lighter road wheels--how much difference on climbs?

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Comments

  • goco
    goco Posts: 35
    PianoMan wrote:
    So, lighter wheels will help you accelerate better (due to less inertia and lower weight) and make you ever so slightly slower on the flat

    So you saying that Gipiemme Tecno Pro wheels: http://www.shop.kinetic-one.co.uk/gipie ... -487-p.asp

    would be actually quicker on the flat than Campag Zondas even though the Zondas are 300 grams lighter? If so that write-up by Kinetic-1 isn't just marketing dross, it's for real! Do they make ceramic bearings too?

    Would they be quicker? Don't know, but the extra weight won't make a difference on the flat (unless you count increased rolling resistance from extra deformation of the tyres), and the rims look more aero, (40mm vs 24/30) so I'd guess they might be. But then you would feel the extra 300g going up hill.

    Either way, reckon the differences are all very marginal here - I recently swapped a 9.5kg Aluminium bike for a 7.2kg piece of carbon loveliness. I can certainly feel the weight difference when I pick it up, and its maybe a little bit faster going uphill, but by far and away the biggest difference is the ride quality. Wonderful. And of course the bling.
  • wildmoustache
    wildmoustache Posts: 4,010
    NapoleonD wrote:
    One thing I do notice with lighter wheels is when you do this -

    Hold the hub and spin the wheel (fast)

    Then rock the hub along the horizontal axis simulating the movement when giving it big legs out of the saddle.

    Lighter wheels are much easier to control when doing this.

    Whether or not it has any relevance whatsoever when riding I know not...

    The gyroscopic effect is noticeable I agree and does feel different on the bike.

    ++1 for your previous post too.

    Agree a somewhat aero front wheel at least is worth having if you race. Small advantage but they can all count.

    Other than that, a stiff rear wheel is noticeable and very nice to have on climbs.
  • Anonymous
    Anonymous Posts: 79,667
    NapoleonD wrote:
    One thing I do notice with lighter wheels is when you do this -

    Hold the hub and spin the wheel (fast)

    Then rock the hub along the horizontal axis simulating the movement when giving it big legs out of the saddle.

    Lighter wheels are much easier to control when doing this.

    Whether or not it has any relevance whatsoever when riding I know not...

    The gyroscopic effect is noticeable I agree and does feel different on the bike.

    ++1 for your previous post too.

    Agree a somewhat aero front wheel at least is worth having if you race. Small advantage but they can all count.

    Other than that, a stiff rear wheel is noticeable and very nice to have on climbs.

    Stiffness and strength is key for me as I'm a big bugger. I notice stiffness rather than weight more when climbing/sprinting etc...
  • zoid
    zoid Posts: 100
    Slightly off top but related....

    Does pedal weight make a difference, for example say you saved 100g a pedal (200g in total) by upgrading would this saving have more of an effect than a 200g saving on static components?

    I can't quite decide on one hand each pedal counter balances the other so while you are working against gravity to lift one pedal the other pedal is being pulled down by gravity and the 2 forces cancel each other out, does that sound logically or is there more to it?
  • PhilofCas
    PhilofCas Posts: 1,153
    zoid wrote:
    Slightly off top but related....

    Does pedal weight make a difference, for example say you saved 100g a pedal (200g in total) by upgrading would this saving have more of an effect than a 200g saving on static components?

    I can't quite decide on one hand each pedal counter balances the other so while you are working against gravity to lift one pedal the other pedal is being pulled down by gravity and the 2 forces cancel each other out, does that sound logically or is there more to it?

    Not sure, this might explain it?, the 'Equivalence principle', http://en.wikipedia.org/wiki/Equivalence_principle.
  • meanredspider
    meanredspider Posts: 12,337
    goco wrote:
    but conversely will require (very marginally) less effort to keep it spinning..

    Not true. Requires exactly the same effort to keep it spinning and requires more energy to stop it. Flywheels are only energy storage systems. Unless you want a smoother ride (because your pedalling action is poor), I can't think of an upside to heavier wheels:

    1. They take more energy to start
    2. They take more energy to stop
    3. They require more force to turn (gyro effect)
    4. They require more energy to take uphill (they return it downhill but the effect is mitigated by the aero losses of the higher downhill speeds)

    Basically your bike will be lighter and more responsive with lighter wheels.
    ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH
  • goco
    goco Posts: 35
    goco wrote:
    but conversely will require (very marginally) less effort to keep it spinning..

    Not true. Requires exactly the same effort to keep it spinning and requires more energy to stop it. Flywheels are only energy storage systems. Unless you want a smoother ride (because your pedalling action is poor), I can't think of an upside to heavier wheels:

    1. They take more energy to start
    2. They take more energy to stop
    3. They require more force to turn (gyro effect)
    4. They require more energy to take uphill (they return it downhill but the effect is mitigated by the aero losses of the higher downhill speeds)

    Basically your bike will be lighter and more responsive with lighter wheels.

    Afraid I disagree. What you say would be true in a vacuum, but with air resistance an identical shaped, but heavier wheel will spin for longer. Therefore it will decelerate less quickly, and so requires ever so slightly less effort to keep it going. Not that anyone would notice it.

    I'd agree with all your points 1-4 though, lighter wheels are definitely better in almost every respect. Just saying that the weight penalty on the flat is actually not a penalty at all, and that there is a lot of gumpf written about rotating mass......

    oh yeah, and the only upside to hevier wheels is if the entire ride is dead flat (ie not even 1in of climb) and a rolling start, in which case i'd wager that a heavier wheel will make you faster, all else being equal. Little bit hyopthetical though.

