Cadence range for time trial ?

Quoted message said:

For a completely flat, no-wind, straight time-trial course, what kinds of
cadences do fast riders use? I realize that this is intimately related to
which gearing they use, so I'm also interested in that, as well.

Aim for 53x11 at 100 cadence. ;-)

Sorry, I'll shut up now,
Musashi

Can't you guys ever be serious?

I'm really interested in optimum cadences. For the same speed, slightly
different gearing makes for different cadences. I'm interested in whether the
fast riders go for slightly higher cadences & lower gears, or whether
they go for lower cadences & higher gears.

musashi said:

Quoted message said:

For a completely flat, no-wind, straight time-trial course, what kinds of
cadences do fast riders use? I realize that this is intimately related to
which gearing they use, so I'm also interested in that, as well.

Aim for 53x11 at 100 cadence. ;-)

Sorry, I'll shut up now,
Musashi

Quoted message said:

I'm interested in whether the
fast riders go for slightly higher cadences & lower gears, or whether
they go for lower cadences & higher gears.

Like Chung said, optimum cadence depends on power output. More power,
higher cadence. So generally (if they know what they're doing) faster
riders will use higher cadence, in same or higher gear.

--
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"Ewoud Dronkert" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Quoted message said:

I'm interested in whether the
fast riders go for slightly higher cadences & lower gears, or whether
they go for lower cadences & higher gears.

Like Chung said, optimum cadence depends on power output. More power,
higher cadence. So generally (if they know what they're doing) faster
riders will use higher cadence, in same or higher gear.

Very rough guide for a road TT
250 watts 25mph 80rpm
350watts 28mph 90rpm
450 watts 31 mph 100rpm

Crank length also plays a role as foot speed is considered to be the
optimizing factor and not cadence per se. Longer cranks result in a
lower optimum cadence. Any number you derive from the above should be
considered as a rough starting point. Individuals vary significantly
within this general range.

Phil H

Philip Holman said:

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

Quoted message said:

Quoted message said:

I'm interested in whether the
fast riders go for slightly higher cadences & lower gears, or whether
they go for lower cadences & higher gears.

Like Chung said, optimum cadence depends on power output. More power,
higher cadence. So generally (if they know what they're doing) faster
riders will use higher cadence, in same or higher gear.

Very rough guide for a road TT
250 watts 25mph 80rpm
350watts 28mph 90rpm
450 watts 31 mph 100rpm

250 watts for 25mph seems kind of low to me. Maybe that's feasible
for someone with an extremely aero position, but is that typical?

JT

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"John Forrest Tomlinson" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Philip Holman said:

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

Quoted message said:

On Sat, 22 Jan 2005 16:37:31 GMT, [email hidden] wrote:
> I'm interested in whether the
> fast riders go for slightly higher cadences & lower gears, or
> whether
> they go for lower cadences & higher gears.

Like Chung said, optimum cadence depends on power output. More
power,
higher cadence. So generally (if they know what they're doing)
faster
riders will use higher cadence, in same or higher gear.

Very rough guide for a road TT
250 watts 25mph 80rpm
350watts 28mph 90rpm
450 watts 31 mph 100rpm

250 watts for 25mph seems kind of low to me. Maybe that's feasible
for someone with an extremely aero position, but is that typical?

Note "Very rough guide". On the low end of the range, Andy Coggan puts
out 28mph at 300 watts so it isn't too far out. Myself, I'd be at around
270 watts and yes, this is assumed to be appropriately aero.

