UK National Soapbox Rules under discussion

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There have been a set of National Soapbox Rules around for a few years now, and some events have adopted them as a separate class which they run alongside their own "local class" carties. However, the National Rules are very restrictive, which may explain why there are still only a handful of carties built to the National spec' and the mooted "National Championships" has largely failed to get off the ground.

In an attempt to open up the National competition a bit, a discussion has been started over on the UKGSA's forum. I'm optimistic that something constructive will come of it and that we might have a meaningful National Championship Series next year. See the discussion for futher details.

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Suggested National Rules

I can't understand why the suggestion has been made that ballast should be water contained in plastic containers. This surely adds more problems than it solves and could constitute a danger in that unless the containers are full, or baffled into small segments there would be instability problems in the carts handling.

I don't see any good reason for restricting the wheelbase of carties to 1300mm anymore than the 700mm eyeline rule which ends up making all the carts look the same.

Wheel size and tyre width is another rule which is as much historical as anything else.

Having said that I think having strict design criteria to work within is in many ways a good thing. Cartie racing should be friendly, competative, creative and fun and I am afraid a laid back attitude to a set of rules once set and agreed would be bound to cause dispute. In the mean time it is sense to accept that each organiser of an event has the final say.



peasnbarley | October 8, 2009 - 21:40
scottishcarties's picture

Water ballast considered silly

I agree that water ballast is a bit silly. We based the Cairngorm rules on the draft set, but dropped the water ballast rule and tightened up/clarified some other points.

The draft rules dropped the wheelbase and eyeline rule. I must admit I'm not really sure why there was a minimum eyeline rule in the first place. If it is to prevent drivers being prone then it clearly failed (e.g. "Crockle").

The draft rules suggested the following dimensions;

  • Maximum overall length - 2300mm

    Maximum overall width - 1500mm

    Minimum track width - 700mm

    Minimum wheel diameter - 200mm

  • Maximum weight of vehicle and ballast - 100kg

Belchford also relaxed their rules in line with the above, although they changed them slightly, dropping the min track, adding a max track of 1200mm and increasing the max length to 2500. They also kept the water ballast requirement.

We had planned to have a meeting before Cadwell in February this year to talk about rules and see if we could come to a consensus. Unfortunately, Cadwell was postponed so the meeting never happened. Consequently the SCA had little choice but to go ahead with the draft rules, which was the closest we had at the time to an agreed set.

Hopefully we'll be able to discuss things at Cadwell in November and come up with something that we can all accept. I don't know if it will be possible to impose a national standard, but I think the various rule sets will tend towards each other over time anyway. I'm coming to the view that we probably don't need a single set of rules, provided all the rules are not mutually exclusive.

I agree that the rules need to be framed in such a way that they do not put potential competitors off. They should be fairly broad, to allow individual creativity and imagination to shine through.


scottishcarties | October 9, 2009 - 08:59

I accept that in any

I accept that in any competition rules will have to be applied somewhere and I would rather see rules for safety reasons rather than creative restriction. A set standard for the UK would be a good thing, there are too many variations.  

I see the reason for the 700mm eyeline as I think this was introduced so drivers will adopt a sitting rather than lying position. So, in the event of an accident the body is not in line and the spine ios not subjected to in-line impact.

Surely introducing narrower track and wheelbase is going to promote instabilty and also the amount of space between human body and hard object in the event of an accident? 1500 is a good maximum and allows a couple of carts to race together.

Why only water as ballast? a properly fixed weight or sand has got to be better than water

What I am in favour of though (and this will upset some) would be the introduction of a rule which does not allow the feet of a driver to be infront of the front axle. All forms of motorsport enforce this rule, other than Formula student. The other rule which I think the British enforce, but not the Americans is the "no heads first",  great for creating aerodynamic shapes not very good if you hit something hardCry

Thats me had my say and I'm sure this subect will promote some healthy debate.

azuma | October 8, 2009 - 23:53
scottishcarties's picture

Rule changes and pragmatism

I think you're absolutely right that the basis for the rules needs to be safety. We're reviewing the Cairngorm rules, and will be changing them slightly for next year. There does need to be a bit of pragmatism when introducing rule changes though, as it'd be a mistake to introduce new rules if it means effectively disqualifying lot of potential competitors. Anything major needs to be signalled well in advance so if (for instance) we decided to implement a "no feet in front of the front axle" rule, which would rule out quite a few perfectly reasonable machines, it would be deferred for at least a year.

