They're in the GCRs. Really mate, it doesnt affect you so let it go.
Col don't you like me trying to understand your rules of CMX ?
16.11 MACHINE ELIGIBILITY
16.11.1 Eligible Machines
16.11.1.1 Only machines conforming to the requirements set out in this chapter will be accepted for competition.
16.11.1.2 The onus of proof of eligibility shall rest wholly upon the rider or entrant of the machine. Service and parts manual publication dates are not proof of eligibility.
16.12 SOUND EMISSIONS
16.12.0.1 Sound testing must be carried out at all permitted events; however, it is not mandatory to test all machines.
16.12.1 Specifications
16.12.1.1 Sound emissions are set out in the table below:
30 metres (from side of track) ride by test
DISCIPLINE
LIMIT dB(A)
Dirt Track & Track (incl. Quads) 95
Record Attempts
No limit
16.12.2 Sound Control During Competition
16.12.2.1 The Sound Control Officer (SCO) must arrive in sufficient time for discussions with the Clerk of the Course and other Technical Officials in order that a suitable test site and testing policy can be agreed.
16.12.2.2 Machines can be tested before, or after competing in an event, chosen by ballot, or as required by a Steward, Clerk of Course or SCO.
16.12.2.3 Where government regulations or planning orders exist in relation to lower sound emissions or where a venue has lower sound emission requirements as part of the hire contract, the sound emission required will prevail over General Competition Rule 16.12.1.1.
16.12.3 Use of Sound Level Meters
16.12.3.1 Sound testing apparatus must:
Comply with international standard IEC 651, Type 1 or Type 2.
Include a compatible calibrator, which must be used immediately before testing begins and always just prior to a re-test if a disciplinary sanction may be imposed.
16.12.3.2 Sound testing apparatus must be set to:
‘Fast response’
‘A’ weighted,
Select range High 80~130 dB,
Activate the function MAX MIN – set on MAX,
16.12.3.3 ‘30 Metre ride by’ test
The sound levels will be measured with the sound meter/microphone fixed on a tripod, in the horizontal position, 30 metres from the edge of the track at a high speed point.
16.12.3.4 Tests shall not take place in the rain
16.12.4 Machine testing
16.12.4.1 If a machine fails, it can be represented for re-testing.
16.12.4.2 No person may compete in any event on a machine whose noise emissions exceed the prescribed levels.
16.12.4.3 A machine which does not comply with the sound limits can be presented several times.
16.13 FUEL
16.13.1 Fuel Warning
16.13.1.1 Fuels and lubricants are highly specialised substances and participants must be aware they may contain substances that are extremely dangerous to human health if misused, inhaled or allowed to contact skin.
16.13.1.2 Some of the components of fuel and lubricants are suspected of having the potential to cause cancer in rare circumstances.
16.13.1.3 The use of petrol as a general cleaning and washing agent is a common misuse of a potentially dangerous substance.
16.13.1.4 Fuels should be used and stored with extreme care and in accordance with the manufacturer’s instructions.
16.13.2 Fuel Testing
16.13.2.1 For any event, meeting or series, the relevant controlling body may direct that no fuels other than fuels of prescribed specifications and from a prescribed source may be used.
Tests to ensure that only prescribed fuels are used in an event, meeting or series may be administered at any time and place during the course of the same,
The Clerk of Course, Race Director or Chief Scrutineer may direct the administration of fuel tests.
16.13.2.2 Fuel tests must comply with the following procedures:
All containers for holding samples must be clean and constructed of robust non-reactive impermeable material, must be sealable, and must have provision for identification,
Equipment used for the extraction of fuel from machines must be clean and constructed of fuel non-reactive material,
All samples must be divided into two lots (Sample A and Sample B) of not less than 5ml each, which must be placed in separate containers,
Once samples are placed in containers, the containers must immediately be sealed and identified by reference to the machine from which the sample was taken. This information must be entered on a fuel sample certificate which must certify the date, place and time of taking the sample, the identity of the machine from which the sample was taken and the identity of the rider,
Both samples must remain in the control of the official who administered the test.
