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Post by Scottish Cartie Association on Oct 28, 2009 22:54:04 GMT
Quick update, to help focus on the minefield that we currently have. I've produced a table of all the rules I know about, and have derived a set of dimensions for a cartie that could, in theory, compete at every event. They are somewhat restrictive, to say the least. See scottishcarties.org.uk/files/derived%20national%20rules.htm
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Post by Scottish Cartie Association on Oct 29, 2009 11:23:14 GMT
Some observations on the "derived rules"... * Only 4 rule sets out of 13 require roll bars. Of those 4, two (UKGSA and Formula Gravity) are not actually associated with any events and are not in use anywhere. Formula Gravity rules seems to be an old version of the set that eventually became the "draft national rules". * Cadwell only requires a single roll bar over the head. However, if you fit one to comply with Cadwell rules, you then have to also fit one over your hands as well otherwise you would no longer be legal for Belchford, Cairngorm, Border Bogies, etc. * the derived maximum width (1100mm) and minimum track (900mm) are too close together. However, if we remove the (unused) Formula Gravity and UKGSA from the equation, the min track drops to 700mm and the max width increases slightly to 1118mm (still too narrow, imho). * As it stands at the moment, if you build a cartie to the following measurements, you can race it everywhere except Richards Castle and Mansel Lacy. If you don't fit a roll bar, you only have to miss Cadwell as well. - Max Weight (dry) : 80Kg
- Max Weight (with driver) : 175Kg
- Max Length : 2300mm
- Max Width : 1200mm
- Max Track : 1200mm
- Max Wheelbase : 2100mm (ie Max length - max wheel diameter)
- Min Track : 700mm
- Min Wheelbase : 1300mm
- Min Wheel Diameter : 200mm
- Brake Force : 50Kg
- Roll Cage : Required
- Harness : Required
- Wheels : 4
* That derived max length may well change next year as Cairngorm will probably move to 2500mm to match Belchford and Cadwell, and I don't expect Border Bogies (who copied the Cairngorm rules anyway) will have much difficulty in making that change too.
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Post by woody on Oct 29, 2009 13:19:09 GMT
Ok, thats looking better , so i have an idea what to aim for you are saying that they are still too restrictive , i wont know this untill i start my build and try racing
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Post by azuma on Oct 30, 2009 0:51:38 GMT
Just looking at the proposals above. You have max width as 1200mm and track also as 1200mm?? What happend to the max 1500mm rule (proposal)? Just rebuilt the axles etc on our cart with a 1200mm track, but by the time you add the other half of the wheel, wheel nuts etc it will fall outside the 1200mm. Also, there are some other carts running more than 1200mm - is that them stuffed as well?
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Post by Scottish Cartie Association on Oct 30, 2009 9:14:50 GMT
Those figures aren't the proposals. They are derived from all the existing rules and give some dimensions that people could build to now and be able to race everywhere except Richards Castle and Mansel Lacy. "Max track" is not entirely relevant in the above instance, but kind of ends up there because Aldington has a max track of 1219mm (4 feet), which is actually wider than the max width for Belchford... so I left it in as 1200mm since track must be less than the width. In fact, if you account for hub width, in practice max track would work out closer to 1100mm. If you wanted to race everywhere (ignoring Formula Gravity and UKGSA Rules), then you'd need to build a cartie complying to the following; - Max Weight (dry) : 80
- Max Weight (with driver) : 175
- Max Length : 2135
- Max Width : 1118
- Max Track : 1118
- Max Wheelbase : 1935
- Min Track : 700
- Min Wheelbase : 1300
- Min Eye Line : 762
- Min Wheel Diameter : 200
- Brake Force 50
- Roll Cage : Required
- Harness : Required
- Min Wheels : 4
I don't know how many carties actually fit those measurements, but my guess would be "not many". So - to answer the question... you and all the other carties wider than 1200mm are not stuffed, but at the moment you can only race at Cairngorm, Cadwell, Belchford, Border Bogies, Catterline, Stonehaven and possibly Aldington.
