Training wheels and Racing wheels

[Slave]

 

Only the sponsored dudes and the ones with wallets bigger than their brains have training wheels and racing wheels.

 

 

So wat maak dit my - ek het 'n oefen fiets' date=' 'n "racing" fiets, 'n TT fiets en 'n bergfiets. O ja, daar l? nog 'n raam en 2 stelle wiele ?rens op 'n kas...

Ek word nie gesponsor nie...

[/quote']

 

At a guestimate, Sias, I would say a very serious cylcist with a much bigger budget and more time available for cycling than many.

 

My post was intended to be funny and not offensive. If you were offended, I appologise.

 

I was quite shocked the other day to see that some wheelsets cost around R20,000 and I'm guessing that this is probably not the most expensive wheelset around.

 

Considering that I do not even have that kind of budget for a bike, jealousy made me NASTY.

 

Just a question. What sort of positions do you come in when you race?

 

In my not at all humble opinion, if we are not making prize money, then it just becomes a matter of pride that we come in in say the top 100 or top 200 or whatever we achieve. Nothing wrong with the achievement at all, I just dont see myself ever achieveing that sort of level and I would be very happy if I can get to do the 94.7 in 2 hrs 59 min.

 

I just can't see myself throwing big budget at the task to try and achieve it. If I can't do it on my 18 year old peugot, then I can't do it at all.

 

No amount of money can replace good solid training and effort.

 

Giving me Dura Ace (or whatever) hi-tech is like feeding your caviar to the pigs. In other words, I am a Philistine on which such technology would be wasted.

 

A little tech would help, but training and racing wheels would be a serious waste on the like of me.

[JoeK]

Hey hubbers, a few weeks back I saw a link on the hub to a site where they experimented with the weight of a bike when climbing. I can't seem to find that post with the link

Any help?

I remember the slowest time for the cyclist was when they filled the wheel with water. 

They also taped a 1kg botle of water to the frame of the bike. Can't remember the other ways to put weight on.

[Christie]

The equation linking I (or more commonly used, J) to work is still missing. 

 

It will show that more rotating mass takes more energy to accelerate

 

On a road bike, speed fluctuates very little, so it means that on a bike mass is mass, does not make a noticable difference if it rotates or not.

 

Seems I&J has very little to do with cycling, then.

Christie2008-10-16 11:33:50

[Minion]

 

 

 

Seems I&J has very little to do with cycling' date=' then. [/quote']

That sounds fishy

 

It seems that small fluctuations in speed may actually have some effect. This extract comes from an article written by the chief engineer at Zipp:

OK, having said all that. Weight is important, but is generally always

trumped by aero. The analytic cycling calculator helps out with this,

although we are now understanding better from our work with CSC and

Phonak, that on steeper grades weight is more important than these

models show. The theory is that since nobody really makes constant

power, the dead spot in the pedal stroke allows for a slight

deceleration that then requires a re-acceleration during the power

stroke. These fractional acclerations really can sap power, and weight

definitely affects this quite considerably, although aero has a small

affect as well.

http://www.zipp.com/support/askjosh/wheels.php#

 

No mention is made of the magnitude of this effect and it may be that, at all but the highest levels of performance, it's largely irrelevant.

 

I would recommend reading the rest of the FAQs on the Zipp site and the technology section. There's some pretty interesting stuff there that, for the most part, seems technically valid and not overly steeped in marketing BS.

Edman2008-10-16 12:46:15

[Christie]

The small acceleration/deceleration is also referred to as "micro accelerations". Im not a fan of that theory. A micro variation on what is a small amount of power over a very small increment = a very very small number?  Had a quick look at my candence curve from last weekend's race, not a lot of acceleration there, and thats sampled at 66.7 Hz or some funny number there abouts.

I am a fan of Zipp, though, they talk a lot of sense, mostly, and publish solid test data for their stuff, but I dont agree on this point.

Christie2008-10-16 12:41:33

[Johan Bornman]

Seems I&J has very little to do with cycling' date=' then. [/quote']
That sounds fishy

It seems that small fluctuations in speed may actually have some effect. This extract comes from an article written by the chief engineer at Zipp:

OK, having said all that. Weight is important, but is generally always trumped by aero. The analytic cycling calculator helps out with this, although we are now understanding better from our work with CSC and Phonak,

 

Cut cut cut cut

 

Edman, I also don't like the small accelleration theory. Firstly, we (the bike and I) have significant intertia that smooths the curve very well.  Had we been a piece of confetti in the wind I'd say micro accelleratons was possible, but we're not.