Phil H

I've studied this a bit, and find the answer is a highly individual matter.
The correct answer for my body may not be the correct answer for yours.
The "higher cadence = higher power" statement is not true. Don't be
deceived. Assuming the same torque output in both cases, then yes, a higher
cadence will calculate out to more power. Power is basically equal to
torque multiplied by rpm divided by a constant. You can easily put together
a scenario where a lower rpm case will produce more power than a higher rpm
case, because the other variable, torque, must also be taken into account.
Reality on a bike, however, will usually mean decreasing torque past a
certain cadence. That point is an individual matter.
Also, physiological differences play a big role. One rider's makeup may
allow him to put out huge torque at lower rpm's, and develop big power.
Another rider may spin at higher rpm's, putting out a bit lower torque, but
developing higher power.
Or not.
The modern day pro cycling example is obviously the comparison between
Ulrich & Armstrong.
I've done some studies of myself using a Powertap and controlled courses and
rollers. I would suggest doing that yourself if you're truly dedicated to
finding your optimum cadence.
Develop a protocol where you ride given lengths of time on the rollers (or
clamp-on trainer, whatever you use) at various combinations of cadence and
power output (or speed if no power device available), and monitor your
heartrate throughout. You should be able to find your own sweet spot.
Be careful doing this on the road, as very small wind shifts during
measurements will throw your results off. Inside is much more controllable.
What you basically want to do is minimize your heartrate for a given
power/speed. Whether your body is more efficient at low rpm's or high, this
type of basic study should give you an idea. Ride at, say, 300 watts for 5
minutes at 80 rpm, 90 rpm, 100 rpm, and 110 rpm (or whatever rpm range suits
you). Then look at your avg. heartrate in each case. If you are developing
the same amount of power in each case, your optimum cadence will be where
you heartrate is minimized. This is where your body is most efficient at
that power output.
Another way of looking at this, then, is that you're maximizing your power
output at a given heartrate by adjusting to your optimum cadence. Now all
you need to do is increase your max sustainable HR for your target TT length
through training, then ride at your optimum cadence, and you've gone a long
way toward maximizing your personal performance.
Also, your body will change over time, so the answer to this is not a
constant, but repeating the same series at different times should be a
fairly good indicator for you.
There are many factors that go into determining these parameters, but this
is really just a basic start down the road.
Good luck.

"Bob De Jonge" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I've studied this a bit, and find the answer is a highly individual
matter.
The correct answer for my body may not be the correct answer for
yours.
The "higher cadence = higher power" statement is not true.

Many world hour records were performed at >100. A noted exception was
Obree at 93.
http://ida1.physik.uni-siegen.de/menn/hourrec.htm

Don't be

Quoted message said:

deceived. Assuming the same torque output in both cases, then yes, a
higher
cadence will calculate out to more power. Power is basically equal to
torque multiplied by rpm divided by a constant. You can easily put
together
a scenario where a lower rpm case will produce more power than a
higher rpm
case, because the other variable, torque, must also be taken into
account.
Reality on a bike, however, will usually mean decreasing torque past a
certain cadence. That point is an individual matter.
Also, physiological differences play a big role. One rider's makeup
may
allow him to put out huge torque at lower rpm's, and develop big
power.
Another rider may spin at higher rpm's, putting out a bit lower
torque, but
developing higher power.
Or not.
The modern day pro cycling example is obviously the comparison between
Ulrich & Armstrong.
I've done some studies of myself using a Powertap and controlled
courses and
rollers. I would suggest doing that yourself if you're truly
dedicated to
finding your optimum cadence.
Develop a protocol where you ride given lengths of time on the rollers
(or
clamp-on trainer, whatever you use) at various combinations of cadence
and
power output (or speed if no power device available), and monitor your
heartrate throughout. You should be able to find your own sweet spot.
Be careful doing this on the road, as very small wind shifts during
measurements will throw your results off. Inside is much more
controllable.
What you basically want to do is minimize your heartrate for a given
power/speed. Whether your body is more efficient at low rpm's or
high, this
type of basic study should give you an idea. Ride at, say, 300 watts
for 5
minutes at 80 rpm, 90 rpm, 100 rpm, and 110 rpm (or whatever rpm range
suits
you). Then look at your avg. heartrate in each case. If you are
developing
the same amount of power in each case, your optimum cadence will be
where
you heartrate is minimized. This is where your body is most efficient
at
that power output.

Is it efficiency or effectiveness we are after. See.......

