YoshiNakatani

81 months ago

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3 seconds is all you need to avert a motorcycle crash

Toronto, Ontario, Canada

In North America, we hear and see motorcycle related traffic accidents mostly happening at intersections or in a curve / corner. The majority of news reports tell us “Speed was involved”.

Obviously when operating a motorized vehicle, speed is involved, but why and how does speed determine safety on a motorcycle?

Speed affects your breaking or stopping time. Riders may not scan the traffic and road conditions ahead as frequently as they could. Which means they don’t see the need to stop in time.

In my previous article Advanced motorcycle braking techniques for the best cornering I revealed breaking tips for corning. Let’s recap them first.

How to avert a motorcycle crash

How to avert a motorcycle crash

Steps to approach normal braking when cornering

1, I see the corner ahead (either a right or a left corner)

2, I slightly offset my body (not like race-style but only an inch or so)

3, I start applying the REAR BRAKE first

4, I gently apply the FRONT BRAKE only after first applying the REAR brake

5, I bring my body upright a little bit, even at slower speeds, using wind-resistance to slow me down. Because the braking momentum moves the body forward, by sitting up I’m adjusting the weight balance between the front and rear tires. I brace my body with my abs, thighs and feet. I NEVER brace with my arms

6, I gear down one gear at a time while applying both front and rear brakes

I also use the BRIPPING technique WHILE braking if needed. The most difficult part of bripping while braking is that you MUST open the throttle as well otherwise the bike will not be stable.

7, I complete adjusting my speed before getting to the "turn-in" zone (or the “start-leaning” zone)

8, Just before entering the "turn-in" zone, I turn my HEAD & CHEST towards the exit of corner and prepare for leaning

How much time do you need to prepare for your corner?

The time execute steps 1-8 will take only 3 seconds.

If you're riding at 100 km/ph (60 mi/ph) your speed will give you approximately 30 m/sec to do all the steps. So start preparing the above 1~8 steps, 90 meters (300 feet) or about 10 car lengths before the corner.

If riding at 80 km/ph (50 mi/ph), your speed will give you about 24 m/sec, so start preparing the above 1~8 skills at 72 meters (240 feet) before the corner.

If riding at 60 km/ph (40 mi/hr) you have 18m/sec so start preparing at 54 meters (175 feet) before the corner.

Some of you remember this story?

How much distance can your motorcycle achieve in one second? How do we convert from KPH to MPS?

Most motorcycle riders rarely think about their stopping distance, however, it's VERY important knowledge in averting an incident on the road, especially when you apply a threshold maneuver.

The easiest formula is achieved by multiplying our kilometre per hour (KPH) by 0.3 to calculate our stopping meter per second (MPS). Here is the formula, {? KPH x 0.3 = ? MPS}

Technically, multiply by 0.277777777, but round up to 0.3 to make it easy for everyone. Please see the conversions below.

30KPH = 9MPS

40KPH = 12MPS

50KPH = 15MPS

60KPH = 18MPS

70KPH = 21MPS

80KPH = 24MPS

90KPH = 27MPS

100KPH = 30MPS

As you might have noticed, those KPH above are popular posted speed limits in North America touching residential area, school zones, industrial area, and highways. Remember when you took your road safety course? Your safe distance ahead is approximately 2 seconds or more.

Now that you're aware of your stopping distance, the next thing you must consider is your "REACTION / THINKING Time"

Reaction time is different for every individual and is based on age, driving experience, road conditions, and weather conditions. Let’s assume fine sunny weather conditions with good visibility and good dry asphalt road surface. A good reaction time will be somewhere around 0.7 seconds, and a long reaction time might be around 1.3 seconds to notice something on the road (possible hazard such as a pot hole or debris to avoid).

To calculate your unique stopping distance consider two parts.

Your thinking distance + your braking distance = your stopping distance.

STOPPING DISTANCE

STOPPING DISTANCE

Yoshi just experienced (almost) a threshold situation!

To demonstrate, please allow me to share my experience of what happened very recently.

I went on a group riding on my Aprilia Shiver 750. A group member stopped and took photos of me cornering. The posted speed limit on the corner was 30KPH because it was slightly blind with a very narrow lane. Coincidently two pictures were taken.

Photo #1 was taken approaching/initiating the lean and photo #2 was taken as I came to an emergency stop in the middle of cornering.

In photo#1 as I prepared for the corner, I adjusted my speed from 50KPH to 30KPH and I initiated leaning. Then what happened next was, behind the photographer, I saw a car crossing the centre line into my lane (half of the car crossed the line). To avert a crash I initiated braking and sat up to bring my bike upright as much as possible. I changed line to slightly outside because I noticed the driver of this car saw me and steered the car, so I stopped in a safer spot in the corner.

The distance it took to come to a stop between photo #1 and #2 was around 20 meters, and I was neither able to apply threshold braking nor swerve as I had already adjusted my speed and my bike started leaning. My only option was gradually come to a stop in the narrow curve.

In this situation, adopting the formula above, 30KPH = 9 MPS. My average reaction time took appx. 0.7seconds, I reacted by rolling off my throttle and the bike moved approx. 6 meters, this is the point I recognized the hazard. Once I sat upright and changed my line outside, I travelled another 6~8 meters.

When I applied gradual braking it took another 5~7 meters to stop. The total distance from the recognition to need to stop was approx. 17~21 meters.

I put 4 meters or a 2 bike length gap in this number as I did not check the exact stopping distance (but I am 100% sure I stopped less than 20 meters).

Hey, this formula looks it's working. Under the conditions of a slight blind corner, with rough a road surface, nearly 30 years of riding experience (a 15 years career as a Motorcycle Rider Training Instructor) it took approx. 20 meters to stop. And all of this happened in 3 seconds.

   Poto #1                                                     Photo #2
EVASIVE MANEUVER PICS

EVASIVE MANEUVER PICS

Using the "3 second rule" will save your life

Calculations aside, if you remind yourself to keep a minimum 2 second or more safe gap in front and look at least 3 seconds ahead, you'll have enough distance to make an emergency stop. Remember, the faster your go, further you must look.

I will post more topics that relating to braking and turning/cornering and also rider safety tips.

God speed everyone!

For your information, the knowledge of this conversion from KPH (kilometres per hour) to MPS (metres per second) is very common at riding schools in Japan

Stopping calculations are taught in every motorcycle training course to remind us to be cautious on the road. Theory class consists of two modules consisting of 5 hours to 26 hours of study based determined by your driving experience.

The practical (operating vehicle) portion of the motorcycle training course in Japan also consists of 2 modules lasting 8 hours to 36 hours. (Obviously, if you do not have any driving experience, you will have to take the maximum hours for both theory and practical to pass your license.)

You must take a test after finishing each module, and you must take a “graduation test” for the practical portion.

Japan has 3 levels of gradual licensing system that is based on engine displacement. If you already have a small displacement license (up to 124cc) and wish to upgrade to regular size (up to 399cc), you must take lessons and pass a test to prove you have enough knowledge and vehicle operating skills and the third level graduates to a large size (no cc limit). I will introduce more details how their practical lessons and test are designed in the future. It's not easy!

Want to learn more about getting your motorcycle licence in Japan? Take a look at Japanistry Good luck!

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cdnpuck

40 months ago

Statistically, in multi vehicle crashes involving a motorcycle, the motorcycle is the striking vehicle 96% of the time. Practice your emergency braking skills! Expect that cars or other hazards will come into your path and if there is enough time/space to stop, make sure you have the skills to perform that stop. Practice your emergency braking skills!!