Bike weight loss - measured advantages?

james22b2
james22b2 Posts: 132
edited July 2015 in MTB beginners
Hi
I have been bashing my head against the wall trying to understand the real advantages of buying a lighter MTB as i look at models ranging from around 13,5kg to 11,5kg with dramatically increasing prices. Aren´t the real world speed/power advantages minimal, especially if you are not in peak physical fitness?
http://velonews.competitor.com/2014/08/news/bike-weight-myth-fast-bikes_339880
http://mccraw.co.uk/bike-weight-performance/
Etc
Would it be more cost effective to spend the money on improving physical fitness.. or eating better!?
Thanks!

Comments

  • The most important part of a bicycle is the engine which drives it. That engine is you the rider, the fitter you are the more efficient you will be at propelling yourself along with the bike. The biggest advantage to weight loss is on your body not the bike.

    If you give an athlete a heavy steel frame bike with average components and you give an average person a top of the range carbon fibre bike with the best components the athlete is still going to win, by a considerable amount too!

    Yes saving weight on the bike will help if you are competing in events against other fit riders, you may shave a second or two off here and there. The real difference is between the riders skill level, fitness and stamina.

    The rider is the engine, it doesn't matter what the bike is unless competing with very close competition.
  • cooldad
    cooldad Posts: 32,599
    Nonsense actually. That's a 15% reduction and you will certainly notice it. Your body is used to carrying your body weight around. A lighter bike is easier to ride, and more responsive, especially if the weight savings are in the right places.

    As we are what we are, unless you are thinking of riding really seriously, the comparison with athletes is a non starter.

    Getting fit need not cost money and eating better will often cost less, although might take more time than ordering Macpuke.
    I don't do smileys.

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  • The Rookie
    The Rookie Posts: 27,812
    As CD says, its not just a matter of looking at the whole Mass (weight) being moved Rider, plus kit, plus bike), your body (unless doing serious training) is used to (and muscled for) your weight, so the benefit of a lighter bike is greater than that simple percentage, a lighter bike also accelerates quicker (and as the rotational inertia is almost certain to be lower as well, the effect is multiplied), a lighter bike is also easy to move around, bunny hop/manual etc.

    Building a lighter bike (unless you just throw money at it) can also be fun in itself.

    See top two links below in my sig to my light(ish) bikes. Neither cost a fortune to build.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • There is no denying that a lighter bike is going to be marginally easier to ride. It's not night and day though, not for an unfit rider.

    I would recommend concentrating on fitnes level and body weight more than bike weight to begin with. It's all very well saying that your body is already used to carrying your weight and is muscled for it etc, but it's not muscled for cycling it up hills etc if you aren't fit and haven't been training. Cardiovascular strength and efficiency means so much more than a gram or two on a bike.

    The athlete analogy was to get the point across, that the best bike in the world is still slow with an inefficient engine, ( an un fit rider). A very fit rider can still propel a low spec bike at a decent pace.

    Realistiacally the average person doing the average bike ride isn't going to shave much time off with lighter components. Although the bike will feel nicer to ride.
  • The Rookie
    The Rookie Posts: 27,812
    I would recommend concentrating on fitnes level and body weight more than bike weight to begin with.
    You haven't explained WHY you would do that? Why not both at once for example?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Chunkers1980
    Chunkers1980 Posts: 8,035
    If you have a nice shiny light bike you're much more likely to want to ride it than some lumpy thing. What comes first?
  • I would recommend concentrating on fitnes level and body weight more than bike weight to begin with.
    You haven't explained WHY you would do that? Why not both at once for example?

    There is nothing stopping anyone doing both at once. What I mean is the real priority is the riders fitnes level. Why go and buy or build a top spec bike if you can't pedal 10 miles without dying or stopping for refreshments halfway through?

    How many people buy expensive bikes and loose interest in the sport because they realise it requires too much effort? They think the best kit is going to make it all a walk in the park. Getting properly fit isn't easy, it doesn't matter what bike you choose.

