# How much faster would "x" make me?



## Machin (15 Jan 2014)

I hope nobody minds me posting this here:-

I'm a mechanical engineer by trade and "a bit" geeky. Like a lot of other people I wanted to know how much faster "x" would make me on my bike so I wrote a little program and began gathering as much real-life data as I could from scientific papers published on the subject of bicycle performance... 

Once I'd written the program it seemed a waste to keep it to myself so I registered a little web domain and put it on the web... I hope nobody is upset if I post a link here.... it's totally free to use; just fill in your data hit "calculate" and it'll tell you how much faster "x" would make you on your bike over the same ride:

CYCLE SPEED MARGINAL GAINS CALCULATOR

Because the gains are presented relative to one of your actual rides then the results should be a very good indicator of what you'd expect to see _-as long as you put in the same effort and the wind conditions are the same!_

one point I will make is that whilst the program says that riding on the drops compared to riding on the hoods might be worth X minutes and XX seconds, in reality the actual difference will depend on how high your handlebars are and how low you are when you get "on the drops"... everyone is different, but the program gives you a good idea of how much difference to expect.

Likewise the program says that aero rims might save you 34.5 seconds in an hour long ride at X MPH, whereas in reality some aero rims might make 40 seconds difference and others 30 seconds difference due to differences in the design of the two wheels.

So please don't think that the program is "exact". What it does do is give a _quantitative_ indication of the relative differences based on actual scientific studies compared to just someone on a forum or at the local club saying "this will make you much faster than that", etc etc.

Any feedback appreciated!


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## PpPete (15 Jan 2014)

Miles ?
Feet ?

Sorry - all my riding is metric.


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## Dusty Bin (15 Jan 2014)

I like it - it's a bit of fun. There's a few things it doesn't account for, such as adopting multiple hand positions while out riding, like most probably do. Also, if you have a category for 'under-inflated' tyres, you should also have one for 'over-inflated' as well.


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## Machin (15 Jan 2014)

PpPete said:


> Miles ?
> Feet ?
> 
> Sorry - all my riding is metric.



Good point; I will add a button to allow you to change the units to whatever you prefer. Thanks!


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## Machin (15 Jan 2014)

Dusty Bin said:


> I like it - it's a bit of fun. There's a few things it doesn't account for, such as adopting multiple hand positions while out riding, like most probably do. Also, if you have a category for 'under-inflated' tyres, you should also have one for 'over-inflated' as well.



Thanks! Do you mean changing between different hand positions during a single ride? That could be difficult to account for: how much of each position would you typically use on a ride? How much would someone else typically ride in each position? I'll have a think about what I could do for that one....

I think I might have info for over-inflated tyres; I'll add that when I do the next update. 

Thanks!


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## jazzkat (15 Jan 2014)

Interesting, now all I've got to do is find that 5% increase in power

I like it.


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## 400bhp (15 Jan 2014)

Nice website - a good CV to use when looking for a job

Calling @fossyant and chain cleanliness


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## fossyant (15 Jan 2014)

400bhp said:


> Nice website - a good CV to use when looking for a job
> 
> Calling @fossyant and chain cleanliness



Did you see the state of my fixed chain posted in commuting yesterday. Horror !


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## Dusty Bin (15 Jan 2014)

Machin said:


> Thanks! Do you mean changing between different hand positions during a single ride? That could be difficult to account for: how much of each position would you typically use on a ride? How much would someone else typically ride in each position?  I'll have a think about what I could do for that one....
> 
> I think I might have info for over-inflated tyres; I'll add that when I do the next update.



I haven't really thought about it before, but in a typical ride, I might spend about 70% of time on the hoods, 15% on the tops and 15% on the drops. In a race, it may be 60% hoods, 40% drops..


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## 400bhp (15 Jan 2014)

yes - very poor show


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## potsy (15 Jan 2014)

400bhp said:


> yes - very poor show


Even I was horrified


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## Machin (15 Jan 2014)

jazzkat said:


> Interesting, now all I've got to do is find that 5% increase in power
> 
> I like it.


 Ha Ha; yes, easier said than done!

Thanks!


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## Pro Tour Punditry (15 Jan 2014)

Very good. I could have got round my 45 mile loop yesterday in almost half the time if I'd known about this beforehand!


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## Octet (15 Jan 2014)

A brilliant website!

It must of taken you ages to collect all that data, certainly something I'll bookmark.


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## Machin (15 Jan 2014)

Ha Ha, thanks.... Yes, I have been accused of having too much spare time on my hands!


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## jowwy (17 Jan 2014)

Machin said:


> Ha Ha, thanks.... Yes, I have been accused of having too much spare time on my hands!


