Eligibility: Current regulations

GP Originals held it’s first pilot race meeting in 2017 at Oulton Park, hosted by No Limits Racing. Our eligibility regulations were adapted from the Goodwood Members Meeting Hailwood Trophy regs for post classic Grand Prix motorcycles.


Please download the current eligibility document.


Please download the machine registration form.

The regulations have remained focused on period style since their inception. We have been working extremely hard to clarify points in more detail, please always refer to the file in the link on this page as the current document. We are constantly working to confirm timelines for specific parts, for example, four-pot brake calipers. The rules are intentionally very simple and we welcome input from all our riders. In the light of any genuine reason to question a particular rule we have, to date, carried out a questionnaire and the majority opinion taken. There are no individuals making decisions on rules.


The 250 class is expanding rapidly! Most of the 250s we have at GP Originals are very similar in spec with very few eligibility complications. We have received lots of comments however about the vents in the TZ fairings – 1984 250L did not have vents. The 1985 N-model, for example, are almost identical in appearance, widely available and they accommodate a slightly wider radiator. We allow the use of N fairings but we ask that you blank off or remove the vent. Many of our riders have been doing this already and you will be asked to remove the vent on the day if you have not already blanked them off. S-fairings are not permitted.

The blanks are extremely easy to make yourself to a high standard of finish and cost very little money. Bay Plastics offer a 1mm high-impact polystyrene sheet that can be cut with a scalpel and finished off with some wet and dry in about 10 minutes and will cost you about £5 each!

350 bodywork should be of the kind that could be purchased in 1981 or before. The original TZ350 fairing is the preferred choice. You may use a Maxton, Don Vesco or Bimota Ringhini style fairing but please do not put later 250 fairings on your 350. Please visit Ragged Edge Racing.

The ACU has now included post-classic machines in their rules about brake lever guards. We have a special price on PDQ Precision guards for GP Originals members. The guards are also mandatory for all track days on any machine. We have no further information regarding rain lights, therefore they are currently not required for our bikes.


Materials should reflect what was used in the 1970s and early 80s. Titanium and carbon fibre were in existence and were used. However, even factory machines did not typically use extensive titanium parts. Titanium exhaust systems are not permitted and have not been historically allowed in other established Post-Classic Series. A cheaper and more competitive answer to weight-saving is to go on a DIET! It is your responsibility to know the ACU rules regarding construction materials across all classes of motorcycle racing.

The use of titanium in the construction of the frame, the front forks, the handlebars, the swinging arm spindles and the wheel spindles is forbidden. For wheel spindles, the use of light alloy is also forbidden.

ACU Handbook 2020. 14.20 Construction

We ask that riders consider the concept of GP Originals with every new part they buy – the Series is more competitive and more accessible the more simple we all keep it.

Period racing

The machine requirements are based on what was commonly being raced at international level during the period for each class:

  • Up to 31st December 1981 for 350cc machines
  • Up to 31st December 1984 for 250cc machines

Please read the Eligibility document regarding digital ignitions. Additional digital technology is not part of the period concept, lap-timers and digital dashboards are not permitted during the race day. A discreet separate digital temperature gauge is the only exception as there does not seem to be a consistently reliable alternative to the original gauge. This may change subject to a reliable analogue alternative becoming available. An example of an allowable digital temp gauge can be found here.

We are open to new evidence should it be presented by riders which may allow a machine part to be made eligible or ineligible. However, we also assess the impact any new information could have on competitiveness. If a modification is likely to create a large divide between the classes or throughout field then it may be disallowed.

Kit parts that were used solely by professional factory riders may be permitted by special agreement only. It must be the original, authenticated item only. Reproductions are not permitted.

Buying replica parts

We all know that classic racing presents different challenges to modern classes. Most of our members are always on the hunt for spares as and when they come up. We urge riders to think about the focus of this Series when buying replacement or replica parts. Please do not replace good originals with modern replicas unless 100% necessary.

Tuning, upgrading and specials

These are Grand Prix machines and we understand that no-one ever raced them out of the box. Modifications and upgrades such as wheels, brakes and suspension were typically the first items to be changed back then as it is today.

There are a wealth of very good replica parts that fit the bill and you are welcome to use them. However, it is the rider’s responsibility to purchase products suitable for period racing with GP Originals. Please be aware we are not following in the footsteps of any other Championships and what may be commonplace elsewhere may not be suitable for GP Originals.

Engine tuning inside is free but you cannot alter the external appearance of your major engine components. Please contact us directly with your questions and browse the articles on this website for more information.

One-off specials using unrelated parts are not automatically eligible. These projects may qualify for consideration as a guest ride should the machine be deemed of special interest, guest rides are agreed at the discretion of the GP Originals team only. Genuine, original concept machines of the period that can be verified with date-proven evidence are welcome. Please get in touch with your questions.

Tony Perkin and Derek Skinner GP Originals masters© Alex James