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Old 01-14-2020, 06:12 PM   #1
ThinkFast
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Speed kills (still) - even "expert" riders

[NOTE: if the mods don't think this belongs here feel free to take it down or move to the appropriate forum. Thanks.]

On a group ride to Baja last year, one of the guys in a group ride with my brother died in a crash with a car on a road an hour north of La Paz.

Since then my brother has been pretty shaken up. This morning we talked about it again, since he has just returned from a vacation trip down there and he drove back to the spot where the crash happened.

After I talked with him I did a ilttle research and sent him an email about what I thought might account for why such an expert rider died. I've shared that below. First, here's what I know about this crash.

The group consisted of very experienced riders who were riding various makes/models of bikes. According to my brother, there was one rider in their group - call him Tim - who was far and away the best rider of the bunch - and one of the best riders he's personally ever ridden with. Tim was a former club level road racer who had racked up a lot of miles adventure riding and touring in recent years. Tim is the one who didn't make it back from this trip.

The short version is that toward then end of a riding day Tim decided to break away from the group to run an errand on his BMW R1200GS (that's a story for another time). On his return journey to catch up with the group he broadsided a pickup truck that was turning from a sideroad onto the road he was on. LEOs on the scene estimated his speed was over 100 mph upon impact, but no one knows for sure. He died either en route to the hospital in La Paz or shortly after arriving there. Again, details are sketchy.

What is known is:
a) a highly experienced and skilled rider died after hitting the side of a truck that was turning onto the roadway.
b) it happened in the afternoon while it was still light out.
c) the stretch of road where this happened was level and straight, with good visibility on both sides.
d) the impact was hard enough to create significant destruction of the motorcycle - parts of it are still there a year later.

After my brother and we talked I did some research on stopping distances and wrote him an email, explaining my take on how something like this happens. I thought I'd share here, since it seems to me it's a lesson that we all need to continue to remind ourselves of.

Via email

Bro - great to catch up with you today. Found this item on MSF about their research on stopping distances.

Source:
https://msf-usa.org/downloads/imsc20...ance-Paper.pdf

All values are metric. So 128.8kph is around 80mph. 78m is about 250 ft - nearly a football field. That’s on a BMW 2002 R1200R - the sport version of the GS - so lighter weight than your buddy's GS.

As you can see from the data in the above table, weight makes a difference, and stopping distances are not linearly proportional to speed (or load). If you’re going 2x faster, the stopping distance needed is greater than 2x what it would be at the slower speed.

At 48kph the stopping distance is just under 13m. But look what happens when you're going 128kph, about two and half times as fast: the stopping distance jumps to 78m, or six times as far!

And that’s only 80mph. If your buddy was doing big speed - you thought maybe 120mph (245kph) - that stopping distance would probably be over 400 feet (just a guess - no data shown for that speed).

Shit happens in a hurry at that speed, and that's a long way to travel before you can stop. Add to that the difficulty car drivers have of gauging distance when a m/c is involved - it presents a much smaller cross section than a car, and sometimes can even be mistaken for a car with its lights on that is a long way off, rather than a motorcycle that is much closer.

Add to that a rate of closure that is two or three times the rate of other vehicles traveling at the normal speed for that section of road, and it’s easy to see how a vehicle driver might misunderstand what they are seeing as they look down the road and judge whether it’s ok to turn out or not.

I know no one knows for sure what happened that day, but it sure seems like going way too fast for that stretch of road was a key part of why your buddy didn't make home with your group.

End of email
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Last edited by ThinkFast; 01-15-2020 at 07:01 AM.. Reason: fix typo
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Old 01-14-2020, 08:26 PM   #2
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Honestly, this accident has nothing to do with braking distance. The rider simply never had a chance.

Doesn't matter what the braking distance is if the car cutting in to your lane does so within your reaction and stopping envelope.

He was simply going far to fast to the point that the truck driver either did not seem him, or saw him and grossly underestimated his closing distance and "thought he could make it".

It would not surprise me if the driver, assuming he did see him, simply wasn't used to anyone closing that fast, so any guess he would have made would have probably been wrong.