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8775571

Quoted message said:

Another way of looking at this, then, is that you're maximizing your
power
output at a given heartrate by adjusting to your optimum cadence. Now
all
you need to do is increase your max sustainable HR for your target TT
length
through training, then ride at your optimum cadence, and you've gone a
long
way toward maximizing your personal performance.
Also, your body will change over time, so the answer to this is not a
constant, but repeating the same series at different times should be a
fairly good indicator for you.
There are many factors that go into determining these parameters, but
this
is really just a basic start down the road.
Good luck.

HR can be unreliable for this kind of test.

Phil H

In article <[email hidden]>,

Philip Holman said:

"Bob De Jonge" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I've studied this a bit, and find the answer is a highly individual
matter.
The correct answer for my body may not be the correct answer for
yours.
The "higher cadence = higher power" statement is not true.

Many world hour records were performed at >100. A noted exception was
Obree at 93.
http://ida1.physik.uni-siegen.de/menn/hourrec.htm

There's also a very good listing of technical info on the recent hour
records here:

http://www.bikecult.com/bikecultbook/sports_recordsHour.html

Get a load of Indurain's crank length: 190!

--
tanx,
Howard

Butter is love.

remove YOUR SHOES to reply, ok?

Bob De Jonge said:

Reality on a bike, however, will usually
mean decreasing torque past a certain cadence. That point is an
individual matter.

Right. But there's no evidence that exogenously altering cadence away from
the freely-chosen cadence will result in higher FTP (except for truly
cadence- or torque-limited cases).

Quoted message said:

I've done some studies of myself using a Powertap and controlled
courses and rollers. I would suggest doing that yourself if you're
truly dedicated to finding your optimum cadence.

[and]

Quoted message said:

Be careful doing this on the road, as very small wind shifts during
measurements will throw your results off. Inside is much more
controllable.

I wouldn't bother. First, because optimal cadence for one ride doesn't
mean you should use that cadence on all future rides; but second, even if
you believed that to be so, rollers don't have the same crank inertial
load as the road and we know that freely-chosen cadence responds to it.
That makes the experiment doubly vain.

Quoted message said:

Develop a protocol where you ride given lengths of time on the rollers
(or clamp-on trainer, whatever you use) at various combinations of
cadence and power output (or speed if no power device available), and
monitor your heartrate throughout. You should be able to find your own
sweet spot. What you basically want to do is minimize your heartrate
for a given power/speed.

Yikes. HR is an unreliable metric for this type of test. In addition, the
OP's goal was to minimize time in a TT, not to minimize HR for a given
power. To minimize time in a TT, his best bet is to improve his
power-to-drag ratio.

http://anonymous.coward.free.fr/wattage/components/components.html

Quoted message said:

For a completely flat, no-wind, straight time-trial course, what

kinds of

Quoted message said:

cadences do fast riders use? I realize that this is intimately

related to

Quoted message said:

which gearing they use, so I'm also interested in that, as well.

I've done many TT's, but never did completely flat, no-wind, straight
TT.
Many responses about this topic is from "science" guys, and I don't
even use a HR monitor - so for another perspective I'll throw in my 2
cents. The easy joke, use a large gear, fast cadence.
Most fast guys use high cadence, 90-100, for most riders and
conditions, it's most efficient and "fastest"
Some fast guys use low cadence (think Gontchar, who regularly uses a
56by11, and got 2nd in the giro last year, and he also uses ridiculous
gears UP mountain passes. He's a freak, but it's an example, like Lance
is an example of equally freaky high cadence.)
I use a large gear and low cadence, in the low 80's I bet, and I like
the 53by11 on flat courses even with a head wind. I TT with a lower
heart rate than most people.
The only TT's I've ever won have been very short, like 3 miles, or in
very windy conditions, this probably has something to do with a lower
cadence somehow being a little more efficient in windy conditions. I'm
also tall, 6'2" and about 185 pounds these days.
I am more comfortable TT'ing a very large gear, and TT's are
uncomfortable enough, I've never tried using higher cadences, I know it
would take at least a few months to train yourself to do it. So maybe I
would go faster using a higher cadence, that is the argument many
people will make about "mashers"
A final exapmle, I've done the moriarty record challenge 40K a few
times, and never went very fast (low 53's), I used a fixed gear once, a
56by13, and did a 53:20 - it was too big on the way out.
The guys who go under 50 and the record holder usually use a fixed
53by15 or something similar, and a local guy named marcel used to use
very small gears to go under 50 minutes, like 52by16 maybe (can't
remember everything) so he was an example of someone who was successful
using small gears at very high cadences.
My free unscientific (and yes I know kinda obvious) advice for a TT:
start, then find a comfortable gear and cadence, then can you go
faster? then go faster by shifting into a larger gear and/or increasing
your cadence right to +/- a few beats of your AT depending on the
conditions, then ride to the finish. Don't try to simulate anyone elses
"style" of cadence and gearing, you aren't them.

