chaadster

Although I think I’m pretty attuned to my bike and aware of what I want the parts to do, the idea that I could maintain speed without power is foreign to me. Maybe it’s to due with Clydesdale-class physique, but then I think any human body would generate far more speed-sucking drag than a wheelset. But even if I consider the effect “maintaining speed without power” is perceptible enough to feel bizarre, is it sustained long enough to do anything? I mean, I wonder can he stop pedaling and maintain speed long enough to get recovery? Does the effect outweigh the benefits of being quick to pedal-up? I kind of wonder if he’s maybe he’s feeling the combined effect of light weight and poor aerodynamics compared to his other wheels, and he just has to work harder to keep the tubs at speed?

Abe_Froman

Basically, he’s imagining things. Human perception of things is generally not particularly close to actual reality. To think a few hundred grams difference in rotating weight(hell.. a couple pounds) is going to be noticeable in terms of speed variation throughout an individual pedal stroke is ridiculous.

Hunterdog

This thread really has me confused. I recently purchased a 2018 Roubaix Expert fitted with Roval SLX 24 disc wheels. I have only ridden them a couple of hundred miles (damn Central New York weather) and think they are "okay". My old bike had Mavik Krysium Elites (rim brake) that, I think, seemed to handle better, certainly did in the wind. Are commentators saying that it's all in my head and there is no difference between a set of Zipp 303s and a set of inexpensive alloys?

chaadster

No.

Adonis72

Like most things a wheel upgrade is subjective. It depends on what you are looking for and how crappy your stock wheels are. I think good tires make a huge difference for $100 or less. If its just a training bike then for me a wheel upgrade wouldn't be a worthwhile upgrade until they need replacement.

kbarch

I wouldn't be so sure. You know how many molecules - in parts per million - it takes to be able to detect a difference in the taste or smell of something? Why shouldn't our kinesthetic sense be as refined when it comes to mass and velocity when we are trying to move our bikes as effectively as possible? I'm not suggesting that our sense of these things corresponds directly with their actual magnitude, or that we always know exactly what it is we are sensing, only that we can sense very small differences if they are important and we aren't too distracted. If you're riding with someone who's hammering away in front and it takes five watts more than your FTP just to hold his wheel, you know you'd appreciate some gear that could save you 5-10 watts.

Hunterdog

Thanks for the prompt and concise response. It was very illuminating as the usefulness of the board.

Seattle Forrest

But @chaadster didn't say within a pedal stroke, he even asked if it's long enough to recover from a serious effort.

I can tell the difference in weight between my metal and silicone watch bands. I can absolutely tell the difference in swing weight between my nice ski poles that I broke in a crash and the crappy replacements I got for them. I test rode a set of nice wheels against a set of decent ones and had no trouble feeling an immediate difference.

Abe_Froman

I was referring specifically to the previous comment about the flywheel effect of wheels. I guess I inadvertantly inserted the pedal stroke comment.

But yea I still call BS. I dont believe anyone can tell the difference in flywheel effect due to weight differences of road wheels.

chaadster

Well said. Perhaps the bridge between what you are saying and what Abe Froman is saying is a matter of duration, intensity, and experience.

To Abe's point, if you were given a bike and instructed to ride it 500m out and 500m back on a flat road at an easy pace, you'd probably not be able to determine wheel weight in any meaningful way. If I understand your point, though, if someone had a bike and two wheelsets, both with the same tire and one substantially heavier than the other, and had the opportunity to live with and do their rides with them, that through the course of riding up and down, and hard and slow, and through turns and across good pavement and bad, that they would likely, in time, be able to discern the differences.

It is in the experience and range of effort that we develop that kinesthetic sense, I think.

chaadster

Exactly. I don't think so either (as you rightly understood from my earlier post). We can feel other effects related to wheel weight, though.

chaadster

Great analogies to the point of kinesthetic sensitivity!

Abe_Froman

Of course, I’m not saying weight doesnt matter...I’m saying any discussion about wheels acting as a flyweight is pretty off base from the beginning.

Seattle Forrest

Ok, I'll buy that we probably can't perceive the difference in flywheel effect between two road wheelsets. I think people can feel the difference between wheels, but if we're only talking about flywheel, I don't think that's what anybody is feeling.

kbarch

Thanks. Absolutely, one would have to compare in order to be able to discern the effect. I think when/where we most develop these sensitivities is on rolling courses - when we have opportunities to take brief advantage of the terrain to do a little sprint, push ourselves over an easing crest, stuff like that - short efforts that are really about change in speed. Of course one could expect to develop the same in racing. It's unlikely that one would develop a sensitivity to it if the only accelerations one experienced were when casually getting underway from a stop, or if one spent over 95% of ones rides cruising at more or less constant speeds.

