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Mark Hinchliffe·
Motorbike adviceTips/training
··20 Comments·2 min read

Do motorcycles brake better than cars?

Craig Lowndes races Casey Stoner brake
Craig Lowndes races Casey Stoner

There has always been conjecture about whether a motorcycle can brake in a shorter distance than a car.

Many experienced riders believe they can stop faster than a car which is probably why they tailgate cars.

Meanwhile, rider trainers warn their students to keep a safe following distance because a car can stop faster.

So who is right?

The arguments

The argument for a motorcycle is that they are much lighter and have bigger brakes for the size of the vehicle.

The argument supporting a car is that they have much bigger contact patches with the ground because they have four wide tyres.

Both arguments have merit.

However, it depends on the bike and the car.

If you like to maintain your car or bike yourself, you would know how troublesome it could be to find the best brake line flaring tool.

The truth

If we look at the ultimate race vehicles — a Formula 1 car and a MotoGP bike — the answer is that the race car can brake with up to 5.7g of force and the GP bike with only 1.8g.

G-force is the pressure that gravity exerts on an object when it is accelerating relative to freefall. A sneeze is about 3g and a cough about 3.5g.

The physics

Jeromy Moore fuel economy brake
Jeromy at work

For a scientific explanation, we went to Jeromy Moore, former Craig Lowndes race engineer, Porsche world endurance champions race engineer and now chief engineer at Triple Eight Race Engineering.

“It is clear that a car has the potential to brake with more deceleration due to having more rubber, less weight transfer for the same deceleration due to a low centre of gravity height versus wheelbase,” he says.

A hard-braking sportsbike will shift most of its weight to the front tyre and even lift the back wheel off the ground.

So it’s not just two skinny tyres versus four wide ones, but one tyre contact patch versus four!

Jeromy also points out that a race car has significant aerodynamic downforce which puts more weight and traction on the tyres.

The real worldFollow too closely tailgate downhill

But that’s physics and not the real world.

In the real world there are passengers, luggage loads, rider and driver skills, surface traction, panic and technology to consider.

In fact, some suggest that a standard car (whatever that is) and a standard motorcycle have about the same braking force of about 1g.

But to extract 1g of braking force from a motorcycle, a rider needs to be highly skilled.

Almost any novice driver can simply slam on the brakes of a modern car and pull up with the same force as a highly skilled rider.

The conclusion

What this all means is that you may be able to out-brake a car if you practised hard and were aware when you needed to emergency brake.

But in the real world, panic can set in and it is much easier to lock up a front wheel and crash a motorcycle than it is in a car, especially with all the braking technology fitted to modern passenger vehicles.

So go out and practise your emergency braking skills until it becomes second-nature.

Meanwhile, don’t tailgate.

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Mark Hinchliffe
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20 Comments

  1. Whilst a bit of side point, what still has me stuffed is the rider training in Queensland says don’t cover your brakes. Quite frankly the difference between being able to brake immediately and having to open your grip and close it again is large (not to mention if your already holding on to the grips it, is likely to tighten)

      1. The rider training advice to not cover brakes is global. British advanced riding instructors and British police riding instructors will all tell you not to habitually cover your brakes. It’s a bad idea. If something spooks you and you tense up, you potentially just locked a wheel. Having to open the hand and/or move the foot gives time to calculate a controlled braking response or choose an evasion. It’s not about reflex times, it’s about choosing the right action and executing it skillfully.

        It’s different when you are negotiating a complex hazard and are already contemplating whether a roll-off is enough or a braking action is required, but habitually and unconsciously riding with fingers on the brake “just in case” carries more risk than reward.

  2. I think some people in charge of motor vehicles, car or motorcycles, rely heavily on braking and usually drag the brakes (over brake) for far too long when approaching even a simple set of traffic lights with no hazards, confusion or panic triggers in sight. Timing is the key & reading the road ahead. Sometimes good old momentum and correct gear or revs can have you simply flow through many intersections without too much halting at all.

  3. Back in the day when cars had 4 drums or disks at the front and drums at the rear, I would have said yes, but times have changed and the tables have turned somewhat.

  4. Going back to my apprenticeship days, (ok get off my case, yes we did have apprenticeships way back then) a wise old instructor asked this simple question, after having walked through the car parking area for the students) Which tyres will offer better grip under acceleration, braking and cornering?

    Same car, same tyre make, same model designation, same construction and compound, the standard 175/75/13 tyres or the same car with 195/75/13 tyres?

    All us young start ass apprentices said the wider 195/75/13. Wider and larger contact patch means more grip.

    Wrong, he then proved mathematically our mistake, in conclusion the wider tyres contact patch had less pounds per square inch downward force, than the narrower tyre.

    Just saying, something else to add to the mix and ponder over.

      1. That’s quite and in depth paper. The TL;DR is tyres stick by adhesion (chemically bonding), viscous deformation, elastic deformation and eventually tear, and all 4 behavours are nonlinear.

        I’ll conceed that even a cheap semi-modern bike has better tyres and better brake friction material than a typical family car. This is an advantage in achieving the braking performance limits of the chassis, that is wheelbase and weight distribution factors that result in the vehicle pivoting catastrophically in the form of a stoppie/endo

        If both vehicles have perfect ABS, allowing maximum braking performance to be extracted, a performance motorcycle may have an advantage over a ‘family’ car in some areas, particularly sustained braking from high speed, but the car wins on initial deceleration and on fade-free tests such as 30mph (50kph) to 0 which are typical reacting to traffic scenarios.

