How much does rotating wheel weight matter?

[presta]

go-faster-hoops to get up that hill 1% faster

Going uphill, weight saved off the rims won't be any better that the same weight saved anywhere else, you only get additional benefit from the moment of inertia whilst accelerating.

 

[wafter]

I don't know but I can tell the difference between 32h traditional training wheels vs rs10 and vs DA c24 /c35 / c50

You have to be particularly daft to argue no difference between them.

But you wouldn't want to commute or tour on DA c24.

Nor would a century in 6hrs on 32h / marathons on a warm summer's day make for pleasant ride.

Indeed - I'm not questioning that the difference is tangible; more the value of chasing such marginal gains in terms of the associated financial cost and the real-world worth to the average cyclist.

Unless you're competing against other cyclists the only person to beat is yourself; and in that case where's the legitimacy in buying your way to victory?

Kings new clothes comes to mind. You're right, keeps lots of cycle component companies in business.

Absolutely -manufactured demand springs to mind.

Not too long ago there was a lad on the Trek sub-reddit who claimed to have changed his standard wheels for some lighter ones (can't remember what) and gained almost 3mph on his average speed. Amazing!

I'd love to see that claim assessed with scientific rigour; I suspect the only way that could be true under objective conditions is if the route is festooned with lots of accelerations / decelerations..

 

[rydabent]

It is called rotational inertia. It greatly affects acceleration.

 

[Jameshow]

Indeed - I'm not questioning that the difference is tangible; more the value of chasing such marginal gains in terms of the associated financial cost and the real-world worth to the average cyclist.

Unless you're competing against other cyclists the only person to beat is yourself; and in that case where's the legitimacy in buying your way to victory?


Absolutely -manufactured demand springs to mind.


I'd love to see that claim assessed with scientific rigour; I suspect the only way that could be true under objective conditions is if the route is festooned with lots of accelerations / decelerations..

I can believe that to go from stock wheels to lightweight / aero wheels might feel like that 1mph per level of change imho.

 

[wafter]

I can believe that to go from stock wheels to lightweight / aero wheels might feel like that 1mph per level of change imho.

Perhaps; but again cost, real world benefit etc..

 

[Jameshow]

Perhaps; but again cost, real world benefit etc..

I guess that depends on the level of enjoyment you get from cycling. Which on different days is different even to me!

A blast round the new forest on the high mod road bike and a cider is lovely.

So is a century audax or sportive on a endurance carbon or ti.

So is a weekend camping on the steel touring bike.

right job, right bike, right wheels.....

 

[rogerzilla]

Having ridden M+ tyres for many thousands of miles, yes, you feel the weight when starting off, especially starting off quickly, e.g. from traffic lights. Once up to speed, you don't notice as (at least in the 26 x 1.35 size I had) they roll very well.

 

[Milzy]

Can't be arsed to watch the vid but I've done the calcs in the past. From an acceleration perspective rotating mass is disproportionately influential, as you have to accelerate it both linearly and angularly.. so a given mass saved from the rims will have a greater effect on acceleration than the same mass removed from the frame, for example.

As the chap at the beginning of the vid states, input energy isn't lost, it's stored - lighter wheels will accelerate faster for a given energy input, but also decelerate faster. This matters on a course with lots of speed changes (so something tight and twisty) and of course if you're actually concerned with speed. On something like a tourer where you're coasting a lot and anticipating stops in advance it's less of an issue.

Wheel mass also affects gyroscopic stability, with less rotating mass potentially making the bike feel more responsive but also less stable..

That’s why on the Nero show Chris & Jesse tried shallow wheels for their crit racing because of the speed changes and turns. I don’t think they felt much difference tbh.

 

[Drago]

It matters a lot. A pound off the rims/tyres is worth three or four off the rest of the bike.

 

[DogmaStu]

From my own personal experience with modern wheel-set's in the last few years:

I have Hunt 32 UD's on my Wilier road bike which are reasonably shallow and that bike does accelerate noticeably quicker than my other two road bikes but maintaining anything above 25 - 30 mph is also noticeably more watt-consuming than with my Zipp 404's. It's my go-to bike for very windy conditions and long climbing days. It's light and agile.

On my Trek road bike I have a pair of Zipp 404's and at 58mm they are lovely for sprinting with and maintaining higher averages. For sprinting you want to be able to maintain the speed you build up to for as long as possible and circa 60mm or thereabouts is the sweet spot depth for acceleration vs holding speed. My Pinarello road bike has a choice of Dura Ace C50's and Zipp 454's.