Quoted message said:

Quoted message said:

I've done some studies of myself using a Powertap and controlled
courses and rollers. I would suggest doing that yourself if you're
truly dedicated to finding your optimum cadence.

[and]

Quoted message said:

Be careful doing this on the road, as very small wind shifts during
measurements will throw your results off. Inside is much more
controllable.

I wouldn't bother. First, because optimal cadence for one ride doesn't
mean you should use that cadence on all future rides; but second, even if
you believed that to be so, rollers don't have the same crank inertial
load as the road and we know that freely-chosen cadence responds to it.
That makes the experiment doubly vain.

Sorry, but my rollers do represent the actual road load. Your typical
off-the-shelf rollers will not, as you say, which is a good point.
I undertook a serious study a few years ago to design my system to
replicate my dynamics while on the road (level road only). I basically
replace my mass with mass moment of interia of the combination of
belt-driven flywheel, and weighted rims. I also use cogged belts to
solve other issues. There is other more detailed speed-dependant
compensation including the higher rolling resistance on rollers, etc.
The closest I know of that is available off-the-shelf are the Kreitlers
with the flywheel & fan. That gets fairly close. There are a number of
issues with that system, and I won't get into them here, but just check
the front wheel speed vs. the rear wheel speed while driving both
flywheel & fan once!
Anyway, with the off-the-shelf Kreitler system you should have a fairly
nice protocol to establish some good presonal data.

BTW - what would everyone out there think of the marketability of a
system such as this. It is basically a personalized roller system.
I'm more of a traditionalist, and I like the smoothness the rollers
impart on my stroke, but needed to add representative road load, as
unloaded rollers are certainly limited in their effectiveness. This was
an offshoot of a thesis project some time ago, and I've never done
anything beyond my own system.
After seeing products like the Tacx Fortius, I'm afraid the market is
already taken. Plus, they went a number of steps further than I did
when they added the motor element to simulate downhill sections, and the
constantly variable resistance.
While I haven't used one of these (yet!) I would think it would make a
pretty good tool as well for setting up repeatable tests and winter
training protocols.

Bob De Jonge said:

Quoted message said:

I wouldn't bother. First, because optimal cadence for one ride doesn't
mean you should use that cadence on all future rides; but second, even
if you believed that to be so, rollers don't have the same crank
inertial load as the road and we know that freely-chosen cadence
responds to it. That makes the experiment doubly vain.

Sorry, but my rollers do represent the actual road load. Your typical
off-the-shelf rollers will not, as you say, which is a good point.
I undertook a serious study a few years ago to design my system to
replicate my dynamics while on the road (level road only). I basically
replace my mass with mass moment of interia of the combination of
belt-driven flywheel, and weighted rims. I also use cogged belts to
solve other issues.

Yow. Ignoring for a moment that I still don't believe that there is a
single universally optimal cadence, I'm impressed that you did this. It
must've taken quite a bit of effort to match the drag using masses, belts,
and cogs; you can see another attempt to match crank inertial load and
torque of road riding with a lab setup here:
http://aemes.mae.ufl.edu/~fregly/pdfs/jbme2000.pdf

Of particular interest are the estimates of the typical inertial and
torque values associated with a standard set of rollers in Table 2 of that
paper.

