Weight weenies vs watt weenies...

[Kurt1980]

On a related note... has anyone ever tried to rig up a motor (similar to an ebike, but no pedalling to activate) that puts out, say, a consistent 300W? The rider could pedal but it wouldn't add to the power, so take off the chain maybe?

You could do all sorts of testing of wheels, bars, positioning, different sized frames, tubing shapes.

Run each combination multiple times over a course with climbs and descents, crosswinds etc for an hour.

Get a weekly/monthly/seasonal average for each combination.

Not a perfect solution by any means, but it would account for the variability of power input, and likely make it easier to hold positions consistently.

[maxim809]

If I can go on tangent a bit, there are some data i want to show.
snip

However, what you can see here is that a.) not everyone ride top of the line 15k bike. b.) they dont upgrade as often as we like to think. WW is not representattive of any rider demography since this is arguably the most well educated in terms of bike parts and performance forum in the world.

Awesome post. Field data like this is so interesting and not something we get to see every day. Thanks for sharing.

[maxim809]

junk science...

V3Rs, you've been berating people trying to help you.

Either clarify to us what you don't understand. Or think of some way you can contribute constructively so you can build on ideas rather than killing them.

[Andrew69]

I really just wanted to know what if any the OVERALL improvement could be.

Zero. The difference is zero
If you ever race against me, please ride a flat bar with 36 spoke box section rims and some horrid puncture proof tyres.

Since nothing anyone has said is going to satisfy your "lust for knowledge", then just be content knowing that there is zero difference between any bikes and what ever you choose to ride is at least as good as anything else

[Andrew69]

On a related note... has anyone ever tried to rig up a motor (similar to an ebike, but no pedalling to activate) that puts out, say, a consistent 300W? The rider could pedal but it wouldn't add to the power, so take off the chain maybe?

You could do all sorts of testing of wheels, bars, positioning, different sized frames, tubing shapes.

Run each combination multiple times over a course with climbs and descents, crosswinds etc for an hour.

Get a weekly/monthly/seasonal average for each combination.

Not a perfect solution by any means, but it would account for the variability of power input, and likely make it easier to hold positions consistently.

Yep, its called a windtunnel
Data collected on the road between bikes that are already pretty close in drag is next to useless because of all the variables that are next to impossible to quantify.
Even if your position is identical (and thats tough to achieve precisely), wind speed, wind direction, barometric pressure, daily fluctuation weight of the rider...even a passing car will be enough to make the data useless if youre trying to tease out the last little bit of aero gain.
If you were to try to test the variables and you dont have a windtunnel, a velodrome will work much better than the road as the variables are lower, but it still isnt ideal.
An indoor velodromel is even better , but even that isnt perfect as after a number of laps, the rider travelling around the track will cause the air to swirl around the velodrome and lower their apparent CdA and drag.

This is why bikes are tested in a wind tunnel and at 45km/h. Its because the variables are greatly reduced and the air speed allows the differences between equipment to be magnified.

[ghostinthemachine]

I think he's pissed because you can't actually buy that much speed. Unless you only put your bike (no rider) in a wind tunnel at zero yaw and 50kph.

The differences between an old school round tube steel bike with some nice fast rolling tubs and your state of the art aero climbing bike is dwarfed by the difference between good position, comfort, clothes that fit, strategy that works and following the right wheels... TBH the last two apply all the way up to the pointy end of the world tour.
Even when everything else has been honed to perfection.

[wheelsONfire]

On a related note... has anyone ever tried to rig up a motor (similar to an ebike, but no pedalling to activate) that puts out, say, a consistent 300W? The rider could pedal but it wouldn't add to the power, so take off the chain maybe?

You could do all sorts of testing of wheels, bars, positioning, different sized frames, tubing shapes.

Run each combination multiple times over a course with climbs and descents, crosswinds etc for an hour.

Get a weekly/monthly/seasonal average for each combination.

Not a perfect solution by any means, but it would account for the variability of power input, and likely make it easier to hold positions consistently.

Yep, its called a windtunnel
Data collected on the road between bikes that are already pretty close in drag is next to useless because of all the variables that are next to impossible to quantify.
Even if your position is identical (and thats tough to achieve precisely), wind speed, wind direction, barometric pressure, daily fluctuation weight of the rider...even a passing car will be enough to make the data useless if youre trying to tease out the last little bit of aero gain.
If you were to try to test the variables and you dont have a windtunnel, a velodrome will work much better than the road as the variables are lower, but it still isnt ideal.
An indoor velodromel is even better , but even that isnt perfect as after a number of laps, the rider travelling around the track will cause the air to swirl around the velodrome and lower their apparent CdA and drag.

