Maintaining Speed

[John Foltz]

g19glock1 wrote:

> Hi Cletus, and Robert, and all who are following this thread. I appreciate your comments, but want
> to add that the 5 hours and 40 mins are riding time. Not elapsed time, I did not include the
> stopping time for potty breaks etc. This may be a point of contention about the speed. I think
> that I would have to add 35 to 40 mins to the overall time in order for the elapsed time to be
> accurate. I did not realize that you would have to include non riding time to evaluate the overall
> mph for the distance. In that, I am sorry. On future rides I will take elapsed time into
> consideration.
>
Kim, I understood your method of measurement, and I presume the others did, too. Elapsed time is
the most hardcore way to rate your speed, but if you're like me, you almost never do a longer
ride without at least a social stop. IMHO using the speedo's calculated average is every bit as
valid a method. Just bear in mind that a five hour century is not the same as a century with a 20
mph average.

Incidently, there is a third way you will see rides rated, and that is 'cruising speed.' This is the
least accurate method, whereby the rider simply watches the speedo and tries to estimate a
representative speed for tooling along on flat section. Cruising speeds are notoriously high,
because they are a subjective snapshot of an ideal stretch of road, not the whole ride.

>
> The roll out method huh? I will reread the thread and see if I understand the principle. If I have
> further questions I'll shout at ya.
>

Mark the pavement and put your valve stem directly over the mark. Roll the tire for 3 tire
revolutions, stopping when the valve stem is at the bottom the 3rd time. Mark the spot and measure
between the lines. Dividing by 3 will give you the circumference of the tire, probably with more
accuracy than you can use. Ideally you should have a load on the tire when you do the rollout, but
the difference if you don't is minimal.

--

John Foltz --- O _ Baron --- _O _ V-Rex 24 --- _\\/\-%)
_________(_)`=()___________________(_)= (_)_____

 

[g19glock1]

Originally posted by John Foltz
g19glock1 wrote:


Kim, I understood your method of measurement, and I presume the others did, too. Elapsed time is
the most hardcore way to rate your speed, but if you're like me, you almost never do a longer
ride without at least a social stop. IMHO using the speedo's calculated average is every bit as
valid a method. Just bear in mind that a five hour century is not the same as a century with a 20
mph average.

Incidently, there is a third way you will see rides rated, and that is 'cruising speed.' This is the
least accurate method, whereby the rider simply watches the speedo and tries to estimate a
representative speed for tooling along on flat section. Cruising speeds are notoriously high,
because they are a subjective snapshot of an ideal stretch of road, not the whole ride.

>
> The roll out method huh? I will reread the thread and see if I understand the principle. If I have
> further questions I'll shout at ya.
>

Mark the pavement and put your valve stem directly over the mark. Roll the tire for 3 tire
revolutions, stopping when the valve stem is at the bottom the 3rd time. Mark the spot and measure
between the lines. Dividing by 3 will give you the circumference of the tire, probably with more
accuracy than you can use. Ideally you should have a load on the tire when you do the rollout, but
the difference if you don't is minimal.

--

John Foltz --- O _ Baron --- _O _ V-Rex 24 --- _\\/\-%)
_________(_)`=()___________________(_)= (_)_____

Thanks John, I appreciate the insight. I am planning to do the roll out tomorrow. I just finished downloaded the manual for the Cateye Mity 8 which is on the V-Rex. It looks simple enough from the instructions. I do want to be accurate though, so this should remove any question from my mind. It does make me wonder about the cyclo on my Giant DF though. Was that one calibrated properly? I could barely keep 14 mph average on a 20 to 30 mile ride. Had to give that bike up tho, hands have carple tunnel and were alway going to sleep. Not pleasant.

I try to ride 20 to 40 miles everyday that the weather permits. My wife works late so once I get off of work I have the time. I consider myself very fortunate regarding that. My last son graduates this Sunday, then off to the air force. Good for him though! He makes me proud, and reminds me of my service days - 68 to 73. Long time ago.