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Post by Scottish Cartie Association on Oct 30, 2009 9:40:15 GMT
Sorry for the double post.
A different perspective; as a competitor, I want to maximise the number of events I can enter with the mimumum of effort, or at least I want to make sure I can take part I the events that are really important to me, so I'd build to the most restrictive dimensions. That's what the above figures give me.
However, as a race organiser I want to make sure the field of potential competitors is as large as possible, so if I were designing a set of rules from scratch for a specific event, I'd chose the maximum figures from all the current rule sets.
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Post by Ian r on Oct 30, 2009 19:26:26 GMT
Hi, Just thinking aloud here, but don't get too hung up on the ukgsa rules as they were a 'derived compromise' themselves, when they were drawn up, so for arguments sake, lets remove them from the issue? I'm sure David Ackroyd won't mind me saying that currently, Formula Gravity are not currently sanctioning any events and I suspect that as long as the chassis that they produce are not outlawed, there will be no issue there either. So what we really need is an all encompassing set of rules that suit venues such as Aviemore, Scammonden, Cadwell etc that will stand a reasonable test of time, to allow development to take place over a couple of years or more? Personally, as a potential (and past) event organiser the big issue is weight. More weight = greater risk. The compromise to be made is risk v cost / expertise of construction. Hence the rather light 145kgs for previous ukgsa rules. However, if the courses to be used could be (and would need to be0 made safe for a 175kg soapbox, then, knowing this, we plan the course safety accordingly? Add chicanes to reduce top speeds, put a braking zone near the top of the hill (with plenty of run-off) to find out there, before speeds get dangerously high, wether they're good enough. Width should be based upon simply can one overtake another safely on that width of track (assuming we want to race head-to-head, yeah?). If UKGSA were to settle on some new 'all-encompassing' rules (which surely should be the aim) there will always be a chance one or two competitors may be excluded from one or two events, if the competitor had choosen to build to max dimensions of said rules? But if we include far more than we exclude, and are not snobby about making people aware that big is not always beautiful , we can please most of the people most of the time? Does Max dry weight :- 80kgs Max all up - 175kgs max length - 2500mm max width - 1500mm max height - 1500mm min eye height - 700mm min wheel dia - 65mm brake force - 500nm Roll cage / restraining belt - as aviemore, ie in / on = yes / no min wheels - 4 exclude anyone unreasonably? given the kind of venues I would like to see us using in the future? If this exclude YOUR soapbox, please post up details of what it can't meet, if you'd be prepared to alter and how far we'd have to move to accomodate? Sorry for long post, but hey.....
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Post by leew on Nov 1, 2009 11:30:38 GMT
Don't really see the point of the eyeline rule myself. My view is that it is useless and should be scrapped. I seem to remember someone mentioning it was there so people don 't make prone carts. Most rulesets I have seen require a feet first riding position anyway thus ruling out a prone cart and thus making the rule redundant.
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Post by peasnbarley on Nov 1, 2009 19:11:33 GMT
Having read through all the posts I have to admit to becoming even more confused than I was by the various proposals! Like azuma I am somewhat conserned and wonder if I am spending money on modifying a cartie that could well fail to meet new criteria. I also wonder if some folk are getting confused between cartie width and cartie track, or is that just me being thick? What should the measurement be between the front and back axles and is this measurement taken with the steering set at straight ahead?
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Post by Scottish Cartie Association on Nov 2, 2009 13:57:58 GMT
The confusion is probably my fault, 'cos I've started talking about two different things - one being a proposed "national standard" and the other being a set of "universal dimensions" that can be used to build a cartie that could run at any event. Ideally, of course, they should be the same. Sadly, they aren't. Ian's suggested dimensions are not too bad, but I'd make a couple of observations; - Max dry weight - should probably be a little more generous here if we want people to build robust roll protection into their cartie. 100Kg is by far the most common weight limit.
- I'm not keen on max weight with driver, as this implies you have to weight every machine before every run. Race organisers and competitors have enough to do already without giving them more work to do.
