B2B sidecar

Tamiya released only one model equipped with the B2B chassis and obviously kept the name B2B Racing Sidecar: model number 58017, which went on sale in 1979 and was available on the market until 1982. This is the first time for Tamiya to release a chassis on the market with only one model.
It is a unique three-wheeled model that only goes with the six-wheeled Tyrrell P34. It is not known what the sales volume of this unique product was. It is difficult to find spare parts developed exclusively for this model, while it is easier to find those that are in common with other models.

In 1949, the first sidecar world championship was held. In the early years, the vehicle was a pair of the road model consisting of a motorbike with a sidecar attached. In the beginning, these vehicles required a special driving technique due to the asymmetrical shape of the vehicle. Riding involves the rider and passenger moving in unison to counteract the centrifugal force when cornering. The early 1950s saw the first evolution of these vehicles, which were built around a single-beam frame comprising motorbike and sidecar. The sidecar thus constructed allows a different riding position with the rider almost kneeling, which reduces the frontal section. In the early 70’s there was a shift to platform chassis in which the position of the tank was between the driver and the bodywork to bring them closer to the centre of gravity, the front wheel was covered by an aerodynamic bell that improved performance at high speed, the driving wheels became the two rear ones, to reduce the frontal section the wheels progressively decreased in diameter, the first steering wheels appeared and the sidecars became more and more similar to three-wheeled cars carrying a passenger that lost its function of counterbalancing in bends. Tamiya drew inspiration from these models to create its B2B, an acronym that corresponds to the category of the most extreme prototypes.
There are several advertisements that Tamiya or the various importers around the world have published in trade magazines, in the image below is an example.

The sidecar chassis is derived directly from the F1 and F1 CS chassis with which it shares many parts. These are the main features:

– the central frame is Fiber Reinforced Polymers (FRP) material highlighted in green in the picture,
– a metal plate that is an evolution of the one used on the F1 and F1 CS chassis. Its footprint is modified to fit the asymmetrical shape of the sidecar highlighted in red in the picture,

– the 4 service stylus batteries are cantilevered at the rear,
– the bodywork is in styrene and retains the same attachment system to the bodywork as seen on the F1 and F1 CS with 4 metal pins. The scale for this model is 1/8th, the overall dimensions of the project are limited by the fact that Tamiya started designing the sidecar from the F1 and F1 CS chassis,
– no shock absorber system, the task of absorbing bumps is left to the rubber front wheel and the foam rear ones. The chassis is very reactive and understeer, to improve driveability Tamiya plans to install a rubber wheel at the front to reduce grip and sponge tyres at the rear to increase grip; this modification makes the model less understeer and improves driveability.
– RS380motor is available as an accessory to install RS540 part number SP-1023
– in common with the F1 chassis it shares the motor carrier + transmission system in Zama code number SP-1086, rear axle code number SP-1009, double-sided pinion gear 10 – 12 teeth code number SP-1012, the differential – fixed gear code number SP-1077, wheel locks code number SP-1091, rear wire bumper. the rear wheels
– steering system and front bumper are unique to this model,

– the body of the driver is to be constructed by joining the helmet, torso and two arms.


The sidercar chassis has not evolved and has remained a unique model in Tamiya’s production range, to date (2023) there have been no re-reliase of the model.

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