MotoMatters.com | Kropotkin Thinks

Testing after a race is always tricky affair. There is a weekend's worth of Michelin rubber on the track, and then another 24 riders spend all day laying down yet more rubber - a grand total of 1706 between all of them, for a total distance of 7545.638 kilometers. By the end of the day, the conditions are just not going to get much better.

That means you have to treat the times with a touch of caution, and as a MotoGP rider and team, be careful how you interpret what you are feeling. "We know that every time the tests are a bit unrealistic for the grip level," fastest rider Fabio Di Giannantonio told us at the end of the day at Jerez. "For this reason, the focus was to understand what a part does, let's say. Just about the comments, not about the lap time or whatever. Just to understand the characteristic of that part and whether to use it or not at the next few rounds."

Bearing all that in mind, there is not a great deal you can read into the times. There were seven Ducatis in the top ten, with Di Giannantonio ending the day fastest, Franco Morbidelli, Pecco Bagnaia, and Marc Marquez from third to fifth, and Alex Marquez, Enea Bastianini, and Jorge Martin from eighth to tenth. Maverick Viñales was second quickest on the Aprilia RS-GP, while teammate Aleix Espargaro was seventh. And Brad Binder was sixth quickest on the Red Bull KTM, though admittedly, Pedro Acosta was eleventh with the exact same time as Jorge Martin.

Who was working on what? The real interest was in the garages of the Japanese factories. In something of a reversal of fortunes (see also their results), Honda and Yamaha riders are more open about what they have been testing than the Ducati and Aprilia riders. Post-test debriefs for factory Aprilia riders now sound suspiciously like this 1962 BBC radio interview with Dr Hastings Banda, who would become president of Malawi.

Yamaha

There was also a lot happening visually in the Yamaha and Honda garages. Which turned out to the detriment of the Yamaha riders. Yamaha's lead aerodynamicist - poached from Ducati - brought a strikingly different fairing to the Jerez MotoGP test. That raised the hopes of both Fabio Quartararo and Alex Rins, leaving them all the more disappointed when the new aero didn't make all that much difference.

"A different feeling," was how Quartararo summed it up. "Not worse, not better for me at the moment. But sometimes there is in acceleration, some things that that I cannot feel, but on the data you can see. But on my first feeling it was neutral, neutral feeling."

Alex Rins spent a lot more time with the new fairing, and was slightly more positive. "I did many laps on the new fairing, I did many comparisons, many back to backs and honestly I was expecting more difference, more performance. I mean, when you look at the bike with this new fairing, it looks spectacular."

There was a difference, he insisted, but not as much as the looks had led him to expect. "The numbers on the wind tunnel are so different, very different. But on track, I was expecting a little bit more. I was able to ride in a better way with this new fairing, but it was only tenths. One tenth, one tenth and a half. But it's a step forward that we did compared to the base setup."

Yamaha also had a new chassis, which was supposed to help with turning. Quartararo was pleased that he could feel a much bigger difference than he usually felt when he tested a new frame, but the difference in feeling and performance was small. Quartararo could feel a small improvement on corner entry, but Alex Rins felt the difference was negligible.

Yamaha also worked on electronics, to try to smooth the engine out - the aggressive character of the engine is the biggest problem for Yamaha - and there was progress. Work went on traction control and engine braking to make the bike smoother. "The others are smoother!" Rins insisted when I said the bike sounded smooth.

Honda

HRC also had something striking to test, though it was a bike we had seen before in the garage of wildcard and Honda test rider Stefan Bradl all weekend. A bike with a completely new aero package, with the fairing extending much further back, a totally different wing package, different side pods, downwash ducts, tail wing, and a completely new frame.

On the Monday, Takaaki Nakagami and Johann Zarco both got to test the new bike, Repsol Honda riders Joan Mir and Luca Marini having previously tried the bike at a test in Barcelona. The good news was that all four Honda riders agreed on their feedback about the bike. The bad news was that it made no difference, and did nothing to fix the issues which are currently plaguing the Honda RC213V.

The slightly better news, however, is that Honda did bring something else that helped. Though Honda riders remained vague, they admitted that it was "a different concept" that involved engine parts. "Well, we are testing different stuff on the engine…not an engine but different things to understand the direction," Joan Mir admitted when pressed.

What the modified engine did was helped the bike turn, one of the biggest weaknesses of the current iteration of the RC213V. "We are trying to find the turning that we are missing," Mir said. "That is the weakest point tat we have, and with that thing we can understand that we have more turning. It’s true that we lose a lot in other areas but there is a lot of margin to improve and that gives us a direction."

Both Johann Zarco and Takaaki Nakagami agreed with Mir's assessment. The revised engine helped the Honda turn, which is the biggest issue the bike has. Nakagami was pleased with the improvement through the fast corners, places like Turn 11 and 12, as well as Turn 7. Those had always been his strong point, he said, and with the current generation of the Honda, that strong point had disappeared.

