Competition regulations - how do you know what is legal?

[Big Bird]

Greetings all,

I have an utter newbie question here.  I'm building up a 1980 RM125, and longer term another bike for pre-70 class.  Where does one go to find out exactly what is legal for the classes I will enter these bikes in? 

I have looked through the MA GCR's, which are a good starting point - but they are not very specific.  For example, there is much argument here about RM125 swingarms for pre 78 class.  Obviously someone, sometime has made or will make a decision regarding what is legal for this bike.  Where is this recorded?  Where can a bike builder refer to in order to know exactly what is legal or not for the particular bike they are building?

In my own case, what got me thinking was that I'm looking for a pair of dampers for my RM and started wondering what exactly would be legal.  I note there are dampers with no external adjusters for damping, there are others that have basic compression and rebound damping adjustment, and others again that have high and low speed damping both compression and rebound.  How does one know which ones are legal?  I'd hate to buy top of the range and not be allowed to use them, but I'd also hate to buy low-spec and then find out later I could have raced with something better. 

The nature of my question is not specifically about RM dampers or swingarms, so I hope this doesn't end up in detail discussion on these topics.  Rather, I'm just curious as to where I should go for advice on what components are legal for a particular bike.

Cheers, and any advice would be most appreciated,

Geoff

[Iain Cameron]

Geoff the only set of rules are the MA ones . What is legal or not discussed on here has no merit it is only the MA rules that stand .

[GMC]

The short version…
Pre 78 must be bikes that are 77 models or earlier. Etc etc.
The debate about the swingarm is because some guys want to use 78 style swingarms as optional parts.

Evo is for bikes that have drum brakes, non linkage suspension and are aircooled.
Major parts can be used from other bikes so long as the bikes conform to the same rules.


You can use any…
Internal fork mods
Rear shocks
Ignition
Exhaust
Any internal engine mods that can’t be seen
Handlebars



Not written in the rule book but should be to clarify for people better.
Major components that classify a bike into a class are considered to be…
Frame
Swingarm
Forks and triples
Engine crank cases, cylinder & head
Front and rear hubs

[Sorelegs11]

MOMS 18.5.5.1

Acceptable for the pre 78 classes are 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.

[Ted]

The short version…
Pre 78 must be bikes that are 77 models or earlier. Etc etc.
The debate about the swingarm is because some guys want to use 78 style swingarms as optional parts.

Evo is for bikes that have drum brakes, non linkage suspension and are aircooled.
Major parts can be used from other bikes so long as the bikes conform to the same rules.


You can use any…
Internal fork mods
Rear shocks
Ignition
Exhaust
Any internal engine mods that can’t be seen
Handlebars



Not written in the rule book but should be to clarify for people better.
Major components that classify a bike into a class are considered to be…
Frame
Swingarm
Forks and triples
Engine crank cases, cylinder & head
Front and rear hubs

The debate about the swingarm is not about some guys wanting to use 1978 style arms as an option , it is about guys wanting to use swingarms made available to the public in 1976 and were on 125 Suzuki works bikes in 1975.

[GMC]

I did say it was the short version.

[3858]

Halve your age and add seven... 

[Davey Crocket]

Ted, the "works" bikes swingarms where totally different to the "B" alloy arm.

[Rookie#1]

Halve your age and add seven...