Jack Miller and the "Stoppie Challenge"

5/25/2021

 BREMBO BRAKES REVEAL ALL THE SECRETS.

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For a few months now, especially among the World Superbike Championship riders, the Stoppie Challenge has been all the rage. When returning to pit lane after a particularly positive session (nobody likes to horse around after a bad result), the riders show off with what is essentially a reverse wheelie. 


In fact, it isn’t the front wheel that comes off the ground, which is a rather easy feat when you have motorcycles with one hundred plus horsepower, especially if combined with contained weight – the minimum weight for MotoGP motorcycles is 157 kg (346 lbs), 168 kg (370 lbs) for Superbikes and 217 kg (478 lbs) for Moto2 motorcycles (rider included). ​



 

These values are made possible by the incredibly light weight of the Brembo brake components and the Marchesini wheel rims: A set of 17’’ magnesium forged rims weighs just 6 kg (13.23 lbs), whereas a pair of 4-piston monobloc calipers for a MotoGP motorcycle is no heavier than 1.5 kg (3.31 lbs), since they are made from a block of aluminum-lithium. 


In a stoppie, the front wheel remains solidly on the ground while the rear wheel catapults skyward. Doing one does not require high speed which, to the contrary, is counterproductive for good acrobatics. Any stuntman will tell you that you can do one even at just 40-60 km/h (25-35 mph). 


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The first to do it frequently in the last two-year period was Toprak Razgatlioglu, initially with the team Puccetti Kawasaki and then with the Factory Yamaha. His control of the motorcycle is unquestionably exceptional, as demonstrated by the numerous stoppies he does where he manages to turn the motorcycle 90 degrees on the front wheel. 


His usual plan of action includes entering pit lane at 80 km/h (50 mph) in second gear. Then he applies 12-14 bar (174-203 psi) of pressure on the front brake. When the rear wheel lifts, Razgatlioglu reduces the pressure to 2-3 bar (29-43 psi), maintaining his balance. Then he downshifts to first and uses the rear brake to return to the ground. 


















The challenge was accepted by Jack Miller with his team Pramac Ducati Desmosedici in the February 2020 Sepang tests and subsequently in the January tests in Jerez by Stefan Bradl with his Honda R213V. They were joined by Lucas Mahias with the Kawasaki Ninja ZX-10RR. All of them have one thing in common: A braking system with discs, caliper, pads and master cylinder by Brembo. 


This is yet another confirmation of the confidence all the best riders in the world have in the performance and reliability of Brembo brake components, not by chance used by all the MotoGP, Moto2, Moto3 and MotoE riders and by most of those who race in the World Superbike Championship.



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Clearly, to do a stoppie, you have to be decisive on the front brake and ignore the rear. The body position is also rather important, starting with your elbows, which shouldn’t be locked, whereas the knees should be squeezed together almost as if you wanted to hug the fuel tank. 


As the tenths of a second pass, pressure on the front brake should be progressively reduced to avoid flipping over. In these phases, the rear wheel is off the ground and the rear brake should be used only when it begins its descent. 


Using the rear brake in the initial phases of the stoppie would instead block rotation of the rear wheel, impacting the overall motorcycle-rider balance. It would also be a mistake to lean the torso forward in an unnatural position, because it would throw off the overall rider-motorcycle center of gravity. 


 

To do one, the World Superbike riders apply 7.2 kg (15.88 lbs) or 6.5 kg (14.33 lbs) of load on the brake lever, depending on the diameter of the master cylinder used, as opposed, for example, to the 6.1 kg (13.45 lbs) applied on the first turn in the Qatar round, at the end of a 1,068-meter (1,168-yard) straight. ​


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As you have probably guessed, high energy intensity is not required because the braking takes place at low speed. However, good braking torque is handy, the value of which is directly proportional to the effective radius of the disc, the friction coefficient and the clamping force of the caliper. 


Naturally, a brake master cylinder that can ensure responsive and modulated braking is essential. Thanks to the experience gained in designing hydraulic, kinematic and ergonomic components, Brembo master cylinders stand out for the linearity between the applied force and braking response. 


In any case, stoppies do not have any particular negative impact on a track motorcycle’s braking system, since they are done on pit lane. The rider’s low speed on the re-entry lap ensures that the pad and brake fluid temperature is rather low, so the system is not at risk for any thermal stress. ​



















Nevertheless, these antics are frowned upon by various team managers. Not so much because of the risk of ruining any mechanical components, although there are those who worry about the oil in the crankcase moving around, as for the danger of falling, sustaining a stupid injury, breaking some parts of the motorcycle or even just looking foolish in front of all the cameras. 


It is not by chance that, of all the acrobatics that can be done on two wheels, the stoppie is considered the most dangerous, since the rider doesn’t have an unobstructed view of the move. Therefore, Brembo highly recommends not attempting it on public roads or on the track.