How about adding titanium bikes to the list


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## Machin (19 Jan 2014)

jowwy said:


> How about adding titanium bikes to the list


 
Yes thanks, and I guess steel bikes too.


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## Dusty Bin (19 Jan 2014)

Machin said:


> Yes thanks, and I guess steel bikes too.



TBH, I doubt if frame material makes any difference whatsoever. Might be better to add a list of all-up bike weights, like 6-8kg, 8-10kg, etc...


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## Machin (20 Jan 2014)

Dusty Bin said:


> TBH, I doubt if frame material makes any difference whatsoever. Might be better to add a list of all-up bike weights, like 6-8kg, 8-10kg, etc...


 At the moment, when you select one of the bikes it changes two things: the weight and (where applicable) the drag coefficient. If I was going to add other frame materials it would only change the weight. Your suggestion to change materials on the drop down to kg bands instead (plus I'd add a frame style, e.g. 8-10kg road bike, 6-8kg road bike, 6-8 kg TT bike, etc) is a good one. I'll look at changing that for the next update in the mean time......

....I've done a few other updates:-



PpPete said:


> Miles ?
> Feet ?
> Sorry - all my riding is metric.


 
Now updated so that you can choose metric or imperial for distance, ascent, height and weight.

I've also increased the number of options to describe your original ride... this means that if you were already using aero rim wheels for example it will no longer say you could be 30 seconds quicker if you fitted them (it will return a 0 seconds results instead).

Happy riding!


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## gds58 (27 Jan 2014)

This is brilliant, I like it. I work in a high end bike shop and we often get asked when, for example, a customer is looking at deep section aero carbon wheels, questions like "How much difference are these going to make" and this applies to other component changes as well. It's an almost impossible question to answer accurately but in future I may well point them in the direction of your site so that they can get a more calculated answer! other than my stock answer which is "In good conditions you should notice a significant advantage" 
Many thanks, I'll definitely bookmark this one!

Graham


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## Dusty Bin (27 Jan 2014)

gds58 said:


> This is brilliant, I like it. I work in a high end bike shop and we often get asked when, for example, a customer is looking at deep section aero carbon wheels, questions like "How much difference are these going to make"



If someone really has to ask a question like that, then the honest answer is usually going to be _"not much"_...


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## totallyfixed (27 Jan 2014)

Dusty Bin said:


> If someone really has to ask a question like that, then the honest answer is usually going to be _"not much"_...


Good fun, but I don't see an option for "no helmet" or "cap" [worn back to front]. I would be very interested in the calculations for this scenario having discussed the subject on many occasions with those in the TT world.


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## gds58 (27 Jan 2014)

Dusty Bin said:


> If someone really has to ask a question like that, then the honest answer is usually going to be _"not much"_...


I don't agree with that comment. How can that possibly be the 'honest' answer! These sort of questions are usually asked in conjunction with lots of others in order that the customer can justify spending upwards of a £1000 on a wheelset. There are many other variables in this which is why I qualify my answer with 'in good conditions etc' I don't know what your racing experience is like but mine is extensive (http://www.cyclechat.net/threads/time-trial-pbs.139591/page-3) and I can assure you that a 30 second gain in a 25 mile time trial is 'significant' and could be the difference between 1st or 10th place so the 'honest' answer clearly isn't 'not much'. In any case I only used aero wheels as an example, if I was asked about a super-lightweight seatpost for example, then my answer might well be 'not much'


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## subaqua (27 Jan 2014)

Eddy Mercx had it nailed .

don't buy upgrades, ride up grades .


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## Machin (27 Jan 2014)

totallyfixed said:


> Good fun, but I don't see an option for "no helmet" or "cap" [worn back to front]. I would be very interested in the calculations for this scenario having discussed the subject on many occasions with those in the TT world.


I wondered when someone would ask this! I've shied away from looking into this before because _if_ it turns out to be quicker to wear a cap backwards (rather than a helmet) I don't want to advocate such antics! I've added a couple of extra scenarios regarding different Bottom Bracket upgrades... in that scenario the difference really is "not much", regardless of whether you're a pro chasing a time or a commuter!


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## Dusty Bin (27 Jan 2014)

gds58 said:


> I don't agree with that comment. How can that possibly be the 'honest' answer! These sort of questions are usually asked in conjunction with lots of others in order that the customer can justify spending upwards of a £1000 on a wheelset. There are many other variables in this which is why I qualify my answer with 'in good conditions etc' I don't know what your racing experience is like but mine is extensive (http://www.cyclechat.net/threads/time-trial-pbs.139591/page-3) and I can assure you that a 30 second gain in a 25 mile time trial is 'significant' and could be the difference between 1st or 10th place so the 'honest' answer clearly isn't 'not much'. In any case I only used aero wheels as an example, if I was asked about a super-lightweight seatpost for example, then my answer might well be 'not much'



Depends what you're doing, I guess. Time gains in a flat TT would be useful, but aero makes next to no difference unless you are in clean air. It's also pretty irrelevant going uphill. So without knowing more about who is asking the question on 'how much difference they will make', then the honest answer is probably still "not much"...


