Trakhak

Back in the '80's, I used very light tubulars on Hi-E's lightest wheelset - low spoke count, scary light aluminum rim with thin aluminum reinforcements riveted in place at each spoke hole, ultra-light Hi-E hubs, tiny front wheel "quick release" (aluminum skewer with cone-shaped aluminum nuts, one fixed, the other with a teeny tiny post sticking out to serve as a wing nut). I used those wheels mostly for time trials - I was uneasy about using them for road races or crits.

And when I say I used them, I mean I used them for maybe 3 or 4 months. With rims and tires that light, they had an unsettling feel compared to my other wheels with, e.g., Mavic GP4 rims. Must have been a consequence of the reduced flywheel effect: every pedal stroke felt as if I needed to do a miniature acceleration compared to the smoother pedaling feel of the GP4 wheels.

Needless to say, I finally sold them. I hope the next guy wasn't as sensitive to the pulsing effect as I was.

I once asked a successful local racer (he'd won several National Championship medals on the track and countless lower-level road races and crits over many years) how he decided which of his bikes to use for a given race. He said, "If it's a race I don't think I have much of a chance of winning, I'll use my lightest bike. If it's a race suited to me, I'll use my most reliable bike."

Jughed

When I go between my 2300g stock wheelset and my 1500g CF wheelset - I can feel, in a big way the difference in acceleration and ease of pedaling. The bike is actually transformed into a different machine.

That weight delta may fall outside of what you are calling comparable, and 100g more or less may not make a dramatic difference.

Trakhak

The guys who post in BF who actually do science on such topics have shown that the effect of the difference between lighter and heavier wheels in the force required for acceleration might be perceptible but borders on the trivial, even in criterium racing. Remember, what you gain in reduced force needed for acceleration you lose in reduced momentum. I disliked my ultra-light wheelset for exactly that reason. I didn't like the pulsing feel through the pedals.

elcruxio

To be fair, weight reduction on the wheels is still a weight reduction. 800g may be a small change in bike weight and miniscule in system weight, but it might be noticeable, though not really any faster. When lifting up two bikes one of which is 800g lighter, the difference in weight can be felt. Though when riding them, well it's not as noticeable.

Placebo is also has a far bigger impact on how we feel things than many people would like to give credit for.

squirtdad

if you buy into the Jan Heine testing....rolling resistance does not equal fastest look at https://www.renehersecycles.com/tire...-vs-real-road/ https://www.renehersecycles.com/why-...re-not-slower/ https://www.renehersecycles.com/perf...ow-riders-too/

as to lightweight wheels , my personal impression is it is not one single factor but all elements of a wheel. tire, tire type, tube (or not), tube type, rim, spokes with overall weight being least important
Point in case I was given an 84 team miyata by a neighbor....took it out and was not impressed with the ride, handling performance at all. then looked at the wheels, dura ace with MA40 clinchers, tires were heavy 25 bontragers with inner tubes that were as thick and heavy as the tire. Swapping out for conti lite tubes and 28 mm gravel kings made the ride, handling, comfort really good. Putting a set of wheelsmith built wheels (mavic 330 rims, double buttes spokes) and 25 mm challenge elite tubulars made the bike feel like it wanted to just go....improved handling, ride and everything another level above the gravel kings. I went in with no expecations, so pretty sure this was a real result....

Maelochs

I have done back-to-back testing on this topic--lighter rotating mass---and can say with perfect honesty and accuracy that the lighter wheels and tires (I tried three combinations) FEEL faster.

Much more fun to ride, too .... However, over the length of a ride, there is really no difference. The tires/wheels feel faster for the briefest moments of acceleration, the first few pedal strokes, and then they feel the same, and in terms of overall time and speed over a ride .... basically noise. Any difference could be offset by a momentary gust of wind, if I slowed to sneeze, whatever. No faster over the length of ride ... but the perceived difference is huge.

I worked my way through all the math the various mathematicians and engineers posted here. It was clearly demonstrated that rotating mass, static mass, Both pale to aero gain except on steep long climbs, and that rotating versus static mass are essentially equal loads .... the difference is too small to be meaningful.

But ... i don't ride as a scientist, I ride as a rider, and I will accept a little aero loss because the light bike feels more fun to me, and I am not racing. To me, 800 grams is a Huge difference in wheel/tire weight, perceptually--I know because i tested it. And as you say .... makes no real difference in overall speed. But I don't ride to generate data, I ride to generate dopamine and endorphins and such.

I guess for me, bicycling is a mental sport.

PeteHski

I’m sure you can feel a difference, but the difference in actual acceleration is trivial. Your 800g saving does gain you a few seconds up a steady climb, just like saving 800g on static weight, but that’s pretty much all you get in terms of performance gain. But I agree it feels lighter to ride and that is worth something I guess. Are you running the same tyres on these 2 wheel sets?

Dave Mayer

Lighter wheels are the most transformative change one can make to a bike. I think a lot of the naysayers here are used to riding on cargo bikes with farm tractor wheels, and have never experienced the life-altering performance boost of a set of 1,200- gram tubulars.

Since performance group riding involves almost nonstop surges & accelerations, the static metrics here are useless. There is a reason why top riders are willing to pay out of their own pockets for super light wheels, even if they are sponsored. And also ditch your stock tubeless clinchers and use relabeled/rebranded tubulars on race day.

Jughed

Same tires. GP5000's.

And I agree - over a long steady climb or long haul on the flats/in a group ride, not much difference felt.

Initial acceleration - bike feels much better. Accelerations on our short punchy climbs, bike seems to just jump.

But we're talking close to a 40% reduction in rotating weight (and yes - the wheels have better bearings, so that helps) - the stock wheels were bricks.

