Stupid question about weight

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  • vorsprung
    vorsprung Posts: 1,953
    I recently did the Mille Cymru 1000km audax. The idea is that you do 1000km on the roads of Wales in less than 75 hours, including sleep

    The fly in the ontiment is that the 1000km also included 13,500m of ascent

    So my initial training plan included a 3 or 4kg body weight loss. I was down to -2kg in May but by the time the event came around in July I was back to my average summer weight of just over 80kg.

    However, over that sort of distance/climb I figured out that 3kg was good for just 45 minutes of time. This would of course win the Tour de France but on a non race where all I have to do is get around in the time limit 45 minutes is a "nice to have" and not a show stopper

    I'm sure that weight isn't as significant as you might believe even on shorter sportive rides

    Several articles on my blog about the Mille Cymru, linky below
    Audaxing Blog - Long Distance Cycling
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  • Barteos
    Barteos Posts: 657
    A poster has claimed recently that a new set of lighter wheels made him 4mph faster... :shock:


    Anyway, if unlike him, you live on Earth and the laws of physics apply to you and your bike, then this website may help
    http://www.analyticcycling.com/ForcesLe ... _Page.html
    also
    http://en.wikipedia.org/wiki/Bicycle_performance
    (interesting bit about lightweight wheels)
  • Bar Shaker
    Bar Shaker Posts: 2,313
    The mad professor may have assumed that the bike is being pedalled at a constant speed and used the rider's wattage to determine the speed it will be ridden at. On a gentle slope with the rider seated, this may be a fair set of rules for the calculation.

    On the flat, once the bike has been accelerated to the cruising speed, the rider's leg power only has to overcome air and rolling resistance. The bike weight is immaterial once the speed has been reached and as gradients are factored in, the same will apply whilst the rider is seated.

    Up a steeper hill, all of this changes. To overcome gravity, the bike is being accelerated through the power section of the crank's arc and then being decelerated by gravity until the rider's other foot gets into the power section. If the rider is out of the saddle, he will allow his body to move slightly to try and keep his torso at a constant speed but the bike speed will constantly increase and decrease with every crank rotation.

    Up a hill, the bike is repeatedly being accelerated by the rider and its this that makes bike weight so important.

    Cavendish's stages are flat and he is exerting enormous pressure on the bottom bracket. Some extra material may be used but I doubt its much.

    By far the most import weight saving is on the wheels and tyres. You can have a light frame with heavy wheels and tyres versus a heavy frame with light wheels and tyres. Both bikes may weigh the same. The bike with the light wheels and tyres will be much faster as the rider has less mass to centripetally accelerate. It will also corner more easily as there will be less gyroscopic effect.
    Boardman Elite SLR 9.2S
    Boardman FS Pro
  • dennisn
    dennisn Posts: 10,601
    peejay78 wrote:
    for hillclimbing disciplines weight is everything, and power to weight the optimal thing.

    I once heard that power to weight is NOT the optimal thing. It's the ONLY thing. :wink:
  • Barteos
    Barteos Posts: 657
    Bar Shaker wrote:

    Up a steeper hill, all of this changes. To overcome gravity, the bike is being accelerated through the power section of the crank's arc and then being decelerated by gravity until the rider's other foot gets into the power section. If the rider is out of the saddle, he will allow his body to move slightly to try and keep his torso at a constant speed but the bike speed will constantly increase and decrease with every crank rotation.

    Up a hill, the bike is repeatedly being accelerated by the rider and its this that makes bike weight so important.

    I'm well aware of this and totally agree with you, although with a right pedaling technique and gear selection it's not really such a big deal.

    Yes, certainly lighter is better and having lighter wheels is better than lighter frame, but I just don't believe that the differences are as significant as most of people claim.

    Apparently Dura Ace wheels are much faster than Ultegra...(from another post)
    By how much? How do people measure it?
  • dag_on_a_bike
    dag_on_a_bike Posts: 581
    Barteos wrote:
    Apparently Dura Ace wheels are much faster than Ultegra...(from another post)
    By how much? How do people measure it?
    No idea but I recently made just that upgrade and they were noticably faster, both in feel and actual performance. My average over several following rides went up by about 1mph.

    I doubt that was entirely the wheels but I feel it was money well spent and I'm happy with the perceived performance gain. Nothing else matters, surely?
    There's no such thing as too old.
  • lastwords
    lastwords Posts: 304
    I have a lighter bike than my nephew but i am 11stone and he is inly 9 1/2stone there is probably about 2kg in difference between bike weight his is a very cheap road bike to get him started.

    I ride my bike a lot more than him and he only rides with me now and then im 32 and he is 16.

    On anything flat or with a mild gradient and downhill too he cant keep up i can drop him anytime if i want. However get to a steep hill and its me who has to put the effort in to keep up, i can just about drop him if i want but with great effort.

