Wheel weight battle

Discussion in 'Cycling Equipment' started by Chris, Feb 13, 2004.

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  1. Chris

    Chris Guest

    I've been beating my head against my desk here trying to track down this answer on the web or in the
    archives to no success. So here it goes..

    A time trial rider sets off on my made up tt, this course is perfectly straight and has no altitude
    change for 100 miles. The bicycle is a TT styled w/ 650c wheels. The rider is very aero and can
    average 250 watts for the entire distance.

    Now then to my question I'm trying to figure how much time the rider can save by riding with
    tubular's vs clinchers by strictly a weight aspect and how to reach that answer.

    So the tubulars weigh: Zipp 404 650c tubulars set = 1177 Continental Podium tyres 240each x 2=480
    Not sure how much glue weighs when it dires?? Aprox set weight=1657

    The clinchers: Zipp 404 650c Clinchers set= 1523 Continental Supersonic tyres 145each x 2=290
    Innertubes 65each x 2= 130 Ritchey Rim tape 30x 2=60 Aprox set weight=2003

    So the difference is about 346 grams.

    Anyone have an idea how much time savings that would amount to after 100 miles? Maybe I'm asking an
    unanswerable question or possibly a 101 level question, I don't know.

    Thanks Chris
     
    Tags:


  2. S O R N I

    S O R N I Guest

    Chris wrote:
    > I've been beating my head against my desk here trying to track down this answer on the web or in
    > the archives to no success. So here it goes..
    >
    > A time trial rider sets off on my made up tt, this course is perfectly straight and has no
    > altitude change for 100 miles. The bicycle is a TT styled w/ 650c wheels. The rider is very aero
    > and can average 250 watts for the entire distance.
    >
    > Now then to my question I'm trying to figure how much time the rider can save by riding with
    > tubular's vs clinchers by strictly a weight aspect and how to reach that answer.
    >
    > So the tubulars weigh: Zipp 404 650c tubulars set = 1177 Continental Podium tyres 240each x 2=480
    > Not sure how much glue weighs when it dires?? Aprox set weight=1657
    >
    > The clinchers: Zipp 404 650c Clinchers set= 1523 Continental Supersonic tyres 145each x 2=290
    > Innertubes 65each x 2= 130 Ritchey Rim tape 30x 2=60 Aprox set weight=2003
    >
    > So the difference is about 346 grams.
    >
    > Anyone have an idea how much time savings that would amount to after 100 miles? Maybe I'm asking
    > an unanswerable question or possibly a 101 level question, I don't know.

    40.82 seconds.

    Bill "um, the dog ate my workbook" S.
     
  3. Tom Sherman

    Tom Sherman Guest

    Chris wrote:

    > I've been beating my head against my desk here trying to track down this answer on the web or in
    > the archives to no success. So here it goes..
    >
    > A time trial rider sets off on my made up tt, this course is perfectly straight and has no
    > altitude change for 100 miles. The bicycle is a TT styled w/ 650c wheels. The rider is very aero
    > and can average 250 watts for the entire distance.
    >
    > Now then to my question I'm trying to figure how much time the rider can save by riding with
    > tubular's vs clinchers by strictly a weight aspect and how to reach that answer.
    >
    > So the tubulars weigh: Zipp 404 650c tubulars set = 1177 Continental Podium tyres 240each x 2=480
    > Not sure how much glue weighs when it dires?? Aprox set weight=1657
    >
    > The clinchers: Zipp 404 650c Clinchers set= 1523 Continental Supersonic tyres 145each x 2=290
    > Innertubes 65each x 2= 130 Ritchey Rim tape 30x 2=60 Aprox set weight=2003
    >
    > So the difference is about 346 grams.
    >
    > Anyone have an idea how much time savings that would amount to after 100 miles? Maybe I'm asking
    > an unanswerable question or possibly a 101 level question, I don't know.

    Here is a model where you can plug in your variables: <http://www.analyticcycling.com/>.

