Gravity Racing Meta Feed

Texas Red Army Shooting For The Stars On 2015 Triple Crown Trail - Lady and The Track

"soapox racing uk" on Google - January 8, 2015 - 14:48

Lady and The Track

Texas Red Army Shooting For The Stars On 2015 Triple Crown Trail
Lady and The Track
At that time, horse racing was not legal in Texas. He started dabbling in horse pedigree and with ... Dr. Voss it should be noted is one of the few people to have won a G1 race with a QH – Remington Park Futurity with Darlin Sixarun and G1 TB race with ...

roll bar bracing

Scottish Carties Comments - January 6, 2015 - 13:23

In reply to New cart for 2015:

As it stands in the picture, the only bracing you have is going from side to side on the roll bar.  It should have some diagonal bracing going forward between the roll bar and the chasis.

East Allington Whacky Races, Devon

UK Soapbox Race Calendar Feed - January 5, 2015 - 20:07
Start: May 9 2015 - 12:00am End: May 9 2015 - 5:00pm Timezone: Etc/GMT+1

The East Allington Whacky Races is intented to be a fun day out for the local community and visitors to the village and to raise money for local groups and charities. The rules have been designed to keep everyone happy and safe, so please keep within the spirit of the rules and the day.

Karts will race one at a time against the clock. A prize will be awarded to the fastest kart in the final round of racing. Preliminary rounds will be held to eliminate slower karts. The number of preliminary rounds and the exact race format will be determined by the race director on the day and will depend on the number of karts. A prize will also be awarded for the best looking kart.  The race director can disqualify karts at his own discretion and his decision is final. All participants must have fun!

Avon Dassett Soap Box Derby, Warwickshire

UK Soapbox Race Calendar Feed - January 5, 2015 - 17:17
Start: Jun 6 2015 - 9:00am End: Jun 6 2015 - 5:00pm Timezone: Etc/GMT+1

The Avon Dassett Annual Soap Box Derby will take place on Saturday 14th June 2014.

  • CLASS 1: 4 Wheelers
  • CLASS 2: 3 Wheelers
  • CLASS 3: Sidecar outfits
  • CLASS 4: Formula Libre (completely free from regulations but must pass scrutineering,  including brake test).

For further details, please contact the organisers directly.

Tetbury Wacky Races, Gloucestershire

UK Soapbox Race Calendar Feed - January 5, 2015 - 17:03
Start: May 4 2015 - 9:00am End: May 4 2015 - 5:00pm Timezone: Etc/GMT+1

The fourth running of the Tetbury Lions Wacky Races Soapbox Derby will be held on Bank Holiday Monday 4th May 2015. In recent years, many teams have shown some great ingenuity in building carts orientated to speed - but that is not wholly in the spirit of the event, so before you set about the task of spending long winter nights in garage, shed or workshop trying to reduce the drag coefficient of your sleek machine, we can advise that from the 2015 event and henceforth, the emphasis will return to celebrating the most “wacky” designs.

For  full details, see the Tetbury Wacky Races web site.

Richards Castle Soapbox Derby, Herefordshire

UK Soapbox Race Calendar Feed - January 3, 2015 - 01:53
Start: Jul 12 2015 - 9:00am End: Jul 12 2015 - 5:00pm Timezone: Etc/GMT+1

The 2015 Richards Castle Soap Box Derby will be held on Sunday July 12th on Hanway Common, near Ludlow in Shropshire.

The course is 550m in length, with a vertical drop of 50m and can give speeds in excess of 40mph. Full details at

Humber Bridge Soapbox Derby, Humberside

UK Soapbox Race Calendar Feed - January 3, 2015 - 01:43
Start: Jul 4 2015 - 9:00am End: Jul 4 2015 - 5:00pm Timezone: Etc/GMT+1

The Humber Bridge Soapbox Derby was inaugurated by Hessle Town Council and South Ferriby Parish Council in the summer of 2012 as part of the Queen’s Diamond Jubilee celebrations.

It is for amateur teams to enter their handmade carts and have some fun, win prizes and raise money for charity. In 2012 in excess of £4,000 was raised for Help for Heroes and in 2013 a similar amount was raised for Yorkshire Air Ambulance.

The Soapboxes descend from the deck of one of the UK’s most iconic landmarks, The Humber Bridge, on a closed road lined by spectators and into the tourist viewing area. Your Soapbox can be made of any material and teams are made up of school and academy entrants, businesses and private individuals. Creative and crazy designs are actively encouraged, as are business entries with company logos and branding displayed. There are several prizes awarded by businesses to encourage fund raising. The main prize, for the most sponsorship raised, being a mini cruise from Hull to either Bruges or Amsterdam courtesy of one of our sponsors, P&O Ferries.