        Furthermore few bikes have modern ‘cornering’ ABS, and ABS has only recently become mandatory in Europe on large motorcycles, so motorcycles are less likely to have ABS. Whilst a skilled racer can outperform substandard ABS, most of us can’t, so again the cars have a lead.

        The major danger of following a car too closely is there is little penalty for stamping on the brakes on a car without ABS and no penalty for stamping on the brakes of a car with ABS, whereas the dynamics of a motorcycle require a more progressive brake application and snatching the brakes on a motorcycle without ABS can be fatal.

        It’s certainly safe to say a car dynamics react to emergency braking events more quickly and more safely than that of a motorcycle.

        All of that said, an ER6 stops a little bit faster than this Holden https://www.youtube.com/watch?v=loaJVp4ARZA

        A sporty BMW M1 pisses on an S1000RR https://www.reddit.com/r/motorcycles/comments/1nhqx3/an_excellent_illustration_of_motorcycle_vs_car/

        In the latter video, both the rider and driver have had professional racing careers, although the rider has been just a bit more successful.

  5. “G-force is the pressure that gravity exerts on an object when it is accelerating relative to freefall”

    Please consult a school physics textbook before publishing sciencey-sounding nonsence.

    g (always lower case, G is something different) is acceleration due to gravity, thus one accelerates downwards at 1g in freefall in a vacuum. You could say g is force per unit mass, but it’s not a force per unit area, which would be the definition of a pressure.

    as such g is not a force, if you’re looking at the force exerted on an object due to gravity, that would be its weight.

    2. They mean enough force to cause “1g” of deceleration, and “G-force” is common in writing. All writing is tailored to an audience. In this case, it is decidedly not physics majors. Don’t over think it man.

  6. I used to be of the opinion that most bikes can out brake most cars but recent advances in tyres and abs in most cars has put a very large caveat in that opinion. There is the odd situation that a large heavy car could out brake a small lighter vehicle quite significantly because it forced more weight into the front tyres reducing the skating effect. Skating effect is similar to aquaplaning gasses balls of rubber and such actually lift the tyre off the ground reducing grip. A motorcycle is far less susceptible to this than a car due to the high weight to contact area. ABS has altered this scenario however .
    Now most bikes can out brake cars not because of the vehicles abilities but because an experienced rider is more likely to be on the brakes seconds before a driver has even noticed a danger.

  7. We performance test cars and bikes with GPS gear, vbox, and the like. Most decent sportscars can pull up from 100 in near to 30m. Most bikes can’t do much better than 40m. The best we’ve found are cruisers because of their rearward weight bias; two brakes being better than one, as in sportsbikes. The lighter the cruiser the better. Without checking I think 36m and change is the best figure we’ve achieved using ABS. It’s too risky to test non abs bikes but few are without now anyway.

  9. I don’t doubt that cars can out-brake motorcycles but the one thing I really hate was highlighted recently riding in traffic in Adelaide and that is how much I hate city traffic. I was following a vehicle with a reasonable space to allow for sudden braking and then because there was more than a one car length gap between me and the vehicle in front some clown cut in to fill the gap, which then meant I had to slow to allow a gap between me & this “driver”. But what would happen if he had to brake suddenly? Yes that’s right I would most likely hit his rear and get booked for driving/riding too close. This type of driving happens a lot in cities and it really makes you feel for truckies who get chopped off by cars who then brake suddenly, causing accidents which are then deemed to be the truck drivers fault.

  10. Most bikes now hsve ABS so you can ride along at open road speed and literally apply max pressure to both brake levers. Even so we seldom get emergency stops approaching those of even average new cars. That said theres not a whole lot of difference any more. The best bikes weve tested stop in just over 36m. Most cars take about the same distance. Special cars with sports brakes can go close to 30m. Weve had a few go under that over the years but sod all. Its worth learning how to do a full abs stop on a bike. Start slow and work your way up. Do this somewhere out in the sticks on smooth surface and not in real hot or cold conditions. Going under ABS threshold works in cars sometimes to drliver better stopping distances but you have to be v special to achieve the same on bikes.

    1. With my new abs Ninja, i have a much longer brake distance if the abs activates, rather than braking smooth enough to just not engage the abs at all. At 70 kph the brake distance differs about 7 meters (2 car lenghts). A good thing to have below freezing temperatures and when it rains though!

  11. Contact patch is irrelevant. Maximum braking force is Fmax=uN, u is the coefficient of friction and N the normal force from the ground (in this case the reaction force to the weight). There’s no contact area in the equation (more contact patch, means less pressure, means less braking per surface area). While the force will be different because the masses are different, the masses fall out of the equation, meaning max deceleration is the same.

    However the centre of mass of motorcyckes is higher and further forward, so the rate of deceleration that can be attained is smaller (than Fmax above) because the inertial moment around the front axel is greater for the same mass (higher centre of mass) and the weight moment smaller (centre of mass further forward). When the inertial moment exceeds the weight moment, the rear wheel takes off, which is effectively the point of maximum safe braking and this is lower than Fmax above. In a car that pretty much can’t happen so you can use up to Fmax.

    1. That’s not the whole, real world story though Michal. If you imagine a contact patch as a checker board, with each square losing and gaining traction independently, a larger patch would have less opportunity to break free. For example, if a motorcycle hits a marble while in a corner, there’s not doubt, it would affect the bike’s traction. However, if a car hit that same marble, the tire would simply deflect. In the real world, contact patch size does matter.

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