    Tom Sherman - Quad Cities
     
  4. W K

    W K Guest

    "Chris" <[email protected]> wrote in message
    news:BC51C09B.110AA%[email protected]...
    > I've been beating my head against my desk here trying to track down this answer on the web or in
    > the archives to no success. So here it goes..
    >
    > A time trial rider sets off on my made up tt, this course is perfectly straight and has no
    > altitude change for 100 miles. The bicycle is a TT styled w/ 650c wheels. The rider is very aero
    > and can average 250 watts
    for
    > the entire distance.
    >
    > Now then to my question I'm trying to figure how much time the rider can save by riding with
    > tubular's vs clinchers by strictly a weight aspect and how to reach that answer.
    ...
    > So the difference is about 346 grams.

    Theoretically in the above conditions that extra energy is about 0.346/80 of your rolling
    resistance. On a TT, thats a tiny % of a small %
     
  5. Tom Compton

    Tom Compton Guest

    Chris wrote:
    > I've been beating my head against my desk here trying to track down this answer on the web or in
    > the archives to no success. So here it goes..
    >
    > A time trial rider sets off on my made up tt, this course is perfectly straight and has no
    > altitude change for 100 miles. The bicycle is a TT styled w/ 650c wheels. The rider is very aero
    > and can average 250 watts for the entire distance.
    >
    > Now then to my question I'm trying to figure how much time the rider can save by riding with
    > tubular's vs clinchers by strictly a weight aspect and how to reach that answer.
    >
    > So the tubulars weigh: Zipp 404 650c tubulars set = 1177 Continental Podium tyres 240each x 2=480
    > Not sure how much glue weighs when it dires?? Aprox set weight=1657
    >
    > The clinchers: Zipp 404 650c Clinchers set= 1523 Continental Supersonic tyres 145each x 2=290
    > Innertubes 65each x 2= 130 Ritchey Rim tape 30x 2=60 Aprox set weight=2003
    >
    > So the difference is about 346 grams.
    >
    > Anyone have an idea how much time savings that would amount to after 100 miles? Maybe I'm asking
    > an unanswerable question or possibly a 101 level question, I don't know.
    >
    > Thanks Chris

    A 346 gm difference in weight would be about a three second difference in time. However, there would
    also be a difference in rolling resistance due to typical friction losses at the glue line of
    tubulars. These losses would exceed the savings from less weight.

    Regards,

    Tom Compton www.AnalyticCycling.com
     
  6. Werehatrack

    Werehatrack Guest

    On Thu, 12 Feb 2004 23:45:31 -0800, Chris <[email protected]> may
    have said:

    >I've been beating my head against my desk here trying to track down this answer on the web or in
    >the archives to no success. So here it goes..
    >
    >A time trial rider sets off on my made up tt, this course is perfectly straight and has no altitude
    >change for 100 miles. The bicycle is a TT styled w/ 650c wheels. The rider is very aero and can
    >average 250 watts for the entire distance.
    >
    > Now then to my question I'm trying to figure how much time the rider can save by riding with
    > tubular's vs clinchers by strictly a weight aspect and how to reach that answer.
    >
    >So the tubulars weigh: Zipp 404 650c tubulars set = 1177 Continental Podium tyres 240each x 2=480
    >Not sure how much glue weighs when it dires?? Aprox set weight=1657
    >
    >The clinchers: Zipp 404 650c Clinchers set= 1523 Continental Supersonic tyres 145each x 2=290
    >Innertubes 65each x 2= 130 Ritchey Rim tape 30x 2=60 Aprox set weight=2003
    >
    >So the difference is about 346 grams.
    >
    >Anyone have an idea how much time savings that would amount to after 100 miles? Maybe I'm asking an
    >unanswerable question or possibly a 101 level question, I don't know.

    You have left out what may be the most important variable. In real world terms, the clinchers and
    tubulars will probably not have the same rolling resistance; it's perfectly possible for the heavier
    tire to result in less energy consumption if its rolling resistance is lower.

    --
    My email address is antispammed; pull WEEDS if replying via e-mail.
    Yes, I have a killfile. If I don't respond to something,
    it's also possible that I'm busy.
    Words processed in a facility that contains nuts.
     
  7. Which way is the wind blowing? Is it sunny out, or are their clouds?
    What brand of pasta did he carbo load on? Is the moon int the seventh
    house? Does jupiter align with mars? :-3)>

    "May you have the wind at your back. And a really low gear for the hills!"

    Chris Zacho ~ "Your Friendly Neighborhood Wheelman"

    Chris'Z Corner http://www.geocities.com/czcorner
     
  8. Chris

    Chris Guest

    Is there anyway to determine that time amount?

    Thanks Chris

    On 2/13/04 5:49 AM, in article [email protected], "Tom Compton"
    <[email protected]> wrote:

    >
    > A 346 gm difference in weight would be about a three second difference in time. However, there
    > would also be a difference in rolling resistance due to typical friction losses at the glue line
    > of tubulars. These losses would exceed the savings from less weight.
    >
    > Regards,
    >
    > Tom Compton www.AnalyticCycling.com
     
  9. Chris wrote:

    > I've been beating my head against my desk here trying to track down this answer on the web or in
    > the archives to no success. So here it goes..
    >
    > A time trial rider sets off on my made up tt, this course is perfectly straight and has no
    > altitude change for 100 miles. The bicycle is a TT styled w/ 650c wheels. The rider is very aero
    > and can average 250 watts for the entire distance.
    >
    > Now then to my question I'm trying to figure how much time the rider can save by riding with
    > tubular's vs clinchers by strictly a weight aspect and how to reach that answer.
    >
    > So the tubulars weigh: Zipp 404 650c tubulars set = 1177 Continental Podium tyres 240each x 2=480
    > Not sure how much glue weighs when it dires?? Aprox set weight=1657
    >
    > The clinchers: Zipp 404 650c Clinchers set= 1523 Continental Supersonic tyres 145each x 2=290
    > Innertubes 65each x 2= 130 Ritchey Rim tape 30x 2=60 Aprox set weight=2003
    >
    > So the difference is about 346 grams.
    >
    > Anyone have an idea how much time savings that would amount to after 100 miles? Maybe I'm asking
    > an unanswerable question or possibly a 101 level question, I don't know.

    Hardly anything apart from maybe half a second more to accelerate at the start. The rolling
    resistance of the lighter setup may be marginally lower, but Sheldon assures us that tubs can have
    *worse* rolling resistace than good clinchers.
     
  10. Tom Compton

    Tom Compton Guest

    I used the Wind-On-Rider model at www.AnalyticCycling.com, the advanced input form. I defined a 100
    mile point-to-point course (expressed in meters). The calculator defines two rider alternatives. I
    set all parameters to the same for a first trail to be sure that the only difference was the weight
    of the wheel. I changed the weight in the test rider for the comparison.

    http://www.analyticcycling.com/DiffEqWindCourse_Page.html

    Regards,

    Tom Compton www.AnalyticCycling.com

    Chris wrote:
    > Is there anyway to determine that time amount?
    >
    >
    > Thanks Chris
    >
    >
    >
    > On 2/13/04 5:49 AM, in article [email protected], "Tom Compton"
    > <[email protected]> wrote:
    >
    >
    >>A 346 gm difference in weight would be about a three second difference in time. However, there
    >>would also be a difference in rolling resistance due to typical friction losses at the glue line
    >>of tubulars. These losses would exceed the savings from less weight.
    >>
    >>Regards,
    >>
    >>Tom Compton www.AnalyticCycling.com
     
  11. daveornee

    daveornee New Member

    Joined:
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    You are asking the right question and Tom Compton likely know the right sources for the answers.
    The equation and variables below.
    The total power required to ride a bike is:
    Power lost to aerodynamic drag: (½rhoCdAVA3)
    Power loss from rolling resistance of tires: (CRRWTVG)
    Power to rotate wheels (FwVG3)
    Power to overcome gravity on a hill (WTVGsin(arctan(RoadGrade)) (varies greatly)
    Friction losses in the drive and bearings (small except for chain line cross over)
    Power to accelerate and power losses from deceleration (converted to heat).
    Power required = ½rhoCdAVA3 + CRRWTVG + FwVG3 + WTVGSin(Arctan(RoadGrade)
     