Anyway, thank you again. I will let everyone know what I find out about the roll out.

 

[Cletus D . Lee]

In article <[email protected]>, usenet- [email protected] says...

> Hi Cletus, and Robert, and all who are following this thread. I appreciate your comments, but want
> to add that the 5 hours and 40 mins are riding time. Not elapsed time, I did not include the
> stopping time for potty breaks etc.
This is the same time measurement that most of us use for bragging rights IMO this is not wrong. It
just needs to be clearly stated. I just meant that you can develop a higher average speed if you do
not slow down for stops.

>
> Regarding the calculation of the cyclo comp. I was present when the dealer taped the diameter of
> the front tire (20" primo comet) and he

Unless rider weight is included this will be off. A 32-406 Primo Comet should calibrate to somewhere
close to 1476mm. A 10mm difference will result in a .6 mile error in 100 miles. What is the setting
for your bike computer? and which computer? You have my curiosity now.

--
Cletus D. Lee Bacchetta Giro Lightning Voyager http://www.clee.org
- Bellaire, TX USA -

 

[g19glock1]

Originally posted by Cletus D . Lee
In article <[email protected]>, usenet- [email protected] says...


Unless rider weight is included this will be off. A 32-406 Primo Comet should calibrate to somewhere
close to 1476mm. A 10mm difference will result in a .6 mile error in 100 miles. What is the setting
for your bike computer? and which computer? You have my curiosity now.

--
Cletus D. Lee Bacchetta Giro Lightning Voyager http://www.clee.org
- Bellaire, TX USA -

Hi All, me again. Okay, the tire on the V-Rex is a 20 x 1.50 inflated to 80 psi, recommended pressure by my LBS who says that I should run it 20% below the rear which is inflated to 100psi.

The cyclo comp is a Cateye Mity 8 and according to the instruction manual for this tire the setting should be 152cm's.

I used my wife's fabric cm measure and starting at the center of the presta valve and ending at the center of the presta valve (Bike locked into Park Bike Stand) and came up with a diameter of 155cm's.

Next I took the bike out of the stand and centered the valve directly under the bike and marked the spot on my pole barns floor next to an expansion cut (so I could keep a straight line) and sat on the bike and rolled the bike for 3 complete revolutions of the wheel until the valve again was situated directly under the wheel. I then measured the distance with my wifes tape and came up with 456. I divided that by 3 and got the 152cms. I checked the setting on the Cateye and it was set at 155cm's.

I then went to the conversion website listed in one of the threads regarding roll out measurements and did some calculations. http://www.onlineconversion.com/

I converted a mile into cm's = 160,934.4cm's
I divided that by both 155 (1038.29) and 152 (1058.29) and subtracted difference from each other = 20. Now I am really confused do I multiply the difference, i.e. 3cms x 20 to come up with the respective difference per mile = 60cms or 23.6220472 inches and for a hundred miles multiply by 100 = 2362 and divide by 12" = 196.8333 feet?

I need your help. It was much simpler just to look at the ave speed on the cyclocomp.

Oh well, learning something new is fun too.

kim

 

[Robert Siegel]

Just like the sign over the urinal: Please do not throw cigarettes in this urinal. It makes them
soggy and hard to light.

--
Gator Bob Siegel EasyRacers Ti Rush "Daniel Payne" <[email protected]> wrote in message
news:[email protected]...
>
> On 28-May-2003, [email protected] (PeterS) wrote:
>
> > This is my second season riding my Barcroft Virginia. I am not the strongest rider out there so
> > it could just be me but... I just can't see how other recumbent riders can say they are able to
> > "smoke roadies" etc..
> >
> > While under some road circumstances I can get up to a comparable speed there seems no way that a
> > recumbent rider can maintain the same speeds.
>
> I like smoking roadies, but i find that they are hard to keep lit, at my average 13 MPH...
>
> Daniel

 

[Robert Siegel]

Harry, my ******** detector says you speak the truth. ;-) Good riding! Keep it up.

