Why are some people concerned about the weight of their bike even though they are overweight?

Discussion in 'Cycling Equipment' started by lifeonbicycles, May 15, 2013.

  1. lifeonbicycles

    lifeonbicycles New Member

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    This has always puzzled me. I have seen people bragging how light their bike it but they are overweight. Is it just like a backpack where every pound counts? In other words, would a person that is 160 pounds with a 20 pound bike and a person that is 156 pounds with a 24 pound bike technically be the same excluding factors such as fitness level and aerodynamics?
     
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  2. daveryanwyoming

    daveryanwyoming Well-Known Member

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    Climbing a steep hill yes, as it diminishes the importance of aerodynamics the total weight is what matters. On flatter terrain or higher speeds or into headwinds aerodynamics matters more than pure weight.

    But to answer your title question, I'd say it's because many folks don't really understand or have a tendency to ignore physics when it comes to things like sports performance.

    Cyclists are traditionally known to pay far too much attention to things like bike and component weight and many will spend ridiculous amounts to shave very small weight from their bikes when it makes almost no difference in most riding situations. That and folks focus on the bike weight as if the bike can ride itself and tend to forget that it's the entire bike + rider + water + kit package weight that matters.

    From that perspective a 170 pound rider plus full kit moving from a 20 pound bike to a 16 pound bike saves about 2% on steep climbs and much, much less in more varied riding situations. For some like folks doing hill climb time trials that 2% may be important but in most riding situations it really isn't very important at all.

    -Dave
     
  3. alienator

    alienator Well-Known Member

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    Technically it's likely they wouldn't climb at the same rate as the lighter person would very likely have a smaller aerodynamic area, but depending on the speed (i.e. if it's low speed), that difference could be pretty small. As for why some are concerned about bike weight, there can be any number of reasons. They might not understand the magnitude of the change in performance that a change in bike weight might create. They might be losing body weight and want to cut some fat from their bike to add that last little bit of performance gain. Maybe they're weight weenies, people that build light weight bikes as a technical exercise or to satisfy their technical interests. I don't find anything wrong with their approach, their goals, or with them scratching whatever bicycle itch they might have. I don't care at all what someone rides or why they ride what they ride. IMHO, it's a time waster to be concerned about such things.
     
  4. vspa

    vspa Active Member

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    i remember in the early 80's only steel frames were around, for some reason non cyclists people learnt to associate low weight with quality, which by the way is true, so they would ask you how much did your bike weight, then aluminium came and then carbon fiber, and bikes are in fact so light, people have guess that these materials are light so just by the fact that a bike is made of carbon fiber supresses the how much does your bike weight question, now its the material not the bike,
     
  5. CAMPYBOB

    CAMPYBOB Well-Known Member

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    All weight in the formula matters because the road thru life is not flat.

    You can pedal 10,000 miles in a year and the weight of the bicycle will not change. Most riders will lose weight over those miles. Might as well start out as light as possible because over the next 10K miles you will be doing a lot of climbing.

    [​IMG]

    That's right! My Cento Uno weighs only 15.5 pounds!

    There are exceptions to the rule! Let's hope his heart is in good shape!
     
  6. dabac

    dabac Well-Known Member

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    Well...

    Part of it is probably a case of assumed implications.
    While not always true, a lighter part is often also a nicer(= better functioning) part.
    Stands to reason, if you're willing to pay the extra for a better material, you're probably also willing to pay for the extra machining, ASO.
    So a lighter bike is often a nicer bike.
    Maybe not b/c it's lighter, but rather b/c it's more nicely put together.

    Part of it is that weight is such an obvious thing to measure and compare. Aerodynamics, comfort, rigidity and all those are seriously difficult to measure and compare, even in a lab setting.
    And even if you're able to put numbers to them, it's far from certain that riders would agree. One rider's "nicely compliant" frame/fork may be another rider's "horribly noodly" frame/fork.
    But weight? Within the error margins of the scales being used, there's just no discussion about if version A is lighter than version B or the other way around.
     
  7. daveryanwyoming

    daveryanwyoming Well-Known Member

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    Agreed on all points, weight is easy to measure, light weight and high quality are often correlated so it's a quick way to know if a bike is a cheap department store bike or something a little nicer.

    But I suspect a lot of it is unrealistic extrapolation because folks really don't do or understand the math and physics. If lighter is generally a good thing then every gram must count, or that kind of thinking. Same thing with the persistent focus on moment of inertia and rotating weight. Sure MOI matters in the extremes but most riders have no idea how much or how little is actually meaningful and over attribute light tires to performance for the wrong reasons.

