Daniel4

I'm guessing the drivers who do this don't have the foresight to anticipate what would happen if things went wrong. It could cost them a paint job or some body work.

Capt_Sensible

Happened to me a few years back. Commuting to work in very heavy rain along a fairly quiet residential street, a driver coming up behind apparently took exception to my positioning to pass a line of parked cars. He/she first tried to pass me on the right and was blocked by the parked cars, then swung around behind and passed me on the left before cutting directly in front and slamming on the brakes to a hard stop. Even though I reacted very quickly and hit the brakes hard, the conditions were so wet and the car so close that I ended up slamming into its rear. The driver then sped away and unfortunately I was only able to get a partial plate number. There were no other witnesses and the cops, though sympathetic, were not able to do anything. The result was 15 stitches on my right hand and a badly bent fork (no frame damage fortunately). This is the first and only time I've been hit by a car in over forty years of riding on public roads.

+1 to not reacting to provocation and letting the cops deal with the homicidal loonies, but not sure what else I could've done in this case.

Rollfast

What about your paint and body? If you use a large heavy blob of steel as a threat or weapon you may have a breaker tripped.

Hondo Gravel

I’m lucky to have easy going country folks living where I ride gravel and paved roads. Many times when taking a break people have stopped to see if I needed anything and have been offered rides when fixing a flat tire. There is not much through traffic where I ride so most vehicles are residents so I would guess that would be a factor. Generally the people don’t care about sharing rural roads with cyclists so I haven’t encountered any road rage incidents.

JohnnyCyclist

I do the same. No harm, no foul. There are few cyclists where I ride, and I'm easily recognizable by my kit + "daytime running lights", so to have the po-po give them a talk might result in them seeking revenge if/when they see me again.

unterhausen

Just hit the car, it's satisfying. Works best if you are riding a crummy bike and they have a car with a vertical rear end.

Dchiefransom

Caltrops

prathmann

This has nothing to do with reaction times. The basic physics of bicycle geometry limits your maximum deceleration based on where your center-of-gravity is relative to the contact patch of your front tire. Fat bikes may be a bit better than typical road bikes, but unless you can first move your weight back from the normal position your maximum deceleration is limited by the tendency of the rear of the bike to lift and eventually toss you over the bars. OTOH, a car's deceleration is just limited by the coefficient of friction between the tires and road.

berner

There are a surprising number of maladjusted and angry people in the world. the worst is that their numbers seem to be on the increase.

Hypno Toad

A typical cars requires 45 feet to stop from 30 mph; a bike can do it in 35 ft.

Honestly, it's not just with fatbikes, but with larger contact patches and huge rotors you do have more stopping power. However, I can attest to having had cars aggressively stop in front of me and been able to stop quicker. Maybe the driver didn't apply 'full' braking power ... didn't get to ask.

Yes, you have to get out of the saddle and get your weight over the rear wheel, and that is the reaction-speed... how quickly you shift your weight - and bike handling to modulate the brakes to avoid the OTB. I've lifted the rear wheel off and maintained control, scary as *** but not an automatic launch over the bars.

If you really want to dive in on this subject, here's an old thread: https://www.bikeforums.net/advocacy-...-distance.html

prathmann

I already participated in that thread - see post #2. It seemed to me I was in the majority and the group with the most facts and figures in supporting that, in general, the car can stop faster. Now if you have a very skilled cyclist, he has enough pre-warning to get into the right position, and the car has lousy tires, then sure the bike might stop quicker.

But a car with decent tires should be able to stop at about 1g, good sport or race car tires can do even better. In that case, stopping from 30 mph (44f/s) should take 44/32 = 1.375 sec during which it travels 30.25' with no particular driver skill being needed.

And note that in the case you're discussing where the driver initiates a brake check there's no reaction time involved in the case of the driver, but the cyclist has to first recognize that the car is braking, then position their weight far back to avoid an endo, and finally apply the brakes to the point of almost, but not quite skidding the front wheel. Even if all that is done perfectly in zero time the bike will still lose if the car has decent tires and the driver does a hard stop.

I don't doubt your personal experience since I don't think most brake-checkers are actually aiming to create serious injury (who really wants dents and blood all over their trunk lid). So they may well have held off on their braking. But I wouldn't advise anyone to rely on that in all such situations.

CB HI

^^ +1

Hypno Toad

Don't forget following distance, I'm never going to be 5 feet off the back bumper; that following distance offer the safe braking distance needed. I am a defensive-driver/rider.

It is totally true that a person driving needs no skill to push the brake to the floorboard and a person on bike will need strong skills to manage max force braking. I wouldn't suggest every person on a bike can brake faster than a car... and if the car is high-performance, the car will brake faster than even the best biker.

Lastly, I agree, when encountering brake-checkers (in car and on bike), they are typically trying to make you mad... they don't want a collision. It would take a person with murderous intentions to brake-check me and cause a collision.

rachel120

There is one time though you can't have a safe following distance, the exact situation the OP faced. When a car passes you (no difference between you being on a bike or in your own car) and cuts back in just a few feet in front of you and immediately slams on the brakes, there is zero time to back off to a safe distance prior to the sudden stop/slow.