--
Gator Bob Siegel EasyRacers Ti Rush

"harryo" <[email protected]> wrote

> I won't tell my averages because I suspect you wouldn't believe them, but to respond to the
> original post of this thread, I am faster on my Optima Baron, on the flat to rolling terrain
> here in Central Illinois, than all but the fastest DF riders(racer types}, on the invitational
> rides I do. When stiff headwind is a factor, which is common here, I can blow almost any DF
> rider away, pun intended. I don't think I am extraordinary, just highly motivated to ride fast.
> Oh yes, I do enjoy my riding, too, just as much when riding fast as when I ride at a more
> leisurely pace with others.
>
> Harry Jiles

 

[John Turner]

g19glock1 wrote:

> Cletus D . Lee wrote:
> > In article <[email protected]>, usenet- [email protected] says... Unless
> > rider weight is included this will be off. A 32-406 Primo Comet should calibrate to somewhere
> > close to 1476mm. A 10mm difference will result in a .6 mile error in 100 miles. What is the
> > setting for your bike computer? and which computer? You have my curiosity now.
> > --
> > Cletus D. Lee Bacchetta Giro Lightning Voyager http://www.clee.org/http://www.clee.org
> > - Bellaire, TX USA -
>
> I then measured the distance with my wifes tape and came up with 456. I divided that by 3 and got
> the 152cms. I checked the setting on the Cateye and it was set at 155cm's.

Really simple. Your cyclometer measurements will overstate speed and distance. To get closer to the
real value multiply what the cyclometer says by 152/155 (0.980645161). Your cyclometer is about 2%
out on the high side (~2 miles in 100). When it says you have gone 102 miles *then* you have made
your century. Fabric tapes can be a bit stretchy, and there will be enough measurement error anyway
to make 2% good enough for most practical purposes.

--
John Turner http://www.wireless-route-sales.com

 

[Cletus D . Lee]

In article <[email protected]>, usenet- [email protected] says...
> Cletus D . Lee wrote:
> > In article <[email protected]>, usenet- [email protected] says... Unless
> > rider weight is included this will be off. A 32-406 Primo Comet should calibrate to somewhere
> > close to 1476mm. A 10mm difference will result in a .6 mile error in 100 miles. What is the
> > setting for your bike computer? and which computer? You have my curiosity now.
> > --
> > Cletus D. Lee Bacchetta Giro Lightning Voyager http://www.clee.org/http://www.clee.org
> > - Bellaire, TX USA -
>
>
>
> Hi All, me again. Okay, the tire on the V-Rex is a 20 x 1.50 inflated to 80 psi, recommended
> pressure by my LBS who says that I should run it 20% below the rear which is inflated to 100psi.
>
> The cyclo comp is a Cateye Mity 8 and according to the instruction manual for this tire the
> setting should be 152cm's.
>
> I used my wife's fabric cm measure and starting at the center of the presta valve and ending at
> the center of the presta valve (Bike locked into Park Bike Stand) and came up with a diameter of
> 155cm's.

OK a Primo Comet (20X1.5) is a 37-406 Just using the numbers on the tire, a calculated diameter is
406mm + (37X2) = 480mm Diameter or a circumference of 1508mm = 150.8cm. If you recall a 1cm
difference will result in a 0.6m discrepancy in a century. So Just using your numbers
155cm/152cm you are probably about 2 miles off for every 100 traveled.

Back to the average speeds, 19mph or 17 mph is still impressive for an old fart just switching
to a bent.

FWIW, I use a steel tape on my driveway. Measure in inches and multiply by 2.54 for CM. Another
test is to take the bike to the local High School track and measure 4 laps. (Caution newer tracks
may be metric).