    -Dave
     
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  8. alienator

    alienator Well-Known Member

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    Yes, people tend to have a poor sense of scale and/or a poor sense of the magnitude of the influence a given factor has. It is also easier (discounting the financial cost) to remove a bit of weight from a bike than it is from your corpus. Big changes to a bike can excite someone to ride more and faster, but that excitement wears off and performance returns to where it should be. I'm amazed by the claims of how a new set of wheels resulted in a 5mph improvement or how a new frame did the same. With all that said, bike companies are working hard to make such small improvements. In about 2007 or 2008 (give or take a year), Brent Ruegamer (now Breanna Ruegammer) built a 600-ish gram frame, and at the time there was no shortage of cyclists saying that such a frame couldn't be safe. Now we have companies manufacturing frames that weigh 700-800g that anyone can buy at an LBS. Frame aerodynamic improvements have also been revolutionary. Credit Cervelo for really starting that road bike trend their Soloist. While many cyclists scoff at industry innovations and label them products of marketing trickery, there's a lot of excellent engineering being done. For a tech geek and for cyclists in general, this is a great time to be a cyclist.
     
  9. qdc15

    qdc15 Member

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    Was the sex change an attempt to lop off some extra weight?
     
  10. alienator

    alienator Well-Known Member

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    You'd have to ask Breanna about her motivations.
     
  11. dabac

    dabac Well-Known Member

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    Let's not forget that humans aren't exactly great as measuring devices.
    We do well at noticing differences, but we are quite sucky at absolute values. A change that'll be quite minor in terms of speed/efficiency can mean a huge change in how a bike feels. And if it feels better, you ride harder and enjoy yourself more.

    I go through that phase myself everytime I change the commuter bike over from studded tires to slicks. That cuts tire+tube weight to almost 1/3, and the bike gets a lot livelier. Ride enjoyment improved by 25%. Ride time reduced by maybe 8%.

    I try not to be judgemental about those things, I haven't got them figured out well enough. But sometimes it does get ridiculous. Years ago someone posted on this site about how much faster uphill his new and lighter seat post had made him, and, yeah, that I'd put down to placebo.
     
  12. alienator

    alienator Well-Known Member

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    Unfortunately, humans can do pretty badly at noticing differences, too. The problem is that the human system is easily biased, and it's exceedingly difficult to conduct comparison tests completely blind. As such some element of bias will likely remain.
     
  13. CAMPYBOB

    CAMPYBOB Well-Known Member

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    " Brent Ruegamer (now Breanna Ruegammer)"

    wait...wut???

    [​IMG]
     
  14. Nukuhiva

    Nukuhiva Member

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    Some people also order cake with whipped cream , but take Sweet 'N' Low in their coffee......
     
  15. vspa

    vspa Active Member

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    sometimes i eat 500 kcal hotdogs... with a diet coke :(
     
  16. swampy1970

    swampy1970 Well-Known Member

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    Who cares what people ride? I tend to swing from being a lard ass to "average" weight during the course of any given year but I like the good equipment because its shinier, more fun to service and might work just that little bit better... But mainly I get the nicer stuff because I can and it makes me happy - and because when I did race I couldn't afford the really good stuff. If it was all about weight then I already know I can lose 2lb per week on a regular basis - so by the time it took to order the latest super wizzo chainset and waited for it to arrive by standard mail, I could have lost much more weight than the few grams saved on that component... But the only components that I really value the extra functionality of are the Dura Ace calipers and brifters. The brakes offer repeatable hurculean braking and I really dig the ergo adjustability on the levers and after 12+ hours on the bike in the hills it's things like this that make the difference for me. I couldn't really give a hoot that they're a few grams lighter than Ultergra or 105.
     
  17. Insightdriver

    Insightdriver New Member

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    I have an expensive custom carbon fiber bike set up as primary transportation. People always ask me how much it weighs. It might be light, but I carry nearly 20 pounds of stuff on my bike plus my weight. Anything that would reduce the weight of my bike would be so such a small percentage of the total weight that the difference would not be detectable. That said, I replaced my tires today because I had worn out my tires on my bike and I was wondering why I wasn't riding a faster average over my 18 mile ride with my new higher pressure and lighter tires. Ironically in a review of the brand of tires I got (because they were on sale at the bike shop) was by someone that said they were ok for training but too heavy for racing and that he felt the difference. Sad to say, there were those who praised his review as they bought into his belief.
     
  18. alienator

    alienator Well-Known Member

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    That person could very well have mistaken the difference in rolling resistance between tires for the difference in weight. The difference in rolling resistance can be noticed if the difference is large enough.
     
  19. Insightdriver

    Insightdriver New Member

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    I notice a difference in rolling resistance with a change of pressure in the same tires. Unless one is using scientific measurements of resistance, a human is a poor instrument to determine specific degrees of drag. Just saying.
     
  20. BostonRoadBoys

    BostonRoadBoys New Member

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