    This is pure and simply because he is so light, i have to drag around 2 stone extra up the hills than him. His advantage only lasts a short distance though because he hasnt got the stamina yet and wont unless he rides more.

    My view is buy lighter kit if you can afford it everyone likes a bit of bling however dont expect it to turn you into a speed machine.
    Losing wieght is cheaper and you have the added benefit that you will get faster because you have to train to lose it, plus it is cheaper.
  • pianoman
    pianoman Posts: 706
    I think any ascent favours someone who is light, regardless of their power. It's the steep "kicks" on certain climbs like Parbold Hill where the slightly heavier rider who has more power can make the difference.

    But good to see people finally coming around to the idea that you can't "buy" all that much speed for climbs. Things like energy levels and how well blood is pumping make more difference. And whether you have an "Army Mentality" too :twisted:
  • Barteos
    Barteos Posts: 657
    DAG on a bike wrote:
    Barteos wrote:
    I feel it was money well spent and I'm happy with the perceived performance gain. Nothing else matters, surely?
    I can't argue with that :)
  • Dodger747
    Dodger747 Posts: 305
    PianoMan wrote:
    It's the steep "kicks" on certain climbs like Parbold Hill where the slightly heavier rider who has more power can make the difference.

    Ah the staple of my Sunday morning ride. It's funny how I always see loads of cyclists in the surrounding areas, yet in over 4 years of riding up there I've only seen a handful of riders riding it... :lol:
    VO2 Max - 79 ml/kg/min
    W/kg - 4.9
  • EV!lution
    EV!lution Posts: 51
    I found getting a carbon bike alot lighter then the one i had before didnt make me any faster,

    it just made alot of things easyier to do like climbing
  • sam_m
    sam_m Posts: 61
    PianoMan wrote:
    Parbold Hill

    Had a go at this the other week (my first decent climb) - had to stop once or twice, but it was good fun and I reckon I'll be able to handle it pretty soon.

    It's also a good excuse to stop at the Eagle & Child for their awesome fish and chips.
  • pianoman
    pianoman Posts: 706
    Had a go at this the other week (my first decent climb) - had to stop once or twice, but it was good fun and I reckon I'll be able to handle it pretty soon.

    It's also a good excuse to stop at the Eagle & Child for their awesome fish and chips.

    You're not based anywhere near Ormskirk by any chance are you? If so, come down to the shop on a Sunday morning - over 40 riders every week in three groups! Can't beat that can you? And we always stop at a cafe. Don't think anyone else would agree with us on the idea of fish and chips followed by another 20-30 miles back home though :wink:

    Agree with you on Parbold - the first time I tried it was on a 22.5lb Giant OCR a weeks after I started riding in 2005! With flat pedals no less. And I ended up pushing the bike past the church. Nowadays on an 18lb titanium bike I can do it non stop if I dig in, Contador-style, just before that point as the extra speed gives me the rush I need to black out the pain - and get to the top first if I'm lucky :D
  • sam_m
    sam_m Posts: 61
    St.Helens, so not far at all. Which shop do you go from?
  • rdt
    rdt Posts: 869
    From reading these forums, you might conclude that the activity known as "cycling" has evolved into one predominantly about shopping for bikes and bike componentry, rather than the actual physical riding of bikes.
  • pianoman
    pianoman Posts: 706
    St.Helens, so not far at all. Which shop do you go from?

    Sam, I'll send you a PM :D
  • dennisn
    dennisn Posts: 10,601
    rdt wrote:
    From reading these forums, you might conclude that the activity known as "cycling" has evolved into one predominantly about shopping for bikes and bike componentry, rather than the actual physical riding of bikes.

    I think you've got something there. It does seem a little sad with all the new riders wrttting in and asking crazy questions about whether a DA crank is BETTER than a Sram Red or something along those lines. Advertising has become a very powerful tool, especially to
    the unsuspecting newbie(and a few who should know better). Everything is you need this to win. I'm amazed at the people who now believe that you must have this or that energy bar. That even a 10 mile ride requires the proper gel shot. That you must put some sort of electrolyte product in you bottle at all times, as if your diet doesn't provide these things. OK, I quit, starting to rant here.
  • pianoman
    pianoman Posts: 706
    I'm amazed at the people who now believe that you must have this or that energy bar. That even a 10 mile ride requires the proper gel shot. That you must put some sort of electrolyte product in you bottle at all times, as if your diet doesn't provide these things.

    At least that's something that most people can improve greatly on, rather than worrying about whether to buy a Campag Record or FSA K-Force seatpost. (Answer - Campag Record has more street cred every time) :lol:

    Having said all that, I'm often much quicker post-cafe when I've had some good old British breakfast food e.g. bacon sandwich, than a quick hit of sugar e.g. brownie. It IS true that you should experiment to find what works best for you, but once you're comfortable, it's stupid to worry about whether choosing bacon or eggs with give you 0.6watts extra power on the way back :shock:
  • rdt
    rdt Posts: 869
    dennisn wrote:
    rdt wrote:
    From reading these forums, you might conclude that the activity known as "cycling" has evolved into one predominantly about shopping for bikes and bike componentry, rather than the actual physical riding of bikes.

