Disc V Rim brakes
The Rookie
Posts: 27,812
Came across this video https://www.youtube.com/watch?v=HXQuSnKkS-I and was quite surprised at the result!
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.
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For something like that I guess wife taxi is the first call. If not proper taxi, if you can figure out who to call in the area you're in.0
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Came across this video https://www.youtube.com/watch?v=HXQuSnKkS-I and was quite surprised at the result!
On another test they mention moutain biking is significantly faster in lycra
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They really pay people to waste time at Specialized...
Who cares if one system gives you a quarter of a Watt advantage over the other...left the forum March 20230 -
You know cyclists, right?Who cares if one system gives you a quarter of a Watt advantage over the other...
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They really pay people to waste time at Specialized...
Who cares if one system gives you a quarter of a Watt advantage over the other...
I'm impressed that they think that they can measure such a difference with any degree of precision or accuracy. And, in reality, I doubt they do - it's just for funROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0 -
Surely the point was to establish that, which they did? If the difference was significant (lets say 20 watts) then I think a lot of people would want to know.They really pay people to waste time at Specialized...
Who cares if one system gives you a quarter of a Watt advantage over the other...
This was showing that if you're choosing rim brakes ahead of disks because they're more 'aero' then you're wasting your time. Unfortunately, weight and race-legality remain somewhat valid reasons!0 -
[If the difference was significant (lets say 20 watts) then I think a lot of people would want to know.
Yes - but it was never going to be as much as 5W let alone anything more significant.ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0 -
People place way too much faith in bicycle aerodynamic improvements. The most important improvements are rider position, the rest is largely insignificantleft the forum March 20230
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People place way too much faith in bicycle aerodynamic improvements. The most important improvements are rider position, the rest is largely insignificant
I think the move away from 23 mm tyres to 25 mm (or even wider) is quite a big improvement - wouldn't have happened without people looking into these things.You'll not see nothing like the mighty Quin.0 -
Not so sure about that. For instance, I managed to gain nearly 10 seconds per mile purely by transferring my existing position to a new bike. Same wheels, same bars, same position, and aswell as being obviously quicker I have the aerolab data to back it up. The change was pretty extreme (from round section steel tubes with external cables to a relatively modern TT frame) but we're still talking about just the frameset and a handful of other bits.People place way too much faith in bicycle aerodynamic improvements. The most important improvements are rider position, the rest is largely insignificant
The same guys also demonstrated a 3 second per mile saving from shaving your legs (obviously depends how hairy you were to begin with, but my own data points to a similar figure).Pannier, 120rpm.0 -
People place way too much faith in bicycle aerodynamic improvements. The most important improvements are rider position, the rest is largely insignificant
I've always been in the weight of bike and aerodynamics are important, but not vital
The biggest way to improve is practice and lose a bit of the belly. Unless you are Chris Froome then there is quite a lot of headroom between your actual and maximum ability. I see people spending £50 on carbon fibre bottle cages which are 40g lighter than the normal plastic ones and just thing, 'work a bit harder, eat a bit less cake and you'll save a lot more than 40g' *.
* I know someone is now going to prove that 40g saving on bike is equivalent to 80g on the rider or somesuch stat, but the principle is the same0 -
Not so sure about that. For instance, I managed to gain nearly 10 seconds per mile purely by transferring my existing position to a new bike. Same wheels, same bars, same position, and aswell as being obviously quicker I have the aerolab data to back it up. The change was pretty extreme (from round section steel tubes with external cables to a relatively modern TT frame) but we're still talking about just the frameset and a handful of other bits.People place way too much faith in bicycle aerodynamic improvements. The most important improvements are rider position, the rest is largely insignificant
The same guys also demonstrated a 3 second per mile saving from shaving your legs (obviously depends how hairy you were to begin with, but my own data points to a similar figure).
I would be inclined to laugh at these numbers and here is why:
The difference between the record time Rohan Dennis did to win the 13.8 Km TdF TT and someone who finished 132nd (happen to be Riblon) is 90 seconds... or in other words about 10 seconds per mile.