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## totallyfixed (27 Jan 2014)

Machin said:


> I wondered when someone would ask this! I've shied away from looking into this before because _if_ it turns out to be quicker to wear a cap backwards (rather than a helmet)* I don't want to advocate such antics! * I've added a couple of extra scenarios regarding different Bottom Bracket upgrades... in that scenario the difference really is "not much", regardless of whether you're a pro chasing a time or a commuter!


Oh dear, and you were doing so well...


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## gds58 (27 Jan 2014)

Dusty Bin said:


> Depends what you're doing, I guess. Time gains in a flat TT would be useful, but aero makes next to no difference unless you are in clean air. It's also pretty irrelevant going uphill. So without knowing more about who is asking the question on 'how much difference they will make', then the honest answer is probably still "not much"...


With the greatest of respect you seem to be using terminology that you know little about, such as 'clean air'. This is a term often used in motor racing and is generally the un-interrupted air in front of a vehicle which has not been disturbed and deflected by another vehicle. For a vast majority of the time bikes* will* be riding in 'clean air' albeit approaching from varying angles. Modern aero wheel technology is such that they are designed to work (sometimes even better) in varying approach angles of air, thereby giving an advantage in all but the most blustery conditions. These are not my opinions but those of experts and I have done a lot of research into bicycle aerodynamics. Also, as you rightly say, without knowing more about the person asking the questions you cannot give an honest answer, so your response of 'not much' will in most cases be wrong.
One thing is for certain though Dusty Bin, you'll never make a good salesman!


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## Dusty Bin (27 Jan 2014)

gds58 said:


> With the greatest of respect you seem to be using terminology that you know little about, such as 'clean air'. This is a term often used in motor racing and is generally the un-interrupted air in front of a vehicle which has not been disturbed and deflected by another vehicle. For a vast majority of the time bikes* will* be riding in 'clean air' albeit approaching from varying angles. Modern aero wheel technology is such that they are designed to work (sometimes even better) in varying approach angles of air, thereby giving an advantage in all but the most blustery conditions. These are not my opinions but those of experts and I have done a lot of research into bicycle aerodynamics. Also, as you rightly say, without knowing more about the person asking the questions you cannot give an honest answer, so your response of 'not much' will in most cases be wrong.
> One thing is for certain though Dusty Bin, you'll never make a good salesman!



'Clean air' is a perfectly valid term, providing you understand what is meant by it. In a solo TT, you will be in clean air. In a bunch race, you won't be - unless you are either off the front, or off the back. And if you are off the back, then it doesn't matter anyway.


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## gds58 (27 Jan 2014)

Dusty Bin said:


> 'Clean air' is a perfectly valid term, providing you understand what is meant by it. In a solo TT, you will be in clean air. _*In a bunch race, you won't be*_ - unless you are either off the front, or off the back. And if you are off the back, then it doesn't matter anyway.



Oops wrong again! Specialized have done extensive aerodynamic testing in conjunction with McLaren and it has been consistently shown that when riding in a bunch you are actually in 'cleaner' air than when at the front or in a solo TT. The 'dirty' air is channelled around the bunch and is at the back. In a bunch you are however still moving air out of the way, so good aerodynamics are still important as they conserve energy for the latter stages or climbs etc when that saved energy will be most useful. Why do you think that all the Pro's will use deep section aero wheels in anything but the hilliest of races.
I'm sure you would find the recent articles produced by Specialized very informative and enlightening, might I suggest you read them before arguing with those who have! So, I stand by all that I have said previously. I didn't win five consecutive National Championships without understanding a bit about good aerodynamics, but thanks for your input.


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## Dusty Bin (27 Jan 2014)

gds58 said:


> Oops wrong again! Specialized have done extensive aerodynamic testing in conjunction with McLaren and it has been consistently shown that when riding in a bunch you are actually in 'cleaner' air than when at the front or in a solo TT.



Manufacturer-sponsored research? Gotta love it. Suprised you are falling for it.



gds58 said:


> The 'dirty' air is channelled around the bunch and is at the back.



Er, no. The turbulent air is *in* the bunch, as well as around it. Of course it is. We don't ride in a vacuum.



gds58 said:


> Why do you think that all the Pro's will use deep section aero wheels in anything but the hilliest of races.