- Max height is only specified in the UKGSA rules. If we are ignoring these rules, we don't need a max height. You're not doing yourself any favours in making your cartie very high anyway.
- Min wheel diameter - only used at Cairngorm and Border bogies, and then only because it was in the Draft National rules. I'd happily drop this requirement entirely.
- Min eye line. I don't see how it makes carties safer. Stability requires keeping the as COG low as possible, so I think we should either remove this or make it much lower.
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Post by Ian r on Nov 2, 2009 15:26:22 GMT
Hi, yep, take your point on the 100kgs dry weight ;D Weight with driver is a little more problematic. I understand the organiser workload bit, but, knowning how extra weight used to be sneaked on at belchford & that when some courses are used (long, straightish ones, or those with 'flat' sections, like aviemore?) they favour the more 'pie' orientated of us, lol . Now you could argue that at high speed these folk will have , by neccessity, a wider, less aerodynamic profile and, all things being equal, over a number of events, becomes irrelavent. But the real sticky issue for me is again max weight from a safety viewpoint. It good to know what the 'worst case scenario' froma high speed crash is, and to be able to use a max figure in the maths. Besides owt else, it gives insurance companies some faith that there's some logic behind our risk assesments I agree, max height, min wheel diameter & eye line can take a running jump. (How?) do we legislate against a prone riding position, if we choose to? Though, from bitter experience, I would not want to hit a straw bale head first for anything, its bad ebough feet first on a luge And i have no idea how to make it acceptable from a risk point of view...... Peasnbarley & azuma, I feel for you just now, but we've gotta have this conversation sometime, otherwise we're really gonna leave folk out in the cold...... Yep a rule stating max width & max track is just duplication & confusing surely? I'm pretty confident that distance between front & rear axel centres is 'wheel base' and its measured with steering set straight ahead Hope this help, rather than muddies?
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Post by Scottish Cartie Association on Nov 2, 2009 16:26:53 GMT
To prevent prone driving position, we do just that. Most of the rules have wording to the effect "the driver must be seated and forward facing" or similar, which explicitly prevents the drivers being prone. Min' eyeline doesn't actually prevent the driver being prone anyway, as you could still be prone while 700mm off the deck.
Some rules state max track and max width (or max length and max wheelbase) separately because of their own particular circumstances. For instance, Belchford & Cadwell use a weighbridge, and the wheels need to fit on it even if the bodywork overhangs. Aldington use a 4' by 8' ramp for brake testing, with similar implications for the track and wheelbase. Richards Castle dimensions are, I understand, limited by the trailer they use as a start ramp.
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Post by peasnbarley on Nov 2, 2009 21:31:34 GMT
Thanks lads for the feedback and believe me I am all for attaining standardised set of rules. However I know that our cartie in its present form is fast, stable and predictable and I would not be a happy bunny if I had to compromise the design to fit in with some rule which demands a minimum wheelbase length that in my opinion does not match the minimum track width. True we built specifically for Cairngorm and with hindsight perhaps we should have compromised the built. Our wheelbase of 930mm, Track 1000mm, body width 480mm at widest, Overall length 1980mm front overhang 610mm from front axle to nose end, 20mm axles with 20" wheels, eye line 685 - 700 mm depending on how tight you clench your buttocks. Running hight 90mm and Roll bar and hand protector bar as per Cairngorm requirements. Initially our wheelbase was longer and the nose overhang shorter but I/we decided steering would be helped by increasing the nose overhang which proved in practice to be correct.
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Post by Scottish Cartie Association on Nov 2, 2009 23:15:33 GMT
I'm not fussed about the min wheelbase myself. Cadwell is the only rule set that specifies a min wheelbase, which is why it is in the "universal set", but personally I think it could easily be reduced or dropped.
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Post by gravitygrump on Nov 6, 2009 13:00:47 GMT
I have been following this thread with interest and it's great to see renewed enthusiasm from competitors for a universal set of rules.