This is why bikes are tested in a wind tunnel and at 45km/h. Its because the variables are greatly reduced and the air speed allows the differences between equipment to be magnified.

Yeah, i hear many of you talk of variables are not possible to measure as they are to fluctuating

I don't condradict anything here. I just ask, does anyone of you have an average speed that is pretty close day in day out?

If you imagine you have that as a reference and think you would go further on going all aero and you probably do that to get a faster average.
I don't aim at you who have race as hobby or love to read wind tunnel tests. Rather a normal (just) cycling dude who have an urge to be faster (which i think are many).
I think aero would sell if you could in fact see that happen, i can ride this aero bike (ok, even more of a concept) and on my routes and have a way better average.

[Kurt1980]

On a related note... has anyone ever tried to rig up a motor (similar to an ebike, but no pedalling to activate) that puts out, say, a consistent 300W? The rider could pedal but it wouldn't add to the power, so take off the chain maybe?

You could do all sorts of testing of wheels, bars, positioning, different sized frames, tubing shapes.

Run each combination multiple times over a course with climbs and descents, crosswinds etc for an hour.

Get a weekly/monthly/seasonal average for each combination.

Not a perfect solution by any means, but it would account for the variability of power input, and likely make it easier to hold positions consistently.

Yep, its called a windtunnel
Data collected on the road between bikes that are already pretty close in drag is next to useless because of all the variables that are next to impossible to quantify.
Even if your position is identical (and thats tough to achieve precisely), wind speed, wind direction, barometric pressure, daily fluctuation weight of the rider...even a passing car will be enough to make the data useless if youre trying to tease out the last little bit of aero gain.
If you were to try to test the variables and you dont have a windtunnel, a velodrome will work much better than the road as the variables are lower, but it still isnt ideal.
An indoor velodromel is even better , but even that isnt perfect as after a number of laps, the rider travelling around the track will cause the air to swirl around the velodrome and lower their apparent CdA and drag.

This is why bikes are tested in a wind tunnel and at 45km/h. Its because the variables are greatly reduced and the air speed allows the differences between equipment to be magnified.

True.

I was thinking of my idea in the real world as a way to shift away from:
steady state/laminar flow in a wind tunnel
- maybe not accurate at measuring absolute gains losses
- maybe not even accurate at predicting general trends

toward:
transient/turbulent flow in the environment
- giving you an actual indication of what setup is faster

This is on the back of Hambini's critique of steady state vs turbulent analysis of wheels, so take that for what its worth.

I also take your point about external variables you can't account for, but over along enough time scale would these variables not shrink to almost no influence?

You could also go back and forward between 2 different setups to pick trends, but probably not absolute measurements.

[Andrew69]

There are ways of teasing out the differences between setups "in the wild" , but because we are talking about small differences, you need as close to ideal conditions as possible to be able to measure the differences, which makes it next to impossible to pick the differences when talking about transient/turbulent flow

Google The Chung Method and you will find lots of information on how to conduct your own aero tests outside

[HBike]

On a related note... has anyone ever tried to rig up a motor (similar to an ebike, but no pedalling to activate) that puts out, say, a consistent 300W? The rider could pedal but it wouldn't add to the power, so take off the chain maybe?

You could do all sorts of testing of wheels, bars, positioning, different sized frames, tubing shapes.

Run each combination multiple times over a course with climbs and descents, crosswinds etc for an hour.

Get a weekly/monthly/seasonal average for each combination.

Not a perfect solution by any means, but it would account for the variability of power input, and likely make it easier to hold positions consistently.

Yep, its called a windtunnel
Data collected on the road between bikes that are already pretty close in drag is next to useless because of all the variables that are next to impossible to quantify.
Even if your position is identical (and thats tough to achieve precisely), wind speed, wind direction, barometric pressure, daily fluctuation weight of the rider...even a passing car will be enough to make the data useless if youre trying to tease out the last little bit of aero gain.
If you were to try to test the variables and you dont have a windtunnel, a velodrome will work much better than the road as the variables are lower, but it still isnt ideal.
An indoor velodromel is even better , but even that isnt perfect as after a number of laps, the rider travelling around the track will cause the air to swirl around the velodrome and lower their apparent CdA and drag.

This is why bikes are tested in a wind tunnel and at 45km/h. Its because the variables are greatly reduced and the air speed allows the differences between equipment to be magnified.

True.