Another approach was a motorized treadmill, described in this paper:
http://aemes.mae.ufl.edu/~fregly/pdfs/jb2002.pdf

Quoted message said:

After seeing products like the Tacx Fortius, I'm afraid the market is
already taken. Plus, they went a number of steps further than I did
when they added the motor element to simulate downhill sections, and the
constantly variable resistance.
While I haven't used one of these (yet!) I would think it would make a
pretty good tool as well for setting up repeatable tests and winter
training protocols.

I agree. I haven't yet seen one, either, but I suspect that the
motor-driven nature of the trainer would have a lot of potential,
depending on how quickly the motor responded. As an aside, I've been very
unimpressed with the ability of my Tacx Flow (magnetically-braked) trainer
to maintain constant load under varying wheelspeeds (it appears to do
better in power-measuring mode); I know that this is the fault of the
control head because the Tacx Grand Excel uses the same load generator but
with a different control head and it does a much better job of maintaining
constant load. The bottom line is that while a motor-driven unit has a lot
of potential, what matters is exactly how it is controlled.

Robert Chung said:

Yow. Ignoring for a moment that I still don't believe that there is a
single universally optimal cadence, I'm impressed that you did this. It
must've taken quite a bit of effort to match the drag using masses, belts,
and cogs; you can see another attempt to match crank inertial load and
torque of road riding with a lab setup here:
http://aemes.mae.ufl.edu/~fregly/pdfs/jbme2000.pdf

Of particular interest are the estimates of the typical inertial and
torque values associated with a standard set of rollers in Table 2 of that
paper.

Another approach was a motorized treadmill, described in this paper:
http://aemes.mae.ufl.edu/~fregly/pdfs/jb2002.pdf

Thanks for the comments - yes it was quite a project, one that is only
done when the motivation is there. I spent winter after winter riding
my rollers knowing that 20 or 30 miles on them was not the same as those
on the road in terms of energy expended, etc. My earlier rollers were
the typical Performance plastic jobs. I used a number of the magnetic
resistance units. The rollers would wear out fairly quickly (cracks,
bearings, etc.) but at $10 replacement cost, no big deal. The mag units
were a series of experiments in themselves.
Then I got my Kreitlers, upon which I based my current system. It's
pretty good, not time-efficient to derive, but fun & interesting. I'm
sure the people on that flat 1-mile stretch of road I used as my
measurement zone thought I was nuts going back & forth uncounted numbers
of times at 1-mph increments, once on the drops, then on the tops, then
on the hoods, etc. Lots of early mornings taking measurements before
the wind came up, then filtering once I downloaded data & seeing what
damage a slight breath of air will do to correlations.
Anyway, fun & interesting learning experience. I did learn that there
is a direct correlation between M & I, in that one can use proper
rotating masses to simulate a translating mass in terms of dynamics - at
least in a limited speed range. There are a lot of factors involved.
Thanks for the references to the papers - I'll get them & read through.

I am comfortable that my system is pretty realistic, but limited to
being customized for my equipment. I could not find measurable
differences between various wheel/tire combos I use, as that amount of
difference was beneath my measurement resolution threshold. But, my
wheels/tires are all pretty much the same - all Mavic O4CD or Open Pros,
with 23c tires of various brands.

I had to do some tuning with the aero drag device (belt-driven fan). It
is tuned for typical riding speeds, for a given riding position on the
road (hoods) and equipment (normal road bike, 32spoke wheels). I had to
limit myself to 18 to 25 mph, as anything below that got grainy, and
anything above that got ever more aero-dependent, and those 1-2 mph
breezes are hard to measure and compensate for. BTW - I used one of
those Oregon Scientific weather stations for ambient condition
measurement at the road 'test track'. They work really well, and now
works well in the house! The anemometer was quite good when set up out
in the open, or on the top of my van.

Quoted message said:

As an aside, I've been very

Quoted message said:

unimpressed with the ability of my Tacx Flow (magnetically-braked) trainer
to maintain constant load under varying wheelspeeds (it appears to do
better in power-measuring mode); I know that this is the fault of the
control head because the Tacx Grand Excel uses the same load generator but
with a different control head and it does a much better job of maintaining
constant load. The bottom line is that while a motor-driven unit has a lot
of potential, what matters is exactly how it is controlled.