 

Secondly, someone once challenged me on this and I asked him to pick a figure per pedalstroke. He chose 1kph of loss of speed per pedalstroke. I calculated that the energy required to do a 100km race with X accellerations of 1kph/pedalstroke was more than our possible calorific intake in a week.....even if you drink beer.

 

Obviously this pulsating progress is visible during hard climbing but that's not the general picture in cycling and, it is much, much smaller than most people think.

 

I think the point I'm trying to make is that the easy way of disproving the theory is to use reductio ad absurdum and calculate the enery required to accellerate a mass X times of pedalstrokes. I haven't seen anyone do it that way but I cannot find fault with the validity of my thinking. Perhaps you can?

 

 

[Johan Bornman]

Seems I&J has very little to do with cycling' date=' then. [/quote']
That sounds fishy

It seems that small fluctuations in speed may actually have some effect. This extract comes from an article written by the chief engineer at Zipp:

OK, having said all that. Weight is important, but is generally always trumped by aero. The analytic cycling calculator helps out with this, although we are now understanding better from our work with CSC and Phonak,

 

Cut cut cut cut

 

Edman, I also don't like the small accelleration theory. Firstly, we (the bike and I) have significant intertia that smooths the curve very well.  Had we been a piece of confetti in the wind I'd say micro accelleratons was possible, but we're not.

 

Secondly, someone once challenged me on this and I asked him to pick a figure per pedalstroke. He chose 1kph of loss of speed per pedalstroke. I calculated that the energy required to do a 100km race with X accellerations of 1kph/pedalstroke was more than our possible calorific intake in a week.....even if you drink beer.

 

Obviously this pulsating progress is visible during hard climbing but that's not the general picture in cycling and, it is much, much smaller than most people think.

 

I think the point I'm trying to make is that the easy way of disproving the theory is to use reductio ad absurdum and calculate the enery required to accellerate a mass X times of pedalstrokes. I haven't seen anyone do it that way but I cannot find fault with the validity of my thinking. Perhaps you can?

 

 

[Minion]

 

I think the point I'm trying to make is that the easy way of disproving the theory is to use reductio ad absurdum and calculate the enery required to accellerate a mass X times of pedalstrokes. I haven't seen anyone do it that way but I cannot find fault with the validity of my thinking. Perhaps you can?

This is really something I should have done from the start, even if just to satisfy my own curiosity.

I'll have a large amount of waiting-for-computer time tomorrow, so such a calculation might just be forthcoming.

 

[Yang]

JB, someone else said it- "I believe, therefore I am". If I believe that my wheels make me faster, then the the self-fulfilling prophecy component of my physical performance kicks in. Give me cheaper, heavier tyres, and my mind will control my output to a slower time, to prove my belief that these tyres slow me up. This is the non-technical, part of the argument. So the perception becomes the truth in the heads of those who believe. I personally believe that at my level wheels don't make a difference beyond fractions to my seeding of 20. To a pro the seconds over a 120 to 230 k race will make a difference.

 

Now- how's this- I have non-poofter wheels on my training bike, and non-poofter wheels on my racing bike. I pull out my racing bike 3 weeks for training before the race, and train in between on my training bike. My racing bike has Record, and my training bike has 105. Does this make sense? I believe it makes cents. 

 

PS- truly hilarious story about the flies. The one that got away probably made you his Lord.  

Yang2008-10-16 14:51:51

[Wannabe]

JB' date=' you can be pedantic when you want.

The Mavic's bearings are a lot smoother (i.e they turn easier with less resistance than the Rolf's.) The Rolf's are also heavier than the Mavic's, etc. It all adds up to quicker wheels. But maybe I'm blinded by the hype about unsprung weight and smoother bearings etc, benefitting you when cycling.

[/quote']

 

Not the first time I've been called a pedant....or worse.

 

However, lets stick to the facts, shall we?

 

Lets assume the Rolfs are very bad and the Mavic's very good. Thus, the Rolfs sap, at 40kph, 1 Watt through bearing drag.  You put out 100 Watts. How will you feel the 1% difference. Note that I've used extreme examples.

 

Lets assume the Rolfs are 1kg heavier than the Cyriums. You and your Cyrium bike weigh 80 kgs. You and your Rolf bike weigh 81kgs. After a 10 000 meter climb you've exerted 10000 joules (10 kilojoule) more energy to get the Rolf's to the top. 1 Windhoek light provides 126 kilojoules and a Coke Zero 26 kilojoules.  Just lying on your bed costs more kilojoules per minute than that.

 

How did you feel or measure the difference? 

