Small wonders

Motogp bikes are vast battleaxes compared with Moto3’s scalpels. Here’s what makes them fast…

As usual, this season’s Moto3 has provided outrageously close racing and brilliant spectatoring. At the Jerez GP, for example, Ryusei Yamanaka finished just 1.5 seconds behind the winner… and came 10th. When the racing is that tight, every change to the machine can have a dramatic impact, but what actually makes a difference? We ask John Mcphee’s Petronas Sprinta Racing crew chief Daniel Bonmati to explain all…

Remind us of the Moto3 rules…

All the bikes are 250cc singles with a set rev limit and bore. The engines are sealed so we can’t tune them – they make about 60bhp, though we don’t know exactly because Honda [the team’s engine supplier] don’t tell us and we’re not allowed to dyno them. The bikes must not weigh less than 84kg and not less than 152kg including rider.

So how much difference can you make?

In terms of the engine, the main parameters we can adjust are fuelling and engine braking. How we adjust the engine braking can have a big effect in races [because of the knock-on effect it has on corner speed]. You can adjust other things too like the traction control, but in Moto3 that’s not as important because the riders can open the throttle fully at maximum lean [depending on the track they can spend up to 60 percent of the time at full throttle].

So you’re tuning the engine using the electronics?

Yes. Every time we use a new engine [each team is allowed six per year], there will be small differences so we need to tune it with the electronics. Depending on the weather conditions we alter the ignition as well – so when it is wet we give the throttle a softer response.

What are the electronic differences between Moto2 and Motogp?

There is no inertial measurement unit in Moto3, which limits what you can adjust. In Motogp and Moto2 it’s used to adjust traction control, anti-wheelie and engine braking. Also, there is no ride-by-wire throttle in Moto3, so that’s another restriction. But in qualifying you may be 0.2 seconds from the pole time and you are in 12th position, so even small changes can be very important.