I was thinking of my idea in the real world as a way to shift away from:
steady state/laminar flow in a wind tunnel
- maybe not accurate at measuring absolute gains losses
- maybe not even accurate at predicting general trends

toward:
transient/turbulent flow in the environment
- giving you an actual indication of what setup is faster

This is on the back of Hambini's critique of steady state vs turbulent analysis of wheels, so take that for what its worth.

I also take your point about external variables you can't account for, but over along enough time scale would these variables not shrink to almost no influence?

You could also go back and forward between 2 different setups to pick trends, but probably not absolute measurements.

I can understand your intention, but it won't work as easily.

1) It is paramount to equalize initial and boundary values + parameters as much as possible. Otherwise how will you know how a change in your design is delivering or not? There could be numerous other factors being responsible for the difference. So you need excellent statistics

2) A wind tunnel provides the means to compare the bikes to provide a database you can rely on without having to include numerous other causes. It is even possible to include inflow turbulence and modify boundary layer thickness if you like, include gusts etc.

3) Testing in the environment is difficult
- > Temperature/pressure therefore density change, wind pattern changes, humidity, street surface changes, turbulence levels change, your bike might get dirty, affecting frame roughness and performance, your position on the bike changes, clothing is not perfectly similar, your daily performance isn't equal or fitness level:

-> You need to do >100 runs for every parameter which changes to do statistics afterwards and get meaningful results
-> You need to run that for each track/change in course again, measure the environment each time (T, p, density, wind speed and direction, turbulence level, surface roughness, your power or velocity)
-> you will need to buy new tires regularly to provide similary tire profile and grip
-> ...

Without rigorous statistics, how will that "giving you an actual indication of what setup is faster"?
Being a scientist I would question this approach, to be honest.

[HBike]

I think he's pissed because you can't actually buy that much speed. Unless you only put your bike (no rider) in a wind tunnel at zero yaw and 50kph.

The differences between an old school round tube steel bike with some nice fast rolling tubs and your state of the art aero climbing bike is dwarfed by the difference between good position, comfort, clothes that fit, strategy that works and following the right wheels... TBH the last two apply all the way up to the pointy end of the world tour.
Even when everything else has been honed to perfection.

I don't understand that statement, as you are not forbidden to wear clothes that fit, have a working strategy, an aerodynamic but still comfortable position and nice rolling tubs on an aerobike, too.
When you do, the aerobike will save you quite a few Watts. Good aero wheels alone make a difference. In my opinion we don't always have to go to extremes to make a point. However I think your point targeted a different thing. The thing is most here are not world tour cyclists. For those, gains are less relevant and important as for cyclists riding at 6.2 W/kg at their absolute limit in a competition against the very best (WvA will be excellent with an old steel bike, too).
Same with weight, 400g more or less will gain an average rider roughly 0.04 km/h at the same power on a 10% slope, which for most is irrelevant.

So is it worth it to spend so much for an aero bike? This is something everyone has to decide on his own. For my training and riding it usually isn't an issue, but when riding with a friend who has a modern road bike vs. my Salsa Cutthroat I can feel the difference dramatically (all that is needed is switching bikdes ).

[FlatlandClimber]

Don't know if posted here before.
https://www.cyclingnews.com/features/wi ... e-fastest/
For an aero geek like me, very underwhelming differences. Basically nothing in it (weight saving gains are that low too though).

[alanyu]

Don't know if posted here before.
https://www.cyclingnews.com/features/wi ... e-fastest/
For an aero geek like me, very underwhelming differences. Basically nothing in it (weight saving gains are that low too though).

A test w/o rotational drag, and even worse, w/o a bike? ...

[ichobi]

What we can gather from these kind of tests are probably not the winner or loser, but the trend - as in if you view this in conjunction with other wheel reviews with similar protocol, you start to see which one is actually fast (in many test conditions). For example - the DT Swiss ARC 1100 has proven to be decently fast in all test from various publications either ranking 1st or in the top 3. I believe they produce really low drag in Tour test too. Not surpring given the designer is Swissside whose lead engineer is respected in the industry, (even Hambini praise him lol) and the way Swissside design also take into account transient / real world drag /.rotational drag way before other companies do too.

https://www.swissside.com/blogs/news/ro ... ?locale=de

[FlatlandClimber]

Don't know if posted here before.
https://www.cyclingnews.com/features/wi ... e-fastest/
For an aero geek like me, very underwhelming differences. Basically nothing in it (weight saving gains are that low too though).

A test w/o rotational drag, and even worse, w/o a bike? ...

Apparently not rotating, but fitted with a 25mm Schwalbe Tire and on a standardized bike. No rider.