Had a Truck roll coal on me and another rider today

[SeanScott]

Today on a ride a large red Ford diesel passed myself and another rider that was infront of me and slowed down to belch a huge black cloud on us.
It made me feel terrible and really makes me sad that someone would do this.
I really can't stand the bully mentality and I sincerely hope there is some sort of cosmic karma.

[cbbr]

I drive a Miata, so I feel your pain.

[Spaghetti Legs]

Karma is the guy drives on and continues the crappy life that made him want to do that. Sorry that happened, but try to put it behind you and ride on.

[stephenmarklay]

Those vehicles should be ticketed. I hate that.

[shoota]

Karma isn't real so don't worry about that. I've been thinking more and more about getting a camera, so we can prosecute these bungholes. Someone did this to my wife last night out on a gravel road.

[Louis]

I sincerely hope there is some sort of cosmic karma.

http://www.landships.info/landships/softskin_articles/images/armed_bikes_1.jpg

[jtbadge]

https://i.imgur.com/vYcjPVR.gif

[kramnnim]

Be glad that this was unusual enough of an incident that you posted about it. lol.

[Veloo]

Highly recommend a camera. Even if it's not a GoPro, a Chinese cam from Amazon that records 1080p will do. They are all pretty much GoPro mount compatible as well so set up is pretty straightforward.

Clear footage showing plates and faces will help expedite the karma.

[charliedid]

These posts always make me chuckle just a little. I know it’s not funny but it’s a little funny.




Sent from my iPhone using Tapatalk

[Ken Robb]

What is "Roll Coal"?

[dustyrider]

Freedom (https://m.youtube.com/watch?v=xf25OwYuE3o)!

[cbbr]

Freedom (https://m.youtube.com/watch?v=xf25OwYuE3o)!

If I was a cop and you did that to me, you would spend the rest of my shift on a roadside safety inspection. Those guys and smokers are a real aggravation if you drive a convertible. Fortunately, they can't keep up in traffic.:butt:

[sipmeister]

I've found the best response to this type of exhibition by a member of the 'neck crowd, is a friendly smile and wave. They're just trying to get a cyclist angry while they chuckle and cheer as they speed off. But a smile...and a wave, that'll thrown them off and they'll soon realize it doesn't get the desired out lash as they had hoped. Eventually they'll stop. After practicing this method for about a year, I haven't been bother for almost 9 years now.

[GOTHBROOKS]

a thumbs down is a better approach. kind of like that feeling where youre making your parents disappointed, not mad.

[dancinkozmo]

These posts always make me chuckle just a little. I know it’s not funny but it’s a little funny.




Sent from my iPhone using Tapatalk

what the eff is funny about it ???

[Ozz]

What is "Roll Coal"?
com'on Ken, you know how to google!;)

diesel vehicle...stomping on loud pedal....blows black smoke on cyclists and Prius drivers......

[bthornt]

What is "Roll Coal"?

This is rolling coal: https://www.youtube.com/watch?v=3tKJ6oZOkNo

[9tubes]

I've found the best response to this type of exhibition by a member of the 'neck crowd, is a friendly smile and wave. They're just trying to get a cyclist angry while they chuckle and cheer as they speed off. But a smile...and a wave, that'll thrown them off and they'll soon realize it doesn't get the desired out lash as they had hoped. Eventually they'll stop. After practicing this method for about a year, I haven't been bother for almost 9 years now.

You know how with some people you see them for the first time and wonder whether they are a real asshole?

Yep, I just smile and wave, and quietly thank the guy for eliminating the mystery. It's even better if he marks himself with a confederate flag or something.

[CMiller]

These posts always make me chuckle just a little. I know it’s not funny but it’s a little funny.




Sent from my iPhone using Tapatalk

I don't really see what's funny? Sounds awful.

[cmg]

had some dip ****e do that once. went to the other side of the road where the cloud wasn't. smiled and waved. all that effort and 2 pedal strokes and it was for nothing.

[peanutgallery]

I'm sensing some classism and stereotypes here:)

This is why I make sure that I am no longer in a situation where I would be considered car bait. With the number of distractions drivers face, the amount of traffic, sense of entitlement and so on...life is too short for the aggravation on my end and an easy out for the driver that turns me into a pancake ...it was an accident. Rolling coal is annoying, but you don't spend any time in traction or a coffin as a result

If you're car baiting...be safe and be situationally aware

[FriarQuade]

Why is this kind of vehicle mod legal at all?

