Sepang Test Notes: How Much Does Top Speed Matter?

One of the most keenly watched figures at the Sepang MotoGP test is the top speed of the Yamahas. That was the reason that Yamaha couldn't compete at a number of circuits. Maverick Viñales and Fabio Quartararo found themselves coming up short against Marc Marquez in a number of races, Marquez using the speed of the Honda to drive past the Yamahas, or stay with them, at crucial points, negating the superior handling of the Yamaha.

So all eyes in Sepang are on the top speed figures of the Yamaha. Have they improved enough to be competitive?

But how important is top speed really? Even Gigi Dall'Igna, MotoGP's unofficial king of horsepower, is aware of the limits power can bring. It is an advantage, but only as an added extra. "It’s important to have the power in the pocket," Dall'Igna said at the launch of Ducati's 2020 MotoGP project. "When you have it in the pocket you can make the decision if you want to use it or not. If you don’t have the horsepower in the pocket then you cannot use that."

Horsepower is very much an added extra, however. Speed in terms of lap times were what counted, and extra horsepower was only useful if you could already do the lap times. "I think to manage the race where you have the speed, for sure it’s important to have some horsepower more than your competitors. For sure. But if you don’t have the speed it’s not so important to have this horsepower. So the priority is to have the speed first of all. After that, if you don’t have the horsepower then you have to fight a lot more to win the race."

The second day of the Sepang test illustrates this principle, that top speed might count, but not for that much. As of 1pm on Saturday, Jack Miller topped the timesheets on the Pramac Ducati, ahead of Joan Mir on the Suzuki. Jack Miller also topped the speed charts - hardly a surprise: with Sepang's long straights, four of the five highest speeds have been set by riders on Ducatis.

Miller is head and shoulders above the rest, though. His speed measured through the speed traps was a remarkable 338.5 km/h. That is 6 km/h quicker that Andrea Dovizioso recorded during qualifying. Compared to Joan Mir, second on the lap time charts, Miller's advantage is over 11 km/h.

How much does that give you in lap time? Miller's fastest lap at 1pm was 1'58.641. Mir's best lap on the Suzuki GSX-RR was 1'58.731. The difference between those two lap times is just 0.09 seconds. How much of that top speed advantage translates into lap time? Not much, really, as the table below shows:

  km/h lap
Jack Miller 338.5 1:58.641
Joan Mir 327.2 1:58.731
Difference 3.45% 0.08%

Jack Miller's top speed is 3.45% faster than Joan Mir's. But the Pramac Ducati rider is lapping just 0.08% faster than the Suzuki.

That difference should not really be a surprise. After all, Sepang has two of the longest straights on the calendar, but it also has 14 corners. A big gain in the straight is quickly lost to a bike which is a little bit faster through each corner. The big horsepower bikes have only two chances to open a gap; the bike which can brake deep, carry corner speed, and get good drive on exit has fourteen opportunities to squeeze out an advantage.

So should Yamaha fans be worried if the 2020 M1 is still down on top speed compared to the Hondas and the Ducatis? Not necessarily. If the gap is huge, then there might be reason for concern. But if Yamaha can restrict its deficit to a few km/h, then they are in with a fighting chance. After all, it was a Yamaha which started from pole in the 2019 race, and another Yamaha won the race by over three seconds, with yet another Yamaha crossing the line in fourth.

Each manufacturer in MotoGP follows a different line, a different concept. They focus on different areas, believing that is where they can gain the most advantage. Each choice involves compromise, sacrificing one area in pursuit of gains in another. Want more top speed? Then you will need a more stable bike, which will then be more difficult to turn. Want a more agile bike? You need smoother power delivery, and something which turns a little better, and that means giving up outright top speed.

The art of racing motorcycle design is the art of compromise, in making the right choices which will allow you to win. It is impossible to build a bike which is better than the rest in every area, so all that is left is to ensure you gain more in your strong areas than you lose where you are weakest. You have to pick your poison.


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if history has told us anything, over the course of a year a nimble but slower bike loses most of its advantage when a faster poorer handling bike gets in front and simply parks itself in the corner.  With the exception of the suzuki I can't see the yamaha being good enough to get around a semi stationary object such as a ducati or honda on almost any of the corners.  So I am remaining on the skeptics side for the moment.

So far, the only motorcycle to beat Marc Marquez to a championship is a Yamaha. And in the 11 season of MotoGP before Marquez entered the championship, the slow Yamaha (it was always slow) won six titles to four for Honda and one for Ducati.

Wasn't really disagreeing Dave and I can't argue with the stats but it seems that if you also have to manage your tyres (and you do now, thank goodness) the yamaha does not seem to have been in the hunt.

rider, bike, tyres all three matter and given the current rules have effectively eliminated tyres we are almost down to rider and bike (not a bad thing) but it is making it harder for those on the tuning fork.  Still, it makes it interesting and keeps the "inventivness" of motogp alive, otherwise we might as well have a spec motor.... please no :-)

Really interesting to see the lack of overall difference a top speed advantage makes. Paints quite a picture of what the Suzuki must be doing elsewhere on track to recover so much time. 

Could this comparisom of top speed against overall lap time prove useful as an illustration of the various machines strengths, or am I just massively over simplfying?


Informative David, thank you. And you yourself have already explained well how the way the M1 works makes it almost impossible to overtake once there are bikes in front of it. When the track is open she can fly, but to pass bikes squaring the corners... the M1 can only do it in certain circuits.

In my opinion top speed is less important in testing as you can ride alone in your best lines

Completly diffrerent is when you race together, it that case having less top speed is much important as other riders overtake you continuisly  and probably you cannot make your best lines

... battling head-to-head, I think you would see the Ducati come out on top simply by having the advantage in the "easiest" passing zones, i.e. the end of those long straights. Mir would have to work a lot harder than Miller to make a pass stick. We saw this countless times last year with the Yamahas and Suzuki's vs the Ducati's and (some) Honda's.

The lap time V's top speed analysis is fine for a fast lap, but during a race, a higher top speed makes for a low risk pass. The bike that corners faster has to be able to pass in the corners, but there tends to be more risk passing into, out of and through corners. 

I think that is why if the Yamazuki gets far enough ahead during the race it tends to stay there, but if there's competition for the lead the Yamazuki tends to get passed by a Honcati on the straight. The Honcati corner well enough that the Yamazuki can't so easily pass in the bendy bits.

The laptime is made in the corners, but the race is won on the straight!