Bah Humbug

I even can't stand writing with a pen with the cap fully off instead of on the heel of the pen; it's unbalanced, and not by a little. There are other examples not coming to mind now.

Of course, that's a different question from speed; I don't type faster with the cap on (or off). And heck, different training suits in the pool have hugely different feels, and do affect speed.

Hiro11

No, it really isn't straight forward. As subsequent conversation has indicated, there's a long standing debate about the effects of wheel weight. The effects of increasing wheel weight are myriad. The more I looked into this, the more confused I got.

For example:
Cycling myths busted: Da Vinci, dead frames, skinny tyres, rotating weight and more | road.cc

Technical FAQ: Does wheel weight matter? | VeloNews.com

So defining the effects is one issue here. Secondly, you've got the issue of the size of any possible effects. The difference between a "heavy" rear wheel and a "light" rear wheel might be a 200g-300g, normalizing for tires. It's far from settled that the effect of that small a difference actually matters. You've also got the issue of where in the wheel you have a weight variance: in the hub or in the rim. Etc.

As I don't race, I gave up worrying about this. What matters to me more is quality (fit and finish, freehub engagement etc), price and long-term reliability. Weight is a distant fourth when it comes to wheels. Usually good quality stuff is reasonably light as well, but that's a second order effect for me. This is solely MY OPINION, YMMV.

RPK79

I think some ultralight headset spacers are the most bang for your buck upgrade available.

mstateglfr 

Ok, ill give a synopsis since there seems to be confusion between us.

- you said you are skeptical that rotational weight exists/matters.

- i snarkily responded by saying you question physics. I then stats heavier wheels are slower to get up to speed and that more mass means more effort to get a bike(the wheels) up to speed.

- you then linked a Zinn article to show physics isnt straigh forward, even though it supports my comments. You then question how much of a difference increased rotstional weight matters.



Ok, so- Zinn states that heavier wheels take longer to get up to speed, which is what i said. He also stated more rotational weight slows the acceleration.
Zinn agrees with physics.

As for how much of a difference a lighter wheelset makes, sure that can be discussed and opinions formed.
But your skepticism of rotational weight mattering is unfounded oer Zinn and physics. Trust its real. Whether it matters to you or not, well thats individual and for each of us to decide.

Sullalto

I'm in the rainforest west of seattle. Looking at last year's rain totals in iches right now: April-September: 16 inches of rain. The rest of the year, each and every single month was at 22 inches.

So summer isn't so bad. This winter has been drier than expected, too.

edit: Actually I just checked, November had 33.8" inches of rain. I, uh, use fenders. If I could find XXL shoe covers, I'd use those too.

Sullalto

But can you tell the difference in true double blind tests?

Time and time again, the vast majority of people can't in all sorts of tests. To borrow a phrase from another hobby, 'the butt dyno is poorly calibrated.'.

mercator

I doubt very much if I could detect a difference between my heavy and light wheels using the flywheel effect, but I have no problem feeling the difference when I stand and hammer, particularly at a reasonable speed.
I guess I'm sensing the gyroscopic effect as the heavier wheels require more effort to rock the bike from side to side. The difference in weight between my heaviest and lightest wheelsets is about 600 grams, so I don't think I'm claiming any sort of special sensitivity, but I'm fairly confident I'd pass a double blind test.

chaadster

Holy smokes, that's over 220 inches of rain annually! That's, like, inconceivable to me!

GuitarBob

That's ~18 years worth of rain here in the Sonoran Desert (~12"/yr).

Sullalto

It's like...~170" normally. Summer is dry. But yeah. They aren't kidding when they say rainforest. Actually it's been a dry year. We might not hit 150 unless the 2nd half of December is especially wet.

I work in a hotel. I very regularly get people asking for discounts because of the 'bad weather'.
"Excuse me, bad weather?"
"It's been raining our entire stay. And it's ruined my weekend. What can you do for me?"
Uh, nothing. It rains. Get over it. We sell umbrellas and rain gear in the gift shop. Deal. I only give discounts for the hotel's mistakes. And we don't control the weather. Now pay me.