I know Roy was working on some changes to the Cairngorm construction rules during his period of enforced home rest, although I've not seen them yet. I've a few ideas too, such as;

  • Max length 2500mm (immediate, to be in line with Belchford) 
  • Min wheel size 120mm (immediate, to allow 5" kart wheel)
  • Min steering ratio? at least 2:1?(immediate)
  • Mandatory rear view mirror(s) (immediate)
  • Mandatory nerf bars & bumpers front & rear (for 2011)
  • Feet must be at least 150mm behind front bumper (for 2011)

It's important to note that most events started as independent local races, and all have developed their own rules that are appropriate for what they are doing. For instance, rear view mirrors only make sense for group racing, and in a pure time trial event would be totally unneccessary.

I'm really looking forward to having chance to talk about rules with everyone at Cadwell, as I think it'd be good to move things along a bit.

scottishcarties | October 20, 2009 - 09:02

Not really sure about front

Not really sure about front and rear nerf bars as this is deff going to mess with aerodynamics, construction and weight. Also, if the front and/or rear bodywork extend beyond the wheel line, then effectively the bodywork is the contactable area. Side bars if there is a gap between the wheels is a good idea as it stops carts becoming entangled.
The one big issue with bars though is the difference in wheel sizes. If a cart is running 24" bike wheels and another is running kart wheels then depending upong the size and position of the bars there is still the possibility of the smaller wheels getting under the bars.

You are right about not rushing in changes and ruling out perfectly good carts, people have spent money and time building and developing. Speaking to a few at the Cairgorm event, many were already planning changes.


azuma | October 20, 2009 - 23:14
scottishcarties's picture

The main thing is the nerf

The main thing is the nerf bars to prevent wheels getting interlocked. Obviously if there is bodywork at the side then nerf bars wouldn't be required. To prevent wheels of different sizes getting under the bars, we'd need to define the height of them - if the min wheel diam is 120mm, and taking a reasonable expected maximum of 24", then the nerf bars would need to fill the gap between front and rear wheels from 100mm to 300mm above the ground.

Front and rear bars are probably not so important, although I think there probably ought to be something substantial in front of the drivers feet.

scottishcarties | October 21, 2009 - 09:26

Don't see the point of

Don't see the point of having to have your feet behind the front axle myself, what would be the benefit of that? I wonder how many existing carts have the front wheels that far forward? I feel having the front wheels that far forward to result in uneven weight distribution with less weight on the front wheels than back wheels thus more chance of the front wheels loosing grip in a turn. My feet are some 400mm or so forward of the front axle. My cart is fitted with a block of expanded polystyrene about 80mm thick on the front to act as a bumper and to help absorb impact. After that there is about 120mm of hollow body and then there is a bulkhead before the start of the steel cage and the foot area. Not sure about a steering ratio rule myself. I have a ratio of less than 1:2 and my cart is very stable even at around 45mph. Other changes sound good. Altough I feel mirrors and nerf bars are not needed for time trial type events like belchford.
Anonymous | October 21, 2009 - 21:03
scottishcarties's picture

Feet position and steering ratios

I'm trying to think which cartie yours is. I'm probably being a bit dense, but I can't think of any I know that fits your description - which one is it?

I think the idea with the "feet behind the front axle" idea - and I'm sure Azuma will correct me if I've misunderstood this - is that the feet should be behind something substantial. I can see the logic of that, although like you I'm not sure that the front axle should be the reference point. I can think of several perfectly reasonable carties that would fall foul of this rule.