[SeanScott]

I love road bikes, the rides, the culture, but the more stuff like this and I find myself off the paved road more and more. I wish it wasn't how I felt about it.

[ChainNoise]

If I was a cop and you did that to me, you would spend the rest of my shift on a roadside safety inspection. Those guys and smokers are a real aggravation if you drive a convertible. Fortunately, they can't keep up in traffic.:butt:

You have no idea what you're talking about. Diesels are so incredibly easy to make fast.


Why is this kind of vehicle mod legal at all?

It isn't.

[cbbr]

You have no idea what you're talking about. Diesels are so incredibly easy to make fast.




It isn't.

I'll bet that I have a better idea than you think. Fast, sure. In a straight line. Ever try to slice through traffic in an F-250? Most of my neighbors drive them. My parts hauler/hunting rig is a Z71 Suburban. Pretty difficult to move around in Baton Rouge/New Orleans.

My daily, a very dialed in Miata, cuts traffic like a dream. So while I can't outrun a built F-250 in a straight line, I have 1/2 the length, far, far better brakes, zero body roll, 10X the ability to see... it's never even a contest. And that is in a straight line, I hit cloverleaves in the mids '80s.

https://photos.smugmug.com/photos/i-Dq8dStG/0/0519c818/L/i-Dq8dStG-L.jpg

[witcombusa]

com'on Ken, you know how to google!;)

diesel vehicle...stomping on loud pedal....blows black smoke on cyclists and Prius drivers......

I can't really fault them for the Prius drivers...

[zambenini]

Was on a nice gravel ride in the ancestral homelands in Indiana around the time of the summer family reunion this year and a massive dually passed me with a massive "Prius killer" rear window decal. I think I was wearing a pink jersey, too.

I thought I was going to be sucking coal, but he passed me quite respectfully.

That said, as a cyclist with a sizeable nose, it's amazing what smells you can smell riding ... whether someone is smoking, what they're smoking, the car exhaust, what's a diesel or using regular gas, a pzev, etc. Probably not good.

[PaMtbRider]

We had a lifted diesel pickup behind us on a ride the other day. I felt sure he was going to smoke us out. He actually waited till it was safe to pass, gave us
plenty of room, and waved as he went by. Not all rednecks are inconsiderate jerks.

[SeanScott]

Not all Rednecks drive lifted trucks
and not all lifted trucks are driven by Rednecks.
AND many Prius are driven by Maniacs!

[cloudguy]

I can't really fault them for the Prius drivers...
:eek:

[dookie]

I got myself a John Deere jersey and am amazed at the respect it commands on the back roads of NC.

For real.

[SeanScott]

Now that is smart!

[soulspinner]

Happened to me the first time this week. Laughed and blew the bearded man a kiss:p:p:p

[Elefantino]

From the late, great Performance Bicycle blog last year.


There’s a first time for everything. I was coal-rolled the other day.

If you’re not familiar with the term, rolling coal is when a driver dumps excess diesel fuel into the engine, generally with a modification or sometimes, I’m told, simply by flooring the accelerator. The result is a noxious cloud of diesel soot that says as much about the driver’s anger as it does about his or her lack of concern for air quality or fuel mileage.

I’ve known about truck drivers – not to be stereotypical, but very few Jetta station wagons roll coal – who have “fun” blowing smoke at hybrid cars that draw their ire, mostly Toyota Priuses. (Prii?) It’s been called a form of road rage at either liberal politics generally, the environmental movement specifically, or both. There are videos to be found on the Internet and websites that sell merchandise glorifying the practice even though tampering with your diesel emissions controls is illegal nationwide and rolling coal specifically is illegal in many states.

Coal-rollers also target cyclists, presumably for the same antisocial reasons.

I hadn’t been the enemy until a regular lunchtime ride from our office in Chapel Hill, N.C. I had turned off a four-lane highway onto a quieter, two-lane county road, a favorite for local cyclists and one that during weekdays has the occasional bit of construction traffic. I was hugging the white line on the right side of the road, as usual, when I was passed by a red Dodge Ram pickup towing a trailer. Suddenly, I was in the middle of a black cloud, thick and acrid, which not only made it difficult to breathe but impossible to see. I felt lucky to emerge after a few moments having not ridden into a ditch.

Funny, huh?

Like many longtime cyclists, I’ve had my share of run-ins with drivers. I’ve listened to taunting and threats, had drinks and other objects thrown at me and once, on a century ride in Georgia, had a driver flash his pistol.