Don't bring the pros into this. Their kit choices are largely influenced by their sponsorship deals.



gds58 said:


> I'm sure you would find the recent articles produced by Specialized very informative and enlightening, might I suggest you read them before arguing with those who have! So, I stand by all that I have said previously.



Got any links?



gds58 said:


> I didn't win five consecutive National Championships without understanding a bit about good aerodynamics, but thanks for your input.



Congrats, but your 5 titles don't make you correct - although they do appear to make you arrogant..


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## Scoosh (27 Jan 2014)

MOD NOTE:
Please do NOT derail this thread by going off-topic and arguing.

If you wish to continue the discussion about who-knows-more-about-clean-air, start another thread.

Thanks


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## Dusty Bin (27 Jan 2014)

Scoosh said:


> MOD NOTE:
> Please do NOT derail this thread by going off-topic and arguing.
> 
> If you wish to continue the discussion about who-knows-more-about-clean-air, start another thread.
> ...



Maybe you could clarify - the thread title is _'how much faster would 'x' make me'_ and we are having a discussion about how much faster people would go (or not) with aero kit. So where exactly is the 'off topic' bit..?


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## gds58 (27 Jan 2014)

Dusty Bin said:


> Manufacturer-sponsored research? Gotta love it. Suprised you are falling for it.
> 
> _It was actually general research to see how products can be improved and they actually found a different manufacturers wheels were fastest!_
> 
> ...



_Yep, probably. I'm very proud of what I achieved and I like to think I can give good advice to others to help them achieve good results or improve their riding._


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## Dusty Bin (27 Jan 2014)

The air in a bunch is not 'still' - I've no idea where you got that from. The area behind each rider is effectively a low pressure area, which is the bit that makes drafting easier - but the fact that there are loads of gaps in between each rider in a group means that the air in general is anything but still.

Cavendish's rear wheel choices are more likely to do with the additional rigidity provided by a deeper section rim, as opposed to any aero advantage.


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## gds58 (27 Jan 2014)

Dusty Bin said:


> The air in a bunch is not 'still' - I've no idea where you got that from
> _I got that from my own experiences of road racing in races all over Europe - something I doubt you have ever experienced yourself_
> Cavendish's rear wheel choices are more likely to do with the additional rigidity provided by a deeper section rim, as opposed to any aero advantage
> _That's not what he told me last week when we chatted about this very thing. The deeper section is faster and every tiny little bit makes a difference when you might be measuring a stage win in millimetres. That's also why he chooses to wear an Evade aero helmet as the little extra energy he saves during the stage translates into more power at the end._



I'm kind of done with this now as it is clear that you will continue to have the last word even though it will be based on little or no experience or knowledge of the subject.
Thanks very much, it was interesting


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## Dusty Bin (27 Jan 2014)

gds58 said:


> I'm kind of done with this now as it is clear that you will continue to have the last word even though it will be based on little or no experience or knowledge of the subject.
> Thanks very much, it was interesting



Your arrogance is astonishing. I ask you for evidence and you can't find any - and yet you continue with this mantra of "I must be right, cos I am awesome" - the weird thing is, you don't seem to see a problem with that. The ability to ride a bike fast does not automatically qualify you as being invincibly correct all the time. This could be a useful discussion, were it not for your patronising tone.

Incidentally, Cav's deep section being 'more rigid' and 'faster' are not incompatible from a sprint pov. What did Cav actually tell you then? Surely that's gotta be worth sharing with the group?


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## gds58 (27 Jan 2014)

Dusty Bin said:


> Your arrogance is astonishing. I ask you for evidence and you can't find any - and yet you continue with this mantra of "I must be right, cos I am awesome" - the weird thing is, you don't seem to see a problem with that.
> 
> What did Cav actually tell you then? Surely that's gotta be worth sharing with the group?


You are incredible! I never said I couldn't find any evidence, if you care to look back you will see that I stated that I read it in two different articles in publications. One I think was in Rouleur and the other I cannot remember the title but a similar genre of magazine. At no point have I said 'I'm right because I'm awesome' merely imparting some knowledge from my own personal experiences, which happen to be quite extensive. So no, I don't see a problem with that. And, in answer to your last question, I have already told you what Mark said to me, so I consider that shared! I'm certainly not intending to share everything I talk to him about, on here. Those conversations are private and most of it that's nothing to do with anybody else will stay that way.


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## Dusty Bin (27 Jan 2014)

Ironic, you calling me 'incredible', when nothing you've said so far seems to be supportable. Magazine articles are not evidence. Personal experience is anecdote, not evidence. Science is evidence. Science, or GTFO. Come on mate - you're supposed to be a 'Technical advisor to Team GB' - surely you can do better than this?