I think Cadwell's current rules are based on an old version of Belchford's. We used to specify a minimum wheelbase because we believed short carts would be too twitchy and we were keen to keep speeding carts and competitors out of the crowd of spectators.
Now that we have efficient barriers to keep pedestrians and gravity heros separate, we have relaxed the rules on the basis that if competitors want to try something we don't want to stop them innovating. We also concluded that the 700mm eyeline rule should be abandoned, as we had noticed that drivers were moving toward lying flat of raised floors, which only serves to raise the c of g, to the detriment of stability and safety. Our most recent set of rules - used for 2009 - are quite flexible and seem to have been very popular with competitors. At the moment I do not anticipate we will alter anything significantly for next year.
I was initially keen to reduce the weight of carts for the reasons put forward by Ian r, but thinking as an organiser, I now take the view that 100kg is about right, as it allows larger people to build a cheap, safe and attractive cart using simple materials and techniques. Although heavy = fast on straight courses, it does not when the course demands braking and includes tight corners.
My suggestion is that we allow people to build what they like within reason. On some courses heavy will be best, but if the same cart is used to compete in several events the heavy cart will be at a disadvantage elsewhere. As a course designer I have aimed for the last two years to equalise the advantages of the heavy and light carts by the use of chicanes at Belchford and analysis of the results indicates that this approach works well, as it generally rewards driving skill as well as good cart design and build.
Perhaps we should consider outlawing removable ballast, as this would encourage constructors to design and build a good "all rounder" if they want to compete in several events, rather than build light, then burden their creation with lumps of lead for courses like Cadwell.
So far as dimensions are concerned, I quite like 2.5 metres for length, as it allows some space for an impact absorbing structure at the front - Not keen personally on my feet and ankles being the crumple zone! I don't see why we need to regulate cart width, particularly if course designers adopt the idea of chicanes, which I suggest could be of a standard width, say minimum 1.7 metres, which we have found creates a challenge, but is not un-drivable.
Looking forward to discussions on Saturday evening.
GG
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Post by Ian r on Nov 8, 2009 10:16:18 GMT
Good good. We seem to be drawing some conclusions? ;D
Only reason for stipulating max width is to allow safe head-to-head racing really. ie:- road width divided by 2 minus a bit of wriggle room....
Is everyone ok with the max (with driver) of 175kgs? It does mean that the heavier drivers would have to commit to building a lighter soapbox, but it means we're all on a level playing field, shouldn't be too expensive and its acceptable from a physics / risk angle? Do we even do away with the soapbox max 100kg & just use the all up weight of 175kgs? with weighbridge after the finish. Overweight = disqualified from whole event?
How about a minimum weight to future proof the rules and keep costs sensible should teams with mega budget become involved?
I realise I may seem to be over-complicating this, but surely one set of rules being used, unmodified, for a number of years would be better than revisions every year (like F1 !)?
Oh yeah, now here's a can of worms. What about push starts?
Initially I was not particulary keen, but having seen it work really well & belchford, I think that as long as there is a 'squeeze' point, like a chicane or a corner that HAS to be braked for, not too far from the start line, (this reduces the advantage / disadvantage of how good your pushers were, whilst allowing racers to get up to speed rapidly. this being better for spectators and competitors alike.), it can work very effectively ! If we don't have the squeeze point, everyone will be competeing with offers of free beer for burly rugby players up and down the country, lol.
Looking forward to cadwell. Bring your winter woolies !
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Post by djmogy on Nov 8, 2009 12:07:39 GMT
Just been reading through peoples comments on rules and I agree that they need to be simplified but as organizers we have to make it safe as practically possible for competitor so the is no come back if anything does go wrong.
Safety •Roll Bar/seat belt: we are not being funny when we have asked for roll bars to be fitted. I know we have let Kart's run in the past but this year for the first time we have got our own insurance, so it’s us personally if there is any come backs. After talking to people at motorsport vision, were they have people that have come off their bike on a track day and injured themselves and tried to sue Cadwell even though they have signed a disclaimer. Then the organizer has to prove that they have done everything practically possible to keep them safe. So we feel that having a roll bar is a must at our event especially with multi karts racing being thrown from a kart into the path of another wouldn’t be a brilliant thing.