But never coal-rolled.

I suppose the driver could have vented his or her frustration by driving me off the road or just hitting me from behind. I’m grateful that didn’t happen. I’m not so keen on being doused with a Group 1 carcinogen.

After the smoke cleared, literally, I continued my ride trying to reconcile in my own mind why someone would want to purposely poison me, which led me to the larger picture of why some drivers hate cyclists, period, and will go to violent ends to make their point.

For the record, I don’t hate drivers. I’m one myself. I know the feeling of annoyance that can creep in when you’re stuck in traffic. (I’m from California, where road rage was invented.)

I’ve also been the two-wheeled voice of reason in countless discussions about whether bikes belong on roads at all. I’ll save time by saying that unless posted otherwise, they do. Absolutely. And it’s been proven in the U.S. and elsewhere that cities and towns that embrace cycling have a healthier population and a better standard of living. And yet throughout the country there are running battles about whether communities should accommodate cyclists, how and to what extent.

There are things we do as members of society that are by their nature inconvenient. I get that. We pay taxes. We wait in lines. We take our shoes off at airport security if we’re not TSA Pre-Check.

And there are things we shouldn’t do despite the inconvenience. We shouldn’t cheat on our taxes. We shouldn’t cut in line. We shouldn’t yell at the TSA agents.

And we shouldn’t try to hurt people.

So, to my coal-roller I’ll say this: I’m happy to share the road with you. All I ask is that you don’t try to harm me when you reciprocate.

[Spoker]

Had a stinking diesel pull over in the grass to let me by(on the bike) on a descend this week.
otoh I always hope to have one of those coal rollers behind me (in the car) on a 2 lane road. Make them feel what 30 mph is.

[9tubes]

I'm sensing some classism and stereotypes here :)




Jerks come in all classes. I make fun of all of them.

Anyone rolling coal in a poser truck wants to be stereotyped.

[Spaghetti Legs]

I got myself a John Deere jersey and am amazed at the respect it commands on the back roads of NC.

For real.

Good call. I save my Fly Navy jersey for days I expect heavier traffic.

[sipmeister]

You know how with some people you see them for the first time and wonder whether they are a real asshole?

Yep, I just smile and wave, and quietly thank the guy for eliminating the mystery. It's even better if he marks himself with a confederate flag or something.

Yeah those flags are another indicator!

[Clean39T]

Had a clapped-out Miata pass a diesel-dually on a double-yellow two lane straight road and almost take our group out from the oncoming lane today... And a dude in a minivan honk and flip us off again from the oncoming lane. Extended truck mirror come within probably 1-2ft of me at 50+mph, again on a two lane road with a double-yellow. Cops could be printing money w $1k tickets on these roads - never see a single one. Got coal-rolled three times today too. This was a group of 8-10 people, mixed women and men, riding two up or single file, w lights. God bless America.

Sent from my Pixel 2 XL using Tapatalk

[19wisconsin64]

The scary thing is that the drivers of those black-smoke gushing trucks are angry, often drunk, and have guns. Worse, they don't care and are antagonistic.

Stay safe, don't engage them...the only thing possible would be to report them with a video (?). Any confrontation would not end well for a cyclist.

Don't know if a camera front / back which would clearly show a license plate would be evidence enough for the police to do something if the video showed this extremely dangerous driving behavior. Would it?

[shinomaster]

From the late, great Performance Bicycle blog last year.

amen

[tctyres]

I can't really fault them for the Prius drivers...

Go ahead and explain this. I'm listening.

[Bruce K]

Basically a running joke from Top Gear...

BK

[TiminVA]

Weekly occurrence around here

[witcombusa]

Go ahead and explain this. I'm listening.

Let's just say that my driving likes do not align with Prius or EV mentality so a little 'coal' in their direction doesn't bother me at all.
The Prius drivers are off one end of the spectrum and the coal rollers the other!

You asked.

[mdeth1313]

I can't really fault them for the Prius drivers...


Not a great position to take. Opens it up for others to justify going after other groups. Starts taking on a larger scale and it's a slippery slope.

My wife drove a prius and then a prius V. Just switched over to a hyundai ioniq. When you commute 130 miles round trip getting 40-60 mpg is more of a financial thing.

[GregL]

Let's just say that my driving likes do not align with Prius or EV mentality so a little 'coal' in their direction doesn't bother me at all.
The Prius drivers are off one end of the spectrum and the coal rollers the other!