Hypno Toad

Post #5 in this thread:
Bold added for emphasis.

It is stressful to have a driver do something stupid and hateful like a brake check. Not everybody on a bike has the ability to handle their bike the same and not all bikes are equally maneuverable. Also if the person driving that car really wants to run down a person on a bike... there's very little chance you'll avoid that murder.

In my experience*, a defensive rider with a well-maintained bike and decent bike handling skills will be able to avoid most collision (except the aforementioned murder), just like the OP avoided a wreck.

* Decades of bike-commuting, year-round, in rush hour traffic does a lot for your ability to read traffic and hone your bike-handling. Also many years driving for one of the best trained fleets in commercial driving did a lot for my defensive driving/riding.

ItsJustMe

In general at the same speed, modern cars can stop faster than bikes can. Also factor in your reaction time; they're already braking at the beginning of your reaction time.

Hypno Toad

Let me try a different angle on this dialog: has anybody on BF rear-ended a car/truck that did a brake-test?

I openly admit, that I have no idea if I can out braked a car/truck. I have come to a very fast stop when a vehicle stops in front of me. Also, I have used braking and maneuverability to avoid collisions when a vehicle hits the brakes.

My one experience rear-ending a vehicle was purely rider error - back when I was a dumb college kid, a city bus was in front of me making a right turn, I was going straight and moving fast, I wanted to get around the bus on the left. It was a busy city road at rush hour so I was looking over my left shoulder and failed to see that the bus came to a complete stop. I clipped the bus with my right shoulder, knocked me down, happy the bike didn't hit the bus so I was able to get back up and ride the rest of the way home.

In summation, with 5,000 to 6,000 miles of riding a year in urban and suburban environments, I've been brake-tested many times and the only collision I had wasn't a brake-test and was my fault for not being a defensive rider.

mr_bill

I’ll be honest, I’m not shocked.

-mr. bill

rachel120

I'm not sure if a car can stop more quickly or if a bike can stop more quickly. Not going to test it myself. But one good point was brought up. Mechanical speed is not the entirety of the factors at play. The driver of the car in front of you has already mentally planned how close in front of you he's going to cut back in and then immediately slam on the brakes. You are not going to be aware of it until after the brake lights come on. Typically most people who brake like that are only slowing down 5-10 mph quickly, so not only is the person behind having to react to brake lights on, the person also has to realize how hard the stop is. If you default to "they are always going to fully stop" then you will be slamming on your brakes too much for every quick slow down and you'll be the one smacked in the rear end at some point due to your own bad defenses.

To my shame I used to know a couple of people that were hot headed enough and drove crappy cars and would teach someone behind them a lesson by forcing a rear end collision. Cutting in far too close and slamming on the brakes hard. Assuming the couple of people I know are average for people who do that, they don't care if they get hit in the rear by a car. Why would they fear a bicycle hitting them if they are ticked off enough? No amount of defensive bicycling will avoid such an encounter if the motorist decides to teach the bicyclist a lesson in a way that might get them off the hook legally.

Hypno Toad

I feel so special that you read my posts and cherry-picked text that makes me look foolish... like I've ever needed anybody's help to look stupid.

Since you read the posts, I know you understand the point - there's no way to know if the person driving in front of you make a full force stop or just 80% force.

I know that I've never collided with a vehicle when the driver slams the brakes; it's happened to me a lot over the years and I've been able to stop and/or maneuver around the vehicle without a collision.

To repeat earlier posts: if the person driving wants to cause a collision, they will likely cause a collision. That kinda hateful person is thankfully rare.

Happy now?

I-Like-To-Bike

So rare that I've never seen it in 65 years of cycling. Never heard of hateful motorists wanting to cause collisions with cyclists being any sort of problem except for reading on the BF about this issue from some posters who seem to have an inordinate number of negative encounters with the driving public.

jfowler85

This has quite a bit to do with reaction times - the faster you can shift your weight and thus your center of gravity to the rear, the more leverage is required to move your center of gravity over the pivot point and thus the faster you can stop. You can do this while decelerating in anticipation of a panic stop, which is what the poster to which you responded was alluding to.

Daniel4

You're so lucky to be so blissfully unaware of all the hazards the rest of us have been diligently avoiding.

I-Like-To-Bike

And you continue to enjoy wallowing in self pity and paranoia about all the hateful motorists trying to do in the "rest of us" whom you think you represent.

italktocats

you randomly bring this up with people you meet or wait for them to tell you all about their murderous fantasies?

pretty much every car will stop quicker than a bicyclist will, at least at the speed it matters, 20mph and up

pretty much every motorcyclist will stop quicker than a car, at pretty much any speed

but obviously if some $#&* cut into your path, youd go around em, dont try to outbrake