As I said just now - what Cav told you last week (presumably on the phone from Argentina - unless you were there with him) is not evidence either - and unless you can shed more light on that, then it's just another meaningless name drop.

Do you mind me asking - what years did you win your five consecutive titles?


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## VamP (27 Jan 2014)

Entertaining as the exchange is, I have to say @gds58, that you are not coming out of this victorious so far. Browbeating and name dropping doesn't come across too good, basically.

@Scoosh - that was a bit of random mod noise??


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## gds58 (27 Jan 2014)

VamP said:


> Entertaining as the exchange is, I have to say @gds58, that you are not coming out of this victorious so far. Browbeating and name dropping doesn't come across too good, basically.
> 
> @Scoosh - that was a bit of random mod noise??


1. I wasn't aware that this was a competition
2. Not name dropping at all, merely passing on some info from somebody who is the most driven and practical person I have ever met and who would never do anything that wasn't for a good reason.
3. Certainly not 'Bullshit' as mentioned earlier just proven FACT and if you either don't agree or believe it TOUGH as it matters not one bit to me. I don't ever 'bullshit' just tell it how it is whether you like it/agree with it or not.
Mod Edit. Deleted

Thank you and Goodnight


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## VamP (27 Jan 2014)




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## Dusty Bin (27 Jan 2014)

gds58 said:


> 1. I wasn't aware that this was a competition
> 2. Not name dropping at all, merely passing on some info from somebody who is the most driven and practical person I have ever met and who would never do anything that wasn't for a good reason.
> 3. Certainly not 'Bulls***' as mentioned earlier just proven FACT and if you either don't agree or believe it TOUGH as it matters not one bit to me. I don't ever 'bulls***' just tell it how it is whether you like it/agree with it or not.
> 4. Dusty Bin = Dick
> ...



It's not a competition, but it is a discussion in which you have singularly failed to provide any evidence to support your 'facts' - despite being asked several times. For someone claiming to be a 'technical advisor to team GB' (it says so on your profile page, I'm presuming you are not advising the netball team), I would not have expected this to present too many problems.

Further, for someone who is clearly proud of his 'five consecutive national titles' you seem fairly guarded in providing further info on them.


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## Scoosh (27 Jan 2014)

Dusty Bin said:


> Maybe you could clarify - the thread title is _'how much faster would 'x' make me'_ and we are having a discussion about how much faster people would go (or not) with aero kit. So where exactly is the 'off topic' bit..?


I will clarify.

This thread is about a _Calcuator_ a new CC Member has designed and is entitled


> How much faster would "x" make me?


The member has requested feedback on what other things might be added to his Calculator.

It is NOT a thread to be arguing about who is right/ wrong about the effects of 'clean/turbulent air' in a group riding situation.

If you wish to discuss that topic - start another thread, as I have instructed.

And stop the personal name-calling and abuse.


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## VamP (27 Jan 2014)

Scoosh said:


> I will clarify.
> 
> This thread is about a _Calcuator_ a new CC Member has designed and is entitled The member has requested feedback on what other things might be added to his Calculator.
> 
> ...



With all due respect, I would say that the impact of clean/turbulent air on the performance of deep section wheels in a group riding scenario was precisely the kind of issue that sucha calculator would have to take into account.

The name-calling is unnecessary, but it does seem like you are pulling up the wrong party for that particular crime.

Are there mod qualifications?


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## Dusty Bin (27 Jan 2014)

Scoosh said:


> And stop the personal name-calling and abuse.



Why do you keep deleting my reply? I haven't called anyone names on here. The only abuse has been from the other guy.


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## Dusty Bin (27 Jan 2014)

VamP said:


> With all due respect, I would say that the impact of clean/turbulent air on the performance of deep section wheels in a group riding scenario was precisely the kind of issue that sucha calculator would have to take into account.



Agree completely.


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## Scoosh (27 Jan 2014)

If you or anyone else is able to give the OP a method of calculating "_the impact of clean/turbulent air on the performance of deep section wheels in a group riding scenario _[which is]_ ... precisely the kind of issue that such a calculator would have to take into account_", rather than just arguing about it, please do - as I am sure he would be very interested and would like to add it to his Calculator.

If you wish to discuss that matter in a manner that would be beneficial to the OP, please start another thread and so do.


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## Dusty Bin (27 Jan 2014)

Scoosh said:


> If you or anyone else is able to give the OP a method of calculating "_the impact of clean/turbulent air on the performance of deep section wheels in a group riding scenario _[which is]_ ... precisely the kind of issue that such a calculator would have to take into account_", rather than just arguing about it, please do - as I am sure he would be very interested and would like to add it to his Calculator.
> 
> If you wish to discuss that matter in a manner that would be beneficial to the OP, please start another thread and so do.