So...there is a clear and noticeable difference that the average non-pro 55 yr old can appreciate between a 32mm and 58mm deep wheel-set where there is only about 200g weight difference. This isn't marketing, this is User-verified fact.

How much that difference means to the individual though very much depends upon what type of cycling they do. Obviously, Club and racing cyclists will appreciate it whereas a Commuter or Tourer may not given their bikes typically have other design priorities and speed isn't a thing as such.

The difference between the C50's and 454's is more subtle. There we are only talking about 8mm in depth difference so the advantages of the 454 are that their wavy design from shallower to deeper allows them to have a mix of characteristics and behave like a much shallower rim - you effectively get a 40-45mm wheel-set's acceleration, weight and cross-wind handling with a 58mm wheel-set's ability to hold speed and save watts. Again, an average cyclist can notice the difference but it is only at speed and whether that difference is worth it depends upon needs and goals.

Many for whom these differences won't matter much, if at all, and who have never actually ridden 1000's of miles in trying them, like to think that it is all marketing nonsense and only relevant to Pro's where marginal gains can make a more significant difference. They are however, wrong. Average cyclists can feel the difference and it can have a noticeable effect upon how a bike handles and how much they enjoy riding it for a given course.

 

[simongt]

All I understand are the basics of physics; the bigger the wheel, the greater the mass that had to be overcome in accelerating and decelerating.
That's why I can initially get away from the lights on my Brommy quicker than most other cyclists - !

 

[Milzy]

From my own personal experience with modern wheel-set's in the last few years:

I have Hunt 32 UD's on my Wilier road bike which are reasonably shallow and that bike does accelerate noticeably quicker than my other two road bikes but maintaining anything above 25 - 30 mph is also noticeably more watt-consuming than with my Zipp 404's. It's my go-to bike for very windy conditions and long climbing days. It's light and agile.

On my Trek road bike I have a pair of Zipp 404's and at 58mm they are lovely for sprinting with and maintaining higher averages. For sprinting you want to be able to maintain the speed you build up to for as long as possible and circa 60mm or thereabouts is the sweet spot depth for acceleration vs holding speed. My Pinarello road bike has a choice of Dura Ace C50's and Zipp 454's.

So...there is a clear and noticeable difference that the average non-pro 55 yr old can appreciate between a 32mm and 58mm deep wheel-set where there is only about 200g weight difference. This isn't marketing, this is User-verified fact.

How much that difference means to the individual though very much depends upon what type of cycling they do. Obviously, Club and racing cyclists will appreciate it whereas a Commuter or Tourer may not given their bikes typically have other design priorities and speed isn't a thing as such.

The difference between the C50's and 454's is more subtle. There we are only talking about 8mm in depth difference so the advantages of the 454 are that their wavy design from shallower to deeper allows them to have a mix of characteristics and behave like a much shallower rim - you effectively get a 40-45mm wheel-set's acceleration, weight and cross-wind handling with a 58mm wheel-set's ability to hold speed and save watts. Again, an average cyclist can notice the difference but it is only at speed and whether that difference is worth it depends upon needs and goals.

Many for whom these differences won't matter much, if at all, and who have never actually ridden 1000's of miles in trying them, like to think that it is all marketing nonsense and only relevant to Pro's where marginal gains can make a more significant difference. They are however, wrong. Average cyclists can feel the difference and it can have a noticeable effect upon how a bike handles and how much they enjoy riding it for a given course.

You’ve sold me, my next pair will be super deep.

 

[Ming the Merciless]

I can believe that to go from stock wheels to lightweight / aero wheels might feel like that 1mph per level of change imho.

You can get that from tyres no wheel change required

 

[rydabent]

A little true life adventure here. My first recumbent a RANS Tailwind had 20 inch wheels. When a light turned green, I was way ahead of everyone, including cars.

 

[Mr Celine]

I've never seen anyone claim lighter rims made any difference except when climbing.

If you sit down and spin your way up hills with a high cadence it shouldn't matter either but what happens if you stamp on the pedals and throw the bike from side to side?

In that scenario the plane of rotation of the wheels is constantly changing and this requires an input of energy to overcome the inertia of the wheels. The energy required to do this is lost - the bike doesn't spring back upright if the rider does nothing. A wheel with a lighter rim and tyre has a lower moment of inertia than a wheel with a heavier rim, so less energy is required on the climb. (This may be small or even negligible and I CBA working it out even if I could remember how to.)