Better Riding: when do I run out of grip?

No matter if you’ve just started riding or have decades of experience under your belt, there’s always something new to learn. That’s the spirit behind the Bennetts BikeSocial Better Riding series. We’ve enlisted the professional guidance of expert motorcycle coach, Mark McVeigh (www.motorbikecoach.com), to delve into one of the most powerful yet often overlooked concepts in bike control: the Kamm Circle — a key to understanding the hidden limits of grip.

Read on for an overview of the accompanying video or watch it in detail here:

Better Riding: when do I run out of grip?

Mark and Michael discuss how a powerful physics model can transform your riding skill level with a deeper understanding of tyre grip

This diagram shows the friction circle with longitudinal (braking/acceleration) and lateral (cornering) axes. Staying inside the circle means you’re within the tyre’s grip limit.

What Is the Kamm Circle?

The Kamm Circle, also known as the GG diagram or friction circle, is a visual model that represents the maximum grip your tyres can deliver at any given moment. Think of it as a compass for traction: if you stay inside the circle, you’re safe. Step outside, and physics will spit you off.

Mr McVeigh is an ex-MotoGP engineer and founder of MotoDNA, likens tyres to athletes: they only have so much energy to give. The Kamm Circle helps riders understand how that energy is distributed between braking, cornering, and accelerating. “You can brake hard in a straight line—pulling grip from the longitudinal axis. When you lean into a corner, you’re using grip from the lateral axis. But when you brake and steer at the same time, you’re asking your tyres to share their grip,” explains McVeigh.

If you’re looking for a more technical breakdown:

• Longitudinal Axis (Y-axis): Represents braking (negative) and acceleration (positive).

• Lateral Axis (X-axis): Represents cornering forces—left or right lean.

• Vector Sum: The total force vector must remain within the circle’s radius, which is determined by the coefficient of friction (μ) and the normal force (N):

If the combined forces exceed this limit, the tyre loses grip resulting in a slide or crash.

Why It Matters: Grip Isn’t Infinite Nor Constant

Many riders assume grip is either limitless or disappears randomly. The truth lies somewhere in between. Tyres don’t have infinite grip and understanding how to manage it is crucial, especially when blending inputs like throttle, brake, and lean angle.

McVeigh warns against common traps:

• Overconfidence in lean angle: Modern tyres are impressive, but every tyre has a limit.

• Abrupt braking mid-corner: Overloads the tyre already busy with cornering forces.

• Aggressive throttle while leaned over: Can cause the rear to spin out.

• Ignoring surface changes: Rain, gravel, oil, or even paint can shrink the Kamm Circle.

 The size of the Kamm Circle isn’t fixed. It shrinks or expands based on:

• Surface type: Tarmac, gravel, paint, oil.

• Weather: Wet roads reduce μ significantly.

• Tyre compound and temperature: Cold tyres offer less grip.

• Suspension and load transfer: Braking shifts weight forward, increasing front grip but reducing rear.

Understanding these variables helps riders adapt their input strategy dynamically.

I recall one journey on an Africa Twin where I got caught out by a white line in the rain – as a slow-moving vehicle turned off, impatience got the better of me so swung out to overtake but misjudged the lack of grip on that wet white line/cat’s eye combination. One broken collarbone and 50-days without riding.

The diagram demonstrates how grip is shared when blending braking, lean angle, and throttle such as during trail braking and corner exit.

How to blend inputs

“Riding is a dance with physics,” says Mark. The Kamm Circle is your dance floor, and each input - braking, accelerating, cornering - is a step. But you can’t lunge in two directions at once.

“Like dancing, you need balance, rhythm, and awareness. Smoothness is the hallmark of good riders,” he says. “Fast riders have slow hands,” to quote racing legend Freddie Spencer, but this concept isn’t just for racers. Everyday road riders benefit from understanding how to blend inputs smoothly. It’s the difference between reacting with panic or precision when something unexpected happens. And in every situation in life, our natural reaction is to resort to our basic understanding – fight or flight. Or, in motorcycling terms, we react in accordance with the level of our training/practice/understanding.