Rules, entry forms, etc., will be available on from 2nd week in January 2015.


UK Soapbox Race Calendar Feed - January 3, 2015 - 00:41
Start: Jul 12 2015 - 9:00am End: Jul 12 2015 - 5:00pm Timezone: Etc/GMT+1

"Worlaby is a small village located on the western edge of the Wolds near Brigg. It also has the perfect assest for Gravity Racing, The Hill. With a steep gradiant and natural bends it makes the perfect location to hold a Gravity Competition.

Apple Head Gravity Sport are holding a competition on Sunday 12 July 2015 which will start at 9:00 hrs."

Entries for this year Worlaby event will open on the 1st February. This year there will be 20 Soapbox, 5 sidecar and 12 Gravity bike places up for grabs. Entries will be taken on a first come first served basis, so please don't delay as last years event was full subscribed in 5 days.

More details at or on their facebook page at

  • Course length : ~750m
  • Average gradient : 1 in 15
  • Maximum gradient : 1 in 10
  • Typical top speed : ~40mph


Soapbox racing event to be held in Groveland - Orlando Sentinel

"soapox racing uk" on Google - January 2, 2015 - 22:00

Soapbox racing event to be held in Groveland
Orlando Sentinel
GROVELAND — Soapbox derby racing enthusiasts will be out in force today for another round of races organized by CM Boxcar Racing founder John Bomm. The races on a hilly portion of Wilson Lake Parkway will start at 9 a.m. Races also are planned for ...

Getting it right … and wrong -

"soapox racing uk" on Google - December 26, 2014 - 20:15

Getting it right … and wrong
This time last year, StarNews features writers Ben Steelman, Paul Stephen and Hunter Ingram put their heads together to come up with predictions for the year that was to be 2014. Most of their predictions centered on the beats that they cover ...

Plan your Boxing Day in Sydney with our city-wide events guide - Sydney Morning Herald

"soapox racing uk" on Google - December 24, 2014 - 13:16

Sydney Morning Herald

Plan your Boxing Day in Sydney with our city-wide events guide
Sydney Morning Herald
Big Bash Sydney Derby. The Boxing Day Test might be out of reach for Sydney-siders, but cricket fans can compensate by enjoying the match-up between the Sydney Sixers and Sydney Thunder. With the Big Bash season in its infancy, there's plenty of energy ...

and more »

Museum Musings: Unpack your suitcase and hit the slopes - Whistler Question

"soapox racing uk" on Google - December 21, 2014 - 10:51

Museum Musings: Unpack your suitcase and hit the slopes
Whistler Question
This involved racing down the mountain in a Samsonite suitcase. It seems that the first one took place on March 10, 1984 and ... Organizers are calling it a soapbox derby on snow. The jury's still out on what the competitors will call it. The suitcase ...

Hi where abouts do you mean 

Scottish Carties Comments - December 12, 2014 - 17:02

In reply to New cart for 2015:

Hi where abouts do you mean 

Gravity Racer World Record: The Record Attempt

Engineering Sport - December 8, 2014 - 14:56

It was time to see if we could set a world record speed for a gravity racer. The weather was 21ºC in nearby Avignon and the wind on the 2 km road section was light. Feeling buoyant from the previous day’s 81.8 mph and having a number of further changes up our sleeves — we were optimistic.


Stunning views in the morning at Mont Ventoux – outlook is positive (Photo Christina King)

The record

The weight of the racer before the attempt was 194.5 kg and we added 5.5 litres (5.5 kg) of water to reach the maximum 200 kg weight. This was distributed mainly to the rear of the gravity racer following Guy’s feedback on its driveability. Brake bias was adjusted and the tyres were pumped up to 84 psi. It is important to stress that all of these changes were made incrementally on each run to allow Guy to adjust to the changes in handling and for us to verify what each speed increase was attributed to. Eventually, the optimum set up was achieved and Guy drove the gravity racer into the Guinness World Record book with a speed of 85.6 mph!

The team get the news (photo Channel 4)

Official print out of the record 85.612 mph (Photo Christina King)

The crash

The record had been broken and Guy was already looking to the next challenge; to see how fast the gravity racer could go. Thoughts of breaking 90mph were clearly on his mind. Our time on the mountain was also coming to an end so there was not the time to make further incremental changes. A number of further changes were made at once, including adding further weight. The braking and handling had significantly shifted and Guy commented that he probably should have come to a stop after the first bend but it was now or never and what was the worst that could happen…..