Sorry for your friends loss.
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Old 01-15-2020, 05:22 AM   #3
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^^^^^^this
Not much more to be said and it’s Baja where you need to practice 5th level vigilance. There are a gazillion small dirt roads and driveways that the connect to Hwy 1 all up and down the length of Baja. It is not the place to do triple digits. You have to watch for turning cars, trucks, donkeys, cows, horses, piles of rocks, trash, whatever.
Sorry for your loss.
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Old 01-15-2020, 07:58 AM   #4
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Quote:
Originally Posted by ThinkFast View Post
Shit happens in a hurry at that speed, and that's a long way to travel before you can stop. Add to that the difficulty car drivers have of gauging distance when a m/c is involved - it presents a much smaller cross section than a car, and sometimes can even be mistaken for a car with its lights on that is a long way off, rather than a motorcycle that is much closer.

Add to that a rate of closure that is two or three times the rate of other vehicles traveling at the normal speed for that section of road, and itís easy to see how a vehicle driver might misunderstand what they are seeing as they look down the road and judge whether itís ok to turn out or not.
Tragic, avoidable loss.

You make very perceptive points about problems caused by speed on public roads.

From my 2011 post, Vanishing Act:
Out-riding your sight distance. At high speed a motorcycle becomes a danger that a driver must reckon with when it is still far down the road. In the worst case, the motorcycle is on a collision course even though it is out of sight, beyond an intervening rise or bend.

Extraordinary speed in ordinary traffic. A speeding rider can also be in danger when the road is straight, level, and unobstructed because a driver has a limited decision horizon, or span of road he checks before crossing traffic.

The difficulty of judging speed. Even if a driver does see a motorcycle coming from beyond his decision horizon, he may not be able to judge its speed very well. When a motorcycle is moving straight toward an observer, it is a stationary dot in his field of vision that doesn't grow much in size until it is very close.

The acceleration deception. A motorcycle's acceleration can be deceptive too, because from a standing start, an aggressively accelerated bike can cover ground in half the time it takes a car.

Limited opportunity to be seen in the mirror. Speed reduces the visibility of a motorcycle to vehicles ahead traveling in the same direction because it decreases time spent in the mirror field, and that reduces the chance of being seen by a motorist scanning for traffic approaching from behind.

Quote:
At 48kph the stopping distance is just under 13m. But look what happens when you're going 128kph, about two and half times as fast: the stopping distance jumps to 78m, or six times as far!

And thatís only 80mph. If your buddy was doing big speed - you thought maybe 120mph (245kph) - that stopping distance would probably be over 400 feet (just a guess - no data shown for that speed).
Deceleration achieved in that test was nearly 1g, very good performance. Because stopping distance increases with the square of speed, assuming the same deceleration rate, it would take 500ft at 120mph.
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Old 01-15-2020, 12:00 PM   #5
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Originally Posted by DataDan View Post
Tragic, avoidable loss.

You make very perceptive points about problems caused by speed on public roads.

From my 2011 post, Vanishing Act:
Out-riding your sight distance. At high speed a motorcycle becomes a danger that a driver must reckon with when it is still far down the road. In the worst case, the motorcycle is on a collision course even though it is out of sight, beyond an intervening rise or bend.

Extraordinary speed in ordinary traffic. A speeding rider can also be in danger when the road is straight, level, and unobstructed because a driver has a limited decision horizon, or span of road he checks before crossing traffic.

The difficulty of judging speed. Even if a driver does see a motorcycle coming from beyond his decision horizon, he may not be able to judge its speed very well. When a motorcycle is moving straight toward an observer, it is a stationary dot in his field of vision that doesn't grow much in size until it is very close.

The acceleration deception. A motorcycle's acceleration can be deceptive too, because from a standing start, an aggressively accelerated bike can cover ground in half the time it takes a car.

Limited opportunity to be seen in the mirror. Speed reduces the visibility of a motorcycle to vehicles ahead traveling in the same direction because it decreases time spent in the mirror field, and that reduces the chance of being seen by a motorist scanning for traffic approaching from behind.