 Training for Mastery: Skill, Craft, and Mind

Mark’s own MotoDNA training method sees rider development built on three pillars:

1.       Skill – Machine control and drills.

2.       Craft – Roadcraft and situational awareness.

3.       Mind – Confidence and mindset.

The Kamm Circle sits firmly in the Skill pillar with advice that riders should practice in controlled environments, stretching their abilities by 5% increments until techniques become intuitive and repeatable.

One of his students came to the school short on confidence having crashed due to grabbing the front brake mid-corner. After learning what the Kamm Circle is and its effect on riding, one the student had practiced relevant drills, confidence was restored. It’s not the most difficult of equations yet how many golfers do you know who practice their swing versus the number of motorcyclists who practice their emergency stop?

Trail braking and emergency stops are just two of the recommended drills to understand grip

What drills can I practice to better understand motorcycle tyre grip?

Understanding the theory is step one. Step two is feeling it. Here are three drills Mark recommends the following to help riders develop muscle memory and confidence, especially when faced with surprises on the road: 

1. Braking Drill

• Practice braking harder in a straight line. How does it feel if you modulate the feeling of the front brake by squeezing harder during the middle part of the stopping phase?

• Use ABS as a guide - squeeze until it activates, then back off slightly.

• Repeat in dry and wet conditions to understand grip thresholds. 

2. Trail Braking Drill

• Mark out a circle and enter tangentially.

• Start at a comfortable speed, finishing braking before leaning.

• Gradually increase speed and delay braking to feel how grip is shared between braking and cornering. 

3. Throttle Control Drill

• Focus on smooth throttle application during corner exit.

• Use onboard accelerometers (available in many action cameras) to visualise grip usage.

• Learn to transition from braking to cornering to accelerating without exceeding the circle.

The KAMM circle of a road rider (left) vs a racer (right) who takes rider inputs to the extreme

How to visualise grip?

Road riders typically operate within 0.4–0.5 G (the force of gravity), while racers push closer to 1.2 G or more, with slick tyres and aerodynamic aids, especially evident in this modern MotoGP era.

The Kamm Circle helps visualise how forces shift during braking, cornering, and accelerating. Racers brake to the limit, trail off as they lean, hit the apex, and then pick up the throttle as they exit. Road riders follow a similar pattern just with more margin for safety. 

Confidence Through Understanding

Confidence is key to better riding. Riders who understand grip:

• Trust their tyres.

• Ride smoother.

• React better in emergencies.

• Avoid panic and overreaction. 

“If you ignore the Kamm Circle, you’re riding in the dark,” says McVeigh. “Learn it, and suddenly things are clearer, safer, and a lot more fun.” The Kamm Circle isn’t just a diagram, it’s a mindset. It helps riders understand the invisible edge of grip and how to stay within it. Whether you’re braking, cornering, or accelerating, the trick is to blend inputs smoothly and dance inside the circle.

So next time you roll into a corner or squeeze the brakes, remember: the circle is always there. Ride with awareness, practice with purpose, and enjoy the journey toward mastery. 

This Better Riding series is brought to you in partnership with Honda Motorcycles UK whose goal: zero traffic fatalities involving Honda mobility products worldwide by 2050. Better Riding is a collection of self-help videos and written guides packed with practical tips, expert advice, and simple yet effective exercises. Designed for riders of all levels, it aims to boost confidence, improve machine control, and complement traditional post-test training. Because when your skills improve, so does the fun. 

Try this: I’ll often commentate when riding to remind myself of potential hazards and what my responses are to avoid possible danger. If you don’t already, why not try it? Nobody can hear you!

If you have an action camera (here’s a link to our reviews of the most recent 14 options), record your ride and review it afterwards looking at possible areas to improve. You can always ask specific question over at BikeClub or on our private Facebook Group, or tune in to the other episodes in this series on our YouTube channel.