 

Don't use terms like "roll better" - all wheels roll well. Square wheels roll not so good and triangular wheels a little better since they have one bump per revolution less.

 

See my point? This wheel weight nonsense is nonsense. Stop it.

 

 

JB, so what you are saying is that there is absolutely NO performance difference between your No-Name wheels and the top of the range wheels, like say, Dura Ace or Bora's?

 

Ok, I'm grabbing my jacket, and I know where the door is.

[Johan Bornman]

JB' date=' so what you are saying is that there is absolutely NO performance difference between your No-Name wheels and the top of the range wheels, like say, Dura Ace or Bora's?

 

 

[/quote']

No

[Johan Bornman]

I think the point I'm trying to make is that the easy way of disproving the theory is to use reductio ad absurdum and calculate the enery required to accellerate a mass X times of pedalstrokes. I haven't seen anyone do it that way but I cannot find fault with the validity of my thinking. Perhaps you can?

This is really something I should have done from the start' date=' even if just to satisfy my own curiosity.
I'll have a large amount of waiting-for-computer time tomorrow, so such a calculation might just be forthcoming.
[/quote']

 

I still have it somewhere...but posting it is hell since I'm not good at putting formulae on a screen.

 

However, it is easy. Assume a given decelleration between pedalstrokes. It is not important what the actual figure is. I think the 1kph/pedalstroke was a rationale of say 1/30 of the average speed lost per stroke.

 

Then assume a weight for the rider/bike. Say 80kgs.

 

Then assume a cadence - 100rpm sounds nice.

 

 

Therefore there will be 200 accellerations per minute of 1kph/h

 

Force required is a product of mass and the accelleration (in m/s/s)

 

Work can then be calculated from that eventually you'll have the total energy input for a fictitious 3-hokur ride. You'll find that this input is more than you can eat. Therefore it is not possible and you move on to a smaller figure until it gets ridiculous and you say "micro accellerations are in the nonsense end of the scale."

 

Christie mentions that he has some instrument to help? Christie, if you're looking at average rpm sampled at 66Hz, I don't think it helps. The pedal stroke is only 3.3 Hz at a cadence of 100.

 

I can't think of a way to measure micro-accellerations and although lots of wheel companies hint towards it, I've never seen one produce data, hence my going the opposite route proving that any thumbsuck is absurd.

 

 

 

 

 

[JoeK]

JB' date=' someone else said it- "I believe, therefore I am". If I believe that my wheels make me faster, then the the self-fulfilling prophecy component of my physical performance kicks in. Give me cheaper, heavier tyres, and my mind will control my output to a slower time, to prove my belief that these tyres slow me up. This is the non-technical, part of the argument. So the perception becomes the truth in the heads of those who believe. I personally believe that at my level wheels don't make a difference beyond fractions to my seeding of 20. To a pro the seconds over a 120 to 230 k race will make a difference.

 

Now- how's this- I have non-poofter wheels on my training bike, and non-poofter wheels on my racing bike. I pull out my racing bike 3 weeks for training before the race, and train in between on my training bike. My racing bike has Record, and my training bike has 105. Does this make sense? I believe it makes cents. 

 

PS- truly hilarious story about the flies. The one that got away probably made you his Lord.  

[/quote']

 

"I think, therefore I am" William Shakespeare

[GoLefty!!]

The issue with micro accelerations is that one needs several sample points for the rotational speed per revolution.

Most equipment aonly measures at 1 point per revolution, so this in act is actually comparing the time taken per rev and not the the time taken per segment of the revolution.

If you could arrange sensors at regular intervals at say 30degrees then it would be possible to measure the micro accelerations.

[Johan Bornman]

The issue with micro accelerations is that one needs several sample points for the rotational speed per revolution.

Most equipment aonly measures at 1 point per revolution' date=' so this in act is actually comparing the time taken per rev and not the the time taken per segment of the revolution.

If you could arrange sensors at regular intervals at say 30degrees then it would be possible to measure the micro accelerations.

[/quote']

 

Tim, when you guys gave me a hard time on Warthogs I thought of this but you still sit with the same problem. The instrument (bike computer) will only measure RPM, in other words average out the pulses from the magnets. If you were to put many magnets on there and then divide the RPM by the number of magnets, you're back to RPM again.

 

You need a different instrument that will measure time between pulses.

 

This is not a garage operation and I'm not spending money on something I can prove with math.

 

 

[jabbathemutt007]

 

"I think' date=' therefore I am" William Shakespeare

[/quote']

 

AKA Rene Descartes