Future of three-wheelers at the Tourist Trophy secured with new regulations

The training accident involving brothers Ryan and Callum Crowe, in which their sidecar overturned after a jump, led the organisers to decide this year not to hold the two races for safety reasons. Before allowing the three-wheelers back onto the Snaefell Mountain Course, the cause of the accident was to be investigated in detail and the technical regulations amended in light of the findings.

Pessimists had already predicted the end of the class, but riders and fans can now breathe a sigh of relief. As the organisers have now announced, the sidecars will once again be part of the Tourist Trophy, at least from 2027 to 2029. The plans envisage two sidecar races being included on the programme once again. In the first year, the races will be run over two laps; thereafter, the race distance will be reviewed in light of experience with the new package.

Engines from the sportsbike class and a standardised ECU

At the heart of the changes is the move away from 600cc four-cylinder engines towards a new engine concept derived from production models, which is tailored to the technical regulations for British sports motorbikes. The new regulations stipulate engines derived from modern mid-range production bikes, including the Yamaha R7, the Aprilia RS660 and the Kawasaki Ninja 650, as well as other engines that comply with the specified regulations.

This reflects both a desire to better control the performance of the sidecars and a need to take account of changes in the market for production motorbikes, as the traditional 600cc four-cylinder supersport platform is increasingly reaching its limits in terms of current production machines and manufacturers’ development. Rather than simply restricting the existing formula, the new direction aims to offer participants a more sustainable engine platform that can be further developed in the coming years.

The control electronics will also be switched to the Mectronik ECU, which creates a standardised electronics framework and gives the Technical Director of the Tourist Trophy greater scope to manage and monitor the class’s performance spectrum. The new regulations will also introduce a ‘Balance of Performance’ approach, which aims to achieve greater parity in performance between the permitted engines.

Under the current regulations, substantial investment in engine development can give the best-funded teams a significant performance advantage. The new regulations are intended to limit this possibility and create a more strictly controlled and potentially more competitive field, in which raw engine power is much more evenly matched.

Significant restrictions on aerodynamics

Existing sidecar chassis designs will remain permitted, meaning participants will not have to switch to a standardised chassis design. However, new requirements will strengthen technical safety standards regarding design, identification, modification, repair and inspection. The regulations governing the bodywork will also be revised, with clearer limits introduced for the underbody, wheel arches and other aerodynamic elements. Separate wings, ailerons, fins and spoilers will be banned.

The aim is to limit aerodynamic development whilst improving structural integrity, technical inspection and access for medical and rescue personnel. Further measures relating to weight, fluid retention, engine safety and technical compliance will form part of the final regulations.

The 2027 format has been deliberately designed as a starting point for the new sidecar formula, rather than its final form. The regulations for qualifying and the races will remain in place, whilst the two shorter races in the first year of the revised machines and regulations will offer a more conservative race format.

The entry requirements and qualification standards for competitors will also be tightened, with greater emphasis placed on recent competitive experience and physical fitness. The performance of the new formula will then be assessed on the basis of technical data, incident records, rider feedback, as well as entry numbers and experience gained from qualifying and the races, before decisions are taken on its further development for 2028 and 2029.