  12. Jobst Brandt

    Jobst Brandt Guest

    Chris <[email protected]> writes:

    > A time trial rider sets off on my made up tt, this course is perfectly straight and has no
    > altitude change for 100 miles. The bicycle is a TT styled w/ 650c wheels. The rider is very aero
    > and can average 250 watts for the entire distance.

    > Now then to my question I'm trying to figure how much time the rider can save by riding with
    > tubular's vs clinchers by strictly a weight aspect and how to reach that answer.

    > So the tubulars weigh: Zipp 404 650c tubulars set = 1177 Continental Podium tyres 240each x 2=480
    > Not sure how much glue weighs when it dries?? Approx set weight=1657

    > The clinchers: Zipp 404 650c Clinchers set= 1523 Continental Supersonic tyres 145each x 2=290
    > Inner tubes 65each x 2= 130 Ritchey Rim tape 30x 2=60 Approx set weight=2003

    > So the difference is about 346 grams.

    > Anyone have an idea how much time savings that would amount to after 100 miles? Maybe I'm asking
    > an unanswerable question or possibly a 101 level question, I don't know.

    Weight differences within the range of 1% of rider and bicycle weight has no practical effect on a
    flat TT that lasts more than about 10 minutes. Rolling resistance, in contrast, does. You might
    consider the points brought out in the following FAQ item:

    http://draco.acs.uci.edu/rbfaq/FAQ/8b.14.html

    Jobst Brandt [email protected]
     
  13. Jens Heycke

    Jens Heycke Guest

    Tom Compton <[email protected]> wrote in message news:<[email protected]>...
    > I used the Wind-On-Rider model at www.AnalyticCycling.com, the advanced input form. I defined a
    > 100 mile point-to-point course (expressed in meters). The calculator defines two rider
    > alternatives. I set all parameters to the same for a first trail to be sure that the only
    > difference was the weight of the wheel. I changed the weight in the test rider for the comparison.
    >
    > http://www.analyticcycling.com/DiffEqWindCourse_Page.html
    >
    >
    > Regards,
    >
    > Tom Compton www.AnalyticCycling.com
    >
    >
    >
    > Chris wrote:
    > > Is there anyway to determine that time amount?
    > >
    > >
    > > Thanks Chris
    > >
    > >
    > >
    > > On 2/13/04 5:49 AM, in article [email protected], "Tom Compton"
    > > <[email protected]> wrote:
    > >
    > >
    > >>A 346 gm difference in weight would be about a three second difference in time. However, there
    > >>would also be a difference in rolling resistance due to typical friction losses at the glue line
    > >>of tubulars. These losses would exceed the savings from less weight.
    > >>
    > >>Regards,
    > >>
    > >>Tom Compton www.AnalyticCycling.com
    > >
    > >

    The other factor that I think has been missed here is the aero differences between the clincher and
    tubular rims. As I understand it, the tubular is likely to have a much greater discontinuity where
    the tire meets the wheel than the clincher, resulting in a considerable aero disadvantage. I'm
    putting this to the test this year, using a clincher on the front for TTs.

    -- Jens
     
  14. Jobst Brandt

    Jobst Brandt Guest

    Jens Heycke writes:

    > The other factor that I think has been missed here is the aero differences between the clincher
    > and tubular rims. As I understand it, the tubular is likely to have a much greater discontinuity
    > where the tire meets the wheel than the clincher, resulting in a considerable aero disadvantage.
    > I'm putting this to the test this year, using a clincher on the front for TTs.

