The age old question of bike weight.

BMKN
BMKN Posts: 222
edited December 2013 in Road general
I have searched around for answers on this but people only say lose weight on the rider or train more. I train alot do weekly club spins, commute to work and run. I cant afford to lose 5lbs. I weighed my current bike and it clocked 22lbs full set up, 24lbs with water bottle, figures are rounded up. I am looking at a planet x bike rt58 that weighs 17lbs fully set up. Will this make faster overall?
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Comments

  • imposter2.0
    imposter2.0 Posts: 12,028
    Losing 5lbs off the bike will certainly help on the hills, by a small amount. But if you 'can't afford' to lose 5lbs yourself, then what about increasing your aerobic fitness instead?
  • cmhill79
    cmhill79 Posts: 138
    In my experience of dropping roughly 4 pounds by changing bike yes it will make a noticeable difference. I was in a similar situation where didn't really have weight to lose so the only way was changing bikes and I noticed a big difference and still do when I hop back on the old bike.
    If you weigh 100 kilos then changing bikes probably isn't the best place to start
  • BMKN wrote:
    I have searched around for answers on this but people only say lose weight on the rider or train more. I train alot do weekly club spins, commute to work and run. I cant afford to lose 5lbs. I weighed my current bike and it clocked 22lbs full set up, 24lbs with water bottle, figures are rounded up. I am looking at a planet x bike rt58 that weighs 17lbs fully set up. Will this make faster overall?

    On the flat or downhill - no. On the hills - yes.
  • cmhill79
    cmhill79 Posts: 138
    Yes should qualify that a heavier rider/ bike will gain more momentum on the flat/ downhill.

    You'll notice the reduced weight going uphill and also taking off from a standing start
  • cmhill79 wrote:
    Yes should qualify that a heavier rider/ bike will gain more momentum on the flat/ downhill.

    You'll notice the reduced weight going uphill and also taking off from a standing start

    and sprinting to break away from a group, and handling, and braking.
  • this is a nice wee video demonstrating the power output difference between a light bike and an entry bike. Little bit at end on rider weight too. For a 2.5kg increase in bike weight the power percentage is actually quite an eyeopener.

    http://www.youtube.com/watch?v=5DRQwKREgvI
  • chris_bass
    chris_bass Posts: 4,913
    when you say you cant afford to lose any weight yourself, is this due to being underweight?

    i was quite underweight this time last year, have actually gained some weight whilst still cycling and keeping up the exercise and my cycling has also improved quite a bit!
    www.conjunctivitis.com - a site for sore eyes
  • Anonymous
    Anonymous Posts: 79,667
    My winter bike is 21lb and my other one is under 16lb.
    They feel a world apart to me and I cannot see that losing 5lb off myself would make one feel like the other.

    I suspect that a lot of people saying to lose it off the rider are just trying to justify cheap bikes lol

    The answer to the question is very simply to lose weight and buy a light bike, but if you only do one........ buy the light bike :wink:
  • It's just not that important. Pushing air out of the way accounts for the vast majority of your effort. Would you go significantly faster if you left your bottles behind? Had a really good dump beforehand?

    Often folk will try to claim that because their best bike weighs less than their next best bike, that they produce faster times on it is down to the weight, but this is of course an oversimplification. If you are overweight you probably aren't very fast or good at climbing hills anyway, so losing weight from the bike isn't going to make a big difference to you. Think of any potential weight savings in realistic terms - if it's less than or equal to any fluctuations in your body weight, luggage carried (e.g. extra clothes and tools) and sustenance, it's probably not going to change your life.

    Buy the bike you can afford - as bikes and bits get better they tend to get lighter - and don't waste your money on expensive weight saving measures.
  • BMKN
    BMKN Posts: 222
    Im not under weight but I id look too skinny if I lost anymore so option for a new bike stands
  • gozzy
    gozzy Posts: 640
    Ah, vanity.
  • diamonddog
    diamonddog Posts: 3,426
    BMKN wrote:
    Im not under weight but I id look too skinny if I lost anymore so option for a new bike stands
    If you want a new bike get one and make it a light one. :)
  • t4tomo
    t4tomo Posts: 2,643
    I lost 6lbs over the last 3 days due to a stomach bug - I can't wait to get out and smash all my PB's on Strava.

