Antonio Cobas, technical director of the Camel Pramac Pons team, describes the challenges that will face the MotoGP teams at this weekend's Malaysian Grand Prix...

"The first obstacle to overcome at this circuit is the climatic conditions in which the bikes and riders have to work, notably the high temperatures and the humidity. The
temperatures often reach more than 35 degrees and, with humidity levels above 75 per cent, the engines lose a considerable amount of power compared to most other circuits with temperatures around 25?C.

"The ideal temperature to work with the four-stroke machine is between 70? and 90?C, but the climatic conditions in Sepang often mean that temperatures exceed 115?C. At these temperatures, the loss of power can be so great that, often, we must incorporate changes to the aerodynamics of the bike so that the heat from the engine is evacuated more efficiently from the bike fairings.

"The harsh conditions also have an effect on the physical capabilities of the riders. After nearly an hour of riding on a bike that is more than 100?C hot, in the Sepang heat and humidity, riders finish the race completely exhausted.

"One of the first settings to work on at Sepang is finding the right gearchange ratios for the rider in question. What?s more, it is necessary to find the closest ratios
possible because the Sepang circuit combines two of the most difficult factors for deciding the gear changes.

"On the one hand, first gear must be very short to negotiate the sharpest corners of the circuit - which are taken at less than 65kph - whereas the two long straights are taken at more than 300kph. Therefore we must spread 180kph over five gears and also ensure that the gear ratios are suited to every corner. The rider enters the two straights in second gear and finishes in sixth, so if the gear ratios are not correct we will notice a loss of speed on the two main straights.

"Secondly, there are also several shorter straights at Sepang which mark the top speed of nearly all the gears as the rider gets to the end of these straights doing the maximum revolutions for each gear.

Regarding suspension, this circuit is not one of the most complicated since the surface has a lot of grip after the second day of qualification and it is not excessively bumpy. On clear days, the track can reach temperatures of nearly 55 degrees and, in these conditions, the tyres are working on the limit, so we must use fairly hard compounds to resist the high temperatures.

"This means that, on occasions, we may use slightly different settings for qualification, where we may use a softer compound, than for the race where the settings are conditioned by the type of tyre used and its duration during the race itself."