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  1. #1
    Senior Member TrekmanDan's Avatar
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    Max Speed on Flat Ground

    My bro in law and I were doing some bike talk just recently and he claims that he did a top speed of 50mph according to the app on his Motorola Droid phone. I basically told him to get a cyclometer because it'd be more accurate, but he says that it IS pretty accurate. He just got his bike over the summer and it's not like he has crazy leg muscles, so is 50mph even possible on flat ground with no wind!? He has a 2009 Jamis Ventura Comp.

  2. #2
    Unobtanium-Based Lifeform calamarichris's Avatar
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    It is possible if your sister is married to Mark Cavendish, Rob McEwen, Thor Hushovd, Alejandro Pettachi, or perhaps Oscar Freire.
    If your sister is married to someone else, I'm afraid the Droid Phone is in error.

  3. #3
    Senior Member
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    Several options here...

    a) reading is in km/h not m/h
    b) BIL is compensating for something being rather small by exaggerating to the point of ridiculousness
    c) app is wildly inaccurate

  4. #4
    Quirky Grifter LesterOfPuppets's Avatar
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    d) 30 kt tailwind.
    1980ish Free Spirit Sunbird fixed * 1996 Mongoose IBOC Zero-G * 1997 KHS Comp * 1990-ish Scapin * Lemond Buenos Aires Triple

  5. #5
    Senior Member
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    Clock him in a car.

    Brad

  6. #6
    Senior Member Mr. Fly's Avatar
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    Quote Originally Posted by calamarichris View Post
    It is possible if your sister is married to Mark Cavendish, Rob McEwen, Thor Hushovd, Alejandro Pettachi, or perhaps Oscar Freire.

    If your sister is married to someone else, I'm afraid the Droid Phone is in error.
    50 mph is about 80 kph. Even if his sister is married to Mark Cavendish, Rob McEwen, Thor Hushovd, Alejandro Pettachi, Oscar Freire or even Super Mario (in his prime), that Droid phone is still wrong.

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    No way, in my opinion. If he gets out of the 30's he's done well.

  8. #8
    Cycle Dallas MMACH 5's Avatar
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    He probably has it set to kilometers.

    50 kph = 31.0685596 mph
    Which is still moving at quite a clip.
    That's gonna leave a mark.

  9. #9
    coprolite fietsbob's Avatar
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    HPV, fully streamlined, one guy, Sam Whittingham, pedaling,
    current mark is at 133 km/h (83 mph).

    http://en.wikipedia.org/wiki/Sam_Whittingham


    http://www.ihpva.org/hpvarec3.htm#nom01
    Last edited by fietsbob; 12-23-10 at 03:18 PM.

  10. #10
    2 Fat 2 Furious contango's Avatar
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    Quote Originally Posted by MMACH 5 View Post
    He probably has it set to kilometers.

    50 kph = 31.0685596 mph
    Which is still moving at quite a clip.
    Quite a clip but if he's talking about a peak speed rather than a sustained speed it's believable. I can hit 25-26mph on flat ground (tarmac) on my mountain bike, so don't have a problem believing someone could hit 30mph on a road bike without being an Olympic athlete.

    Sustaining that speed is another matter, of course.

  11. #11
    Senior Member BlazingPedals's Avatar
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    I think 45-46 mph would put him in world record territory for a flat-ground, no-assist sprint.

  12. #12
    Uber Goober StephenH's Avatar
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    Just go ride with him and ask him to demonstrate..assuming you're in better shape, that is.

    Be careful about the "no wind" assumption. There are times when I feel exceptionally fit and fast, and don't realize I have a tailwind. I doubt he did 50 mph with a tailwind, either, but if you want to be sure, go both directions and average or something like that.
    "be careful this rando stuff is addictive and dan's the 'pusher'."

  13. #13
    Senior Member Keith99's Avatar
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    Quote Originally Posted by contango View Post
    Quite a clip but if he's talking about a peak speed rather than a sustained speed it's believable. I can hit 25-26mph on flat ground (tarmac) on my mountain bike, so don't have a problem believing someone could hit 30mph on a road bike without being an Olympic athlete.

    Sustaining that speed is another matter, of course.
    I've hit 35 on flat ground. That was a few years ago, but I was still over 50 when I did it. Of course I did it coming off a wheel going probably 27 or so and got to 35 and held it for all of 3.5 seconds before realizing that if I held it for 10 I'd puke.

    But remember you are pretty much overcoming wind resistance, and the drag is a function of the SQUARE of yuor speed. That means going 50 would require twice the power outout that 35 does.
    Last edited by Keith99; 12-23-10 at 05:58 PM.

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    If an observer is in a vehicle travelling at 35 mph toward your BIL riding his bike, then this is feasible.

  15. #15
    Senior Member Keith99's Avatar
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    Quote Originally Posted by BlazingPedals View Post
    I think 45-46 mph would put him in world record territory for a flat-ground, no-assist sprint.
    Looking this up is a real pain, it is easy to find records for HPV, whicj means fully enclosed and recumbent.

    I pretty much think your numbers are pretty close, but hard to be sure.

  16. #16
    Senior Member CNY James's Avatar
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    sounds like bs.

    Tell your BIL that you will give him $10 for every MPH over 30 he can do on flat ground, not coming off of a hill. Subsequently, he owes you $10 for every MPH under 50 he goes. I'll bet his story changes real quick.