    .....oh hang on I feel like crap because I've only eaten 2 slices of toast and marmite for the past 3 days too.

    anyway I wouldn't recommend it as a weight loss method.
    Bianchi Infinito CV
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  • t4tomo wrote:
    I lost 6lbs over the last 3 days due to a stomach bug - I can't wait to get out and smash all my PB's on Strava.

    .....oh hang on I feel like crap because I've only eaten 2 slices of toast and marmite for the past 3 days too.

    anyway I wouldn't recommend it as a weight loss method.

    But keep the weight off and you'll be onto a winner - although isn't it just that you're dehydrated?!
  • I'm currently 5'6" and 79kg.

    NHS says I should be, at most 70kg, which means I have the potential to lose the entire weight of my bike.
    It also says I could get down to 53kg :o. Which would be a massive 26kg less than I am now - which I find hard to comprehend.
  • Sprool
    Sprool Posts: 1,022
    Carbonator wrote:
    ... are just trying to justify cheap bikes lol..
    I think you got this the wrong way round. As Simon M says wisely - choose the bike you can afford. You should not need to justify it to anyone else. Of course expensive bikes are not just about weight, they are about mechanical strength and component quality too, so losing weight on a 'cheap' bike will not turn it into an exotic carbon racer.
  • BMKN
    BMKN Posts: 222
    My reason for a lighter bike is to help for head winds on solo rides to. Im after just battling a 30kph head wind an im bet. I love cycling but I hate the head wind and im bruttle at it
  • Don't forget that as well as being lighter a new, more expensive and ultimately lighter bike will probably be comprised of better quality components and may even be more aero. These things will add - if only marginally - to it possibly being faster.

    I don't notice the difference between riding with two full water bottles (4-5lbs) compared to no bottles, but if I were to ride a high quality carbon bike weighing 5lbs less then I'd probably notice a difference!



    EDIT: Okay, maybe I notice a *slight* difference grinding up a 15+ percenter. If only mental...
  • kajjal
    kajjal Posts: 3,380
    If you drop 5lb's of weight assuming the bike suits your riding style and is properly setup you will notice the difference.
  • smoggysteve
    smoggysteve Posts: 2,909
    Don't forget that as well as being lighter a new, more expensive and ultimately lighter bike will probably be comprised of better quality components and may even be more aero. These things will add - if only marginally - to it possibly being faster.

    I don't notice the difference between riding with two full water bottles (4-5lbs) compared to no bottles, but if I were to ride a high quality carbon bike weighing 5lbs less then I'd probably notice a difference!



    EDIT: Okay, maybe I notice a *slight* difference grinding up a 15+ percenter. If only mental...


    Don't forget that comparatively, AERO frames and TT bikes weigh more than a standard road race machine. weight is not the be all and end all. its more about where you distribute the weight. heavy wheels on a light frame will handle much different to light wheels on a heavier frame.
  • simon_e
    simon_e Posts: 1,706
    I'm currently 5'6" and 79kg.

    NHS says I should be, at most 70kg, which means I have the potential to lose the entire weight of my bike.
    It also says I could get down to 53kg :o. Which would be a massive 26kg less than I am now - which I find hard to comprehend.
    I'm 2" shorter than you and 61kg. Not skinny and still have a few kilos I could lose if I wanted.

    53kg is extreme, I could not ever recommend that! But if you dropped 10kg it would bring lots of benefits and no drawbacks (except perhaps needing a new belt and trousers).

    To the OP: some people say 5lb is significant, others that it's barely noticeable. Tejvan's bike weight article suggests that the time saved when climbing is small. A lighter bike won't make any difference into a headwind, that's entirely down to aerodynamics. Everyone struggles into a headwind.

    I would recommend that you spend your money on something that will genuinely make you happy. It might be a nice bike, a holiday or a fancy home cinema setup, only you can decide that.
    Aspire not to have more, but to be more.
  • smoggysteve
    smoggysteve Posts: 2,909
    I am 5'6" and weigh 68kg. according to charts I should be 65kg. Thing is, for my job I need to have a decent amount of strength and since muscle weighs more than fat I can be leaner and weigh more. you need to get a proper BMI reading before you decide what your ideal weight should be. you could get down to your supposed weight but sacrifice muscle. no point being light if you dont have the power in your legs. I bet someone like Cav weighs more than someone like Chris Froome even though he is shorter purely cos he has much more powerful muscles for sprinting which Froome does not need. He just needs to have lean but economical muscles for endurance so mass is less.