The rider or the representative must sign the fuel sample certificate acknowledging samples have been taken and are sealed,
All samples held by the official must be delivered as soon as practicable after the competition to the relevant controlling body which must deliver the Sample A as soon as practicable to a laboratory approved by MA where they must be tested for content and quality in accordance with standard scientific procedures,
The relevant controlling body must as soon as practicable after receipt of the results notify the rider or rider’s team representative and MA,
If the rider is dissatisfied with the test result of sample A, they may request sample B be tested at an MA approved laboratory in their presence.
16.13.3 Refuelling
16.13.3.1 During refuelling, each machine must be stationary with the engine stopped.
16.13.3.2 Refuelling will be deemed to have commenced when the fuel tank has been opened and completed when the tank is closed.
16.13.3.3 Smoking is strictly prohibited in areas where refuelling is permitted.
16.13.3.4 Riders are liable for exclusion from an event for failing to adhere to General Competition Rule 16.13.3.3, and are responsible for the actions of their mechanics and support team members.
16.13.4 Homologation of Fuel
16.13.4.1 Unleaded fuel produced by an oil company for sale in the Australian general transport fuel market through retail petrol pumps in at least five states does not have to be homologated. For the avoidance of doubt this means the fuel must be available for sale on demand from a roadside bowser outlet at each of at least five separate service stations in each of at least five Australian states or territories.
16.13.4.2 Organisations seeking homologation of fuel must provide MA with:
Two one-litre sealed containers of the fuel for analysis,
Details of the fuels characteristics,
The distribution network,
The price structure,
A homologation fee of $2,500 in the first year and $2,000 per year thereafter.
16.13.4.3 Fuels approved under this General Competition Rule will be published at
www.ma.org.au.
16.13.5 Fuel: Classic Motocross and Classic Dirt Track
Classic Motocross and Classic Dirt Track fuel used for competition must be:
ure methanol with no additives other than lubricating oil, or,
Unleaded fuel that is no more than 100 RON and meets rule 16.13.4.1,
Which contains no additives other than those added at the point of manufacture except for lubricating oil, or,
Be a brand of fuel homologated by MA that is compatible with the “Fuel Quality Standards Act 2000”, or,
Leaded fuel provided that the fuel is purchased from suppliers approved by Environmental Australia.
16.14 ENGINES: GENERAL
16.14.1 Reciprocating Engines
16.14.1.1 Cubic capacity = (D2 x 3.1416 x C x N)
4Where:
D = Bore in centimetres,
C = stroke in centimetres,
N = Number of cylinders.
16.14.2 Engine capacity tolerances
16.14.2.1 The actual engine capacity of a machine competing in a capacity class may not exceed the prescribed capacity for that class by more than 5%.
16.15 MACHINES AND COMPONENTS
16.15.1 Centre and Side Stands
16.15.1.1 Centre and side stands must be removed for all types of competition
16.15.2 Handlebars
16.15.2.1 The ends of the handlebars or twist grip sleeves must be securely plugged so as to present a flush or rounded end.
16.15.2.2 Handlebar levers must:
Have ball ends with a minimum diameter of:
15mm, for levers longer than 76mm,
10mm, for levers shorter than 76mm.
Measure no more than 200mm from the fulcrum to the extremity of the ball.
16.15.2.3 Throttle controls must be self-closing.
16.15.3 Kick Start Levers
16.15.3.1 Kick start levers, other than transverse, must be folding.
16.15.4 Drive Chain Protection
16.15.4.1 Primary drives (the drive connecting engine to clutch) must be guarded so as to prevent direct access to the chain or sprockets with the fingers.
16.15.4.2 The guard must be constructed of:
Metal having a minimum thickness of 1.6mm, which may be mesh or expanded metal provided the openings do not exceed 10mm, or
Fibreglass having a minimum thickness of 3mm.
16.15.4.3 If a plastic, fibreglass or part open chain guard is used, a steel bolt of not less than 10mm diameter, placed outside the bottom rear quadrant of the clutch sprocket. This bolt, if damaged, must be replaced.
16.15.4.4 Projecting sprockets, which are not behind a clutch assembly or directly behind a frame member, must be guarded where the sprocket teeth are further than 30mm from a frame member or swinging arm.