    Anyone starting out I would recommend a modest but reasonable bike suitable for the job and concentrate on getting themselves fit first, before worrying about grams.
  • markhewitt1978
    markhewitt1978 Posts: 7,614
    If you're 100% sure that you're going to stick with cycling then getting a good bike up front makes sense, and is cheaper in the long run.

    But, of course, who can really be 100% sure at the start? Who can really be 100% sure even years in that their interests aren't going to take them in a different direction?
  • james22b2
    james22b2 Posts: 132
    Nonsense actually. That's a 15% reduction and you will certainly notice it.

    I think the two articles are saying that the true comparison is total weight - body weight plus bike weight plus kit weight? So if I weigh 80kg, the bike weighs 15kg and I have 5kg of kit including water and shoes etc, then a 2kg reduction in bike weight is actually only 2%. This amounts to seconds saved per hour uphill if constant power is maintained. So at elite levels it might matter, but generally doesn´t have a big impact for everyone else.
  • Chunkers1980
    Chunkers1980 Posts: 8,035
    No, like CD says, that way of looking at it is nonsense.

    In a 30lb HT and a 24lb HT the difference in rideability is huge.
  • The Rookie
    The Rookie Posts: 27,812
    Yes but as mentioned above it doesn't work like that, two people of different weights (all else being equal) will have muscle tone to suite their weight.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • james22b2
    james22b2 Posts: 132
    No, like CD says, that way of looking at it is nonsense.

    In a 30lb HT and a 24lb HT the difference in rideability is huge.

    Are you talking about just ease of ride and responsiveness of the bike, or speed climbing as well? And if the latter, are you saying the speed difference is proportional to the difference in bicycle weight?
    The Rookie wrote:
    Yes but as mentioned above it doesn't work like that, two people of different weights (all else being equal) will have muscle tone to suite their weight.

    So a big guy can handle a heavy bike better than a small guy, because it is a lower percentage of total body weight?
  • Chunkers1980
    Chunkers1980 Posts: 8,035
    I don't think you can look at it in terms speed more smiles. Like you say ease of riding and responsiveness is what gives me the smiles. Some people also value flying up hill rather than grinding it out that gives them the smiles. Going up kills speed, you'll feel lighter much much more on uphills. But to answer your question, it's what you value. Some people are happy to lug 32lb trail bikes up hill as they get more from them on the down than a light bike. Some wouldn't even consider riding up on a bike above 30lbs.
  • The Rookie
    The Rookie Posts: 27,812
    The Rookie wrote:
    Yes but as mentioned above it doesn't work like that, two people of different weights (all else being equal) will have muscle tone to suite their weight.

    So a big guy can handle a heavy bike better than a small guy, because it is a lower percentage of total body weight?
    True, but still benefits from the lighter bike....
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • kajjal
    kajjal Posts: 3,380
    The most important thing is the bike fits you, your riding style and the trails you ride. Dropping 2kg in weight off a bike is a big difference but getting fitter, losing body weight, eating healthily and not carrying too much stuff around with you all adds up.
  • supersonic
    supersonic Posts: 82,708
    If you are going to keep the bike on the level and spin at the same rpm on a flat surface, then yes, where the mass is makes little difference. If you are going to use it for mountain biking, even quite easy stuff, the difference from losing weight on the bike is very noticable. I have one bike at 19lbs, the other at 29lbs. The difference is night and day - even with a rucksack on the lighter bike, it still feels so much more nimble, agile, easier to hop and lift over obstacles.

    Sure I want to lose some weight off my beer gut too ;-). But don't under estimate how much difference lightweight parts make.
  • Thewaylander
    Thewaylander Posts: 8,594
    Yup weight makes a huge difference.

    When I swapped from my lightish 27pound full sus XC bike, to my last 33pound trail machine my time at my local trail for a loop went from 1h5min to 1h15m... the difference in climbing is huge! ok the big bike is more fun and faster on the downs, but time is made on the climbs in reality..

    I know that's not truly scientific but its a fair comparison.. made a massive difference if I was a xc race type dude.
  • cooldad
    cooldad Posts: 32,599
    And it's an unfortunate fact that whilst the fun downhills last about 20 seconds, climbing back up again takes roughly 17 years. Or so it feels.

    Weighty matters.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools