possible pea
Years ago I was heavily into bikes and would ride pretty much every day. My mate and I would finish our daily toil and go to his so he could change into his gear and get his bike then he'd give me a lift, pillion to my house for me to do the same before our blast round the countryside.

One particular day we were en-route to mine and were followed and stopped by a panda car. "Do you realise what speed you were just doing?"
"Not really"
"You were doing 40 in a 30 zone and your passenger isn't even wearing a helmet"
"We're really sorry. We're just on our way to get it now."
"How far away does he live?"
"Just a couple of streets down there." *points*
"OK he walks and don't let me catch you again."

Oh, we were 11 and riding a ten-speed racer bicycle.
(Greencloud Wanted to go fishing on, Mon 9 May 2011, 16:24, 22 replies)

40mph on a bicycle?
That's quite impressive.

Sorry, I meant a blatant lie.
(TheColonel, Mon 9 May 2011, 16:38, closed)

You horrible troll bully warrior racist.

( Dr. Shambolic je suis charlie, Wed 11 May 2011, 8:35, closed)

Cool.
So he cycled faster than a pro cyclist at full sprint? On a normally-geared bicycle? With somebody on the back? At the age of eleven?

This is certainly the most completely true thing I have ever read on the internet.
( Dr. Shambolic je suis charlie, Mon 9 May 2011, 17:27, closed)

Those poor billy goats.
They wouldn't stand a chance here eh?

I did leave out the fact it was down a rather massive hill though. Exaggeration by negligence be my crime. Not lying. Want the street name to check a topographical map??
(Greencloud Wanted to go fishing on, Mon 9 May 2011, 17:40, closed)

Its ok
I know loads of hilly roads too
(Dan dan dan They tik urh jerbs!!!, Mon 9 May 2011, 17:45, closed)

I bet the passanger did have a helmet too!
You can't trust anyone these days.
( Ungersven would support SpankyHanky's patreon, Mon 9 May 2011, 18:22, closed)

You're still lying.
And also: www.b3ta.com/questions/greed/post1174534/
( Dr. Shambolic je suis charlie, Mon 9 May 2011, 19:13, closed)

You warrior
Have you ever been far enough from your armchair to ride a bicycle?

In fact, you know what? I'm totally lying. I only wanted people to think i'm big and tough and cool, like you.








Twat.
(Greencloud Wanted to go fishing on, Tue 10 May 2011, 0:43, closed)

Smashing.
You're still a liar.
( Dr. Shambolic je suis charlie, Tue 10 May 2011, 19:20, closed)

Not necessarily
I do a fair bit of cycling in the countryside and there are three or four hills on my normal route that I regularly hit 30-35mph on without pedalling. 40 would be pushing it, but with a long steep hill it could be possible. Being eleven would give you the advantage of being smaller - less wind resistance.

As for my speeds, I measure them with a gps reciever that I originally bought for navigating while skiing. Better accuracy than a car speedo.
( MatJ LOOK, Tue 10 May 2011, 1:10, closed)

Ithankyou
I still cycle to work on occasion and generally manage to AVERAGE about 12 or 13mph on a flat route. That's an 19stone 6foot bloke under my own steam. The hill is about 3/4 mile with a decent grade and only one twist. 40 would be possible but breaking 30 a piece of piss.
(Greencloud Wanted to go fishing on, Tue 10 May 2011, 8:04, closed)

A fat mess and a liar.
Double win.
( Dr. Shambolic je suis charlie, Tue 10 May 2011, 19:20, closed)

Oh come on
Where's the satisfaction? There's nothing much wrong with the OP, and harpooning a fish after you've already hooked it seems a little pointless.
( MatJ LOOK, Tue 10 May 2011, 21:39, closed)

Don't you oppress my rights as an indigenous hunter-gatherer!
The story is demonstrably bullshit. He knows it's a lie. I know it's a lie. I don't know why anybody should get pissy with me for pointing it out.
( Dr. Shambolic je suis charlie, Tue 10 May 2011, 22:19, closed)

Which bit is bullshit?
40mph on a pushbike is far from impossible downhill.
( MatJ LOOK, Wed 11 May 2011, 12:31, closed)

All of it.
40mph is faster than the terminal rolling velocity on hill more than a mile long averaging 1 in 8 with no turns and assuming a seriously efficient bike and a rider weighing 100kg. Two eleven year olds would have to be in the top fifth percentile of fat biffers to weigh that much put together and their rusty old racer would be several times less efficient.

And given that the cadence at 40mph for a normally-geared childs racing bike would be comically fast, you'd have a job to keep up let alone add any power. So terminal rolling velocity is as fast as they'd ever get.

The story is made up. I don't know why I'm the one who has to spell this out given that the very first person to respond to the thread said it was a blatant lie.
( Dr. Shambolic je suis charlie, Wed 11 May 2011, 14:01, closed)

I see your point, and I agree that it's not possible for a 1 in 8 gradient
But there's no reason to assume a 1 in 8 gradient. A quick google search turns up plenty of streets around the country that are considerably steeper than that - I could walk a few hundred yards out of my front door and find one. I think the steepest you could reasonably expect (without talking about rare outliers) would be about 1 in 4.

Edit: OK - Taking the formula in this post (quoted as coming from DiPrampero et al., 1979) as a start, I put in a few likely values. Using a 10 degree hill (~1 in 4) with a combined bike and rider mass of 80kg, a front surface area of 0.7 and a drag co-efficient of 0.7, the terminal velocity comes out at 38mph. 0.7 is on the high side for a frontal area, so I think it's safe to assume the terminal velocity won't be less than that. The question then becomes whether or not they would have had time to get close to the terminal velocity - since drag varies as a square law I think it's a fair assumption that they could have come within 10-15% even on a relatively short hill. If the hill was steeper than 10 degrees or the bike was heavier than normal then it becomes easier.

So I was wrong to say it would be easy (I thought the terminal velocity would be higher than that) but I maintain that it's not impossible.
( MatJ LOOK, Wed 11 May 2011, 17:40, closed)

So even with a hypothetical mile long 1 in 4 straight hill and assuming the pillion rider has no legs to add to the drag you've still not hit even a theoretical 40mph.
Kids were telling tall tales about being speed trapped on bicycles at least as far back as the 1970s. It was balls then. It's balls now.
( Dr. Shambolic je suis charlie, Wed 11 May 2011, 19:10, closed)

It wouldn't have to be a mile long and they could have tucked down and and and...
OK, I was wrong.
( MatJ LOOK, Wed 11 May 2011, 23:05, closed)

Let's hug until the bad man goes away.

( Dr. Shambolic je suis charlie, Wed 11 May 2011, 23:23, closed)

I've done 30mph on a bike downhill without pedalling
I fell off, mind you.
( K2k6 has a proper job these days, Mon 9 May 2011, 18:35, closed)

I remember being given a 'backie" down a steep hill at about that age
We didn't get stopped by the police, but I did scream like a sissy girl.
( Colonel Dracula Two manky hookers and a racist dwarf, Tue 10 May 2011, 12:09, closed)