16.15.4.5 A counter shaft sprocket which is more than 30mm from the outside of the swing arm pivot must be covered.
16.15.4.6 Other than CMX/CDT A chain guard made of suitable material must be fitted in a way to prevent trapping between the lower drive chain run and the final drive sprocket at the rear wheel.
16.15.5 Tyres
16.15.5.1 Tyres must comply with the following:
Metal studs, spikes, chain, rope or other non-skid attachments may not be used unless permitted by the relevant Supplementary Regulations.
Paddle or scoop treaded tyres may not be fitted.
16.15.5.2 Valve caps must be used for all competitions.
16.15.6 Mudguards
16.15.6.1 Either a rear mudguard or a seat must be fitted which extends at least 20 degrees to the rear of a vertical line drawn through the rear wheel axle.
16.15.6.2 Mudguards must be made of a material, which is not liable to cause personal injury if deformed.
16.15.7 Acceptable machines and components: Pre 60 Solo
16.15.7.1 Acceptable for the pre 60 class are machines and components built up to and including the 1959 model. The only exception to this General Competition Rule is where the model remains unaltered after this date.
16.15.7.2 Frames of any manufacture are acceptable within the suspension criteria and considerate of the era.
16.15.7.3 Front wheel travel will not exceed 178mm (7 inches) rear wheel travel will be limited to 102mm (4 inches) measured at the axle. Rear shock absorbers will be in the original position using the original mounting points.
16.15.7.4 Plastic and fibreglass is not permitted.
16.15.7.5 Engines and gearboxes must remain externally unchanged.
16.15.7.6 Period carburettors or Amal Mk1 Concentric.
16.15.7.7 Exhaust may be modified but must follow the original lines and meet sound control regulations in GCR 16.12.
16.15.7.8 Folding footrests must be fitted.
16.15.7.9 Countershaft sprocket covers will be fitted.
16.15.8 Acceptable machines and components: Pre 65 Solo
16.15.8.1 Acceptable for the pre 65 class are machines and components built up to and including the 1964 model. The only exception to this rule is where the model remains unaltered after this date.
16.15.8.2 Frames of any manufacture are acceptable within the suspension criteria and considerate of the era.
16.15.8.3 Front wheel travel will not exceed 178mm (7 inches) rear wheel travel will be limited to 102mm (4 inches) measured at the axle.
16.15.8.4 Rear shock absorbers will be in the original position using the original mounting points.
16.15.8.5 Engines and gearboxes must remain externally unchanged.
16.15.8.6 Carburettors of any type pre 75 round slide may be used.
16.15.8.7 Exhaust may be modified but must follow the original lines and meet sound control regulations in GCR 16.12.
16.15.8.8 Folding footrests must be fitted.
16.15.8.9 Countershaft sprocket covers will be fitted.
16.15.9 Acceptable machines and components: Pre 70 Solo
16.15.9.1 Acceptable for the pre 70 class are machines and components built up to and including the 1969 model. The only exception to this rule is where the model remains unaltered after this date.
16.15.9.2 Front wheel travel will not exceed 178mm (7 inches) rear wheel travel will be limited to 102mm (4 inches) measured at the axle. Rear shock absorbers will be in the original position using the original mounting points.
16.15.9.3 Engines and gearboxes must remain externally unchanged.
16.15.9.4 Carburettors; any type of pre 75 round slide may be used.
16.15.9.5 No reed valves permitted.
16.15.9.6 Exhaust may be modified but must follow the original lines and meet sound control regulations in GCR 16.12.
16.15.9.7 Folding footrests must be fitted.
16.15.9.8 Countershaft sprocket covers will be fitted.
16.15.9.9 Yamaha XS1 and XS650 engines are eligible.
16.15.9.10 Acceptable follow on models pre 70
AJS Stormer 250,
Greeves griffon models,
Yamaha AT1, DT1, CT1, RT1 pre reed block.
16.15.10 Acceptable machines and components: Pre 75 Solo
16.15.10.1 Acceptable for the pre 75 class are machines and components built up to and including the 1974 model. The only exception to this rule is where the model remains unaltered after this date.
16.15.10.2 Front wheel travel will not exceed 178mm (7 inches) rear wheel travel will be limited to 102mm (4 inches) measured at the axle. Rear shock absorbers will be in the original position using the original mounting points.
