Viewing 40 posts - 1 through 40 (of 47 total)
  • Interesting article on how weight affects speed
  • cynic-al
    Free Member
    wilburt
    Free Member

    The focus appears to be on touring rather than someone trying to take 6 seconds off their PR for a 2 minute climb.

    Also just some charlie ont web so not really conclusive.

    Interesting never the less.

    whitestone
    Free Member

    Cycling Weekly did a video of the time differences extra weight makes when hill climbing – http://www.cyclingweekly.co.uk/videos/cycling-tech/how-does-weight-affect-your-climbing-speed-video

    scotroutes
    Full Member

    Bikepacking bags are faster than panniers too. Damn those new-fangled ideas…..

    (he does make the point that weight matters when you have lots of climbing and/or longer rides.)

    benpinnick
    Full Member

    What I learned from that –

    Weight does matter about as much as you’d think.
    Existing calculations on that are about right.
    Its all irrelevant for mountain bikes.

    whitestone
    Free Member

    Its all irrelevant for mountain bikes.

    I’ll remember that for the next “how much does your bike weigh?” thread 😀

    nwill1
    Free Member

    What I find very interesting following adding circa 750g to my Orange Five with my CCDB Coil is this…20kg slows you down by circa 10%, 10kg by circa 5% so 750g is seeker FA.

    And with tyre choice, set up, line choice an other variables it mean virtually nothing!

    Rubber_Buccaneer
    Full Member

    Why irrelevant for mountain bikes? Even Swinley has a little elevation?

    Over the past year I have become a convert to the idea that weight is relatively unimportant but surely it’s the same calc on or off road?

    scotroutes
    Full Member

    Its all irrelevant for mountain bikes.

    Depends what type of mountain biking you do.

    whitestone
    Free Member

    Both the original link and the one I posted came at it from the wrong direction – they are maintaining power and then measuring time, what they should have done is keep the time constant and measure the power required. This would be harder to do consistently in a test though.

    The reason to do it that way is that maintaining the speed of the lighter test when loaded up might push the rider into the red and they’d then have to recover from that whereas the lighter rider/bike setup could just keep going. Obviously that’s in a race type situation but it also applies when trying to keep up with your mates – the lighter ones can just keep pushing on whereas the heavier ones need to ease up.

    montgomery
    Free Member

    Box Hill – does 5% even count as a gradient?

    I’ve just straight-swapped all my components (except stem) from a cheap steel frame to an old but expensive aluminium frame – significantly faster uphill offroad. Less to do with weight, more down to stiffness, I think.

    nairnster
    Free Member

    On outright speed I have always thought weight makes little or no difference.

    Accelerating or decelerating though, and therefore average speed, it possibly makes more difference on a mtb than on a road ride with long periods of consistent speed.

    alextemper
    Free Member

    Weight will always make a difference, especially at the sharp end. Maybe not so much for recreactional riders.
    Set up, geometry, length of travel, tyre choice will always help to compensate but all things being equal if you had two bikes the same but sand bagged one of them, it will be the slower bike. You cannot change the laws of physics.

    scotroutes
    Full Member

    Weight definitely makes a difference descending too. A road bike will tend to be faster downhill when heavier (or with a heavier rider) so might overcome some of the climbing disadvantage. It’s less clear cut on a mountain bike where the additional weight could compromise handling and result in it being slower both uphill and down.

    jonba
    Free Member

    In 2014 I was racing hill climbs and managing to top 10. I weight 75kg and rode an 8kg bike.

    In 2015 I weighed 69kg and rode a 7kg bike. I was on the podium in all but one event, won two and took the series over all along with a course record. I knocked chunks out of PBs on 5-8minute climbs and minutes out of the big ones like hartside at <18minutes.

    It matters a lot on uphills provided you are going hard and the difference is large enough. Buying Ti bolts will to F all but dropping significant bodyweight will help.

    Mbnut
    Free Member

    Weight matters in relation to effort/fatigue… I definitely get more fatigued riding a heavier bike at the same pace as a lighter bike.

    For me tyre choice is an important factor in the reduction of fatigue, a fast rear tyre works for me.

    benpinnick
    Full Member

    Im not saying weight doesn’t matter, it does. Just that weight matters in way more important ways on MTBs than the relative total mass of rider and bike (which is what is tested in this post).

    ampthill
    Full Member

    [video]https://www.youtube.com/watch?v=le_LSWfGJUo[/video]

    another variant here. This time adding 2kg to a road bike. Similar conclusion. But they also did a no power meter run. Just using similar perceived effort. In this case it made more odds.

    Of if you are in a race then as we know loosing 30 seconds on every climb due 2kg extra is GC leader to no one cares, in Tour terms

    The other factors are.

    “I like a light bike so its up to me if I’m happy to pay £800 for a rim.”

    and

    “Its alot easier to lift onto my car, onto the train over a mountain”

    cynic-al
    Free Member

    Jonba are you telling us your fitness was the same for those 2 seasons?

    Lots of you are stating the frikkin obvious – of course weight will slow you down, the point is its a tiny factor when you look at changes you canake in eg fitness and aero.

    scotroutes
    Full Member

    🙂

    I’m in no doubt that fitness matters most.