Yes, that's what I'm curious to find out as well - it's control loop
performance.
I understand your comments re the mag units. I had experience with a
number of these years back, and I found the same thing - very
inconsistent. Some units had fatigue related variations, others seemed
to have temperature-dependent variation. I could not find one that was
consistent.
I'm not sure what the Fortius uses, but it must be a sort of 'mini
eddy-current dynomometer'. Not sure. But, given the closed loop
control structure, any variation should be able to be compensated for.
I'm still very anxious to try one of these one day - maybe next winter.
I would think the load control & response would be very good.
Potentially it can be, whether they did it is what I want to find out.
I just love the interactive VR aspect. I wish I could integrate that
with my rollers, as I abhor clamp-on trainers. But, I'm sure I would
ride off my rollers when I go around corners in that virtual world.
I've done that before watching Isle of Man videos while riding!

I won't get into the optimum cadence debate. I'm to a point where I
believe there is such a thing, given a particular point in time,
understanding that the body varies day-to-day, and what is optimum one
day may not be the next. Also, other factors are involved in
determining that optimum cadence (position, ambient conditions, etc.).
This is just what I believe, based on what I've found through my
experimentation, based on a population of one (me).

Howard Kveck said:

There's also a very good listing of technical info on the recent hour
records here:

http://www.bikecult.com/bikecultbook/sports_recordsHour.html

I'm not sure how accurate those wattage figures are but if taken at face
value (yeah, right) this is what they would imply:
http://anonymous.coward.free.fr/rbr/hourrec.png

Robert Chung said:

http://anonymous.coward.free.fr/rbr/hourrec.png

Beautiful. The King Lives!

--
Firefox Web Browser - Rediscover the web - http://getffox.com/
Thunderbird E-mail and Newsgroups - http://gettbird.com/

Ewoud Dronkert said:

Robert Chung said:

http://anonymous.coward.free.fr/rbr/hourrec.png

Beautiful. The King Lives!

Well, that's part of the reason why I was a tad suspicious of the wattage
figures.

BTW, that webpage says Indurain used 190mm cranks while Boardman used
170's. Here's a revised plot that takes crank length into account by
standardizing on pedal speed (which should be related to muscle
contraction speed).

People seem to make a big deal of Obree's "slow" cadence, but it seems not
too terribly out of line with others. What's clearer is that Obree really
had an aero position that let him go pretty far with the amount of power
he had.

http://anonymous.coward.free.fr/rbr/hourrec2.png

Robert Chung said:

you can see another attempt to match crank inertial load and

Quoted message said:

torque of road riding with a lab setup here:
http://aemes.mae.ufl.edu/~fregly/pdfs/jbme2000.pdf

Quoted message said:

Another approach was a motorized treadmill, described in this paper:
http://aemes.mae.ufl.edu/~fregly/pdfs/jb2002.pdf

I've skimmed through these papers this morning, and thanks again for
bringing them to my attention.
Bottom line is -- thanks too, because they've given me the motivation to
publish my results. I think I have some things that could be useful to
people out there, considerations that don't seem to be present in either
paper. My goal was perhaps different than theirs, which resulted in a
different methodology and results.
I can't say anything yet for comparisons, but my method was certainly
different from either paper. I need to read them in more detail, and
perhaps contact the people involved at some point, but there seem to be
a couple of things not taken into account. I'll pull out my equations
and data and do some more study.
Basically, my equations of motion came at the problem from a different
angle than those in the bicycle dynamics paper
Anyway, on and on...., but thanks again for the references. Looks like
I have another winter project!

Bob De Jonge said:

BTW - what would everyone out there think of the marketability of a
system such as this.

it's impressive that you went to so much trouble to reproduce the exact
resistance and inertial loading of real riding.

i think there's few that know the difference or care but there is a
niche market for realisitic inertia trainers, like the velotron and
velodyne. the high inertia feel of spinning bikes probably makes them
more popular than older style stationary bikes too.

the problem is these units are heavy, what would be good is if the
buyer could add the weight after getting it home, say by adding water
or sand or something else common and heavy (concrete?).

-amit