16.15.10.3 Engines and gearboxes must remain externally unchanged.
16.15.10.4 Carburettors; any type of pre 75 round slide may be used.
16.15.10.5 XS1 and XS650 engines are eligible.
16.15.10.6 Exhaust may be modified but must follow the original lines and meet sound control regulations in GCR 16.12.
16.15.10.7 Folding footrests must be fitted.
16.15.10.8 Countershaft sprocket covers will be fitted.
16.15.10.9 Acceptable follow on models pre 75
Honda CR125M1, XL250K1, XL350K1, MT250 and MT125
Yamaha YZ360B, DT250B,
Suzuki TS400 (all).
16.15.11 Acceptable machines and components: Pre 78 Solo
16.15.11.1 Acceptable for the pre 78 classes:
a) Machines and components that are limited to the 1975, 1976, 1977 models alone. The only exception to this rule is where the model remains unaltered after this date.
b) Pre 78 Women’s class: acceptable machines and components are up to and including the 1977 model year. The only exception to this rule is where the model remains unaltered after this date.
16.15.11.2 Front wheel travel will not exceed 229mm (9 inches) rear wheel travel will be limited to 229mm (9 inches) measured at the axle. Rear shock absorbers will be in the original position using the original mounting points.
16.15.11.3 Engines and gearboxes must remain externally unchanged.
16.15.11.4 Carburettors; any type of pre 78 round slide may be used.
16.15.11.5 Exhaust may be modified but must follow the original lines and meet sound control regulations in GCR 16.12.
16.15.11.6 Folding footrests must be fitted.
16.15.11.7 Countershaft sprocket covers will be fitted.
16.15.11.8 Acceptable follow on models pre 78
CZ 125 1978, CZ400 1978,
Montesa VB (must comply to suspension limits),
Yamaha TT500 1978.
16.15.12 Acceptable machines and components: Evolution Class Solo
16.15.12.1 Bikes will be OEM (original equipment manufacturer).
16.15.12.2 Modifications converting later equipment to comply will not be allowed.
16.15.12.3 All components will be of the period the machine was manufactured:
No linkage suspension,
No disk brakes,
Air cooled motors.
16.15.12.4 Carburettors; period flat slide carburettors and any round slide carburettor may be used.
16.15.12.5 Engines and gearboxes must remain externally unchanged.
16.15.12.6 Exhaust may be modified but must follow the original lines and be fitted with an effective muffler.
16.15.12.7 Folding footrests must be fitted.
16.15.12.8 Countershaft sprocket covers will be fitted.
16.15.12.9 The handlebars must be equipped with a protection pad on the cross bar. Handlebars not fitted with a cross bar must be equipped with a protection pad located in the middle of the handlebars covering the handlebar clamps.
16.15.13 Acceptable machines and components: Pre 85 Solo
16.15.13.1 Acceptable for the pre 85 class are machines and components built up to and including the 1984 model. The only exception to this rule is where the model remains unaltered after this date.
16.15.13.2 Carburettors; period flat slide carburettors and any round slide carburettor may be used.
16.15.13.3 Engines and gearboxes must remain externally unchanged.
16.15.13.4 Exhaust may be modified but must follow the original lines and be fitted with an effective muffler.
16.15.13.5 Folding footrests must be fitted.
16.15.13.6 Countershaft sprocket covers will be fitted.
16.15.13.7 The handlebars must be equipped with a protection pad on the cross bar. Handlebars not fitted with a cross bar must be equipped with a protection pad located in the middle of the handlebars covering the handlebar clamps.
16.15.14 Acceptable machines and components: Pre 90 Solo
16.15.14.1 Acceptable for the pre 90 class are machines and components built up to and including the 1989 model. The only exception to this rule is where the model remains unaltered after this date.
16.15.14.2 Carburettors; period flat slide carburettors and any round slide carburettor may be used.
16.15.14.3 Engines and gearboxes must remain externally unchanged.
16.15.14.4 Exhaust may be modified but must follow the original lines and be fitted with an effective muffler.
16.15.14.5 Folding footrests must be fitted.
16.15.14.6 Countershaft sprocket covers will be fitted.
16.15.14.7 The handlebars must be equipped with a protection pad on the cross bar. Handlebars not fitted with a cross bar must be equipped with a protection pad located in the middle of the handlebars covering the handlebar clamps.
