Do cyclists make better motorcyclists?

Mark Hickey writes:

Did no-one else plug a 12 degree (1 in 8) downslope into the
calculator with the White Hawk recumbent option (speed record
holder?) To go 168 MPH (270kph) seems a LITTLE dangerous!

Just out of curiosity - does anyone know what the equivalent speed
rating of a typical road bicycle tire is? What kind of problems
might you expect from using a "normal" bike tire at that kind of
speed?

None required. If you read auto rags with car tests, you'll see a
bicycle wheel with tire attached to the car to measure actual speed.
These are used at more than 168mph.

I'm assuming there is a correlation between the need for special
construction in automobile tires and those on a "bicycle" designed
to go more than 3x the legal speed limit in New Jersey. If the
issue is strictly one relating to heat, there would be less time to
build the heat, but much less mass (meaning they'd hit the maximum
temperature quicker).

Car tires have significant mass and generate inter-ply and tread heat.
The ratings are not for speed but speed-load-temperature consideration
something that is not a problem for bicycles. That should be evident
from the low RR values that converted to energy don't amount to much
in the tire stress problem. So when you hear those SUV's and Pickups
fly by with a yayayayayaya... sound from a tire, it is heat
delamination. They got into this without realizing that highway
tractor-trailer units are the guys that leave entire treads on
roadsides, especially when weather (and road) is hot.

Jobst Brandt

Mark Hickey writes:

Did no-one else plug a 12 degree (1 in 8) downslope into the
calculator with the White Hawk recumbent option (speed record
holder?) To go 168 MPH (270kph) seems a LITTLE dangerous!

Just out of curiosity - does anyone know what the equivalent speed
rating of a typical road bicycle tire is? What kind of problems
might you expect from using a "normal" bike tire at that kind of
speed?

None required. If you read auto rags with car tests, you'll see a
bicycle wheel with tire attached to the car to measure actual speed.
These are used at more than 168mph.

I'm assuming there is a correlation between the need for special
construction in automobile tires and those on a "bicycle" designed
to go more than 3x the legal speed limit in New Jersey. If the
issue is strictly one relating to heat, there would be less time to
build the heat, but much less mass (meaning they'd hit the maximum
temperature quicker).

Car tires have significant mass and generate inter-ply and tread heat.
The ratings are not for speed but speed-load-temperature consideration
something that is not a problem for bicycles. That should be evident
from the low RR values that converted to energy don't amount to much
in the tire stress problem. So when you hear those SUV's and Pickups
fly by with a yayayayayaya... sound from a tire, it is heat
delamination. They got into this without realizing that highway
tractor-trailer units are the guys that leave entire treads on
roadsides, especially when weather (and road) is hot.

Jobst Brandt

wrote in message ...
There only a handful of short sections that reach 10% on the
54 roads profiled in considerable detail at this well-known
site for bicyclists interested in how steep roads a

http://ciclismo.sitiasp.it/motore2.a...05b7602d4b321e
7&lista=true&quanti=20&url=ga&ID=0&pagina=1&filtra =null&da=az&come=af&lingua
=eng&commenti=False

or

http://tinyurl.com/4w7st

To be polite, Wales is not famous for long, steep descents,
and you've previously demonstrated that your judgement of 10
feet, side to side, is open to question.

If this section at Gwernymynydd turns out to be a 10% grade
of a kilometer, you should submit it to the site above. From
being unlisted, it will leap into the half-dozen steepest
road sections in Wales.

It's hard to see how something as obvious as the A494 could
have been missed, but anything can happen.

Still, the site requires some proof.

It would be simple for them to obtain a large scale plan with road heights
from Ordnance Survey. I do not know the current development of this area, I
can imagine that the speed limit is restricted now.

Trevor

wrote in message ...
There only a handful of short sections that reach 10% on the
54 roads profiled in considerable detail at this well-known
site for bicyclists interested in how steep roads a

http://ciclismo.sitiasp.it/motore2.a...05b7602d4b321e
7&lista=true&quanti=20&url=ga&ID=0&pagina=1&filtra =null&da=az&come=af&lingua
=eng&commenti=False

or

http://tinyurl.com/4w7st

To be polite, Wales is not famous for long, steep descents,
and you've previously demonstrated that your judgement of 10
feet, side to side, is open to question.

If this section at Gwernymynydd turns out to be a 10% grade
of a kilometer, you should submit it to the site above. From
being unlisted, it will leap into the half-dozen steepest
road sections in Wales.

It's hard to see how something as obvious as the A494 could
have been missed, but anything can happen.