How do you suggest we arrive at a viable conclusion without first discussing the issue?


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## Scoosh (27 Jan 2014)

Please do discuss the issue - in a separate thread


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## Dusty Bin (27 Jan 2014)

Scoosh said:


> Please do discuss the issue - in a separate thread



So, just to be clear - you want us to continue with an entirely relevant and pertinent discussion which is pursuant to the thread title - but in a different thread??


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## VamP (27 Jan 2014)

Dusty Bin said:


> So, just to be clear - you want us to continue with an entirely relevant and pertinent discussion which is pursuant to the thread title - but in a different thread??



But, presumably, once we have worked it out, we could come back here and tell the OP the good news?


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## Scoosh (27 Jan 2014)

VamP said:


> But, presumably, once we have worked it out, we could come back here and tell the OP the good news?


Yes - Absolutely and Definitely


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## ColinJ (27 Jan 2014)

I think it is a mistake using height and weight ranges since they will give approximate answers - for example, the difference between 120 kg and 140 kg is massive. You must be taking a figure representing the range - e.g. 130 kg and using that in a calculation, so why not just let people enter exact weight and height data and use that? 

Similarly, I'd like to be able to enter the total weight of the bike, and any clothing, tools, spares, food and drink.

Even though I always wear a helmet, lots of people don't so at least include an option for that, and maybe the 2 cap options. (And bald/shaved head?)

It would be nice to be able to enter data for wind speed and direction too.


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## Dusty Bin (28 Jan 2014)

ColinJ said:


> I think it is a mistake using height and weight ranges since they will give approximate answers - for example, the difference between 120 kg and 140 kg is massive.



Don't forget - this whole debate is an exercise in approximation - it almost certainly does not stand up to any form of scientific or technical scrutiny, as we discovered with gds58 last night. In that sense, I can't see that absolute precision on anything is required here.


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## Machin (28 Jan 2014)

ColinJ said:


> I think it is a mistake using height and weight ranges since they will give approximate answers - for example, the difference between 120 kg and 140 kg is massive


 
Thanks very much for your inputs. I went with the selected ranges because it actually doesn't make that much difference to the final result (within reason) because the calculator calculates the improvements *relative* to your actual ride, therefore the effect of the starting weight/height is a lot smaller than you might think. Take as an example, we have two people, Rider 1 who is 5ft 11" and 77kg, and Rider 2 who is 6ft 4" and 85kg (i.e. one range higher in each aspect than the previous rider), the effect on some of the different scenarios (all other inputs left as default) as calculated by the program is shown below:-

Test______________________Rider 1_______ Rider 2
5% decrease in rider weight:__-27.1secs _____-26.8secs
Riding on the drops:_________-1min57.5______-1min57.7
200g Lighter seatpost:_______-1.3secs_______ -1.2secs
Aero helmet_______________-33.8secs_______-31.7secs

You can see that the calculated difference between these two people in those scenarios is very small; indicating that the chosen ranges are close enough to avoid big jumps in performance gains.

Remember that whilst the program says that rider 1 will improve their time by 1min57secs by riding in the drops rather than on the hoods, in reality one person meeting the criteria of "Rider 1" will most likely have a much better "in the drops" position than another person also meeting the criteria of "Rider 1"... e.g. depending on how high their handle bars are set to begin with, whether they ride with straight arms or bent arms, etc, "Rider1a" might improve by 2mins10secs, whilst "Rider1b" might improve by "only" 1min:45secs; much more variation than the effect of different starting height and weight of the riders.

Likewise with something like aero wheels; the program says aero wheels will improve a rider's time by (for example) 34.7 seconds over 18 miles, in reality one set of aero wheels might improve the time by 40 seconds, and another might improve the time by 30 seconds... depending on the shape of the rim, shape of the spokes, the tyre:rim interaction, etc. Again; variation in individuals and kit is bigger than the effect of making the height/weight ranges smaller.


> It would be nice to be able to enter data for wind speed and direction too.


 
In a way this is very similar to the height/weight example's above, bearing in mind that the idea of the calculator is to take one of your existing rides and then advise approximately how much quicker/slower each of the scenarios would make you, if you were to do the *exact same ride* again (e.g. the exact same wind, your power output, whether you waved to your next-door neighbour, etc etc). The program works by initially estimating your power output over your ride based on the options you provide. The calculated power isn't divulged because it doesn't actually matter to the accuracy of the performance improvements; what does matter is that the calculator uses the same estimated power as the basis of all the performance improvement calculations.