16.16 SLIDERS
16.16.1 Slider Frames
16.16.1.1 The frame must:
Have a conventional swing arm rear suspension with twin shock absorbers,
Have a front wheel diameter of 23”,
Have a rear wheel diameter of 19”,
Have rear tyres with a maximum tread pattern depth of 8mm,
Not be fitted with leading-link front forks.
16.16.2 Slider Solo Engines
16.16.2.1 The slider engine must:
Be a single cylinder,
When four stroke be 2- valve push rod operation,
Have a single spark plug,
Be vertical in the chassis,
Be fitted with a round slide carburettor, or
Be a period two stroke compatible with class entered.
16.16.3 Slider Gearbox: Classic Long Track
16.16.3.1 The gearbox must have at least two gears.
16.16.4 Slider Sidecar Frames
16.16.4.1 Conventional type frames as used prior to 31st December 1976 must be used.
16.16.5 Slider Sidecar Engines
16.16.5.1 Engines must have been manufactured before 31st December 1976.
16.17 SIDECARS
16.17.1 All Classes
16.17.1.1 Left -hand and right -hand sidecars may compete against each other in Classic Motocross.
16.17.2 Frames and Parts
16.17.2.1 For the Pre-1975 classes, all performance parts except frames must be manufactured before 31st December 1974 and must comply with the following:
Wheel track measurement, taken between the longitudinal centres of the rear and sidecar wheels must be between 810mm and 1100mm,
The minimum ground clearance must be 175mm unladen,
The maximum lean of the motorcycle at saddle height mustbe 50mm,
The dimensions of the sidecar baseboard in plain view, taken from a line drawn no further rearwards than the lowest point of the front down-tube to the forward most point of the sidecar wheel tyre and terminating no further rearwards than a line drawn at right angles to the machine from the rearmost point of the rear tyre, must be:
At least 760mm long adjacent to the sidecar wheel,
At least 300mm wide with at least 25mm radius to all corners.
There must be no more than 50mm between baseboard and motorcycle and between baseboard and sidecar wheel. The baseboard must be arranged so as not to allow the passenger’s feet to be trapped,
There must be no less than 4 sidecar attachment points,
Stirrup fitting for the passenger’s feet are not permitted,
Handholds:
Must be finished with a loop of at least 100mm,
Must not project beyond a line taken with the outer edge of the sidecar mudguard or bodywork,
Adjacent to the nose section of the sidecar and less than 200mm from the track surface must be at an angle of at least 45° from the horizontal.
The rear end of the rear wheel mudguard must terminate not more than 65° above a horizontal line drawn through the rear wheel axle and be valanced to baseboard level on the inside,
The sidecar mudguard must cover at least 135° of the periphery of the wheel and be valanced to baseboard level on the inside,
No machine may be fitted with scoop or paddle tyres,
Suspension travel must not exceed:
152mm (6”) 178mm (7”) measured at the front axle,
102mm (4”) at the rear axle.
Rear tyre width must not exceed 135mm (5.3”),
Brakes:
Front – single caliper, single disc may be fitted provided they were manufactured before 31st December 1974,
Rear – rear disc brakes may be used provided they were fitted as standard equipment for that particular combination.
Only round-slide carburettors manufactured within the relevant period may be used,
Engine capacity must be up to 1300cc.
16.17.2.2 Pre-1985 is for sidecars constructed with motors manufactured before 31st December 1984.
16.17.2.3 A lanyard operated ignition cut-out switch, operating on the primary circuit, must be fitted to the following with a maximum length of one metre:
DISCIPLINE
MACHINE
Motocross Sidecars
Dirt track Sidecars
16.17.2.4 Pre-1968 will be for sidecars constructed from road going frames and all major components are those commercially available within the period.
16.17.2.5 The following table sets out the machines and components which eligibility scrutineers may use as a guide in determining eligibility. Entrants must prove eligibility of machines not listed below.