So Rohan Dennis with steel tubings would have finished 131st and had he not bothered to shave, then he would have finished 8th or most likely last with the combination of the two...
I think not... left the forum March 20230 -
Like I said, I have all the power numbers to back up my assertions. Since you seem to prefer more circumstantial evidence, I can also show from race results that I reduced my 25 mile PB by around 6 minutes (roughly 12% increase in speed) with a modest (<10%) increase in power.
Not so sure about that. For instance, I managed to gain nearly 10 seconds per mile purely by transferring my existing position to a new bike. Same wheels, same bars, same position, and aswell as being obviously quicker I have the aerolab data to back it up. The change was pretty extreme (from round section steel tubes with external cables to a relatively modern TT frame) but we're still talking about just the frameset and a handful of other bits.People place way too much faith in bicycle aerodynamic improvements. The most important improvements are rider position, the rest is largely insignificant
The same guys also demonstrated a 3 second per mile saving from shaving your legs (obviously depends how hairy you were to begin with, but my own data points to a similar figure).
I would be inclined to laugh at these numbers and here is why:
The difference between the record time Rohan Dennis did to win the 13.8 Km TdF TT and someone who finished 132nd (happen to be Riblon) is 90 seconds... or in other words about 10 seconds per mile.
So Rohan Dennis with steel tubings would have finished 131st and had he not bothered to shave, then he would have finished 8th or most likely last with the combination of the two...
I think not...
How do you know that Rohan Dennis wouldn't have finished down the pan on 15-year-old kit? Because your intuition says he wouldn't have done? You're effectively saying that aerodynamic kit doesn't make a difference because your intuition says it doesn't, and therefore anyone who has actual evidence must be wrong. I thought you were a scientist/engineer?!?Pannier, 120rpm.0 -
You're right about weight, and it's very easy to do the numbers. For those less mathematically inclined, someone did a test a few years back where they set a pro rider up Alpe D'Huez with 1.8 litres of water in their tyres; the time differences are a lot less than you might intuitively guess, though they are consistent with the maths:People place way too much faith in bicycle aerodynamic improvements. The most important improvements are rider position, the rest is largely insignificant
I've always been in the weight of bike and aerodynamics are important, but not vital
The biggest way to improve is practice and lose a bit of the belly. Unless you are Chris Froome then there is quite a lot of headroom between your actual and maximum ability. I see people spending £50 on carbon fibre bottle cages which are 40g lighter than the normal plastic ones and just thing, 'work a bit harder, eat a bit less cake and you'll save a lot more than 40g' *.
* I know someone is now going to prove that 40g saving on bike is equivalent to 80g on the rider or somesuch stat, but the principle is the same
http://www.training4cyclists.com/how-much-time-does-extra-weight-cost-on-alpe-dhuez/
A 40g weight saving would have translated into a 2.5 second time saving for this rider. Possibly worth having if you're time trialling up the Alpe, but probably only after you'd exhausted all your other marginal gains.Pannier, 120rpm.0 -
Like I said, I have all the power numbers to back up my assertions. Since you seem to prefer more circumstantial evidence, I can also show from race results that I reduced my 25 mile PB by around 6 minutes (roughly 12% increase in speed) with a modest (<10%) increase in power.
Not so sure about that. For instance, I managed to gain nearly 10 seconds per mile purely by transferring my existing position to a new bike. Same wheels, same bars, same position, and aswell as being obviously quicker I have the aerolab data to back it up. The change was pretty extreme (from round section steel tubes with external cables to a relatively modern TT frame) but we're still talking about just the frameset and a handful of other bits.People place way too much faith in bicycle aerodynamic improvements. The most important improvements are rider position, the rest is largely insignificant
The same guys also demonstrated a 3 second per mile saving from shaving your legs (obviously depends how hairy you were to begin with, but my own data points to a similar figure).
I would be inclined to laugh at these numbers and here is why:
The difference between the record time Rohan Dennis did to win the 13.8 Km TdF TT and someone who finished 132nd (happen to be Riblon) is 90 seconds... or in other words about 10 seconds per mile.