You asked.
Your statement is much more revealing about your mentality than that of hybrid/EV drivers. You’re making judgements based on someone’s choice of vehicle. Is that really fair to them? Would you want to be judged by your vehicle or (gasp) bike choice?

Greg

[rallizes]

Your statement is much more revealing about your mentality than that of hybrid/EV drivers. You’re making judgements based on someone’s choice of vehicle. Is that really fair to them? Would you want to be judged by your vehicle or (gasp) bike choice?

Greg

mentality, anatomy, could be any number of things

[Peter P.]

... You’re making judgements based on someone’s choice of vehicle. Is that really fair to them? Would you want to be judged by your vehicle or (gasp) bike choice?

Greg

Our choices DO reflect who we are. MAYBE not just ONE choice, but the more choices we are made aware of, the more accurately our conclusions may be about the individual.

[Andy sti]

The scary thing is that the drivers of those black-smoke gushing trucks are angry, often drunk, and have guns. Worse, they don't care and are antagonistic.


OMG, this is redicuclous.

[David Tollefson]

Coal-rolling happens so often it doesn't even affect me any more. Usually I just smile and wave, if I react at all. I figure as long as they don't hit me it's all good.

[dbnm]

If you think that rollin coal is somehow okay, you have a serious mental defect.

Purposefully making someone ingest toxic materials is simply wrong.

[peanutgallery]

OK, I'll bite

Unwrap this one for me? The bold type is yours

If you think that rollin coal is somehow okay, you have a serious mental defect.

Purposefully making someone ingest toxic materials is simply wrong.

[mg2ride]

If you think that rollin coal is somehow okay, you have a serious mental defect.

Purposefully making someone ingest toxic materials is simply wrong.

2 things are clear here:
1. The people doing it are Dbags
2. It aint going kill you

[Hellgate]

The scary thing is that the drivers of those black-smoke gushing trucks are angry, often drunk, and have guns. Worse, they don't care and are antagonistic.



Stay safe, don't engage them...the only thing possible would be to report them with a video (?). Any confrontation would not end well for a cyclist.



Don't know if a camera front / back which would clearly show a license plate would be evidence enough for the police to do something if the video showed this extremely dangerous driving behavior. Would it?Don't come to Texas... It is what it is.

I regularly ride, (you're going to faint) Ronald Reagan BLVD in the Austin area. Once I cross 1431 and the road name changes to Parmer to Ronald Reagan, 50% of the vehicles are crewcab, 4x4, lifted trucks. They're cool with cyclists, and many of them have... bikes in their beds.

Painting with a broad bush typically isn't the way to go.

[Matthew]

Had a guy do this to our group ride last summer. Then a few miles up the road after we made a turn he comes out of nowhere coming straight at us from the opposite direction and then veers back into his lane. Caused two of our riders to go down. And of course the POS kept going. I was on the front pulling when he did it. A little nerve racking to say the least. Fortunately only minor injuries.

[Clean39T]

2 things are clear here:

1. The people doing it are Dbags

2. It aint going kill youUnless you can't see, lose control, and crash...

The anxiety it creates ain't fun either, and honestly is why I'm largely quitting road riding until I move to some other area. It's stopped being fun at this point. And isn't that the whole idea of a hobby and healthy exercise?

Sent from my Pixel 2 XL using Tapatalk

[witcombusa]

Your statement is much more revealing about your mentality than that of hybrid/EV drivers. You’re making judgements based on someone’s choice of vehicle. Is that really fair to them? Would you want to be judged by your vehicle or (gasp) bike choice?

Greg

Judge away, I don't care what you think!
And as stated above, what pepole's choices are do define them.

[Seramount]

another AUS rider here...fortunately, coaling doesn't see to be a big thing here, have only had one loser try it on me.

the perp was a teenager with the 'gimme cap on backwards' fashion look in a brand-new, lifted 4x4 Dodge Ram (present from daddy?) festooned with multiple chromed shocks, huge tires, and gigantic exhaust pipes.

the kid released a huge cloud of soot as he passed, but there was a stiff lateral breeze that day and it all just went downwind without getting anywhere near me.

altho I did get a laugh from his feeble attempt at harassment, and there was no impact to me, it was still an overtly hostile act.

how anyone finds this kind of behavior funny or acceptable is beyond puzzling.