MAKE
MODEL(S)
Wasp All up to and including RT2, RT8 and RT14
Hagon All up to 31st December 1974
Yamaha XS 650 all models
Honda Any K series
Norton All 750, 850 to Mk2 only
Westlake All up to 850cc and 31st December 1974
Triumph All up to T150
CCM All BSA B50 based models
The Evolution Class
original version of the rules for the class had no reference to OEM - this was added to prevent the modification of linkage frames to be twin shock after the first year as there we at least 2 bikes like this and more on the way. There was never a time where the simplicity of Evo was confused by a period, cut off date - nothing. The objective was to keep it as simple as possible. To that end and as the person who (along with the members of the CMX Commission at the time) wrote the rules here it is for you once again.
The interpretation of the Evolution class is
If the frame started life as a non linkage frame thats Ok
If the bike has drum brakes and is air cooled then thats Ok too
If the bike is made from components that started their life as those bits and you havent cut them up to fit - then thats Ok too.
So - lets been quite clear.
If that set of forks you use were made to accept drum brakes and they fit your bike - go right ahead and use them, there are no dates, there is no rule that they must have come of anything other than they started their life as drum brake forks and have a drum fitted.
Thats been my ruling at EVERY national championship.
All the stuff written about Evo is ruining the class - its never been a problem until such time as someone decided they saw it differently and a number of inderviduals thought he was right. He isnt.
Evo was always considered loose in terms of the rule book; there are guys out there with modifications that may not make them legal in pre 85 however Evo bikes are legal pre 85 bikes in the vast majority of cases.
Some other points that need correction
The MA board doesnt make the final decision - it takes final advice from the CMX Commission, always has always will.
The CMX Commission takes its advice from the State bodies of motorcycling and acts on it - always has and always will. The CMX Commission dosnt make the rules - you do.
That said, after discussion with the Commission there will be no change to Evolution this year. The above ruling will stay as it has since day 1. You have an opportunity to change that and I suggest that everyone with a view wanting to change the class make it through the correct channels. Eventually the majority of the views received from your various state bodies will be what makes change or keeps things the way they are right now.
Submissions can be made by Clubs, inderviduals or interested groups to MA directly or through your State committee.
The proposed amendments to the GCRs have come from like minded inderviduals such as yourselves and will only be added or subtracted from the GCRs on your advice.
To those with nothing better to do than to stir the pot - take a read of the things that you have contributed and ask if the best interests of the sport are served by what you are doing. If you dont like it change it but dont bitch from the seat of anonymity if your not prepared to contribute constructivly to the sport.
Happy to reply to constructive comment both for against
David Tanner
Chair of the CMX /CDT Commission
Simo
firstly the TLS front brake isnt important, what is important is that it is a drum brake. If the forks its connected to were made for a drum brake and are unmodified them your fine by me. The measurement of the fork, diameter, whats inside of it, if its painted to look like Simmons Forks dosnt matter.
Second - if the 480/500 engine fits into the 250 RA frame without modification to the frame and engine then by the rules as I see them it would be Ok - however - I dont believe it will fit. Dont confuse this with other parts or classes where fitting different engines into different frames has been done for eons.
There has been discussion on this in the past. Its a restrictive part of the GCRs but it limits the issues as seen internationally where you create your dream machine from just about anything. Some machines are branded in name only and have no resemblance to the source machine/s.
third - to take the frame and modify it to have twin shocks (from linkage to twin shock) would make it ineligible - same as a set of forks that started life as a disc front end - ineligible.
It would be really easy to add bits and pieces to the Evo rules to limit this to allow that and so on; its not that easy and the more you add the more to are allowing conjecture. The 3 rule EVO standard was hoped to make it easy to get involved and for the purest there is pre 90, pre 85 etc. Those classes are alike and black and white, EVO isnt and it was deliberatly so.
one other point
note that EVO hit the rule book before pre 85 and pre 90. It used to be the only long travel class. It was never described as a period, or subject to any cut off date but I hear discussion (and State Committee Minutes) that an Evo bike cant be made up from components of a pre 85 legal bike - this is wrong; period. No one was considering pre 85 as a class when Evolution hit the rule book.
im sorry Col but I can't find it anywhere that says I can't use those forks. Even in the interpretation of the rules by the elligability scrutineer 