--
Cletus D. Lee Bacchetta Giro Lightning Voyager http://www.clee.org
- Bellaire, TX USA -

 

[Daniel Payne]

On 30-May-2003, [email protected] (Robert Milligan) wrote:

> I am doing the Senior Olympics 10k and 5k bike time trials 6/21 The high end of the 65 to 69
> age group. Hope to ave. 24 MPR. on my V2. Last years ave. was overall 25.2 on a DB. I will be
> the only bent more than likely. Will report back. BOB MILLIGAN V2

Bravo, I think this is great! My limited experience is that the starts on the recumbent are a
little slower / rougher than the Upright. I would be working on the starts, If I were in your
position, Esp. considering your average last year, It sounds like you have a good 'Engine'.

Good Luck and Best Regards Daniel

 

[John Foltz]

g19glock1 wrote:
>
> I used my wife's fabric cm measure and starting at the center of the presta valve and ending at
> the center of the presta valve (Bike locked into Park Bike Stand) and came up with a diameter of
> 155cm's.
>
This would measure the circumference of the unloaded tire, which would cause a too-large
measurement. I'm surprised it was even that accurate, considering how tough it'd be to wrap the
measuring tape around a wheel. As you found out, the rollout worked better.
--

John Foltz --- O _ Baron --- _O _ V-Rex 24 --- _\\/\-%)
_________(_)`=()___________________(_)= (_)_____

 

[Louiedafish]

FWIW, I use the roll out method to set the computer than check the computer against measured mile
miarkers. There are some mileage posts at 0.2 mile intervals at a local park multi use path that I
can check, reset the computer and check again to really zero in on the calibration. I also know a
local road with two back to back measured miles that I will check my computer against. I find I get
accuracy within a tenth of a percent or so. Way more accutate than I need for any purpose including
checking against ride cue sheets. Don't bother checking your bike computer against your car's
odometer, in my experience automobile odometers are out by 3 to 10 percent.

"g19glock1" <[email protected]> wrote in message
news:[email protected]...
> Cletus D . Lee wrote:
> > In article <[email protected]>, usenet- [email protected] says... Unless
> > rider weight is included this will be off. A 32-406 Primo Comet should calibrate to somewhere
> > close to 1476mm. A 10mm difference will result in a .6 mile error in 100 miles. What is the
> > setting for your bike computer? and which computer? You have my curiosity now.
> > --
> > Cletus D. Lee Bacchetta Giro Lightning Voyager http://www.clee.org/http://www.clee.org
> > - Bellaire, TX USA -
>
>
>
> Hi All, me again. Okay, the tire on the V-Rex is a 20 x 1.50 inflated to 80 psi, recommended
> pressure by my LBS who says that I should run it 20% below the rear which is inflated to 100psi.
>
> The cyclo comp is a Cateye Mity 8 and according to the instruction manual for this tire the
> setting should be 152cm's.
>
> I used my wife's fabric cm measure and starting at the center of the presta valve and ending at
> the center of the presta valve (Bike locked into Park Bike Stand) and came up with a diameter of
> 155cm's.
>
> Next I took the bike out of the stand and centered the valve directly under the bike and marked
> the spot on my pole barns floor next to an expansion cut (so I could keep a straight line) and sat
> on the bike and rolled the bike for 3 complete revolutions of the wheel until the valve again was
> situated directly under the wheel. I then measured the distance with my wifes tape and came up
> with 456. I divided that by 3 and got the 152cms. I checked the setting on the Cateye and it was
> set at 155cm's.
>
> I then went to the conversion website listed in one of the threads regarding roll out measurements
> and did some calculations. http://www.onlineconversion.com/
>
> I converted a mile into cm's = 160,934.4cm's I divided that by both 155
> (1038.29) and 152 (1058.29) and subtracted difference from each other =
> 20. Now I am really confused do I multiply the difference, i.e. 3cms x 20 to come up with the
> respective difference per mile = 60cms or
> 23.6220472 inches and for a hundred miles multiply by 100 = 2362 and divide by 12" = 196.8333
> feet?
>
> I need your help. It was much simpler just to look at the ave speed on the cyclocomp.
>
> Oh well, learning something new is fun too.
>
> kim
>
>
>
> --
> G19 and a V-Rex
>
>
> >--------------------------<
> Posted via cyclingforums.com http://www.cyclingforums.com