[AngryScientist]

one thing to consider is that "rolling coal" MAY not always be an intentional act.

unless the truck is newer and tuned just right, generally speaking when you step on the go pedal quickly the air/fuel ratio goes rich and black smoke pours out.

I can picture a plausible scenario where a truck may slow down to give a cyclist some space and wait for oncoming traffic to make a wide berth in order to pass, and then, after slowing down creating black smoke while trying to accelerate quickly and safely pass the cyclist as oncoming traffic allows.

of course many times it is intentional, but maybe not every time.

[Clean39T]

Judge away, I don't care what you think!

And as stated above, what pepole's choices are do define them.Not caring what other people think is also quite telling...and a choice that I'd say defines someone quite well...

I drive a Prius Prime (plug-in hybrid). It's a great car, and I enjoy driving it....stereo is excellent, seats are comfy, safety features are wonderful, and it's cheap to own/use. Does that choice define me?

If I need to haul big things, I rent the appropriate vehicle. The rest of the time I enjoy the efficiency of my right-sized car for moving my wife and me from home to groceries, hiking, restaurants, and seeing friends. It would be a different calculus if we had six kids, a Costco membership, and/or were general contractors.

Sent from my Pixel 2 XL using Tapatalk

[Clean39T]

one thing to consider is that "rolling coal" MAY not always be an intentional act.



unless the truck is newer and tuned just right, generally speaking when you step on the go pedal quickly the air/fuel ratio goes rich and black smoke pours out.



I can picture a plausible scenario where a truck may slow down to give a cyclist some space and wait for oncoming traffic to make a wide berth in order to pass, and then, after slowing down creating black smoke while trying to accelerate quickly and safely pass the cyclist as oncoming traffic allows.



of course many times it is intentional, but maybe not every time.True......but also infuriating in the case of commercial vehicles (box vans) that should be routinely checked for emissions controls and fined appropriately. Most rollers know exactly what they are doing and the police look the other way.

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[AngryScientist]

True......but also infuriating in the case of commercial vehicles (box vans) that should be routinely checked for emissions controls and fined appropriately. Most rollers know exactly what they are doing and the police look the other way.

Sent from my Pixel 2 XL using Tapatalk

i agree completely.

i wonder if this is a big problem in CA where they seem to take "smog" pretty seriously?

[Gummee]

I've found the best response to this type of exhibition by a member of the 'neck crowd, is a friendly smile and wave. They're just trying to get a cyclist angry while they chuckle and cheer as they speed off. But a smile...and a wave, that'll thrown them off and they'll soon realize it doesn't get the desired out lash as they had hoped. Eventually they'll stop. After practicing this method for about a year, I haven't been bother for almost 9 years now.

They're looking for you to get mad to somehow justify their actions. Smiling and waving has the opposite effect.

If you must yell something, yell something like 'I love you too!'

Then cuss as much as you want under your breath.

M

[Dead Man]

one thing to consider is that "rolling coal" MAY not always be an intentional act.

unless the truck is newer and tuned just right, generally speaking when you step on the go pedal quickly the air/fuel ratio goes rich and black smoke pours out.

I can picture a plausible scenario where a truck may slow down to give a cyclist some space and wait for oncoming traffic to make a wide berth in order to pass, and then, after slowing down creating black smoke while trying to accelerate quickly and safely pass the cyclist as oncoming traffic allows.

of course many times it is intentional, but maybe not every time.

Just kicking some smoke at you isn't the same. If there's any doubt, it's not "rolling coal."

---

I'd gone my entire cycling life without having ever been successfully rolled-coal upon (couple guys made half-assed failed attempts over the many years), until about two months ago. Now it's happened several times, and I've had things thrown at me, been shouted at, gravel very deliberately kicked up at me, and more. And what's worse, it seems to happen with higher frequency when I ride with my girlfriend than when I'm alone, and she won't even ride alone anymore because of how badly she gets harassed on her own- one guy a couple months ago even driving right at her head-on as if to hit her, before veering off honking and screaming at her.

It feels like there's been some kind of attitude shift out there. Bullying is suddenly cool. Was zur hölle?

[CMiller]

Your statement is much more revealing about your mentality than that of hybrid/EV drivers. You’re making judgements based on someone’s choice of vehicle. Is that really fair to them? Would you want to be judged by your vehicle or (gasp) bike choice?

Greg


+1

When we veer from bike discussion it becomes pretty clear how we aren't all on the same page. A lot of grumpy people on this forum.