E.g. If you did a ride of 17.5 miles in an hour the program might estimate your average power to be 170 watts (number plucked out of mid air!). If you were actually riding with a tail wind your actual power might've been only 145 watts, whereas if you'd had a head wind your power might've been 200 watts, but it doesn't have a big effect on the results because all the improvements are relative to the estimated power value. e.g. a 5% power improvement is a 5% improvement regardless of the starting value. Similarly if your drag reduces by 50% the _power to drag ratio _(which is the main factor determining bicycle speed on the flat) will double whether the starting power was 145 watts (tail wind scenario) or 200 watts (head wing scenario).

I hope that helps to explain why I've done what I've done; I could add those features, but they would make less difference than the variation you should expect from differences in the actual kit, riding position, training regime , etc that you are actually using.


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## ColinJ (28 Jan 2014)

Yes, I was thinking more in absolute terms, than relative terms.


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## Tin Pot (31 Jan 2014)

Machin said:


> Any feedback appreciated!



Hi, thanks for posting an interesting subject. I'm scientifically minded, but without the cycling-specific knowledge I'll set that aside and assume the maths & science behind your site is correct.

So my feedback as an enthusiastic novice;

Just what I've been looking for! Quantative analysis beats the crap out of qualative.

Expect to be confronted. I am bringing Quantative analysis to a completely different field, where at times it seems people will say anything to avoid the facts of the matter.

I'm surprised that the gains are so significant for a cyclist of my poor calibre, an aero bar/TT bike saving me half an hour over 82miles starts to justify the cost...great news for vendors of TT bikes, but will vendors of aero wheels/helmets/overshoes/BB be as happy?

Apart from the estimated nature of the savings, are there any other caviats that should be displayed prominently?


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## VamP (31 Jan 2014)

Well, a TT bike is fairly specialist piece of kit, and the return on your investment in terms of speed will not be linear. The main issue is that the position is different to a road bike, and as such your power delivery is compromised. The extent to which that is the case varies from individual to individual, and depends on a number of factors, such as time spent in new position, suitability of position to athlete, aero gains vs. power loss trade off etc.

But in even in a best case scenario hoping for 30 minutes over 82 miles is over-optimistic.


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## Rob3rt (31 Jan 2014)

Tin Pot said:


> an aero bar/TT bike saving me half an hour over 82miles starts to justify the cost...great news for vendors of TT bikes, but will vendors of aero wheels/helmets/overshoes/BB be as happy?
> 
> Apart from the estimated nature of the savings, are there any other caviats that should be displayed prominently?


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## Tin Pot (31 Jan 2014)

VamP said:


> Well, a TT bike is fairly specialist piece of kit, and the return on your investment in terms of speed will not be linear. The main issue is that the position is different to a road bike, and as such your power delivery is compromised. The extent to which that is the case varies from individual to individual, and depends on a number of factors, such as time spent in new position, suitability of position to athlete, aero gains vs. power loss trade off etc.
> 
> But in even in a best case scenario hoping for 30 minutes over 82 miles is over-optimistic.


I suspect so myself, and partly hence choosing that particular stat for feedback


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## young Ed (31 Jan 2014)

Dusty Bin said:


> I like it - it's a bit of fun. There's a few things it doesn't account for, such as adopting multiple hand positions while out riding, like most probably do. Also, if you have a category for 'under-inflated' tyres, you should also have one for 'over-inflated' as well.


that one is called bang go to wiggle!
Cheers Ed


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## Machin (2 Feb 2014)

Tin Pot said:


> I'm surprised that the gains are so significant for a cyclist of my poor calibre



The "good news" is that the slower you are as a rider the more absolute gain you will see from something like a TT bike; because you are out on the course longer than a faster rider: this effect is greater than the fact that aero is more significant at the higher speeds of the faster rider! So that is good news for us non-professionals!

Re. TT bikes/Aerobars and power output; I do have the caveat on the respective "info" page that I have assumed that your power is unaffected, but that this might not be true for some people... scientific studies into this dual affect are hard to come by (most studies of riding positions are wind tunnel tests, rather than "on the road" tests: which would be affected by variable climate conditions). Whilst a 30 minute gain over 82 miles does sound a lot, it is only about 7 minutes in every hour or a gain of just 2.5mph for the same power output. I've done tests myself and find that 2.5mph (compared to an upright position) is about right for me (although as before everyone is different).

I suppose the other caveat is regarding anything that has a physiological impact on the rider is VERY individual dependant... for example scientific studies into the effects of training show huge differences between individuals; two people doing the same training regime may find that one improves their power by 5% whilst the other may show no gain (known to sports scientists as a "non-responder"). My program presents the average result of a group of people as presented in the results of the original scientific study.

I'm shortly going to add the links/references in to the original scientific studies so people who want to read more, can.