Deceleration achieved in that test was nearly 1g, very good performance. Because stopping distance increases with the square of speed, assuming the same deceleration rate, it would take 500ft at 120mph.
Thanks, DD, for your confirmation of some of my points - and your addition to several more. Will pass along a link to this post to my brother.

500 feet! If he was going that fast he didn't have a chance.
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Old 01-15-2020, 01:57 PM   #6
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Total bummer. A moment in time where choice and chance collide.

He could have been done that a hundred times without incident and circumstance dictated a deadly outcome.

For sure the choice was the major factor.

Sorry that Tim passed and that your bro and likely many others were so deeply impacted.
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Old 01-15-2020, 03:06 PM   #7
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Thanks, Budman, and to the others who have comments. I'll pass those along to my brother. In case anyone's interested, here is the memorial notice about Justin ("Tim" in my original post). https://www.legacy.com/obituaries/co...&pid=191497211

Any discrepancies or inaccuracies in my original description of what happened are mine. None change the basic gist of this thread.
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Old 01-15-2020, 10:19 PM   #8
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He sounds like a great person. I hope your brother feels better soon. There are some amazing posts on the "How do you cope" thread (https://bayarearidersforum.com/forum...d.php?t=540871). Maybe he'll get some peace out of reading them.
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Old 01-16-2020, 07:23 PM   #9
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He sounds like a great person. I hope your brother feels better soon. There are some amazing posts on the "How do you cope" thread (https://bayarearidersforum.com/forum...d.php?t=540871). Maybe he'll get some peace out of reading them.
Great find. Thank you for your thoughts and the pointer. Will pass along.
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Old 01-17-2020, 05:36 PM   #10
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SMIDSY weave

1. twice the speed, four times the stopping distance - covered.
2. left turning drivers cannot judge the approaching speed of a single track vehicle like a motorcycle - covered.
3. Using a SMIDSY weave to increase a left turner's awareness of your approaching speed.

If I am going too fast to safely execute a SMIDSY weave, I am travelling too fast to be safe.
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Old 01-17-2020, 05:48 PM   #11
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Good call Hank.

I use the Smidsy too. In the description given it would not have applied.

Hope change and choice let me keep doing my thing for another decade.
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Old 05-23-2020, 08:02 AM   #12
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Yup.
Going too fast for conditions = Not Safe.
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Old 10-17-2020, 08:07 AM   #13
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Others being able to judge speed of a motorcycle is definitely very hard, as a motorcyclist even I have difficultly.
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Old 10-17-2020, 11:41 AM   #14
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I T-boned cars three times pulling out from side roads into my lane. Two times were on my bicycle going about 20-25mph. I flew over bonnet in one case and slammed into driver’s door 2nd time.

Third time was on my CB350, same circumstances, but I was going about 35mph. Totalled bike and car.

My speed was irrelevant in these cases because it only changed effect of crash (not caused it). Higher speed would result in more injury as effect. But my speed did not cause the incident. Cause was driver didn’t look and see me. If anything, more speed would have me stand out more from background. Or some weaving. Or headlight-modulators.

Now on single-vehicle crashes, speed would play more significant role.

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Old 10-17-2020, 11:56 AM   #15
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RIP to the rider.

All the skills in the world won't save you from poor judgement. We all do it from time to time and frankly it's often just luck that keeps us alive in those cases. The best we can do is practice good habits and learn from our mistakes and the mistakes of others.

I've done a whole lot of street riding and I think the biggest improvement I've done for my own safety is to really drill in the "trust nothing" on the road ahead of you approach. Any vehicle approaching an intersection or anywhere near my path warrants slowing down and covering the brakes. I've noted many situations in recent years that could have become close calls if this wasn't my practice.

Hurrying to catch up with a group is a great example of where we can take extra risks. For me, it's often running late for work. None of these are things worth dying for. Much respect to your friend as it doesn't say anything bad about him as a rider or human being. Only that we are fallible and when the luck runs out the cards may fall.

The best thing to do is read through some of the material that DataDan posted and put it to use the next time you ride.
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