  17. #17
    Senior Member BlazingPedals's Avatar
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    Apparently my estimate was a little bit low.

    There's Wikipedia, here, which shows the UCI record just short of 50 mph, and the 'UCI best human effort' obviously not recumbent, at 56 mph. The recumbent mark is 56 mph, too -- for the hour.

    That doesn't make it any more likely that brother-in-law could come anywhere near 50 mph.

  18. #18
    Senior Member TrekmanDan's Avatar
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    Quote Originally Posted by StephenH View Post
    Just go ride with him and ask him to demonstrate..assuming you're in better shape, that is.

    Be careful about the "no wind" assumption. There are times when I feel exceptionally fit and fast, and don't realize I have a tailwind. I doubt he did 50 mph with a tailwind, either, but if you want to be sure, go both directions and average or something like that.
    I would definitely ride with him, but he's in Michigan and we're down in Texas...

  19. #19
    Senior Member rdtompki's Avatar
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    Quote Originally Posted by Keith99 View Post
    ... But remember you are pretty much overcoming wind resistance, and the drag is a function of the SQUARE of yuor speed. That means going 50 would require twice the power outout that 35 does.
    Not to put too fine a point on this discussion, but power increases as the cube of velocity (no wind, level course). Wind resistance, as stated, does increase as the square. 50 mph versus 35 mph requires that power increase by a factor of 2.9.
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  20. #20
    Senior Member TrekmanDan's Avatar
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    Quote Originally Posted by Keith99 View Post
    I've hit 35 on flat ground. That was a few years ago, but I was still over 50 when I did it. Of course I did it coming off a wheel going probably 27 or so and got to 35 and held it for all of 3.5 seconds before realizing that if I held it for 10 I'd puke.

    But remember you are pretty much overcoming wind resistance, and the drag is a function of the SQUARE of yuor speed. That means going 50 would require twice the power outout that 35 does.
    I've done 30mph on my mountain bike a couple months ago on flat ground and no wind by pedaling my legs off. Once I hit 30, i knew i couldn't go any faster, so i didn't bother trying. I probably held it for a second or two and that was it. So, if he said mid 30's, I'd definitely say it's realistic, but 50 is another story... Although he didn't claim to have sustained it for more than a few seconds, I definitely think him doing 50mph is impossible.

  21. #21
    don't try this at home. rm -rf's Avatar
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    Edit: Here's the video of Theo Bos's world record Flying 200 meter: 9.772 seconds for 200 meters. Per Google Calculator, that's (200 meters) / (9.77200 seconds) = 45.78 mph



    Lets see... using Bike Calculator:

    I'll change bike position to aerobars (yeah, full power on the aerobars, sure.)
    bike weight or rider weight doesn't affect the results,
    keep grade=0, headwind=0, temperature=75
    elevation=1000 feet,
    transmission efficiency: increase to 98% from the 95% default.

    1700 watts = 50.7 mph.

    Changing to drops instead of aerobars:
    1700 watts= 46.7 mph.
    2100 watts= 50.2 mph. That's kinda difficult.

    OK. More realistically, at 1000 watts: a -6% grade (!) would get you 50 mph. That's not bad, since coasting down a -6% grade is about 35 mph.
    Last edited by rm -rf; 12-23-10 at 08:48 PM.

  22. #22
    Senior Member TrekmanDan's Avatar
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    Quote Originally Posted by calamarichris View Post
    It is possible if your sister is married to Mark Cavendish, Rob McEwen, Thor Hushovd, Alejandro Pettachi, or perhaps Oscar Freire.
    If your sister is married to someone else, I'm afraid the Droid Phone is in error.
    HAHA... Mark Cavendish...he's fast, but his big head creates too much drag!
    And just an FYI, I'm married to his sister... Brother in law that is.

  23. #23
    Senior Member Mr. Fly's Avatar
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    Quote Originally Posted by BlazingPedals View Post
    Apparently my estimate was a little bit low.

    There's Wikipedia, here, which shows the UCI record just short of 50 mph, and the 'UCI best human effort' obviously not recumbent, at 56 mph. The recumbent mark is 56 mph, too -- for the hour.

    That doesn't make it any more likely that brother-in-law could come anywhere near 50 mph.
    You need to watch your units. The hour record is in kph, not mph.

  24. #24
    Yabba-Dabba-Doo! AlmostTrick's Avatar
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    Quote Originally Posted by TrekmanDan View Post
    My bro in law and I were doing some bike talk just recently and he claims that he did a top speed of 50mph according to the app on his Motorola Droid phone. I basically told him to get a cyclometer because it'd be more accurate, but he says that it IS pretty accurate. He just got his bike over the summer and it's not like he has crazy leg muscles, so is 50mph even possible on flat ground with no wind!? He has a 2009 Jamis Ventura Comp.
    Flat ground with no wind means the rider must be pedaling. Bikepedia says that bike has a 50/11 top gear and 700x23mm tires. Sheldons gear calculator puts him at 42.6 mph IF he can spin that gear at 120 RPM. (haha)

    Decide for yourself if your brother in law is stronger and can spin the cranks faster than this.
    Have Bike, Will Travel

  25. #25
    coprolite fietsbob's Avatar
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    You need to watch your units. The hour record is in kph, not mph.
    I recall a certain group of Rocket Scientists that got miles and kilometers confused,
    in the communications , and a soft landing on Mars, came out a little hard.

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