How much faster?

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Comments

  • singleton
    singleton Posts: 2,498
    Alex99 wrote:
    -The rider spends more time admiring the fancy bike than pedalling

    We have a winner :D:D:D:D:D
  • Tiesetrotter
    Tiesetrotter Posts: 432
    You will post faster times with disc brakes.

    Because you can leave braking for junctions and lights later.
  • angry_bird
    angry_bird Posts: 3,786
    Todays ride, identical to yesterday apart from the bike. Near enough identical of conditions, maybe 1C warmer today? Wind exactly the same as far as I could tell. Same power output by the top of the mountain 23km into the ride, power output up the mountain within 3W of yesterday.

    55 minutes to get to the top yesterday, 49 today. The actual proper decent bit of the climb itself 20:28 today, 22:14 yesterday. Back down the mountain today 6s faster, again, power was the same as yesterday by the time I got down.

    A few minutes later garmin cut out so now idea about power from there home but got back 1hr23 vs 1hr32, can't exactly compare that figure properly though.

    Only real difference was the bike. Whether I was putting out the power in different places or not, or being more efficient I can't say. Clothing wise there was no difference, positions on the bikes are the same too... bike differences, about 3kg, deep sections, lack of mudguards... Draw from that whatever conclusions you want.
    Angry Bird's offroad bikes
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    Racey
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    If in doubt, blame Wiggle.
  • daddy0
    daddy0 Posts: 686
    FWIW - on my hilly 50 mile RT commute I notice my poorly maintained alu bike is 2-4kmh (10%ish) slower than my poorly maintained carbon bike in similar conditions with same perceived effort. Main reasons being the extra 3kg of weight, higher spoke count and mudguards. Also, riding the alu bike every day makes me fatigue much quicker than the carbon bike.
    https://cyclejames.wordpress.com/
  • svetty
    svetty Posts: 1,904
    Simple physics dictate that a lighter bike that is more aero must be faster for a given power output, all else being equal.
    FFS! Harden up and grow a pair :D
  • singleton
    singleton Posts: 2,498
    Angry Bird wrote:
    Todays ride, identical to yesterday apart from the bike. Near enough identical of conditions.....

    55 minutes to get to the top yesterday, 49 today......

    Only real difference was the bike.....

    There may be a difference between one bike and another, depending on what those bikes are of course, but the difficulty comes with trying to accurately measure how much difference each individual element makes to the overall package.

    BTW - what were the two bikes in your example? Genesis and CAAD?
  • chris_bass
    chris_bass Posts: 4,913
    Svetty wrote:
    Simple physics dictate that a lighter bike that is more aero must be faster for a given power output, all else being equal.

    I may be wrong, but only going up hills or accelerating.
    www.conjunctivitis.com - a site for sore eyes
  • onyourright
    onyourright Posts: 509
    You’re wrong, alright.

    However, Svetty’s statement is trite and uninteresting anyway. The interesting question is how much difference these things make. The answer is a lot, lot less than most cyclists imagine.

    Conversely, the difference made by tyres is much greater than most cyclists imagine. That is where you need to start if you care about going fast.
  • pblakeney
    pblakeney Posts: 25,776
    bernithebiker wrote:
    OnYourRight wrote:
    In practice, there are many things that affect the speed of a bicycle. Chief among them are the tyres, tubes, and pressures, which together dictate rolling resistance.

    Thereafter the aerodynamics. Much more of your energy is spent on air resistance than rolling resistance

    Contradictory statements surely?
    Only if you snip the statements.
    The above may be fact, or fiction, I may be serious, I may be jesting.
    I am not sure. You have no chance.
    Veronese68 wrote:
    PB is the most sensible person on here.
  • bernithebiker
    bernithebiker Posts: 4,148
    OnYourRight wrote:
    You’re wrong, alright.

    However, Svetty’s statement is trite and uninteresting anyway. The interesting question is how much difference these things make. The answer is a lot, lot less than most cyclists imagine.

    Conversely, the difference made by tyres is much greater than most cyclists imagine. That is where you need to start if you care about going fast.


    Why is he wrong? He is right.

    Weight only comes into play when accelerating (change of height, speed or direction).

    If you are at steady speed on the flat, weight does not enter the equation, only aerodynamics and rolling resistance.

    (Technically weight does have a microscopic effect on rolling resistance, as the heavier the rider/bike, the greater the pressure on the tyres but this is so small, that it can be ignored.)
  • cycleclinic
    cycleclinic Posts: 6,865
    No one can tell. tyres can make a difference to pace.

    I know a rack and guards do slow me down. I have a commutor that as soon as I put guards and a rack/panniers on the bike went from 9kg to 16kg and now 15 mph is a good average on it.