 

[Jude T. McGloin]

John Foltz, My fellow riders are pretty picky about calibration. I can be too I once taught
calibration in a standards lab atmosphere Mine is compared to a measured mile and GPS so its pretty
accurate. I'll say this again. Anyone on this NG can post an average speed over a given course. It
can be real or BS. The ones I believe without a doubt are those that I have ridden' with and know
first hand. Your in that catagory, but you still didn't catch George drafting that car at 35 mph
did you. (-:
--
Jude....///Bacchetta AERO St. Michaels and Tilghman Island.. Maryland Wheel Doctor Cycle and Sports,
Inc 1-800-586-6645 "John Foltz" <[email protected]> wrote in message
news:[email protected]...
> g19glock1 wrote:
> >
> > I used my wife's fabric cm measure and starting at the center of the presta valve and ending at
> > the center of the presta valve (Bike locked into Park Bike Stand) and came up with a diameter of
> > 155cm's.
> >
> This would measure the circumference of the unloaded tire, which would cause a too-large
> measurement. I'm surprised it was even that accurate, considering how tough it'd be to wrap the
> measuring tape around a wheel. As you found out, the rollout worked better.
> --
>
> John Foltz --- O _ Baron --- _O _ V-Rex 24 --- _\\/\-%) _________(_)`=()___________________(_)=
> (_)_____

 

[Hwadler]

The magnet is not mounted in the rim it's on the spoke . Won't that give you a smaller diameter?

Herman

g19glock1 wrote:

> Cletus D . Lee wrote:
> > In article <[email protected]>, usenet- [email protected] says... Unless
> > rider weight is included this will be off. A 32-406 Primo Comet should calibrate to somewhere
> > close to 1476mm. A 10mm difference will result in a .6 mile error in 100 miles. What is the
> > setting for your bike computer? and which computer? You have my curiosity now.
> > --
> > Cletus D. Lee Bacchetta Giro Lightning Voyager http://www.clee.org/http://www.clee.org
> > - Bellaire, TX USA -
>
>
>
> Hi All, me again. Okay, the tire on the V-Rex is a 20 x 1.50 inflated to 80 psi, recommended
> pressure by my LBS who says that I should run it 20% below the rear which is inflated to 100psi.
>
> The cyclo comp is a Cateye Mity 8 and according to the instruction manual for this tire the
> setting should be 152cm's.

 

[Iliad]

It won't matter. As long as you have the tire size correct, the computer simply calculates the
rotation, then multiplies it by the circumfrence. The tire will rotate the same wether you have the
magnet on the hub, spokes, or on the tires itself.

"hwadler" <[email protected]> wrote in message
news:I%[email protected]...
> The magnet is not mounted in the rim it's on the spoke . Won't that give you a smaller
> diameter?
>
> Herman
>
> g19glock1 wrote:
>
> > Cletus D . Lee wrote:
> > > In article <[email protected]>, usenet- [email protected] says... Unless
> > > rider weight is included this will be off. A 32-406 Primo
Comet
> > > should calibrate to somewhere close to 1476mm. A 10mm difference
will
> > > result in a .6 mile error in 100 miles. What is the setting for your bike computer? and
> > > which computer? You have my curiosity now.
> > > --
> > > Cletus D. Lee Bacchetta Giro Lightning Voyager http://www.clee.org/http://www.clee.org
> > > - Bellaire, TX USA -
> >
> >
> >
> > Hi All, me again. Okay, the tire on the V-Rex is a 20 x 1.50 inflated to 80 psi, recommended
> > pressure by my LBS who says that I should run it 20% below the rear which is inflated to 100psi.
> >
> > The cyclo comp is a Cateye Mity 8 and according to the instruction manual for this tire the
> > setting should be 152cm's.