As for steering ratio - I think there should be some basic minimum, as their seems to be a tendency - especially with less experienced builders - to have a steering ratio that is close too or even less than 1. Steering ratio in itself is not the only factor in how twitchy a cartie is, as wheelbase, caster, etc all play their part, but its still something that you need to get right. Do you think there should be a minimum, and if so what should it be? What is your steering ratio?

scottishcarties | October 22, 2009 - 08:52

Picture of my

Picture of my cartie: Not measured my steering ratio exactly but I guesstimate it to be somewhere around 1:1.5
Anonymous | October 22, 2009 - 13:04

The feet behind the axle

The feet behind the axle line is something we have used as is it the standard in motorsport. I agree that can mess with balance and you have to compensate for this when building, but its a safety thing and not just a reg for reg sake. Personally I will always build this way, then the front area (which is usually deformable to reduce initial impact shock) and the wheels can take all the impact and not my feet ankles and legs. Yes, we are running at significantly reduced speeds than other sports and there is possible an argument for allowing it, as long as there is significant impact protection.

Also if you look at all the old style bogies/carties/guidies that were built when we were kids, your feet were always on or behind the front axle line anyway.

As for steering it is one of those areas which will always be a bone of contention and not the easiest to master, especially if rack and pinion is not involved. Akerman, how much lock, ratios, steering wheel size etc etc blah blah. Busy with the protractors etc to do the new steering since the current raft of changes.

azuma | October 22, 2009 - 22:54

Feet behind front axle

It is difficult to see quite what the drivers position is set at in the pictures but there is a lot of cartie between the front axle and nose end. The presumption being the driver must sit fairly upright. Building our cart I was conserned with the safety aspect and have to say I knew nothing about feet being kept behind the front axle in motor sports. I can see the sense behind this convention/rule and have to admit that the front axle area on our cart gave me some conserns as to what would bend and brake under severe impact loading. The problem is of course that none of us know and I bet none have actually tested for structural strenght in various crash scenarios. Bargain Hunt last week showed a clip of a cartie crash at Ritchards Castle where the driver was thrown quite a hight to land on his head and shoulders, so the strenght of his cart was somewhat erronious! Azumas cartie crash at Cairngorm showed his cartie could take quite a smack side on to a cartie busting big bale but then he was strapped in and the grass verge slowed him down as the wheels took the loading. Prone drivers no matter what relationship there is to start with between the drivers feet and the front axle are going to suffer in a head on impact, unless they are quick enough to bale out before impact! There is then the problem of following cart avoiding the escapee but then that happens all the time in bike racing. I believe our cart will take quite a smack and the greatest danger to the driver is in the event of a direct wheel impact severe enough to shear the rose bearing joints on the wishbone and steering rod ends, thereby allowing the steering rods freedom of movement. Present rules cater for this and state there must be no possibility of puncture injuries. Interpretation of this rule is up to the scrutineering policy at each event.
Anonymous | October 24, 2009 - 12:43

Feet behind front axle

Sorry above anonymous post was mine due to me forgetting to log in/on.Embarassed

peasnbarley | October 24, 2009 - 22:46

I too would like a

I too would like a clarification in the ballast rules. How does one define "removable" ballast for example. My ballast is steel plate securely bolted to the chassis which the organisers of belchford said was ok. The main concern for organisers I can see is ballast falling off the cart and becoming a missile. Providing any weights are securely bolted down to the chassis I cannot see a problem.
Anonymous | October 25, 2009 - 22:28
scottishcarties's picture

Removable ballast

Removable ballast would be anything you would add to or remove from a cartie for the purpose of changing its weight, and yes the main concern is that it doesn't fall off.

From an organiser's point of view, I'd prefer it if ballast changes were not permitted after scrutineering, as that  means that we should check the cartie weights are still within limits before each run and - frankly - I think we can do without the extra headache. That's why I prefer specifying the maximum dry weight of the cartie rather than the "all up"weight.

scottishcarties | October 25, 2009 - 22:52

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