What could Honda have changed on the engine to help the bike turn? The elements of engine design which affect turning are crank rotation direction, crankshaft weight (which can be modified by the use of external flywheels), and the location of the crankshaft in relation to the bike's center of mass and its geometry. MotoGP bikes have had engines which run backwards for donkey's years, which leaves either crankshaft weight or geometry. Or both. Take your pick.

KTM

The Austrian factory had a new aero package to test, which will go into the development cycle to produce something usable in the second half of the season. It will likely be rolled out again at the Mugello test in a month's time for a second attempt.

The bottom half of that new fairing flew off of one of the bikes during testing. This highlights one of the problems with the current generation of aerodynamics packages. Fairings are becoming so complex that designers are struggling to find the ideal place to put the Dzus fasteners which hold the fairing in place. That is making it easier and easier for mechanics to make a mistake tightening those fasteners, and creating an issue like Jerez.

You might say that it is the responsibility of mechanics to make sure that the bike is perfect every time it rolls out of the garage. Anyone who has watched a MotoGP team work on a bike is astounded by the accuracy, speed, and coordination with which they take bikes apart and put them together again. Mistakes can always happen, but the objective of a bike designer and industrial engineer is to foresee such problems, and try to design the bike in such a way as to minimize the possibility of problems arising.

For the rest, Brad Binder has been working on getting confidence in the front end, but for both Binder and Jack Miller, their main issue has been with a vibration in the rear wheel. Standing track side, that vibration is visible, the rear of the bike jumping and pumping on the exit of fast corners. It is the KTMs which seem to suffer it worst, with other factories having only a little, or in some cases not at all.

Ironically, the additional grip made it harder to try to fix the chatter, as that vibration was proving much harder to produce. Normally, more grip means more chatter, but this particular form of vibration seems to get worse as the grip drops. "Looks like that the less grip we have, the more vibration we have," Ducati's Pecco Bagnaia said. "I think Barcelona is a track where we can have some issues with vibration."

Ducati

Ducati didn't have anything earth-shattering to test. In part because Pecco Bagnaia had tested it already during the race weekend, in a bid to get his 2024 season back on track. "We have to say that most of the things we had to test today, we tested already on Friday. So today was just a day to reanalyze everything and retest. And everything we tried was working well," Bagnaia said. So well that he won a scintillating race the day before.

There were small things to test for all of the Ducati riders, but for the most part, they were focusing on setup and riding style. For Franco Morbidelli, it was a chance to do a lot of laps - 82, the fourth highest total behind Johann Zarco, Fabio Quartararo, and Takaaki Nakagami - and start to catch up with the testing he missed during the preseason, after crashing a Ducati Panigale at Portimão and suffering a concussion.

For Marc Marquez, it was also a chance to start to work on the setup of the bike. "At the Malaysia and Qatar tests I was still adapting my riding style to the bike, and I had some doubts about some comments, and I said to them, ‘maybe yes, maybe no’. But today we made a big step in that way, super precise in the comments and this helps the technicians to know better my riding style," the Gresini Ducati rider said.

This allowed him to take the next step forward. "So then was the time to say to them, ‘now it's time to give me with the setup, not with new things, but with the setup of the bike, my riding style’. Help me in my weak points and try to not go on the strong points only. Also to try to help me in the weak points."

Aprilia

In the factory Aprilia team, both Maverick Viñales and Aleix Espargaro were working on ergonomics, a time-consuming process but one which can reap major benefits. Both riders were looking to improve their position on the bike to help with braking. It is ironic that factories spend millions of euros on aerodynamics, electronics, finite element analysis and computer simulations, but the biggest factor affecting bike performance remains the riders and their body position. The ability to move the 65 to 90 kg a rider in full protective gear weighs around a massive amount has an outsized effect on the bike's behavior. Much to the chagrin of bike designers.

Aprilia was also looking for improvements with their starts, something Maverick Viñales has consistently asked for. That wasn't always possible, MotoGP project lead Romano Albesiano admitted. "What the riders are asking is actually… to be better than the others! So when the qualifying is not super good, like it was here, to have the opportunity to recover."

That was unrealistic, given the current level of MotoGP, Albesiano insisted. "But, you know, everybody's pushing a lot. So even if we keep improving, we are doing unbelievable numbers in terms of starting time, but everybody's doing unbelievable job."

Raul Fernandez also got a chance to ride the 2024 Aprilia RS-GP - the 2023 engine is almost identical to the 2024 engine, so the new bike consists mostly of aero package, and some chassis elements - and came away eager to make the switch, but aware of the limitations making a switch would bring. "I think the bike has a little bit more potential, but it's not easy bike, I can tell you. We need time to know the bike, we need time to see how is the performance on the bike," the Trackhouse Aprilia rider said.

Fernandez will have to wait a few races before he is finally able to make the switch. Until then, he will have to make do.

Full results of the test can be found on this page.

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