    I think you've got something there. It does seem a little sad with all the new riders wrttting in and asking crazy questions about whether a DA crank is BETTER than a Sram Red or something along those lines. Advertising has become a very powerful tool, especially to
    the unsuspecting newbie(and a few who should know better). Everything is you need this to win. I'm amazed at the people who now believe that you must have this or that energy bar. That even a 10 mile ride requires the proper gel shot. That you must put some sort of electrolyte product in you bottle at all times, as if your diet doesn't provide these things. OK, I quit, starting to rant here.


    For anyone interested in equipping themselves to better navigate a path through our compliance-industry (marketing & advertising) swamped world, I'd strongly recommend reading Cialdini's "Influence: Science & Practice".

    Amongst other benefits, it may well save you 10s or 100s of thousands of pounds throughout your lifetime.
  • bompington
    bompington Posts: 7,674
    rdt wrote:
    dennisn wrote:
    rdt wrote:
    From reading these forums, you might conclude that the activity known as "cycling" has evolved into one predominantly about shopping for bikes and bike componentry, rather than the actual physical riding of bikes.
    I think you've got something there. It does seem a little sad with all the new riders wrttting in and asking crazy questions about whether a DA crank is BETTER than a Sram Red or something along those lines. Advertising has become a very powerful tool, especially to
    the unsuspecting newbie(and a few who should know better). Everything is you need this to win. I'm amazed at the people who now believe that you must have this or that energy bar. That even a 10 mile ride requires the proper gel shot. That you must put some sort of electrolyte product in you bottle at all times, as if your diet doesn't provide these things. OK, I quit, starting to rant here.
    For anyone interested in equipping themselves to better navigate a path through our compliance-industry (marketing & advertising) swamped world, I'd strongly recommend reading Cialdini's "Influence: Science & Practice".

    Amongst other benefits, it may well save you 10s or 100s of thousands of pounds throughout your lifetime.
    PM me & I'll sell you a copy for a special offer price of £49.99
  • peejay78
    peejay78 Posts: 3,378
    "I think any ascent favours someone who is light, regardless of their power. It's the steep "kicks" on certain climbs like Parbold Hill where the slightly heavier rider who has more power can make the difference. "

    it also favours those riders who actively train on hills, or seek out tougher ascents.

    it's easy to typecast a rider as a mountain goat, arguing that their whippet-thin torso is primary reason why they are dropping you like an anchor. however, it's usually down to serious training.

    someone mentioned this earlier with regard to par-boild hill or something - on my training route i see riders out and about all the time, but conspicuously they seem to be coming down one of the longer hills and around the bottom, never up it.

    it's 'hill-avoidance'. tackling hills regularly as part of your riding, and riding them fairly hard, will make huge differences to your fitness.
    http://traumradfahren.wordpress.com/
  • ishmael
    ishmael Posts: 35
    I can't agree with you more Peejay.

    I'm a heavy rider (17 stone) but I was 18.5 stone back in April.

    Hills were a real torture and they are still difficult now but by riding them I am developing better fitness and more power. I will never be thin enough though - nowhere near, but I hope to lower my overall weight as much as possible. Right now it feels like I'm converting a lot of useless weight in something more useful.

    A lot of the riders in my group are whippets. But on the flat, into a headwind they are more than happy to sit in behind my vast wind shadow. But back on the hills they are off like goats while I grind it out against gravity.

    Such is the nature of cycling.
  • pianoman
    pianoman Posts: 706
    But on the flat, into a headwind they are more than happy to sit in behind my vast wind shadow.

    Not to mention the fact that on the flat their jerseys, even in small sizes, flap around so much. Speaking from experience of course, until I bought the Endura Equipe jersey back in June. Now THAT has undoubtedly helped into those headwinds :D

    Having said that, many good hillclimbers actually come from fairly flat areas. Isn't it true that employing the "Army Mentality" rule when battling a headwind (in other words pedal like f***, I don't care if your legs explode) is just as good as tackling hills?

    Also, cross-training can make a difference. Doing some running to give the cycling muscles a break, meaning I can keep training 7 days a week most weeks, has made a good difference to my ability to not run out of breath on steep hills, I can keep those lower gears spinning much easier this year. And yes I attack the hills when running too :D
  • peejay78
    peejay78 Posts: 3,378
    "Having said that, many good hillclimbers actually come from fairly flat areas."

    the dutch mountain springs to mind. http://tinyurl.com/33f46k3
    http://traumradfahren.wordpress.com/

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