3/23/2010

03-23-10 - Pinnacle

Bike Snob NYC is really the pinnacle of internet comedy.

I believe there are two major forms of comedy that have been primarily developed by the internet; obviously these existed before, but they have been honed and perfected and seen their hayday in recent years. One is the sardonic / snarky condescension comedy, done so well by Surly Gourmand , but this also goes back to stuff like "Old Man Murray" ; basically in this form you humorously point out how retarded everyone else is. The other major internet comedy form is the "meme" ; this comedy form primarily lives on web forums, 4chan and /b/ being the primary nexus, but most major forums create their own memes. In this form you create a neologism or repurpose a word into a reference, and then it is used repeatedly in humorous ways. The meme is really only super funny if you know the history of where it came from.

Bike Snob combines the snark and the meme to optimum effect. The really amazing thing is that he also pulls off the snark without bile, and he creates all his own memes rather than just stealing them from the net. When you first read Bike Snob you don't really get it, but after following for a few weeks, you see the creation of memes, then the development of their humor value, and then they become funny just any time he drops them.

Linkage :

Quantum Diaries Survivor is a pretty damn good physics blog.

I can never get enough of Denny regrade photos

Scans of Vintage Bicycle Advertisements - Diablo Scott - Picasa Web Albums

Name Your Porsche - in case you thought your Porsche wasn't douchey enough already, you can name it "Bruce". "Bruce" !!

McLaren Automotive officially launches itself and MP4-12C supercar - yeah this thing is pretty fucking hot. The funny thing is that for the masses of technology they put into these super high end cars, they get microscopic returns. It's technology porn really, it's technology for its own sake, to drool over, not to do anything. If you look at the C&D Lightning Lap results for example, the WRX and the Speed 3 are great values at about $25k for a 3:15 lap, and the closer you get to the top the more ridiculous your cost per second gets. Obviously you're paying for looks and feel and so on, the focus on power and speed is all wrong.

fastestlaps.com View topic - airdrag... factory claims vs car magazine tested numbers.. really sweet page of photos and results from the german magazine "Sport Auto". (note that the photos are fakes though still very interesting - the actual runs for Cd are done with much higher air speed and with the wings up, the photos are taken at low speed air flow where you get those nice laminar lines; the real high speed flows have a lot of turbulence wakes; if more photos like this exist, let me know). The key number is not "Cd" , the coefficient of drag, but rather "CdA" , and of course downforce is very important too. The GT3 has very impressive aerodynamics.

Compact Crank Overload - all about the "compact double". I highly recommend compact doubles for all bikes. Sadly my Litespeed is on a 130 BCD crank and I don't want to have to replace the whole crank so I'm fucked.

All About Motor Oil - in case the last one I posted wasn't enough

Aldo's Pic of the Day - classic cycling photos.

14 comments:

Aaron said...

"the closer you get to the top the more ridiculous your cost per second gets."

Is that true even if you account for the fact that small improvements in track times mean more the shorter the track times get? Using BS absolute numbers, getting from a 5 min lap to a 4:45 lap is much easier than getting from a 2 min lap to a 1:45 lap. It seems likely that the fastest cars that are only a tiny bit faster in absolute numbers feel and are significantly faster, even though the absolute numbers differ by only a little bit.

cbloom said...

Yeah you're definitely on to something there.

If you measured performance as a percentage of what is possible given the limits of aerodynamics and the traction of rubber on asphalt, the highest end cars are getting awfully close to the limit of what's possible it seems (if you forbid slick race tires and huge wings).

And of course in terms of "feel" there are tons of other factors. An Elise can feel faster than an M3 because you're lower, it's lighter and stiffer, etc. An Atom or Seven is pretty fast but feels even faster because you're so exposed.

cbloom said...

It's still a matter of diminishing returns though. I think it's an exponential cost thing. It takes double the engineering to go a fixed increment faster. (or for each fixed increment more of engineering you only get half the payoff each time).

The question is - is human perception on a linear scale or log scale?

B. Landers said...

@Aaron

You need to remember that speed is a function of distance in time (that is speed = distance / time.) The cars at the top feel faster because they ARE faster. A LOT faster. Even though the time of the top cars vary ever so slightly, that small difference in time makes a huge difference in speed the closer time gets to 0. This is because speed varies inversely with time.

Let's actually work out some sample numbers to illustrate the point. To simplify the problem, let's ignore acceleration and say that a vehicle can reach its top speed instantaneously (it comes out of the gate at its top speed.) Also let's suppose these cars have to travel 5 miles.

Using your numbers:
Car 1: Finishes in 5 minutes - Travels at 60 MPH.
Car 2: Finishes in 4.75 minutes - Travels at ~63 MPH.
Car 3: Finishes in 2 minutes - Travels at 150 MPH.
Car 4: Finishes in 1.75 minutes - Travels at ~171 MPH.