So Rohan Dennis with steel tubings would have finished 131st and had he not bothered to shave, then he would have finished 8th or most likely last with the combination of the two...
I think not...
How do you know that Rohan Dennis wouldn't have finished down the pan on 15-year-old kit? Because your intuition says he wouldn't have done? You're effectively saying that aerodynamic kit doesn't make a difference because your intuition says it doesn't, and therefore anyone who has actual evidence must be wrong. I thought you were a scientist/engineer?!?
The thing is riders change teams and equipment very often. If equipment had a major impact, then you would see Tony Martin losing the worlds badly becuase he has an inferior machine compared to Cancellara... while in fact, it's pretty much always down to form and results are very predictable. Form seem to trump aerodynamics in every single event.
The scientist in me says that you can only draw conclusions on a wide pool of data. If you can consistently reproduce a 10 sec/mile improvement over the previous setup with frequent changes of set up, so that no other variable is interfering too much, then maybe there is a chance your numbers are meanigful... otherwise they are not.
I once managed 57 mpg on a 100 miles trip on a car rated at 48 mpg... it was a fluke and I am fairly confident that if I did make an average, the number would be very close to the 48 mpg the car is rated for, that assuming what the computer says has actually any meaning at all.
Too many variables, inconsistent results, poor measuring devices... that's cycling for youleft the forum March 20230 -
That's because they're all using the same generation of equipment. So, for example, the difference between a Pinarello Bolide and a Giant Trinity Advanced is pretty small, but they really are way ahead of the kit everyone was using 15 years ago.The thing is riders change teams and equipment very often. If equipment had a major impact, then you would see Tony Martin losing the worlds badly becuase he has an inferior machine compared to Cancellara... while in fact, it's pretty much always down to form and results are very predictable. Form seem to trump aerodynamics in every single event.
On the previous bike I'd never ridden a sub-59 minute 25, and most of the time I was struggling to go below the hour. In my first year on the new bike, riding on similar power, I rode a short 53, a short 54 and quite a few 55s. By far the worst result was a 58, and in that race I'd had to stop and get off the bike for 2 minutes with cramp (but still beat my old bike's PB).The scientist in me says that you can only draw conclusions on a wide pool of data. If you can consistently reproduce a 10 sec/mile improvement over the previous setup with frequent changes of set up, so that no other variable is interfering too much, then maybe there is a chance your numbers are meanigful... otherwise they are not.
I do a lot of TTing at Hillingdon, and have power data for well over 100 laps with each configuration. The very first fast lap I did on the new bike was nearly 10 seconds faster than my previous PB, and I was immediately beating riders who had previously beaten me comfortably; the difference was that dramatic. Aerolab analysis shows a reduction in CdA of about 0.05, which is consistent with a 10s/mile saving. Research suggests that upgrading to a really modern frame (which I can't afford) would probably save me another 0.01 CdA. If you really want to analyse it, I'll happily send you the power data.
That's a summary of the scientific analysis to back up my claim. Where's the scientific analysis to back up yours?
Like you, I was sceptical about the magnitude of the benefit I'd get from a new frame, but I turned out to be wrong.Pannier, 120rpm.0 -
That's a summary of the scientific analysis to back up my claim. Where's the scientific analysis to back up yours?
Like you, I was sceptical about the magnitude of the benefit I'd get from a new frame, but I turned out to be wrong.
I am not making claims... I am skeptical about other people's claims... it's different, I can give you my opinion, but no references. My opinion is that numbers are way too easily made into conclusions
It's hard to say... can you be 100% sure that it's only down to aerodynamics and frame stiffness doesn't play a role in translating the number you measure into seconds you gain?
15 years of frame evolution have brought more stiffness than aerodynamics and I am well aware that my 1980s frame tends to lose a bit in translation over a modern thing with a bottom bracket shell the size of a mug... the same obvioulsy goes for any other part of the frame.
