Valentino Rossi's finger-operated rear brake
Peter Bom: To be able to apply the rear brake deep into right-hand turns (where space to operate the foot pedal runs out), some riders are experimenting with the idea of operating the brake with one or two fingers of the left hand. Valentino Rossi is one of those riders, trying the system at the Monday test after the Barcelona race. The current state of technology in MotoGP, and especially the type of tires being used, makes using the rear brake crucial at various points around a circuit. The rear brake is used particularly to help the bike turn mid-corner. The question is now whether we will see more riders use finger brakes, and at more points in the track.
Spirit level on Dani Pedrosa's rear wheel
Peter Bom: A spirit level in the rear wheel, at a right angle to the direction of travel. Never seen one before or heard of one being used outside of endurance racing, where the wheel stand is asymmetric to be able to stand the bike up horizontally in a pit lane which is not horizontal. I would take an educated guess that the MotoGP teams use a spirit level to ensure the rear wheel is horizontal to be able to zero out the accelerometer sensors, especially the lateral sensor.
Carbon swingarm on Pol Espargaro’s KTM RC16
Peter Bom: In terms of shape, this swingarm is identical to the aluminum version. The advantage is primarily weight, of course, but also that you can modify stiffness in multiple directions quite easily. You do that simply by laminating in a different direction, by placing the layers of carbon at different angles. We can expect to see KTM bring a lot more carbon swingarms now. The initial investment is very high for the first version; making a mold to lay the carbon up in is expensive. But because you can create swingarms with different stiffnesses by changing the way the carbon is laid, it is much less expensive in the long term.
Carbon swingarm on Pol Espargaro's KTM RC16
Peter Bom: Interesting to note that KTM's first attempt at a carbon swingarm gave an immediate improvement. At Aprilia, for example, we have seen a number of different prototype carbon swingarms, but the riders have so far always reverted to the aluminum items. Apart from the weight – Pol Espargaro says the bike is still around 5kg too heavy – carbon fiber has one major advantage as a material for a swingarm: you can modify stiffness in both force and direction just by changing layering, using the same mold. Producing a mold can be expensive, but because it can be reused to produce different swingarms, it is still an attractive proposition.
Load cell on the Ducati GP19, used for the quickshifter
Peter Bom: The red cylinder is a so-called load cell. It measures extremely precisely exactly how much pressure (in compression or tension) is being put through it. This information is used by the ECU to make changing gear up or down easier, by cutting the ignition once the load reaches a preset value as the rider presses the gear lever down or up. The sensors used in MotoGP have to be extremely precise, and most importantly, they have to provide stable output even when exposed to severe vibration and high temperatures. The bolt thread on a sensor like this broke on Fabio Quartararo's bike at Jerez, leaving him unable to change gear.
The carbon fiber covered chassis on the Honda RC213V test bike used by Stefan Bradl
David Emmett: This was the talk of the Jerez weekend. Stefan Bradl had two bikes at his disposal, this one, featuring a different chassis design (see the scalloped section in the center of the main beam), and the standard aluminum chassis. After Honda spent the winter working on the engine of the RC213V, they are now diverting their attention to the chassis. Riders have complained of a lack of front end feel from the 2019 frame, and this seems to be an experiment to create a bit more feel, especially on corner entry and mid corner. Marc Márquez tested this chassis at Jerez on Monday, and set his fastest time on the bike.
Another view of the carbon fiber covered chassis on Bradl's RC213V
David Emmett: A view of the full frame. The welds appear to be in the same place as the standard frame, but the top beams are different.