    (Oh, Jo has the tyre. No slat hoofing was done)

    pdw
    Free Member

    Hill climbs are a bit of a special case. Most HCs are steep enough that you can pretty much ignore aero and rolling resistance, and there’s no downhill that would benefit from the extra weight. It doesn’t surprise me that losing 10% of your weight is the difference between podiums and not. All your power is being used to overcome gravitational force which is proportional to your weight.

    To a first approximation, the time taken to complete a HC at a given power is proportional to your weight. Lop 10% off your weight, and you should ride it 10% faster at the same power. You might even do a bit better because you can hold a higher power for the 10% shorter time you’ll be riding.

    montgomery
    Free Member

    Buying Ti bolts will to F all but dropping significant bodyweight will help

    Isn’t that kind of the point? Work on your fitness rather than spending money on your bike? I’ve just come back from bashing out the local 25% hill climb on my £400 road bike, while the MAMILS are hanging out sipping lattes in Cheddar Gorge Costa admiring each other’s carbon wonderbikes…

    kerley
    Free Member

    Work on your fitness rather than spending money on your bike?

    Are they mutually exclusive?

    mattyfez
    Full Member

    There can be a bit of both, but to put things into perspective, an average guitar player will still sound average playing a fender strat.. But if you give Eric Clapton a £150 squire strat.. He’ll make it sing!

    IdleJon
    Full Member

    I’ve just come back from bashing out the local 25% hill climb on my £400 road bike, while the MAMILS are hanging out sipping lattes in Cheddar Gorge Costa admiring each other’s carbon wonderbikes…

    And??

    Maybe they are out for a social ride, and they do their hill-reps during the week? And why are you doing this – what is the point of your masochism? To make yourself quicker up that 25% climb, or are you actually training for an event. If that’s the case then you’ll be better trained if you choose a variety of hills to beast yourself over.

    Btw it’s no secret that expensive bikes are better. Not necessarily lighter, but stiffer, components work better, forks absorb more. Telling us the cost of your road bike – very much entry level – shows inverted snobbery that’s hard to get past.

    scotroutes
    Full Member

    People do just train to get fitter you know. To cycle further/faster. There doesn’t have to be an event of some sort involved.

    IdleJon
    Full Member

    That’s true scotroutes, but repeating a 25% hillclimb just for the sake of it is as pointless as a 50km ride with coffee and cake at the end. The sort of ride he was mocking.

    montgomery
    Free Member

    repeating a 25% hillclimb just for the sake of it is as pointless as a 50km ride with coffee and cake at the end

    The difference being, I can do both. I’m always trying to improve my fitness on climbs. It’s an entirely personal, almost meditative process.

    Road bikes – simple, simple tech. No point spending lots for anything other than cutting edge racing level – it’s all down to the engine in the saddle, which constitutes by far the biggest proportion of the total weight, even with a cheap bike.

    Mountain bikes, now, are different…

    ghostlymachine
    Free Member

    I bet a lot of the mamils do both.
    They’ve just chosen to spend more on the bike. And TBH life is to short to ride shit bikes.

    ghostlymachine
    Free Member

    And it’s not a particularly interesting article, it’s nothing that’s not been documented several times before.

    crashtestmonkey
    Free Member

    The difference being, I can do both. I’m always trying to improve my fitness on climbs. It’s an entirely personal, almost meditative process.

    the “difference being” to what? Anyone who goes to a cafe stop on an expensive carbon bike can’t ride steep hills? For somebody with a Zen-like approach to climbing you seem to have a very sneery attitude to other riders?

    wilburt
    Free Member

    It takes a certain amount of power to push a certain weight up a hill. More weight requires more power, more power will fatique you more quickly or be beyond what you can produce at all.

    Its not personal or subjective its maths.

    IdleJon
    Full Member

    For somebody with a Zen-like approach to climbing you seem to have a very sneery attitude to other riders?

    And also rather disingenuous. Montgomery seems to have bought a Cannondale CAAD8 Sora two months ago. £750 reduced to £400 (and a very sweet choice, if I may say!) Certainly not the £400 bike he suggested. 😉

    montgomery
    Free Member

    Tee hee. But I DID pay £400 for it.

    Anyone who goes to a cafe stop on an expensive carbon bike can’t ride steep hills?

    Of course they can, some of them – and I have respect for that. Fat knackers on expensive bikes, though? Lose 10 kilos, climb some hills then come back and ask for my respect. Why is that even controversial?

    ghostlymachine
    Free Member

    Lose 10 kilos, climb some hills then come back and ask for my respect. Why is that even controversial?

    If you have to ask there really is no hope.

    ahwiles
    Free Member

    There are many ways to enjoy riding a bike, just don’t be dick about it.

    jmatlock
    Free Member

    I am unsure as to why your respect is so important Montgomery?

    davidtaylforth
    Free Member

    Of course they can, some of them – and I have respect for that. Fat knackers on expensive bikes, though? Lose 10 kilos, climb some hills then come back and ask for my respect. Why is that even controversial?

    Do you compete in Sportives?

    montgomery
    Free Member

    No. I don’t consider myself a road cyclist, I just knock out road miles to keep fit. Switch off, look at the view, avoid getting hit by cars. I look at the current roadie scene and it has no interest for me. Golftastic.

    imnotverygood
    Full Member

    Switch off, look at the view,

    You clearly don’t switch off your sense of superiority, or your need to judge other people.

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