As for the number per se... I tend to take these numbers with a pinch of salt... for instance can you correlate something you measure on a turbo trainer with something you measure outdoor? or something you measure in february with something you measure in July?
different temperature, different humidity, different motion pattern, different inclination with respect to the ground, it all makes up for errors...
I would say that the only mesurement I tend to give some meaning to is time, as we seem to be quite good at measuring that... the rest leaves me rather coldleft the forum March 20230 -
No I can't be 100% sure, but are you trying to tell me I gained 10s per mile by having a stiffer frame?!? Which seems more probable?It's hard to say... can you be 100% sure that it's only down to aerodynamics and frame stiffness doesn't play a role in translating the number you measure into seconds you gain?
Have you actually seen a modern TT frame? They've changed *a lot* since the 1980s (even in the last 5-10 years). Chunky bottom brackets are not a defining feature.15 years of frame evolution have brought more stiffness than aerodynamics and I am well aware that my 1980s frame tends to lose a bit in translation over a modern thing with a bottom bracket shell the size of a mug... the same obvioulsy goes for any other part of the frame.
Who said anything about turbo trainers? All my measurements are taken over the Summer, I don't touch the TT bike in the Winter.As for the number per se... I tend to take these numbers with a pinch of salt... for instance can you correlate something you measure on a turbo trainer with something you measure outdoor? or something you measure in february with something you measure in July?
Most of those (everything except motion pattern) are controlled for by the aerolab analysisdifferent temperature, different humidity, different motion pattern, different inclination with respect to the ground, it all makes up for errors...
I've given you my times. I've offered to send you my data. How do you think I gained 10 seconds per mile with no meaningful change in power?I would say that the only mesurement I tend to give some meaning to is time, as we seem to be quite good at measuring that... the rest leaves me rather cold
Not wanting to get personal, but this discussion reminds me of the numerous times you tried to tell everyone on the cyclocross forum how they should be racing their bikes, what tyres, pressures etc, before finally revealing that you'd never actually taken part in a cyclocross race.Pannier, 120rpm.0 -
If you are happy thinking that you gain 10 seconds per mile thanks to the aerodynamics of a new frame, then bask in your happiness, what can I say?
I made my point ages ago and stick to it... I don't believe it, I am sorry... but you do and that's all that matters
.. .and yes, you do get personal, all the time... and it's tedious... I am not quite sure why you care so much what I think...left the forum March 20230 -
I'm not picking on you. When people make claims about a topic I happen to know a bit about, I think it's reasonable to question those claims; in many cases this turns into an interesting discussion. You seem to have some quite strong opinions, sometimes based on very little experience, which you post on here as if they were fact. When someone dares to disagree with those opinions, you take it as a personal insult; that's not my fault... .and yes, you do get personal, all the time... and it's tedious... I am not quite sure why you care so much what I think...
I don't particularly care about what you think, until you start posting those opinions on here and then getting narky when someone dares to say something different.Pannier, 120rpm.0 -
I'm not picking on you. When people make claims about a topic I happen to know a bit about, I think it's reasonable to question those claims; in many cases this turns into an interesting discussion. You seem to have some quite strong opinions, sometimes based on very little experience, which you post on here as if they were fact. When someone dares to disagree with those opinions, you take it as a personal insult; that's not my fault... .and yes, you do get personal, all the time... and it's tedious... I am not quite sure why you care so much what I think...
I don't particularly care about what you think, until you start posting those opinions on here and then getting narky when someone dares to say something different.
I could say the exact same things about you... the only difference is that you seem to get very crossed, while I don't.
Back on the topic: My very little experience, as you say is just a different experience. You seem to value the numbers that your power meter gives out and draw conclusions based on these, while I am skeptical about those too. Having been involved in measurements of many sorts most of my life, I am always very careful not to believe numbers for the sake of it.
If your pressure gauge says you are running 19 PSI, it doesn't mean it's true. Measuring and even more understanding measurements is not straightforward. The reason why this all aerodynamics area is full of contradictions and people saying one thing and the exact opposite the following year is because everybody put too much faith in what in effect are unreproducible measurements or meaningless measurements.