See the difference? And just for kicks:

Car 5: Finishes in .1 minutes - Travels at 3000 MPH
Car 6: Finishes in .09 minutes - Travels at ~3333 MPH

At these ludicrous times, in order to shave off just 0.6 seconds you need to travel over 300 MPH faster. That's why at the top tier it costs so much to get even the most meager of improvements in time: it's because you have to make significant improvements in speed.

Aaron said...

I bet you can feel the difference. Or at least, you can imagine that you can. Feel-wise, a person probably have a hard time telling the difference between 0-60 in 5.5 seconds versus 4.5 seconds.

sly-id said...

Approximation with const acceleration:

0 to 100kmph in 5.5s ~ const acceleration of 4.5km/s²

0 to 100kmph in 4.5s ~ const acceleration of 5.6km/s²

That's a 25% more powerful acceleration, most people would notice the difference :)

B. Landers said...

Yes you would feel the difference. Just jumping straight to the numbers:

#Assuming linear acceleration
#Also assuming you weigh 150 lb
0-60 in 5.5 seconds - F = 74.66 lb
0-60 in 4.5 seconds - F = 91.13 lb
0-60 in 4.0 seconds - F = 102.52 lb
0-60 in 3.5 seconds - F = 117.17 lb

So yes, you would feel the difference. One way to describe what you felt would be if someone were to place a lead sheet weighing such and such pounds on top of you.

Aaron said...

Sure, an accelerometer would tell the difference. Not sold that a person would be able to tell in a real in-car experience. Esp with two very different cars getting you there.

Aaron said...

BikeSnobNYC: laugh out loud funny. "Topolino Rolling Abortion" put milk through my nose.

Tom Forsyth said...

The difference between 6.5, 4.5 seconds and 3.6 seconds is trivially obvious.

The real measure of acceleration (and braking) is "how much visibility do you need to safety overtake some twit doing 35". In those terms, the difference between those three times is gigantic.

cbloom said...

Yeah of course, but I don't know where you all are getting your sample numbers. The acceleration numbers of most of the cars are more like 4.5s vs. 4.3s for another $10k

Also in terms of feel I think the "jerk" (rate of change of acceleration) may actually be more important.

eg. a car that does 0-60 in 5s with constant acceleration will feel pretty smooth , a car that does 0-60 in 5s with a big turbo lag and sudden kick will have a huge jerk when the turbo kicks and the thing that you will feel as "acceleration" is actually that moment of jerk.

When someone mashes the throttle and it jerks your head back, that's the jerk.

Another way to see it is the 1 g from the earth is more acceleration than these cars, but if you jump off a ledge you don't feel like you're accelerating really hard during that moment of free fall, because there's no jerk.

Aaron said...

@B regarding lead sheets:

0-60 in 5.5 seconds - F = 74.66 lb
0-60 in 4.5 seconds - F = 91.13 lb

I lay a lead sheet on you weighting 75 lbs (but don't tell you the weight). I then remove it, and have you go take a walk, and come back. I then lay a lead sheet on you weighing 91 lbs (and again don't tell you the weight). How confident are you that you'd know which one was heavier? Similar problem: try to guess which of two watermelons is heavier in the grocery store without using a scale. For me almost as soon as I put one down I can't remember what the weight was. My arms get tired from holding them. I lose context, very very rapidly. In a car it's confounded even more, because in one car I might lay the 91 lb weight on you gently, and in the other, the 7 5 lb weight I might just drop it on you all the sudden (charles' 'jerking' argument).

There is definitely a snapover point where you are pretty likely to tell the difference, but I'd bet its something like nearly doubling the forces or so before a person could reliably tell the difference.

B. Landers said...

@cbloom
The sample numbers I generated were assuming constant acceleration. I made this assumption to simplify the results and demonstrate that you could possibly feel the difference in force between different cars.

In practice, vehicles have non-uniform acceleration. So yes, the jerk would become important as different cars would have different acceleration curves and so the force you feel would be dependent on time. The "snapping" feeling is when the acceleration instantaneously changes (meaning there'd be a pole in the jerk curve.)

@Aaron
I predicted that you could feel the difference between 75lb and 90lb from my own experience but to answer a subjective question like "can you tell the difference car acceleration", it'd be better to leave it to experiment. Like you said, there's just no way to tell how accurate a person is as a force probe without testing.

Oh also dropping the plate and placing it on gently would not affect the jerk. The only difference is the dropped plate would have an initial energy greater than 0 and when it hits that energy is transferred. To demonstrate jerk you'd need to attach the plate to a spring.

Tom Forsyth said...

> but I don't know where you all are getting your sample numbers.

3.6, 4.5 and 6.5 are the 0-60 numbers for the three cars I own. The respective list prices if bought new today are $86k, $55k, $25k. Is my fastest car 3.5x more awesome than my slowest car? Hmmm... I think probably yes.

When you add in the childishly obnoxious factor that it's also far more awesome than the cars *everyone else* is driving, 3.5x seems like an absolute bargain!

old rants