•Brakes: my only concern is on baking systems were you have two independently operated brakes on the front wheels. Would it be better to have a lever/pedal to operate both brakes with another back up lever/pedal that also operates both brakes. It’s not a problem at Cadwell were there is plenty of runoff but at higher speed coarse with less runoff it could be a problem. l have noticed that the kart’s pull to one side when applying one brake harder than the other, so if one brake fails altogether I would not like to try and stop at 40+ mph. We have found a low cost easy way to do this with a pulley system.
•Steering: there needs to be a standard that needs to be reached on the steering no free play that sort of thing.
•I would also like to keep a rule about anything that could injure a competitor if they crash e.g. sharp edges on body work or ballast being properly attached so not to come loose that sort of thing.
•Mini/max sizes the only thing that we don’t want is a kart stupidly high and narrow which will fall over at the first sight of a corner.
•Wheels : to have a recommendation that people use strong wheel that can take side load
•Seating position: I think it must be feet first but scrap eye height.
•Weight: 100kg is OK with us.
Like I have told teams entering Cadwell if it’s safe to run we will let it run were not that fussed on mini/max sizes if it fits on our weigh-bridge it’s ok with us, but may be there need to be a minimum width for coarse with a slalom style chicane like Belchford which I thought was a great idea, but if you built a really narrow Kart you would be able to drive straight through which would make it pointless to have. Would it also be possible to have suggestions on how to build certain parts on the Kart's like brakes, steering for the people that are coming into the sport with no cue how to build a soapbox. It is OK to let people have a free hand in building and its great to see the different solutions to problems but it would be safer to give teams help on the important parts of the build cause not every one has a mechanical back ground.
I think if we could have a set of rules made up with maximum safety in mind then if individual events want to relax rules like no roll bar they can . As different event need different rules as each venue is different but if you err on the side of safety they should be OK for every venue.
See you at Cadwell
Graham
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Post by Scottish Cartie Association on Nov 11, 2009 11:02:53 GMT
I'm not totally comfortable with specifying a max all up weight and would prefer to keep the max unladen weight. The main reason is to avoid extra organisational work on the day, because it would make it difficult to scrutineer the carties in advance - something several events do make the day itself easier and also to give teams chance to rectify any problems. Also, as you say, it discriminates against heavier drivers and forces them to build a lighter cartie, making it harder for them to build one robust enough for their weight. I understand the point about keeping the kinetic energy down, but in reality a 100Kg dry weight will do just that anyway. If the concern is that people would cheat by loading up their carties after scrutineering - well that would be against the rules either way, and any team wanting to do it will do so regardless. If caught doing it they would, of course, be DQ'd. How individual events police that should be up to them. I do quite like gravitygrump's idea of not allowing removable ballast at all as it would simplify things greatly. I am a little unsure how that could be enforced from one event to the next, however, as there are numerous ways to "work around" it - (e.g. filling all the tubes with lead shot). While I'm thinking about removable ballast - some rules state that the only removable ballast permitted is water. This strikes me as a bit silly really, as water slopping around in a part filled container would make a real mess of your CoG and handling. I'd suggest removable ballast should be solid. I must admit I'm rather ambivalent about roll bars. I'm not convinced they are anything other than a fig leaf when it comes to safety, as we don't have the ability to check whether they are actually fit for purpose beyond sort of tilting our head to one side and saying "yup that looks about right". They do, however, add significantly to the difficulty of building a cartie and so act as a barrier to entry for new teams. I'm totally comfortable with the wording we came up with earlier this year whereby carties that are not enclosed do not need a roll bar. We need to be carefull not to be actively making it harder for people to get involved. Giving teams the option to choose is the best way forward, in my opinion. I wouldn't be keen to try and legislate against teams with deep pockets, although individual events may well choose to do so. Thinking about it from an organiser's point of view and considering the PR/funding/sponsorship/media angle, a couple of eye catching team