    Bike weight does make a difference but it has to be big. Tried beating some hill climb times today on my Look wheich I set on saturday on a 1994 Pinarello Monviso with period kit and very un aero wheels. that bike is 3.7kg heavier than the Look too and I did not get close. How you feel is a bigger variable.

    So the OP can just enjoy his current bike. Buy a new one because you want one not because it will make you faster.
    You will get quicker by training, having a more aero postion and good low Crr tyres.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • fudgey
    fudgey Posts: 854
    I notice riding a lighter bike up hills.
    Easter Monday we took part in a sportive, approx 15 miles in i rode up Hyde hill near Stroud, it took me 8:14. Alloy frame, stock wheels and mudguards.

    Then on Saturday we ended up riding up Hyde hill again approx 15 miles in (different route to this point tho) and i was on the same frame, but with a light wheel set and no mudguards. This time i done it in 7:23 and was pretty much on the verge of puking at the top. But i did catch and pass a mate...

    My carbon frame with the light wheels feels really nice when climbing so imo, and of course n+1 i think you should buy a nice new carbon bike.
    My winter bike is exactly the same as my summer bike,,, but dirty...
  • onyourright
    onyourright Posts: 509
    bernithebiker wrote:
    Why is he wrong?
    Because Svetty’s statement specified an aero bike, and that matters (albeit very slightly) on the flat. I agree with the rest of your post.
    thecycleclinic wrote:
    You will get quicker by training, having a more aero postion and good low Crr tyres.
    Exactly. In about that order of importance, too. Everything else is marginal gains.

    Fudgey: do you think the fact that you were nearly puking from the effort on your faster run had anything to do with it being faster?
  • fudgey
    fudgey Posts: 854
    Yes, i do think i went faster because i went harder. TBH i dont expect just a pair of wheels to knock a minute off a reasonable climb. Im not 'that' fit, but gave it maximum effort on a slightly lighter bike.
    Yesterday i managed 28 miles at an average 18.8mph on the same setup which is bloody good for me so it must help a bit.
    And everyone likes buying nice new things hahaha
    My winter bike is exactly the same as my summer bike,,, but dirty...
  • Bobbinogs
    Bobbinogs Posts: 4,841
    Fudgey wrote:
    Yes, i do think i went faster because i went harder.

    Yepp, that would be it :)
  • darkhairedlord
    darkhairedlord Posts: 7,180
    Fudgey wrote:
    I notice riding a lighter bike up hills.
    i was on the same frame, but with a light wheel set and no mudguards.
    a clue perhaps?
  • fudgey
    fudgey Posts: 854
    Bobbinogs wrote:
    Fudgey wrote:
    Yes, i do think i went faster because i went harder.

    Yepp, that would be it :)

    Still work to do tho, you are still 1:25 faster than i up there!
    But then you knock out 20mph everywhere, i cant do that!
    My winter bike is exactly the same as my summer bike,,, but dirty...
  • fudgey
    fudgey Posts: 854
    darkhairedlord wrote:
    Fudgey wrote:
    I notice riding a lighter bike up hills.
    i was on the same frame, but with a light wheel set and no mudguards.
    a clue perhaps?

    When grinding up a hill at what, 7-8mph i dont think the drag of mudguards will come into play.
    As i said, i did notice the different wheels tho.
    My winter bike is exactly the same as my summer bike,,, but dirty...
  • simon_masterson
    simon_masterson Posts: 2,740
    One wind tunnel test found that well-fitted mudguards effectively made no difference - the front one fairing the front wheel, the rear one cancelling it out.
    Retro(ish) TT 2017-
    Fixed TT 2015-2016
  • svetty
    svetty Posts: 1,904
    OnYourRight wrote:
    bernithebiker wrote:
    Why is he wrong?
    Because Svetty’s statement specified an aero bike, and that matters (albeit very slightly) on the flat. I agree with the rest of your post.
    thecycleclinic wrote:
    You will get quicker by training, having a more aero postion and good low Crr tyres.
    Exactly. In about that order of importance, too. Everything else is marginal gains.

    If we're being pedantic we could add things like chain lubrication effects and bearing friction losses :D:D
    FFS! Harden up and grow a pair :D
  • fudgey
    fudgey Posts: 854
    While messing around in the garage last night changing tyres etc, and the wife was out... I got the kitchen scales out.

    Weighed the standard wheel set and the nice ones i have. The difference being 140g lighter on the front and 300g lighter on the rear. Not much but i can certainly notice it, and i am far from professional!
    My winter bike is exactly the same as my summer bike,,, but dirty...

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