ThermionicScott 

I'm a "cager" more of the time than not. Not trying to "appease" anyone so much as to do my part in not holding up traffic.

Rhodabike

When you go faster and minimize the difference in speed between you and motorized traffic, they have more time to see you and react to your presence. So yes, you are safer when going faster in traffic. If they're doing 60 kph and you're doing 25, it's as if you've reduced their speed to about 35 or 40 kph.
That's why riding head-on into traffic is so unsafe - riding against traffic at 20 kph effectively increases their speed to 80, in terms of reaction time.

DJ Shaun

I've noticed this when I ride my winter bike (ie. slower bike). I get passed much more and often unsafely. And that's on roads where snowbanks aren't an issue.
When I ride my roadie-hybrid I can go fast enough (~40kph) on many parts of my commute that most cars don't bother passing me in the same lane.

Walter S

I think you're right. I've been experimenting the same way and see it the same as you. I doubt it's the relative difference in speeds. If a car is going 40 they probably can't tell much difference between you at 15 and you at 20. It's the bicycle rider that feels like there's a big difference.

It could be like you say, they see you trying hard so they're more understanding. Or that you seem less predictable. I don't know. I tend to think the later. I guess I think people are pretty selfish about their "mission" in a car and don't give you much consideration out of sympathy. It's more to avoid an accident.

So I wonder if I/you could go slowly but look like you're trying hard??

CB HI

Cars still just 'as' close, is not true. At higher speeds, motorist are less comfortable passing a cyclist as close. They will fully change lanes to pass more often at higher speeds.

B. Carfree

I ride many of the same roads either solo or with my wife with each of us on our own bike or on a tandem. It is pretty clear that while lane position is an extremely important factor in the quality of the passing movements by motorists, my speed may be even more important. When I/we are humming along at 25 mph on a road with 30 mph cars, the few motorists that pass completely leave the lane to do so. When we are traveling at my wife's speed, about 12-15 mph, we are buzzed mercilessly.

erig007

Not so easy. The risk of accident is the product of damage to impact and probability of occurrence. For instance, a plane crash would create a huge damage to passengers but its probability of occurrence is very low vs car accidents. If you ride against traffic the damage to impact could increase due to a higher relative speed but the probability of occurrence not necessarily. Some of the probability of occurrence will increase when the time to react decrease due to the higher relative speed, there is also the increased number of cars that will pass you. But riding against traffic allow the cyclist to see vehicles coming with greater visibility. There is also the fact that now the cyclist can react too because of the added visibility (not necessarily in a good way) when both ride in the same way it's essentially the driver coming from behind who see the cyclist and have to react to avoid the cyclist.
But there is also accidents occurring at crossroads and other accidents like opened car doors...

vol

The faster you ride, the worse the injury when you have an accident.

erig007

The faster you ride, the worse the injury WHEN you have an accident. Like i said before probability of occurrence matter as much as damage. The damage could be bigger with an increase speed but as long as you don't have any accident the damage is null.

Leisesturm

I've read some pointless threads in my life but this one is an order of magnitude in the unbelievable category. Fietsbob is on only poster even remotely cogent, perhaps one or two others but my eyes were pretty glazed after 8 or 9 posters actually agreed with the o.p.'s premise that a piffling 5 or so miles per hour made some kind of difference in the grand scheme of things. Lance Armstrong works hard to sustain 25mph, the rest of us work hard to sustain 20mph. Quite a few are maxed out at 16mph. IF cycling is safer at 20 mph than 15mph... ... I guess a lot of us should just sell our bikes and take the bus because, tell the truth, a lot of us can't GO 20mph.

H

Leisesturm

I think this thread should be locked for everyone's safety...

erig007

Maybe you could add more words to your sentence in order for it to be meaningful because right now i call it trolling.

By the way, I did a small check to see what difference there is for a cyclist between 15mph and 20mph. I found out that the kinetic energy of the cyclist with the bicycle nearly double from about 2.7KJ to about 4.8KJ. I chose a weight of 120kg (cyclist + bicycle). Now how the energy is dissipated is another matter.
I also have in my bicycle directory official data of stopping distance of cars on dry and wet roads. The stopping distance on dry roads more than double when the car speed increase from 31mph (50km/h) to 43.5mph (70km/h), 38.7ft (11.8m) and 84ft (25.6m) respectively. I suspect it is only a guideline as the road quality and car specificity matter as well.

Telly

Had this conversation with co-workers that didn't cycle and it all came down to the above statement.

Astrozombie

Speed is your friend, worked so far and yes looking more like a roadie and less like a Fred does get you more respect.

CB HI

The dynamics of a bicycle crash can be so complex, such a flat statement is far from the truth.

Such a statement is likely true for head on collisions with hard surfaces like motor vehicles.

A slow speed crash can cause you to endo and dump you directly on your head with serious injury.

A how speed crash can cause you to skim across the road surface with only road rash.

jyl

Start of a new week, everyone should be full of pep! You believers in "slow", try going out there and cranking up the speed, see what you think. You believers in "fast", try going out there and cruising slowly, see what you think. Report back!

Please don't try this experiment on a 50 mph limited access or maxi-arterial road w/o bike lane or shoulder - or, to take the other extreme, don't go time trialing at top speed through the nursery school playground . . . as I said, my theory about "fast = safe" only applies to 25-35 mph city streets.

jrickards

It is interesting that you say this because "increased speed = increased focus/attention" is one of the reasons why our province is considering moving the maximum speed on highways (that have suitable road condition/construction) to 110kmh (70mph).

spivonious

I ride 15-20mph and I don't get close passes. You need to move farther into the lane if there's no shoulder or bike lane.

Granted, these aren't city streets, so maybe suburban drivers are different.