Interestingly Guy managed to tame the racer right up until the final straight when he lost control whilst braking and crashed in spectacular style. “That was the best crash of the year!” Guy claimed laughing as he climbed out completed unharmed. The team breathed a huge sigh of relief — the gravity racer’s safety design of steel tubular frame and 5 point safety harness had been tested to its limit, and passed.

The aftermath of the crash — “best crash of the year” Guy Martin (Photos Christina King)

Will we be repairing the racer?

No – although the frame appears intact it has now been put under significant stresses and we can no longer be confident in its structural integrity.

Could we have gone faster?

Yes of course! Our gravity racer was conceived, designed and built within 4 months; this in itself is a fantastic achievement. We had some great comments on the blog and thank you for the interest! We do not think our design is perfect and we look forward to seeing the challengers to our world record!

Nobody wants Wenger sacked but by staying he's tainting his legacy - Daily Mail

"soapox racing uk" on Google - December 8, 2014 - 11:08

Daily Mail

Nobody wants Wenger sacked but by staying he's tainting his legacy
Daily Mail
Arsenal fans came to blows as members of the pro-Wenger camp clashed with those who want him out after the defeat at Stoke; Wenger has won just one trophy in the last nine years at Arsenal; RFU chief Ian Ritchie was unhappy with England's autumn ...

and more »

Boles and Golding say thanks - Kokomo Perspective

"soapox racing uk" on Google - December 6, 2014 - 21:17

Kokomo Perspective

Boles and Golding say thanks
Kokomo Perspective
Addison Boles and Samantha Golding, both students at Eastern Elementary, competed in the 75th running of the All-American Soapbox Derby in Akron, Ohio, last July. After winning the super ... Both girls lost their first round races by a nose. In August ...

Border Bogie Challenge, Denholm, Scottish Borders

UK Soapbox Race Calendar Feed - December 5, 2014 - 10:07
Start: May 23 2015 - 12:00am End: May 23 2015 - 11:59pm Timezone: Etc/GMT+1

The Border Bogie Challenge takes place in the beautiful conservation village of Denholm in the heart of the Scottish Borders.   It's an insane, fast-paced timetrial race down a hill on a typical rural country road, (which will have been closed to vehicles for the duration, obviously!) in a homemade bogie (or a go-kart for those of you who aren't lucky enough to be Scottish).

And don't forget, for those mums and dads who are prepared to endanger their children for the entertainment of others, there will be two, possibly three kids runs in the morning for the under-sixteens.

Juniors and Senior races.
  • Classes for Soapbox Cartie, Gravity Sidecar, Gravity Bike and Pedal Bike.
  • SCA Championship points available.

Check out their web site and facebook page for further details.


Gravity Racer World Record: Location

Engineering Sport - December 4, 2014 - 15:48

Mont Ventoux  — In the Provence region of southern France — is the mountain mecca for road bike enthusiasts. Jam-packed with glorious, sweeping, alpine roads and stunning scenery, “what a location!” I hear you say. Believe me, the selection of a location was no easy task.

Mont Ventoux (Photo – Channel 4)

To give us an idea of the most important parameters in the production of high speeds, Dr. Heather Driscoll created a Newtonian model. This allowed us to tweak various parameters, to see the effects of frontal area, rolling resistance and course incline. Similar to the model used in the downhill toboggan world record by CSER last year, and the free software, CA CartieSim, used by the Scottish Carties Association. After running several simulations it became clear that the course location would play a vital role in the success of the record attempt, and that we must aim to optimise course length, gradient, surface condition and straightness whilst maintaining safety.

The initial suggestion was Teutonic, Rio Grande do Sul in Brazil. A popular course for downhill skateboard and luge events. Not only did it appear to be a good combination of length and incline, as shown in the Newtonian model (below) , but the local authorities were already used to closing the road for events.

Newtonian model Teutonic course route (Image – Dr Heather Driscoll)

However, Teutônia is over 6500 miles away. Not only would have it been extraordinarily expensive, but we would have had to ship the gravity racer over nearly a month before the record.  Practically, we didn’t have the time.

So we cracked on researching alternative locations.  We went through so many options:

  • Eyre Highway in Australia, one of the longest straight roads in the world (1,675 km) – too flat.
  • Baldwin Street in New Zealand, worlds steepest street (average gradient of ~30%) – too short.
  • Col du Tourmalet in France – too short.

