Single bikes are scary!

Clive George said:

Still, got to 55 on the way down the nice straight hill into Cowside, which
is a new record for me on my own :-)

I'm always impressed by the people who can break 50mph. Do you just
coast or are you pedalling like mad?

I've managed 49.9mph on a bike with a 48/13 ratio which works out as a
cadence of about 177 which was absolutely flat out (for me) and
stopping pedalling meant the bike slowed down.

If we assume a 52/12 ratio and a 206cm circumference, 55mph needs a
cadence of 166 which is still pretty extreme.

What sort of gearing do people have on their bikes?

Tim.

[email hidden] said the following on 26/06/2006 09:13:

Quoted message said:

I'm always impressed by the people who can break 50mph. Do you just
coast or are you pedalling like mad?

I've only ever done it twice, both times when I was a darn sight younger
and scaring myself [censored] in the process, and that was coasting down
hills. Pedal? I didn't dare do anything except close my eyes!!!!

And this was steel rims with those ever-so-wonderful leather brake
blocks. Braking at the bottom took a long time for anything to happen...

--
Paul Boyd
http://www.paul-boyd.co.uk/

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Clive George said:

Still, got to 55 on the way down the nice straight hill into Cowside,
which
is a new record for me on my own :-)

I'm always impressed by the people who can break 50mph. Do you just
coast or are you pedalling like mad?

In this case, pedalled a 52/13 gear on 210cm circ. wheels to somewhere in
the high 40s then got in a tuck - there was a pretty good tailwind. I've not
managed over 44 or 45 on that bike before - but then I tend to do the
steepest hill on my normal rides with a headwind.
When I was younger I got to 49 with a 46x12 in the same situation as you
with 48x13.

The road tandem has 50x11 on 195cm circ. wheels, which is a bit easier - I
think we've pedalled at 55, possibly more.

cheers,
clive

Quoted message said:

I'm always impressed by the people who can break 50mph. Do you just
coast or are you pedalling like mad?

I've managed 49.9mph on a bike with a 48/13 ratio which works out as a
cadence of about 177 which was absolutely flat out (for me) and
stopping pedalling meant the bike slowed down.

If we assume a 52/12 ratio and a 206cm circumference, 55mph needs a
cadence of 166 which is still pretty extreme.

What sort of gearing do people have on their bikes?

Once you're up to about 35mph (conventional bicycle) pedalling downhill
is futile or even counter-productive as the pedalling action induces
more and more drag as the speed increases. At some point well below
50mph this extra drag is enough to overcome the extra power generated
at the wheel. A really good aerodynamic tuck is the secret. Bum behind
the saddle, body as flat as possible, head low, feet at
quarter-to-three, knees and elbows in, hands on the tops close to the
stem or, if you're brave enough, flat against either side of the stem.
Put the imaginative faculties on hold.

I've been over 50mph a number of times, but not quite as high as 55.
Maximum respect!

--
Dave...

"dkahn400" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Once you're up to about 35mph (conventional bicycle) pedalling downhill
is futile or even counter-productive as the pedalling action induces
more and more drag as the speed increases. At some point well below
50mph this extra drag is enough to overcome the extra power generated
at the wheel.

Um - that's not actually true. I've got a hill where I regularly do about
40mph. If I pedal, I go faster than if I coast. If I stop pedalling, I slow
down.

My aero crouch isn't that extreme (hands are still next to the brakes for
example) and I've got a pannier and bar bag - this might make the increased
drag from pedalling less relevant, but not that much.

cheers,
clive

Clive George said:

Still, got to 55 on the way down the nice straight hill into Cowside,
which is a new record for me on my own :-)

55 is mega, once got 37 mph down a hill and I was scared ****less.
--
This space intentionally left blank.

"soup" <[email hidden]>typed

Quoted message said:

Clive George said:

Still, got to 55 on the way down the nice straight hill into Cowside,
which is a new record for me on my own :-)

Quoted message said:

55 is mega, once got 37 mph down a hill and I was scared ****less.

Even I've done 38mph down East Heath Road (now humped :-() NW3 and over
40mph in teh countryside.

--
Helen D. Vecht: [email hidden]
Edgware.

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Clive George said:

Still, got to 55 on the way down the nice straight hill into Cowside,
which
is a new record for me on my own :-)

I'm always impressed by the people who can break 50mph. Do you just
coast or are you pedalling like mad?

53.3 mph on my mountain bike, hacking down the Brighton side of Ditchling
Beacon. Had gone well past the gearing of my bike, but had tucked in behind
two racers who gave me a big tow. They were very surprised to see me still
with them at the bottom! 🙂

Helen Deborah Vecht said:

"soup"

Quoted message said:

55 is mega, once got 37 mph down a hill and I was scared ****less.

Even I've done 38mph down East Heath Road (now humped :-() NW3 and
over 40mph in teh countryside.

May have gone faster when I was younger and uncomputerised but that is
the fastest I have gone recently and it was plenty fast for me.
--
This space intentionally left blank.

soup said:

May have gone faster when I was younger and uncomputerised but that is
the fastest I have gone recently and it was plenty fast for me.