    I think you are splitting atoms, the difference of ripple between rim and tires is about as
    important as roughness on the tire tread of different smooth and semi-smooth tread tires. Let's keep
    this in "considerable" perspective. Your concerns sound like those of people who believe radial
    spoking is more aerodynamic than crossed spoking which it is not.

    Jobst Brandt [email protected]
     
  15. Rick Onanian

    Rick Onanian Guest

    On Sat, 14 Feb 2004 04:00:37 GMT, [email protected]
    wrote:
    >I think you are splitting atoms, the difference of ripple between rim and tires is about as
    >important as roughness on the tire tread of

    This whole thread is specifically about splitting atoms.
    --
    Rick Onanian
     
  16. Jens Heycke

    Jens Heycke Guest

    [email protected] wrote in message news:<[email protected]>...
    > Jens Heycke writes:
    >
    > > The other factor that I think has been missed here is the aero differences between the clincher
    > > and tubular rims. As I understand it, the tubular is likely to have a much greater discontinuity
    > > where the tire meets the wheel than the clincher, resulting in a considerable aero disadvantage.
    > > I'm putting this to the test this year, using a clincher on the front for TTs.
    >
    > I think you are splitting atoms, the difference of ripple between rim and tires is about as
    > important as roughness on the tire tread of different smooth and semi-smooth tread tires. Let's
    > keep this in "considerable" perspective. Your concerns sound like those of people who believe
    > radial spoking is more aerodynamic than crossed spoking which it is not.

    Jobst:

    Have you done, or seen, any tests on this? If so, I'd appreciate a link to the results.

    Although it's not the principal focus of the study, the following addresses this issue in part.

    http://www.biketechreview.com/tunnel_main.htm

    Elsewhere, I think John Cobb has averred the importance of matching tire to rim width (I couldn't
    find the link quickly at the moment and I don't remember any reference to a specific test).

    regards, Jens
     
  17. Peter Cole

    Peter Cole Guest

    <[email protected]> wrote
    >
    > Weight differences within the range of 1% of rider and bicycle weight has no practical effect on a
    > flat TT that lasts more than about 10 minutes. Rolling resistance, in contrast, does. You might
    > consider the points brought out in the following FAQ item:
    >
    > http://draco.acs.uci.edu/rbfaq/FAQ/8b.14.html

    Speaking of that section, the following seems contradictory:

    "The tread and the tube together absorb the majority of the energy lost in the rolling tire while
    the inter-cord binder (usually rubber) comes in far behind."

    and...

    "High performance tires with thin sidewalls and high TPI (threads per inch) were low in rolling
    resistance and improved little with increasing inflation pressure."

    Seems to imply that the performance in high performance tires comes from the sidewall (casing)
    material, while the earlier quote says it's the tread & tube almost exclusively. How important is
    high TPI casing material in determining rolling resistance?
     
  18. Jobst Brandt

    Jobst Brandt Guest

    Peter Cole writes:

    >> Weight differences within the range of 1% of rider and bicycle weight has no practical effect on
    >> a flat TT that lasts more than about 10 minutes. Rolling resistance, in contrast, does. You might
    >> consider the points brought out in the following FAQ item:

    http://draco.acs.uci.edu/rbfaq/FAQ/8b.14.html

    > Speaking of that section, the following seems contradictory:

    > "The tread and the tube together absorb the majority of the energy lost in the rolling tire while
    > the inter-cord binder (usually rubber) comes in far behind."

    > and...

    > "High performance tires with thin sidewalls and high TPI (threads per inch) were low in rolling
    > resistance and improved little with increasing inflation pressure."

    > Seems to imply that the performance in high performance tires comes from the sidewall (casing)
    > material, while the earlier quote says it's the tread & tube almost exclusively. How important is
    > high TPI casing material in determining rolling resistance?

    That comes from losses between the fibers of the cords that give the casing wall greater thickness.
    Such losses are apparent when bending flattened tires by hand. A comparable example is flexing a
    thin and a thick rope (cords), neither of which have an elastic binder.

    http://www.terrymorse.com/bike/imgs/rolres.gif

    Jobst Brandt [email protected]
     
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