    Point being, as mentioned above, You taylor your riding to your physique. If you are small but powerful be a sprinter, if you are tall and lean be a climber. you just have to work with what God gave you.
  • ben16v
    ben16v Posts: 296
    work on 4watts per kilo if you are a fit rider, so a bike that is a kilo lighter will save you 4 watts to maintain the same speed assuming all else - aerodynamics and rolling resistance being the same.
    you may or may not be slightly faster on your usual ride, but the main difference might be that you will be able to maintain the speed for slightly longer duration.
    i need more bikes
  • cycleclinic
    cycleclinic Posts: 6,865
    http://www.machinehead-software.co.uk/b ... lator.html
    http://www.mne.psu.edu/lamancusa/proddi ... ecalc1.htm
    http://bikecalculator.com/
    http://www.analyticcycling.com/ForcesPower_Page.html
    http://www.gribble.org/cycling/power_v_speed.html
    http://www.hembrow.eu/personal/kreuzotter/espeed.htm

    Stop guessing have a play with these calculators if you do it make naff difference on the flats but (2kg make about 1W saving at 30 mph) but on the hills several watts saving will result meaning you can hold the power you are trying to deliver for longer. Still we are talking 5W or so per 2kg on a decently steep climb.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • BMKN
    BMKN Posts: 222
    I might consider looking at the ar5 bike as it looks sexy. I really just want to a 2nd bike to keep seperate from my commuter. I currently weigh in at 147lbs n 5ft 10 so I think if I lose any more weight iy will have diminishing returns ie muscle loss.
  • Stop guessing have a play with these calculators ......

    I plugged in a 5% climb over 2.5km, similar to Box Hill for reference:
    http://app.strava.com/segments/box-hill ... -rd-627910

    Then used a combined rider/bike weight of 80kg and power output of 220 watts. According to the calculator a weight saving of 2.2kg (5lbs) will get you up Box Hill around 11.5 seconds quicker. Doesn't sound like much but it would be a noticable difference and put you over 50 meters in front! Interestingly upping the power output to 350 watts means you would only save half that amount of time for the same weight saving.

    http://www.analyticcycling.com/ForcesLe ... _Page.html

    Now just go ride more! :)
  • I am 5'6" and weigh 68kg. according to charts I should be 65kg.

    Hats off to you then, being the same height, but 79kg it's my aim to get down to around 70kg but it still seems a long way off.
  • Then used a combined rider/bike weight of 80kg and power output of 220 watts. According to the calculator a weight saving of 2.2kg (5lbs) will get you up Box Hill around 11.5 seconds quicker. Doesn't sound like much but it would be a noticable difference and put you over 50 meters in front! Interestingly upping the power output to 350 watts means you would only save half that amount of time for the same weight saving.

    Jut ran the numbers and it seems that if I lose my target amount of 10kg I would get up Box Hill 36 seconds faster and be ahead by 180 metres, I gotta take this dieting thing seriously :o
  • BMKN
    BMKN Posts: 222
    After doing all calculations its really not worth going below 18lbs full set up. You only really gain seconds, best to buy a bike thats comfortable and will be a joy to ride which will get u out more and thus making u faster. Ive noticed in my club I have obe of the heaviest carbon bike and im able to keep up with the sprinters on flats but drop on hills by 100m r so. Thats down to fitness and a dodgy heart.
  • diamonddog
    diamonddog Posts: 3,426
    Simon E wrote:
    I'm currently 5'6" and 79kg.

    NHS says I should be, at most 70kg, which means I have the potential to lose the entire weight of my bike.
    It also says I could get down to 53kg :o. Which would be a massive 26kg less than I am now - which I find hard to comprehend.
    I'm 2" shorter than you and 61kg. Not skinny and still have a few kilos I could lose if I wanted.

    53kg is extreme, I could not ever recommend that! But if you dropped 10kg it would bring lots of benefits and no drawbacks (except perhaps needing a new belt and trousers).

    It depends on your overall physique, I am 5'5'' and 51kg well within the normal range for BMI with low body fat and with good muscle definition in the legs, so not skeletal but heavier boned people will naturally be heavier at an ideal weight.