Common sense is a virtue in any science... the world is plenty of fools who published numbers without using their common sense and then published an apologies a few months/years down the line. In the case of cycling, it's all business, so there is no reason to apologize for the nonsense pretty much all manufacturers come out with.
Common sense tell me Rohan Dennis would not finish 131st in a time trial was he given a less aerodynamic frame, but using exactly the same riding position. In my world common sense trumps bad numbersleft the forum March 20230 -
Common sense can sometimes lead you in the wrong direction, and lots of things in this world are counterintuitive. Just look at the world of quantum physics, which defies understanding, yet without it most modern technology wouldn't exist. By all means employ common sense as part of your toolkit, but if all the evidence staring you in the face defies common sense you should question both.Back on the topic: My very little experience, as you say is just a different experience. You seem to value the numbers that your power meter gives out and draw conclusions based on these, while I am skeptical about those too. Having been involved in measurements of many sorts most of my life, I am always very careful not to believe numbers for the sake of it.
If your pressure gauge says you are running 19 PSI, it doesn't mean it's true. Measuring and even more understanding measurements is not straightforward. The reason why this all aerodynamics area is full of contradictions and people saying one thing and the exact opposite the following year is because everybody put too much faith in what in effect are unreproducible measurements or meaningless measurements.
Common sense is a virtue in any science... the world is plenty of fools who published numbers without using their common sense and then published an apologies a few months/years down the line. In the case of cycling, it's all business, so there is no reason to apologize for the nonsense pretty much all manufacturers come out with.
Common sense tell me Rohan Dennis would not finish 131st in a time trial was he given a less aerodynamic frame, but using exactly the same riding position. In my world common sense trumps bad numbers
In my case, a large number of race results show the new frame to 10s/mile faster. What should I do? Accept that it is faster, even though I genuinely didn't expect it to be so until I raced it, or go and have a word with the timekeepers and ask them to adjust my time because the number on their stopwatch defies common sense?Pannier, 120rpm.0 -
Common sense can sometimes lead you in the wrong direction, and lots of things in this world are counterintuitive. Just look at the world of quantum physics, which defies understanding, yet without it most modern technology wouldn't exist. By all means employ common sense as part of your toolkit, but if all the evidence staring you in the face defies common sense you should question both.
Quantum physics defies understanding if you refuse to understand it... I'll have to teach aspects of it...
In my case, a large number of race results show the new frame to 10s/mile faster. What should I do? Accept that it is faster, even though I genuinely didn't expect it to be so until I raced it, or go and have a word with the timekeepers and ask them to adjust my time because the number on their stopwatch defies common sense?
I would accept that you are 10 sec/mile faster as a result of a number of factors, with aerodynamics being one of them, but common sense suggesting not the only one. Stiffness, possibly a better position, although it appears to be the same, maybe improved fitness...
I recall the difference between Pantani and Indurain in a TT was about 10 sec/mile... does it mean Pantani would have matched Indurain, had he had access to the "Pinarello Espada"? Common sense suggests there was a lot more than the Espada to itleft the forum March 20230 -
https://www.youtube.com/watch?v=XE_GKePa3CQ
Aero frame versus a steel, 50s advantage over 40km, 1.25s/km, so about 2s/mile.
As the percentage change stays the same, you would have to be REALLY slow to gain 6seconds/km.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.0 -
https://www.youtube.com/watch?v=XE_GKePa3CQ
Aero frame versus a steel, 50s advantage over 40km, 1.25s/km, so about 2s/mile.
As the percentage change stays the same, you would have to be REALLY slow to gain 6seconds/km.
That is a number that even an aero-skeptic like myself feels comfortable with... left the forum March 20230 -
Glad to be of service!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.0
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I'm surprised nobody has mentioned the psychological benefits.
If you get on an old bike and get a time, then get on a nice shiny new bike, or get a new bit of kit you just feel better.
This puts you in a different frame of mind and you are going to improve.
Not to mention personnel fitness, isn't that going to be a factor?
Doing the same course for a couple of years is going to see improvements due to increased fitness and technical skill.0