[Gummee]

+1

When we veer from bike discussion it becomes pretty clear how we aren't all on the same page. A lot of grumpy people on this forum.

It's been really hot and really humid here in the swamp that is the DC area. Makes for grumpy people despite it not being winter

M

[rallizes]

They're looking for you to get mad to somehow justify their actions. Smiling and waving has the opposite effect.

If you must yell something, yell something like 'I love you too!'

Then cuss as much as you want under your breath.

M

this is actually what it is about IMO

let's just say some, uh, repressed feelings that need an outlet

[Dead Man]

this is actually what it is about IMO

let's just say some, uh, repressed feelings that need an outlet

since everyone is criticizing everyones analysis of everyone, i'll slip in my own:

while i understand the intent is only to be as insulting to the "bully" as possible, and it seems questioning a toxic man's sexuality is one of the more efficient ways of doing so, i think we should move away from using sexuality and sexual identity as a weapon, in general. really seems counterproductive to social progress at this point.

[Elefantino]

Good lord ... everyone needs to take a deep breath.

[Mzilliox]

Judge away, I don't care what you think!
And as stated above, what pepole's choices are do define them.

i drive a ford f250 and a vw wagon, define me...

this thread is so weird, and this forum gets weirder too with every one of these posts. like not a good weird.

[ceolwulf]

Good lord ... everyone needs to take a deep breath.

wait till the smoke clears, though

[tigoat]

I got coal rolled recently. All captured by both of my front and rear cameras in vivid detail. Sent the footage and filed a complaint with our sheriff's. They called the guy and were told it was unintentional. Basically they told me I am SOL. They also told me even with a violation it would be a minor fine.

[GregL]

I got coal rolled recently. All captured by both of my front and rear cameras in vivid detail. Sent the footage and filed a complaint with our sheriff's. They called the guy and were told it was unintentional. Basically they told me I am SOL. They also told me even with a violation it would be a minor fine.
Minor fines are still a deterrent. Coal rolling isn't funny, it's illegal. Modifying a vehicle's emissions system is illegal in many (all?) states. It's also a specific violation to deliberately "roll coal" on other road users in multiple states. These points have nothing to do with the demographics of coal rollers. It's the law, plain and simple. Let's not argue over the motivations of coal rollers. Ad hominem attacks are not going to be effective. Stay calm and report the coal rollers to legal authorities. Tickets and fines are the best way to stop this practice.

Greg

[redir]

Rolling coal is just another way for some men to compensate for their shortcomings. So don't take it personally.

[19wisconsin64]

Nothing wrong with large pickup trucks, or their drivers....unless they "coal roll", or drive aggressively around cyclists. The bad drivers are few and far between, but they are there. Right now, I'm in Missouri, so while there are 99.999% good people with trucks, a few bad ones make it scary to cycle. That's all I'm saying.

[goonster]

unless the truck is newer and tuned just right, generally speaking when you step on the go pedal quickly the air/fuel ratio goes rich and black smoke pours out.

Sorry, but not really. The Cummins/Duramax/PowerStroke trucks that do this are all modified with injectors and software.

Older, clapped out dump trucks, and such, may be a different story, but any 21st century truck belching soot is pretty much doing it on purpose.

[Clean39T]

Newer full-size trucks can get low-20s running regular gas and are fine purpose-built rigs. It's a lifted diesel monstrosities with illegal mods we are talking about here. There are plenty of clean'ish diesel trucks out there driven by reasonable people going about their business. They aren't the problem.

[C40_guy]

one thing to consider is that "rolling coal" MAY not always be an intentional act.

unless the truck is newer and tuned just right, generally speaking when you step on the go pedal quickly the air/fuel ratio goes rich and black smoke pours out.

I can picture a plausible scenario where a truck may slow down to give a cyclist some space and wait for oncoming traffic to make a wide berth in order to pass, and then, after slowing down creating black smoke while trying to accelerate quickly and safely pass the cyclist as oncoming traffic allows.

of course many times it is intentional, but maybe not every time.

I had a Volvo 145 with worn rings that would do this. :)

[Tickdoc]

I live in what feels like the coal rolling capital of the world. Nine times out of ten the sooting of a cyclist is intentional. I can usually hear the turbos spool as they are beginning to pass as they have to time the event to pull it off properly. As I understand it, they intentionally leave the additive out to get a good black smoke.

It is a fineable offense here, but I know of no-one getting fined for it.

Just smile and wave is my usual response.