Still, the site requires some proof.

It would be simple for them to obtain a large scale plan with road heights
from Ordnance Survey. I do not know the current development of this area, I
can imagine that the speed limit is restricted now.

Trevor

wrote in message ...
There only a handful of short sections that reach 10% on the
54 roads profiled in considerable detail at this well-known
site for bicyclists interested in how steep roads a

http://ciclismo.sitiasp.it/motore2.a...05b7602d4b321e
7&lista=true&quanti=20&url=ga&ID=0&pagina=1&filtra =null&da=az&come=af&lingua
=eng&commenti=False

or

http://tinyurl.com/4w7st

To be polite, Wales is not famous for long, steep descents,
and you've previously demonstrated that your judgement of 10
feet, side to side, is open to question.

If this section at Gwernymynydd turns out to be a 10% grade
of a kilometer, you should submit it to the site above. From
being unlisted, it will leap into the half-dozen steepest
road sections in Wales.

It's hard to see how something as obvious as the A494 could
have been missed, but anything can happen.

Still, the site requires some proof.

It would be simple for them to obtain a large scale plan with road heights
from Ordnance Survey. I do not know the current development of this area, I
can imagine that the speed limit is restricted now.

Trevor

wrote in message ...
It gets worse at higher speeds. Here's a table for the same
bike on a 17% grade, where it reaches 70.1 mph and needs 204
rpm to engage a 2124 mm 700c tire with 54 x 12 gearing:

mph rpm watts
70.1 0 0 coasting, not pedalling
62.6 204 0.1 coasting, but pedalling w/no power
70.1 204 1046 pedalling 52 x 12 gear


I think it was E. Merckx whose measured o/p was 1 1/3 hp or 1700Watts
which is 650 watts more than that required for 70mph. High power is
produced at high rpm so a slower cadence is not required.

Not all riders are alike, at what speed would 1700watts attain on a 1in10
grade with this calculator. Use 53x12 700x25C 167.5 cranks, flat back.

Trevor

wrote in message ...
It gets worse at higher speeds. Here's a table for the same
bike on a 17% grade, where it reaches 70.1 mph and needs 204
rpm to engage a 2124 mm 700c tire with 54 x 12 gearing:

mph rpm watts
70.1 0 0 coasting, not pedalling
62.6 204 0.1 coasting, but pedalling w/no power
70.1 204 1046 pedalling 52 x 12 gear


I think it was E. Merckx whose measured o/p was 1 1/3 hp or 1700Watts
which is 650 watts more than that required for 70mph. High power is
produced at high rpm so a slower cadence is not required.

Not all riders are alike, at what speed would 1700watts attain on a 1in10
grade with this calculator. Use 53x12 700x25C 167.5 cranks, flat back.

Trevor

wrote in message ...
It gets worse at higher speeds. Here's a table for the same
bike on a 17% grade, where it reaches 70.1 mph and needs 204
rpm to engage a 2124 mm 700c tire with 54 x 12 gearing:

mph rpm watts
70.1 0 0 coasting, not pedalling
62.6 204 0.1 coasting, but pedalling w/no power
70.1 204 1046 pedalling 52 x 12 gear


I think it was E. Merckx whose measured o/p was 1 1/3 hp or 1700Watts
which is 650 watts more than that required for 70mph. High power is
produced at high rpm so a slower cadence is not required.

Not all riders are alike, at what speed would 1700watts attain on a 1in10
grade with this calculator. Use 53x12 700x25C 167.5 cranks, flat back.

Trevor

Mark Hickey wrote in message ...
wrote:

A superman position raises the estimate to 53.1 mph.

The thought of riding down ANY hill at that speed in the superman
position boggles the mind. One with curves... shudder...


The cloak of infallibility plus that of immortality are heavier when young.

When someone tells you that they have a speedo, you want to know how fast.
It was when the Avocet ones started appearing that all this finding the best
aero position came about. Wouldn't surprise me if C.Boardman attempted it
at the time. Although as far as I know, he wasn't that hot in descending.

Trevor

Mark Hickey wrote in message ...
wrote:

A superman position raises the estimate to 53.1 mph.

The thought of riding down ANY hill at that speed in the superman
position boggles the mind. One with curves... shudder...


The cloak of infallibility plus that of immortality are heavier when young.

When someone tells you that they have a speedo, you want to know how fast.
It was when the Avocet ones started appearing that all this finding the best
aero position came about. Wouldn't surprise me if C.Boardman attempted it
at the time. Although as far as I know, he wasn't that hot in descending.

Trevor