    I think.
  • chris7
    chris7 Posts: 49
    For the vast majority of cyclist I think the science/theory bit can be discarded and just accept that most purchases are for the feel good factor.

    Cycling is my main hobby and I'm lucky to have a disposable income I can spend on my hobby so why not buy a nice bike and upgrade wheels and other bits now and then.

    Will it make me go any faster? I seriously doubt it.

    Will I get enjoyment out of it? Yes! That's all that really matters to me (and there's lots worse things than a bit of cycling bling I could be spending my money on).
    ................................................................................................................................................................................................................................
    http://blog.chrisbarber.co.uk
  • meanredspider
    meanredspider Posts: 12,337
    goco wrote:
    Afraid I disagree. What you say would be true in a vacuum, but with air resistance an identical shaped, but heavier wheel will spin for longer. Therefore it will decelerate less quickly, and so requires ever so slightly less effort to keep it going. Not that anyone would notice it.

    Yes - it will spin for longer if you put no energy in (ie coast) but will take more energy to get it back to the original speed and will have taken more energy to get it to that speed in the first place.

    To MAINTAIN a constant speed you only need to replace the losses - mostly aero and friction. Aero will be identical for indentically-shaped wheels. Friction (and other rolling losses), argueably, will be higher on the heavier wheel.

    I think you are confusing momentum with energy.
    ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH
  • goco
    goco Posts: 35
    goco wrote:
    Afraid I disagree. What you say would be true in a vacuum, but with air resistance an identical shaped, but heavier wheel will spin for longer. Therefore it will decelerate less quickly, and so requires ever so slightly less effort to keep it going. Not that anyone would notice it.

    Yes - it will spin for longer if you put no energy in (ie coast) but will take more energy to get it back to the original speed ......

    But wouldn't you have lost less speed, so less acceleration required? What about the comment earlier about special race wheels with added rim weights?

    Anyway, have to agree with chris7, its all theoretical and we buy nice wheels mostly because they're nice. At least I did. Might make you a little bit faster but not much. And don't be drawn into the myth that saving wheel weight is worth much more than any other weight saving.....expect no miracles
  • rick_chasey
    rick_chasey Posts: 73,245
    http://inrng.com/?p=2538

    For what it's worth, O'Grady won Paris Roubaix on a rear wheel from 1986....

    As ever, it's the rider that makes the difference.
  • wildmoustache
    wildmoustache Posts: 4,010
    goco wrote:
    goco wrote:
    Afraid I disagree. What you say would be true in a vacuum, but with air resistance an identical shaped, but heavier wheel will spin for longer. Therefore it will decelerate less quickly, and so requires ever so slightly less effort to keep it going. Not that anyone would notice it.

    Yes - it will spin for longer if you put no energy in (ie coast) but will take more energy to get it back to the original speed ......

    But wouldn't you have lost less speed, so less acceleration required? What about the comment earlier about special race wheels with added rim weights?

    Anyway, have to agree with chris7, its all theoretical and we buy nice wheels mostly because they're nice. At least I did. Might make you a little bit faster but not much. And don't be drawn into the myth that saving wheel weight is worth much more than any other weight saving.....expect no miracles

    meanredspider is right. What you might be getting at is that in practice no-one can or does maintain a constant speed. Even when cycling along the flat with fairly constant power ouput speed is fluctuating and in the real world there is freewheeling etc. So yes, a heavy wheel in this scenario can smooth out fluctuations in speed a little bit by holding onto speed a bit more ... though of course you need to put marginally more effort in to pick up the speed you've lost.
  • Legs are way more important than wheels. Mark Cavendish cruised past me on a butcher's bike the other day so i threw away my lightweight obermayers. What a load of s**t talked about wheel weight. Differences in weight make minimal changes in speed up hills to the average cyclist who could do with losing a few pounds around the middle. Go for a pair of strong wheels with the best quality hubs you can afford eg Dura ace. All the wheels I have ridden inc open pros, campy protons , mavic aksiums, dura ace sl feel different but long term average speeds over variable terrain remain roughly the same. I only go alot faster with a tailwind. Ignore the marketing hype! Placebo effect makes some wheels feel much faster than others but the speedo does not lie!
  • northpole
    northpole Posts: 1,499
    matt has a rather good point. Get fit, then worry about wheel type. The more bling your wheelset, the worse you'll feel when the guy on the cheap fixie whizzes past on a lung busting climb. I find that getting fit is horribly elusive and much more tricky than buying a new weight saving gizmo for the bike. Equally, it's all harmless fun (until that so and so on the fixie comes past again!!).

    Peter
  • turnerjohn
    turnerjohn Posts: 1,069
    Legs are way more important than wheels. Mark Cavendish cruised past me on a butcher's bike the other day so i threw away my lightweight obermayers. What a load of s**t talked about wheel weight. Differences in weight make minimal changes in speed up hills to the average cyclist who could do with losing a few pounds around the middle. Go for a pair of strong wheels with the best quality hubs you can afford eg Dura ace. All the wheels I have ridden inc open pros, campy protons , mavic aksiums, dura ace sl feel different but long term average speeds over variable terrain remain roughly the same. I only go alot faster with a tailwind. Ignore the marketing hype! Placebo effect makes some wheels feel much faster than others but the speedo does not lie!

    lol....though you do have a point ! Only thing about Cav; although his a quality sprinter, his to heavy for the BIG hills and hence suffers for it...power TO weight is the most important thing in cycling...just look at Wiggo !...the mans no muscle builder but boy is he fast !

    oh hey forgot....light wheels DO make a difference (I should know...Ive got loads of different ones lol) but your right...its FITNESS thats the most important overal !