names makes it a lot easier to raise the profile of the event and get people talking about it. As a competitor, my response would be "Bring it on. You can't buy gravity! ;D" The suggestion of dual redundant brakes seems unneccesarily complex, given that there are several simple solutions to the brake steer effect if independant left and right brakes are not applied equally. In fact, the only time I've seen carties veer under braking is when they have used a badly implemented "balanced brake system". Pulleys can easily be used to balance out the brakes, but the down side is that if there is a failure caused by (e.g) excessive pad wear on one wheel, it can effectively mean that neither brake will work. Slowing with only one brake may be tricky, but it is lot easier than slowing down with none! I think the existing Belchford wording is perfectly acceptable, although I'd like to see brakes that operate by pressing on the road surface or the tyres to be explicitly disallowed, and it should also be possible to apply the brakes without letting go of the steering. I am, however, beginning to wonder if a simple 500 Newton brake force test is adequate, since that gives no allowance for heavier/lighter carties. I wonder if it might be better to require driver to hold the cartie stationary on a ramp instead, as the heavier carties would need better brakes. According to my calcs, 500N is the force needed to hold a 175Kg cartie on a 1:3.28 slope (~17degrees). We put a bit more detail into the steering rules for the Cairngorm rule set - you might want to have a look at them. I think they work quite well without being overly complex or prescriptive. As for push starts - I don't think we need to worry about this at all. How an event is run should be entirely up to the organisers, so whether it be races or time trials, with ramp, push or dead start is entirely up to them. It would be a mistake to start to try and dictate that level of detail.
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Post by Scottish Cartie Association on Nov 12, 2009 14:16:44 GMT
How about the document attached below as a starting point for the discussions on Saturday? I think it reflects reasonably well what we've been discussing, and gives some reasonable dimensions without too much complication. It's based on the rules from Cairngorm, which in turn were based on the draft rules we came up with earlier this year. I've tried to incorporate some of the recent ideas - no wheel dimension, height, eyeline or wheelbase limits, etc, with a beefed up disclaimer at the start and a few bits about clothing from the IGSA rules put in for good measure. Attachments:
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Post by gravitygrump on Nov 13, 2009 20:12:43 GMT
I am in favour of specifying a maximum weight for the cart and leaving it up to the driver to eat as many or as few pies as he chooses. I still think heavier drivers really need heavier carts to be safe, but 100kg should give them ample weight to play with. An alternative, which I throw in more to promote thought than as a genuine suggestion, would be to limit the weight of the cart to the weight of the team's heaviest driver. It would be interesting to see who was recruited to drive!
Lets move forward with the roll cage thing and adopt the rule used at Belchford in 2009, which seems to work OK. Personally, I prefer to run with a roll bar and seatbelts and would do this even if I wasn't running bodywork.
I quite like the ramp brake test idea put forward by Greased Weasel, as this would make sure that brakes were of a reasonably uniform standard and adequate for any particular combination of cart and driver. However, building a ramp and getting it to events would be a pain. Using the same maths that calculated the slope, could a simple spreadsheet be configured that tabulates the braking force required for any cart/driver combination that would equate to 500 Newtons for a 175kg all-up weight? If so it would be simple to weigh the cart with driver and check the brakes agains the table to make sure they complied.
I take GW's point about water ballast on board. However, at Belchford we limit the size of containers to 5 litres to minimise the effects of water slopping about. In any case, the competitor would ultimately have to decide whether to add say 3kg for extra top end speed and take the trade off with poorer handling into account. I still favour getting rid of removable ballast altogether. Filling tubes with lead shot would I think constitute fitting fixed ballast, as I can't see how it would be likely to come adrift while the cart was running.
I agree entirely with the suggestion about the brakes and would be happy to adopt and work to the draft regulations for Cairngorm.
Lets also leave decisions about push, ramp or dead starts and the use of moveable barriers(chicanes) up to event organisers - variety in these things just makes the sport more interesting.
Looking forward to Saturday evening at sunny Cadwell
GG
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