And some a bit closer to home:

  • The Lecht, Cockbridge, Aberdeen, UK.
  • Great Dun Fell, Cumbria, UK.
  • Rosedale Chimney Bank, North Yorkshire, UK.
  • Bealach Na Ba, Applecross, UK.
  • Brown Clee Hill, Shropshire, UK.

A record attempt by a British team in Britain – brilliant we thought. However, what we failed to consider is that councils and local authorities are not so keen to close off roads for you to attempt to break the speed limit, thus the law!

North One (the production company behind the ‘speed’ series) suggested Mont Ventoux, it was perfect, and although the French maximum speed limit is only ~10mph faster than ours, we had been given clearance by the French authorities. After a quick scout out by Heather, Terry and Helene — the decision was made —  we would attempt the gravity racer world record at Mont Ventoux. The final course was ~ 2km long, including breaking distance, with an incline of ~12%.

  Newtonian model Teutonic course route (Image – Dr Heather Driscoll)

Mont Ventoux gradient sign (Photo – Channel 4)

Move over cyclists – the gravity racers are coming through!

Mont Ventoux location sign (Photo – Christina King)


Gravity Racer World Record: Design

Engineering Sport - December 1, 2014 - 00:47

The gravity racer was designed and constructed by the team at CSER (Heather Driscoll, Terry Senior, Alice Bullas, John Hart and Christina King). As with most engineering projects, we did not have an unlimited budget or time, so where possible we tried to use and modify bought in components. Modify is the key word though; apart from the safety harness, there is not one component on the racer that has not been altered.


Our original design intent was to build the racer around a composite monocoque body with no internal frame system. This would have allowed for a much smaller frontal area and low centre of gravity. A well designed monocoque should be as strong, if not stronger than a tubular chassis. As we were unable to make this in-house we were reliant on our external suppliers, who unfortunately were not able to provide us with something that we were confident would take the structural loads in the event of a crash. As such, we changed our original plans and modified the design to accommodate a steel, tubular chassis.

The racer was designed specifically for Guy Martin. We chose to seat Guy in a near recumbent position. This was selected to keep the frontal area low, but allow him to drive naturally and have a clear line of sight. There were discussions on using methods similar to periscopes or front facing cameras to allow Guy to be fully recumbent but these can often give a delayed response and a sense of detachment from the driver and track. Obviously, Guy was an integral part of the system and his superior driving skills needed to be made best use of in order for us to stand a chance of breaking the record.

Using a CAD model of Guy and approximate sizes for the braking and steering components, we were able to design a tubular frame that was close fitting but yet still incorporate standard roll cage features. The track of the racer was approximately 1.025 m and the wheelbase was 1.650 m. When we started the design of the racer the final run venue was not confirmed, this meant we could not optimise the wheelbase to track ratio based on the run profile. If designing for a long straight road, we would have increased the wheelbase, and if designing for lots of winding switchbacks, a wider track might have been better. Although not deliberate (or scientifically based) our wheelbase to track ratio was close to the golden ratio of 1.618.

Gravity racer frame design (image Heather Driscoll)

The frame was fabricated by Parish Engineering from steel tubing. We then calculated the centre of mass of the frame and welded in fixed plates of steel to alter its position to be more central along the wheelbase. We deliberately went under the target 200 kg so we could tune the centre of mass position during the record attempts.


The shell of the racer was made from fibre glass by EPM and was not designed to be load bearing. Its purpose instead was to minimise the aerodynamic drag force by reducing flow separation and stagnation. Dr John Hart optimises equipment aerodynamically on a daily basis so was able to use his experience as a starting point on a suitable shape. This was then further analysed and evolved using the CFD results from ANSYS simulations. The resulting racer had a drag coefficient of 0.3 which although was not as low as it could have been without an internal frame, it was a respectable value for a vehicle of its size. The shell was mounted to the frame using polyurethane adhesive; this ensured it remained flexible and responsive to the compliance of the steel frame.

CAD model of final shell design (image John Hart)

The finished racer (photo Christina King)


The biggest decision here was whether to have suspension or not! Suspension can help keep the car grounded on undulating surfaces and provide stability during sharp turns. But if incorrectly tuned can lead to energy loss and reduced speeds.

We decided to buy the wishbones from Formula Gravity as they gave us the flexibility to include suspension shocks if the surface required them. The intention of purchasing instead of making them ourselves was to save time, but in the end we had to re-machine them anyway to give us the precise geometry we required. We had a double wishbone at the front although they were not parallel; the top wishbone was offset slightly to give better turn-in during steering.