ADDITION :- This was on a "Y" frame with knobbly tyres on.
--
This space intentionally left blank.

soup wrote on 26/06/2006 16:31 +0100:

Quoted message said:

Clive George said:

Still, got to 55 on the way down the nice straight hill into Cowside,
which is a new record for me on my own :-)

55 is mega, once got 37 mph down a hill and I was scared ****less.

I've had over 50 on my mountain bike in the Peak District and regularly
over 40 on the tandem and my road bike. Whether I get over 40 on the
local hill depends not on my pedalling down the hill but how much speed
I carry at the start of the hill. A bit of welly up to 30mph near the
top makes sure I get well over 40 at the bottom, where there is a stop
sign and T-junction to test the anchors, without pedalling.

--
Tony

"Anyone who conducts an argument by appealing to authority is not using
his intelligence; he is just using his memory."
- Leonardo da Vinci

Clive George said:

"dkahn400" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Once you're up to about 35mph (conventional bicycle) pedalling downhill
is futile or even counter-productive as the pedalling action induces
more and more drag as the speed increases. At some point well below
50mph this extra drag is enough to overcome the extra power generated
at the wheel.

Um - that's not actually true. I've got a hill where I regularly do about
40mph. If I pedal, I go faster than if I coast. If I stop pedalling, I slow
down.

My aero crouch isn't that extreme (hands are still next to the brakes for
example) and I've got a pannier and bar bag - this might make the increased
drag from pedalling less relevant, but not that much.

I'm pretty sure it is true, and I don't think you've shown otherwise.
It may well be possible to gain speed at 40mph by pedalling,
particularly with an inefficient tuck, but you would gain more by
improving your position. Don't forget that when coasting at 30mph,
pedalling up to 35mph takes as much power as riding at 25mph on the
flat in nil wind. At 50mph that same amount of power would only
accelerate you up to 52mph, and you will certainly lose more than 2mph
by coming out of an efficient tuck to pedal.

--
Dave...

soup said:

soup said:

May have gone faster when I was younger and uncomputerised but that is
the fastest I have gone recently and it was plenty fast for me.

ADDITION :- This was on a "Y" frame with knobbly tyres on.

The hum from the tyres must have been deafening. :-)

--
Dave...

dkahn400 said:

soup said:

ADDITION :- This was on a "Y" frame with knobbly tyres on.

The hum from the tyres must have been deafening. :-)

Not so much a hum as a R O A R :o)
--
This space intentionally left blank.

Helen Deborah Vecht said:

Quoted message said:

55 is mega, once got 37 mph down a hill and I was scared ****less.

Even I've done 38mph down East Heath Road (now humped :-() NW3 and
over 40mph in teh countryside.

I've managed 44mph on my tourer on the road to Monmouth from Hereford.
I've not had a huge amount of speed from my new-to-me road bike
though. It's too high geared for me and I'm not fit enough to ride it
up any of the decent hills around here, just out across the valley.

Chris
--
Chris Eilbeck

"dkahn400" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Clive George said:

"dkahn400" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Once you're up to about 35mph (conventional bicycle) pedalling downhill
is futile or even counter-productive as the pedalling action induces
more and more drag as the speed increases. At some point well below
50mph this extra drag is enough to overcome the extra power generated
at the wheel.

Um - that's not actually true. I've got a hill where I regularly do about
40mph. If I pedal, I go faster than if I coast. If I stop pedalling, I
slow
down.

My aero crouch isn't that extreme (hands are still next to the brakes for
example) and I've got a pannier and bar bag - this might make the
increased
drag from pedalling less relevant, but not that much.

I'm pretty sure it is true, and I don't think you've shown otherwise.
It may well be possible to gain speed at 40mph by pedalling,
particularly with an inefficient tuck, but you would gain more by
improving your position. Don't forget that when coasting at 30mph,
pedalling up to 35mph takes as much power as riding at 25mph on the
flat in nil wind. At 50mph that same amount of power would only
accelerate you up to 52mph, and you will certainly lose more than 2mph
by coming out of an efficient tuck to pedal.

Still not convinced. I did just try it again :-)

I wonder if it would help if I mentioned that the hills I'm doing this on
aren't that big - eg the one today is only 50m drop in about 800m. (steepest
at the top). This means you don't actually get time to coast up to speed in
a tuck - you need to put in the extra by pedalling. And this is pedalling
quite hard - definitely not at a sustainable pace.

cheers,
clive

Bearing in mind all those good people who were scared "****less" at speed,
are you sure the hum was only from the tyres?
Geoff.
"soup" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

dkahn400 said:

soup said:

ADDITION :- This was on a "Y" frame with knobbly tyres on.

The hum from the tyres must have been deafening. :-)

Not so much a hum as a R O A R :o)
--
This space intentionally left blank.

Tony Raven said:

I've had over 50 on my mountain bike

Much Kudos for that.

--
This space intentionally left blank.

Tony Raven said:

I've had over 50 on my mountain bike in the Peak District

Wasn't it a bit crowded. :o)
--
This space intentionally left blank.