Trakhak

Perhaps you missed my earlier post (for perspective, I raced in the '60's through the '80's and bought lots of high-end equipment during those years, which I imagine means I have a broader perspective on this topic than many here):


Back in the '80's, I used very light tubulars on Hi-E's lightest wheelset - low spoke count, scary light aluminum rim with thin aluminum reinforcements riveted in place at each spoke hole, ultra-light Hi-E hubs, tiny front wheel "quick release" (aluminum skewer with cone-shaped aluminum nuts, one fixed, the other with a teeny tiny post sticking out to serve as a wing nut). I used those wheels mostly for time trials - I was uneasy about using them for road races or crits.

And when I say I used them, I mean I used them for maybe 3 or 4 months. With rims and tires that light, they had an unsettling feel compared to my other wheels with, e.g., Mavic GP4 rims. Must have been a consequence of the reduced flywheel effect: every pedal stroke felt as if I needed to do a miniature acceleration compared to the smoother pedaling feel of the GP4 wheels.

Needless to say, I finally sold them. I hope the next guy wasn't as sensitive to the pulsing effect as I was.

I once asked a successful local racer (he'd won several National Championship medals on the track and countless lower-level road races and crits over many years) how he decided which of his bikes to use for a given race. He said, "If it's a race I don't think I have much of a chance of winning, I'll use my lightest bike. If it's a race suited to me, I'll use my most reliable bike."

elcruxio

I'm assuming you have the math to back up that performance boost. No..? Ok then.

I was about to question some of these quite humorous claims but instead I'll just state that this was the most turbid set* I've seen on this thread so far

*direct translation of a saying where I'm from.

PeteHski

You sound like a shill for ultra-lightweight wheels and tubulars 😂

Nobody is using static metrics when calculating the effect of rotating weight on acceleration.

tomato coupe

It doesn’t matter how many times you repeat a falsehood — it still remains a falsehood.

Eric F 

I hope you're sharing your profound knowledge with World Tour team managers. They seem to be lost in an "aero is actually faster" fantasyland. Idiots, obviously. Or, maybe they just don't do the same hard group rides that you do.

EDIT: Here's the mountain-top finish of today's stage of the Volta ao Algarve, featuring some of the best bike racers in the world. If super-light, non-aero tubulars are so much of an advantage, why are ALL of these guys on (what appears to be) 40-50mm aero wheels?

Eric F 

Here's my current tractor...


Here's my old tractor that I won a bunch of races on...


I've ridden lightweight tubulars, heavy aero wheels, and a bunch of stuff in the middle. They feel different when you put down power. As a sprinter, I was unnerved by the feel of really light wheels. It felt like I didn't have a foundation to work against when winding up to 40+mph at the end of a race. For wheels on the heavy end of the spectrum, the flywheel effect was vivid at high speeds. Most races, I preferred a moderate-weight wheel. These days, I still do. I really like modern blend of pretty light and pretty aero at the same time, such as the Enve 3.4s on my Storck.

Your statements come across as you being the only person here who has ridden a bike fast. You're not. Not at all.

PeteHski

40% sounds like a lot and you can certainly feel it. But unfortunately it doesn’t gain you any significant performance advantage in acceleration. Spinning up a bike wheel requires relatively little effort. You can easily spin up your back wheel on a bike stand and stop it dead again with the slightest dab of the brake.

I’ve posted it numerous times before, but it’s worth looking at the study Swiss Side did comparing the effects of aero, weight and rotating wheel weight on performance over crit, hill climb and flat TT courses. They used a dynamic model and real course data. The crit course was the most interesting, because that’s where you might expect wheel acceleration to be significant, but it was worth next to nothing over the entire course and totally dwarfed by the aero component, which was worth a solid chunk of time. Only the hill climb showed any advantage for the lighter wheels and even that was marginal.

79pmooney

I would tweak the mix to go lighter on the wheels and rubber since I am a skinny climber (sorta a Sepp Kuss type with much less of an engine and no fast twitch muscles). Those 40 mph sprints. I was never there at my racing past in my 20s as a fine tuned machine. But lighter wheels to jump on that wheel going by or just saving a few ounces of effort on each corner was a Godsend. Or doing an acceleration on the steepest part of a hill to "break legs". (About the only place I could have fun.) And those light wheels being too flexy for my immense power? Not happening, sadly. Now, I was racing long before aero anything. That would change things, but if I wanted to play to my strengths, not much.

Sierra_rider

I think he may just be an AI bot. However, this one can't formulate posts based on the entire collective knowledge of the internet. Instead, the information is limited to whatever is on the C&V sub-forum.

Jughed

I will watch that video later...

And you make a good point, my wheels are not only 40% lighter, they are also 40mm deep semi aero wheels - probably feeling both situations.

Whatever the reasons - the bike just feels like a different animal with the wheelset.

Eric F 

This guy isn't C&V, but definitely lives inside a little box, and is trying to convince everyone that his box is superior.

Eric F 

Today, Sepp Kuss is racing to hilltops on aero wheels.

PeteHski

+1
My current tractor wheels are DT Swiss ERC 1400 (1477g)

If I get dropped from a group ride, it isn’t because my wheels weigh more than 1200g or because I’m not on tubulars.

smd4

Some people here would demand math to prove the superiority of a Stradivarius.

PeteHski

Yep, Reserve 40/44 wheels on 28c tubeless tyres. These teams are clueless.

BTinNYC 

Wow! That is very surprising!
Based on my feeeeelings and the feel of different wheelsets, I thought the difference in rotating weight made a huge overall difference. I believe the physics that PeteHski discusses. But the feel of light wheels must be aligned with @Jughed 's thinking, that the first pedal strokes give that feeling. I ride so much in the Land of a Zillion Stop Signs, maybe all the starting from zero colors my thinking.

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