We decided not to include suspension shocks on the final attempt and instead used the compliance from the tyres and tubular frame to ensure all four wheels remained in contact with the ground. Guy’s feedback was that the racer’s handling was responsive and predictable and so we are happy with our decision not to include suspension. We do not believe lack of suspension was the cause of the final crash.

Wheels and Tyres

We used 20″ wheels that we specifically made to be side mounted. They were chosen for their low rolling resistance, good laterally stability and availability for vehicles such as this. The tyres used were Schwalbe Kojak and we varied the pressure from 75 to 85 psi based on Guy’s feedback.

Schwalbe tyres and go faster flames (photo Channel 4)


A small rack and pinion steering system was modified to fit between the wishbones at the front of the racer. The design used gave very quick steering input and precise feedback. Although Guy is more at home racing bikes, we chose a small racing steering wheel rather than handlebars as space and control wise it was more appropriate. The final run had several bends that required Guy to carry as much speed through as possible; the steering system chosen allowed him to do this.


The brakes used were Tech 3 V4 hydraulic disc supplied by Hope Technology. The caliper used four phenolic pistons and we coupled this with the vented disc brake on all four wheels to maximise our braking power. The vented rotor used internal fins between the two friction discs to dissipate the heat build-up. Guy limited his use on the brakes down the run but they were vital to bring the racer to a controlled stop before the final hairpin bend. You could really feel the heat radiating from the brakes at the end of the run, so although some people think they are over spec’d for your standard mountain bike, they were perfect for our use! We modified the standard lever system to run off a single foot pedal. An adjustable bias valve was used to split the braking power between the front and wheel rear sets. When coming to a stop the majority of the braking power was needed on the front wheel, so we were able to shift the bias to prevent the back wheels from locking and going into a skid.

Other Safety Features

As well as the roll cage protection, the racer was fitted with a five-point safety harness (SFI approved) and an energy absorbing (collapsible) steering column. The harness was Crash barriers lined the length of the course and an ambulance also followed Guy down every run.

Safety harness and ambulance crew on hand (photo Christina King)

Final Setup

The racer was initially set-up for stability with the centre of mass near the midpoint of the wheelbase. After an initial ‘slow’ run, Guy reported back that the racer felt too light and skittish on the rear so we added extra weight behind his seat to shift the centre of mass rearwards. Along with the centre of mass, we also adjusted the camber and toe-in incrementally throughout the test runs. The initial runs were set with negative camber and slight positive toe-in. Positive toe-in improves the straight line stability and but too much can affect the cornering ability. It was therefore important that we were able to modify this based on driver feedback. The racer was also initially set with negative camber to allow increased grip during cornering however this could limit the straight line speed as it reduced the contact patch between the tyres and surface.

Checking camber and toe-in angles (photo Channel 4)

Although edited for the programme, we actually did around 15 runs making minor adjustments every two runs to optimise the racer. Each change was based on our theory and understanding of what we expected to happen and Guy’s driving experience and feedback from previous runs. Throughout the two days testing we were able to progress the speed of the racer from 71 mph to 85.6 mph. Some changes hardly affected the speed (camber and toe-in) but were vital to increase Guy’s confidence in the handling of the racer. Whereas others (weight and tyre choice) made a big difference; for example, swapping from the wider test tyres to the narrow, higher pressure Schwalbe race tyres increased the speed by 5 mph. As predicted by the Newtonian model, the weight of the racer was the real game changer. However, we had to be really careful about where the additional weight was added so not to affect the handling. The record run was weighted to approximately 200 kg and the crash run was a little over this. We believe it was the higher than expected forward transfer of weight on the crash run that caused the rear of the racer to become lighter and lose traction. This subsequently caused the rear brakes to lock. With the rear brakes locked, it was then impossible for Guy to keep the racer under control and as the racer spun into the crash barrier he sensibly tucked below the roll cage and resisted the temptation to put his hands down. In hindsight, we should have stuck to our initial plans of making incremental changes; this may have allowed us to adjust the brake bias enough to prevent the rear brakes locking. There is no way of knowing this for sure though, and when setting out to break a world record we knew that we were really going to have to push the racer to the limits. The vehicle was just one part of the system though, whatever design you come up with it still needs a driver, and it’s the driver that can make or break the record (…and the racer).

Heading into the first corner (photo Channel 4)

Next blog article coming soon: location, location, location!


Scottish Carties Comments - November 30, 2014 - 19:25

In reply to New cart for 2015:

Thanks where do yo meen on the cart ? Racing local to Lincolnshire may do scotland 2016