After suffering its worse weekend of the MotoGP season in Barcelona, Yamaha brought new chassis parts for title leader Maverick Vinales and team-mate Valentino Rossi to try at the post-race test.

The developments were declared a success in the hot and slippery Catalunya conditions, prompting the best combination tested to be provided for this weekend's Dutch TT at Assen. spoke to Vinales' Rider Performance Analyst Wilco Zeelenberg over a coffee in the Movistar Yamaha hospitality on Friday morning to find out more about the new parts...
Wilco, the good news for you is that Maverick is still leading the championship after Barcelona...

Wilco Zeelenberg:
"Yes, but we have to face the facts, because we were leading by 27 points after Mugello so finishing tenth in Barcelona was quite a hard feeling, even if we are still leading the championship. Normally these boys, the ones that are able to win races, will not finish tenth unless it is raining or there are strange circumstances."
What is the explanation for what happened in Barcelona?

Wilco Zeelenberg:
"Well the grip level and the window of the tyres is very narrow and it looks like, for our current bike at the moment, if it's a little bit too low on grip level, we just drop off the edge and miss all competitiveness. We lose more grip than the rest in those conditions, that's basically what we believe."
Is it to do with temperature?

Wilco Zeelenberg:
"If the track has low grip and the temperature is high - plus also the Moto2 race being in front of us doesn't help, because that doesn't bring grip. Anyway, it's the same for everybody, but it looks like a combination of low grip level, high temperature and Moto2, the grip level drops a lot, the lap times are slow for everybody, but we are more slow.

"That was proved also on the Monday when the grip level came back, because the Moto2 guys didn't ride. The temperature was again very high, but still we were able to do decent lap times.

"Anyway we need to work on it because finally we have to face the facts; we were the only one that were not able to be competitive. Yamaha built a new chassis, both riders tested it."
Rossi seemed to like the chassis he tried on Monday at the official test, which Maverick was then going to try on the Tuesday...

Wilco Zeelenberg:
"There were many combinations with small differences. But the new one on the Tuesday was clearly [better]. Anyway, we tried many things and with everything Maverick was faster than on Sunday! Even with the Sunday bike.

"So it's difficult to predict here, because everything was tested at Barcelona and now we are here at a new track. So we have to be careful not to lose our strength, which is when we have grip. You can easily make a decision when the grip level is low, but maybe you come here where the grip is okay and maybe the package from Barcelona is not so bad.

"In Barcelona we got beaten by both Tech 3 riders, which is sensitive. But we beat them as soon as there is grip. Their bike is not better everywhere, but in low grip it is a bit better."
Is it because their bike, the 2016 bike, is 'softer'?

Wilco Zeelenberg:
"The stiffness is different, but it is in many areas. So it's difficult to say if they are softer or harder [overall] because the stiffness changes in different areas of the chassis."
Is the new chassis in-between the 2017 and 2016 frames?

Wilco Zeelenberg:
"We are trying to combine all the positive things from both bikes, which is not easy because the advantage of this year's chassis is we have a lot of grip at the end of the races. Which is the are we struggled with last year. From the outside both chassis look the same, but the stiffness is different."

By Peter McLaren

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