Moto3 explained
More fascinating insight from Laverty reveals how the Moto3 men would run rings around the MotoGP top men in the corners
Moto3 requires precision, bravery and a lot of luck. Sometimes the best race strategy isn’t rewarded with the deserved result as slipstream can affect the outcome much more than with the bigger categories. Races are typically fought in a frantic multi-bike battle with up to 20 riders and sometimes more forming the lead group. A minimum rider/bike weight limit of 152kg levels the advantage of the smaller riders, but smaller is still better for aerodynamics and cutting drag plays a huge role.
1 Riding style
The lap times are achieved by late braking and carrying extreme mid-corner speeds. With so little bhp in comparison to the bigger categories the riders need to keep their momentum through the corners to maintain as much speed as possible. On the Qatar circuit through the tricky triple rights, turns 12-14 the Moto3 guys carry between 15 and 20km/h more speed at the apex than the MotoGP and Moto2 bikes. The riders get wheelspin on corners where they spend a long time on the side of the tyre, but the style is more wheels in line exiting the corner, immediately trying to get back into the tuck position to assist in aerodynamics.
2 Chassis tech
Honda run a twin-spar aluminium chassis while KTM have their steel tubular trellis, both use aluminium swingarms. The chassis are rigid, the tyres are narrow and tyre pressures are a little higher so the contact patch is a lot less than the bigger machines. To be fast in Moto3 you need to be brave, the riders must trust that the grip is there rather than the intuition you have with the heavier machine deflecting the tyres to provide that feeling. The rigidity of the package allows them to change direction with incredible speed, they still fight with the gyroscopic effect of all the rotating mass but the bikes are incredibly reactive to rider input.
3 Keep it spinning
The single-cylinder fourstroke engines put out between 62 and 64bhp, both KTM and Honda are estimated to produce similar figures although the KTM reportedly has more torque. Torque is around 22-26lb.ft so it’s crucial to keep the engines buzzing, the riders don’t have an abundance of torque to rescue a missed apex without costing them lap time.
The skills involved in getting the maximum from these engines require a perfect gearbox ratio for every corner to have the engine in the perfect RPM range to maximise acceleration out of the corner which in turn has a big effect on top speed.
4 Gearbox and gearing
One of the most critical points in setting up a Moto3 machine is getting the gearbox ratios and final drive sprockets correct. The teams have two internal ratio options per gear and three primary gear options. Mark Woodage, crew chief to John McPhee tells us that for the race they may need to gear their top speed up around 8km to handle the multibike slip stream. They must always account for changes in wind direction as that can be the difference in being able to make an overtake at the end of the straight in a tailwind or not being able to pull max revs if they get a headwind.
5 Electronics
Moto3 also has a spec ECU, differing from the bigger classes with a Dell’Orto unit. Teams manage the fuel injection and ignition maps to optimise bhp, they also work to the finest margins on shifting gears, as each cut of the quickshift costs time on these little bikes. Corner entry is crucial, the four-stroke engine has a decent amount of negative torque to contend with, Honda utilise a stepper motor to open the butterflies slightly to manage the rear wheel lock on entry, KTM have an air bleed valve for the same purpose. Engineers can fine tune these to the rider’s request, they usually like some drag to assist stopping performance.