karts must be constructed with pedestrian and spectator safety in mind. Sharp edges will not be permitted.
  2. Karts must not have any protuberance that could stick into the ground after the kicker, that would course the kart to flip
  3. No glass or other materials that could shatter or cause injuries to drivers, passengers or spectators in the event of a crash may be used in the construction of the kart.
  4. Maximum width 1.2m measured from outside to outside.
  5. The maximum unladen weight of the kart should not exceed 100kg.
  6. Karts must be fitted with strong 15mm (minimum) eyelets capable of 1500 N front & back to accept the tow ropes provided by the Santas. The chassis needs to be able to take this force between eyelets, as the total weight being pulled by the kart may reach 1.5 tonnes on towing.  it is anticipated that karts will be towed in groups of up to 6 in a daisy chain formation.
  7. No protuberances outside these dimensions will be allowed.
  8. Karts must have a minimum of three wheels. All wheels should be in road contact during normal running.
  9. Good brakes are essential and will be checked. Wheel braking must operate on at least two wheels on the same axle and be effective. The brakes must operate on the kart itself and not damage the road surface.
  10. Seats must be securely bolted to the kart.
  11. Karts must be designed to carry no more than two persons, in a feet first direction.
  12. Any steering column, brake lever or other protrusion must be designed and fitted such that the risk of injuries is minimised and suitably mounted to reduce play while travelling.
  13. Any electrical systems to power lights, or other special effects must be fitted with an identifiable external isolator switch.
  14. Pyrotechnics, such as smoke must be non-flammable and not be possible to act as a source of ignition should it come into contact with dry straw or any other combustible material.
  15. Bodywork and controls must not impede the driver/passengers in exiting the vehicle unaided.
  16. Any doors or hatches required for access must be readily operated from both inside and outside the vehicle without the use of tools.
  17. Steering must not have excessive free play or any characteristic tending to promote instability.
  18. Gravity propulsion only – i.e. no motors, no pedals, no stored potential energy nor excessive ballast.
  19. Seatbelts are not mandatory, but if seat belts are used they must be of a minimum four point fixing and only on karts with a roll-bar.
  20. Secondary Locking methods of all Wheels and critical systems should be used unless justification for omission can be demonstrated to scrutineers eg. cone and nut bicycle wheel, or split pin and nut.
  21. Wheel diameter is not dictated but side-flex during high speed cornering is a known issue with larger wheels and this must be demonstrated to scrutineers that this has been considered in the design.

IMPORTANT – Safety Info and Conduct on the Day

The purpose of the event is to have fun, but the safety of the team, supporters and spectators is paramount throughout the day and, accordingly, the organisers reserve the right to amend these rules or go above and beyond their guidance. With this in mind if in the opinion of the race officials, a competitor’s ability to be safely in control that has been compromised by alcohol, drugs, illness, injury, or emotional stress, that competitor will not be allowed to continue the event.

The Event

  1. Registration will commence at 10:00 am on the day of the event. Racing is expected to start at noon and finish by 4pm to allow the road to be returned to functional public use by 5pm.
  2. All drivers and passengers must familiarise themselves with the course.
  3. All drivers and passengers must attend the Drivers’ Briefing at 11:30am.
  4. All members of the team will be issued a wristband when they sign the required indemnity. Only entrants wearing wrist bands will be allowed on the course or to drive the karts during any part of the event.
  5. After crossing the finishing line drivers will need to apply their brakes and quickly depart from the track under the Marshal’s instructions. An uphill towing service will tow the karts up hill. Please make sure that your kart is strong enough to tow 6 other fully laden (with drivers) karts.

No expressed or implied warranty of safety shall result from the publication of, or compliance with, these rules and / or regulations.

This publication is in no way a guarantee against injury.