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## Machin (2 Feb 2014)

Another couple of notes on the TT bike performance gain: the 30 minutes would've been relative to an upright position on a "standard" roadbike? if you change your starting configuration to riding in the drops (for the whole ride) the gain drops to about 20 minutes... this change is effectively "free" since most road bike have drop handlebars. if you chnage your starting configuration to Aerobars (available for about £40) the gain for the TT bike drops to about 10 minutes in 82 miles... so the cost of a TT bike starts to look quite expensive.....


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## 400bhp (2 Feb 2014)

Machin said:


> Another couple of notes on the TT bike performance gain: the 30 minutes would've been relative to an upright position on a "standard" roadbike? if you change your starting configuration to riding in the drops (for the whole ride) the gain drops to about 20 minutes... this change is effectively "free" since most road bike have drop handlebars. if you chnage your starting configuration to Aerobars (available for about £40) the gain for the TT bike drops to about 10 minutes in 82 miles... so the cost of a TT bike starts to look quite expensive.....



I have heard "save 1 minute over a 10 mile" as a rule of thumb with a TT bike, so sounds about right I guess.


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## Tin Pot (2 Feb 2014)

Thanks, and yes I noticed the TT bike was a cumulative effect -
I was getting tri bars anyway (for tris) so this supports my buying ways 
Cheers.


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## Jon George (8 Mar 2014)

A fascinating calculator - I'll be addressing some of the possible major improvements on a 20 mile BP course in the next few weeks. It certainly looks like I'll have to reattach those aero bars I bought when I was skirting with being a GATGNI.


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## MikeG (8 Mar 2014)

I tell you what would be nice............I don't know if it is possible, though: if the list of gains would organise itself into ranks. In other words, the biggest potential gains would be at the top of the list, with the smaller gains ranked below them.

I'd also like plenty of additional clothing options. What do I tick when wearing a waterproof jacket and longs?

Anyway, this is a wonderful effort, and very useful. Thanks for sharing it.

Mike


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## G3CWI (8 Mar 2014)

Anything that gets me to the pub quicker is a bonus.


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## oldroadman (15 Mar 2014)

All this discussion seems to be about equipment, and assumes that the output of the rider remains the same. Use the right kit and increase the output. The increased output will show some real gains. Here's the bad news - going properly fast is about the ability to sustain pain. Go back to the Lemond quote - never easier, just faster. Enjoy...in a perverse sort of way. I always hated TTs, no chance to have a chat with friends in the peloton in the quieter moments!


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## RecordAceFromNew (15 Mar 2014)

Although a few years old, this is a pretty good road vs tt ballpark comparison by Spesh.

The interesting thing, is while Spesh says Aero is Everything, those Taiwanese appear to be saying Spesh and McLaren have been pissing in the wind...


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## oldroadman (17 Mar 2014)

RecordAceFromNew said:


> Although a few years old, this is a pretty good road vs tt ballpark comparison by Spesh.
> 
> The interesting thing, is while Spesh says Aero is Everything, those Taiwanese appear to be saying Spesh and McLaren have been ****ing in the wind...


 Depends what bikes are in your range and who you want to sell to. Some people will believe anything producers feed them. Cynical, me? Nah...


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## Machin (19 Mar 2014)

MikeG said:


> I tell you what would be nice............I don't know if it is possible, though: if the list of gains would organise itself into ranks. In other words, the biggest potential gains would be at the top of the list, with the smaller gains ranked below them.
> 
> I'd also like plenty of additional clothing options. What do I tick when wearing a waterproof jacket and longs?
> 
> Anyway, this is a wonderful effort, and very useful. Thanks for sharing it.


 
Thanks for the feedback. I'm sure it would be fairly simple to re-order the results... although at the moment I'm not sure how (my html programming skills are fairly basic!). I'll have a look into it.

Re. the clothing options, I have some wind tunnel data for wet weather jackets so I'll add this shorlty. But what I will say is that because the results are relative you should find that the effect of other (non-clothes related) items will be largely unaffected by what you are wearing... (it will make a difference, but not that much)... e.g. if you were wearing a skin suit on an 18 mile 1 hour ride and changed from an upright position to riding on aerobars you would save 4 mins 5 seconds. But if you were wearing a wool jersey and long tights and cycled 18 miles in 1 hour the effect on the position would only change to 4 mins 8 seconds. (Of course, if you were doing the same 18 miles in 1 hour in both clothing configurations it would mean your average power in the skinsuit scenario would've been less because it has less drag.


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## Machin (19 Mar 2014)

Jon George said:


> A fascinating calculator - I'll be addressing some of the possible major improvements on a 20 mile BP course in the next few weeks. It certainly looks like I'll have to reattach those aero bars I bought when I was skirting with being a GATGNI.


 
Cool, have fun, and let us all know how your testing goes!


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