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He's said lighter wheels feel faster, no evidence they are faster.
I say that too...
Rotating mass in bicycle wheels has an insignificant effect, however often the myth is repeated.
If anyone can show it makes a difference, rather than claiming it does, I'm open to having my opinion changed.
TBF crikey me sober chum, so does non-rotating weight.
So in your world, power to weight ratio and rotational mass make no difference to speed or handling.
Hmmm, ok then....
Although this is only partially relevant (as previously mentioned, roadies tend to maintain a more constant pace, what with not having to deal with a plethora of gnar, switchbacks, locked wheels and localized rock and root shaped undulation) despite all your claims to the contrary, this evidence will do me, all the more so since you referenced it in your defence earlier:
[url= http://www.training4cyclists.com/how-much-time-does-extra-weight-cost-on-alpe-dhuez/ ]Duh!! Heavy Wheels Make You Slow [/url]
Stop mis quoting me.
What is your point anyway? You've still not made one.
jivehoneyjive - MemberDuh!! Heavy Wheels Make You Slow
To be fair, filling your tyres with water could have other effects than just adding weight, fluid and gas react differently.
He's said lighter wheels feel faster, no evidence they are faster.I say that too...
Basic physics say they accelerate and decelerate faster Al, leave the science to the adults.
Interestingly enough, we have done this before...http://singletrackworld.com/forum/topic/rotating-weight-does-it-make-any-difference-and-why
Thanks for that link - I checked and appear to have said it all on that thread already, so no point repeating myself. Anybody arguing that light wheels "transform a bike" please go and read my comments on that thread and explain why crikey and I are wrong.
The interesting thing looking back at that thread is that cynic-al appears to have had an epiphany since then, and now agrees with us.
Basic physics say they accelerate and decelerate faster Al, leave the science to the adults.
Basic science says the difference they make to acceleration and deceleration is so small as to be undetectable by an instrument as crude as the human body.
A lot of the research into mass V inertia, power to weight ratio and overall performance has been done in motorsport for years.
Basically, you can get the science perfect, have the optimum package, and still not see any performance gains.
Because at the end of the day, it's the rider/driver that controls the delivery of the power/control.
This variable makes it almost impossible to ascertain whether a weight saving at any point of a vehicle will definately produce a performance advantage during any race or event.(lab results count for jack shit on the track)
You can provide as much data as you like to prove as many points as you want, but human error will nullify them all.
My advice is to save your money, and ride more to develop skills, train harder to build strength, and reap the rewards from hard graft instead of trying to buy performance gains.
The miniscule performance gains from "works" kit only really applies to top athletes, as the equipment is designed around [/u]their[u] needs, not ours.
We just get sold the positive attributes of tech that helps athletes so far removed from "club" racers, it's as good as useless to the majority of us.
A lighter, more responsive chassis can't deliver if the power plant isn't up to the job. So work on the engine first, then consider tweeking the peripherals to fine tune performance.
You know it makes sense, he who dares!!
I'm really unsure how spending £200 can save you 500g anywhere other than wheels
Not even by spending that on some exercise coaching and nutitional advice?
Dougie, skywalker et al, if you're going in with the childish insults, how about actually reading and perhaps even trying to understand my point?
Presuming you are capable of that, of course.
Aracer...I'd hope we're all capable of admitting when we get it wrong...
When I bought my Hope wheelset they were not only lighter, they roll better and have lasted forever. Good wheels are an investment worth paying for. Some people have mentioned saving overall weight. My endura singletrack shorts weigh 500g. Can't say I ride any quicker without them just thought id mention it.
You know when you wish you hadn't started something?
Yeah that 😳 😕
😆
Hope/Stan's wheels made me faster. Prove otherwise.
My endura singletrack shorts weigh 500g. Can't say I ride any quicker without them just thought id mention it.
Sadly for me it's the kilo and a bit cradled at the front of my shorts that slows me down.............. 😛
A few people get out the wrong side of the bed this morning?
Everyone can see you started the childish insults Al, likely because you are unable to explain your thinking. Looking at the other thread its obvious that you really don't know what to believe 🙄
The way I see it in lamens terms is the bike will accelerate faster, ie be snappier off the mark and handle better due to the lower lower weight, but it's not going to add any significant speed, especially with the nature of off road riding
Dug, if you can't understand my point, or that I've read the evidence and changed my position (I can accept you're incapable of the former at least), should I care? Cos I don't.
To paraphrase a legend: I'm right, and you know I am, best leave it.
Blimey! Having just fitted hope hoops / crest / nobby nics and saved 760g over the existing wheel/tyre set up I would suggest that I can definitely feel a difference in the way the bike rides. As to whether that translates to 'faster'; I'm not one for higher level maths, but given that the only power available is human, any small improvements to the mechanical elements must help. Acceleration has been mentioned, but gyroscopic effect will also be diminished by moving to a lighter wheelset. Just try holding your old (heavy) front wheel at arms length with it spinning, and tilt it from the vertical toward the horizontal. Then compare it with your new (lighter set). Then consider how many times you initiate that tilting action on the trail. Over a decent distance, I think that the slightly lower fatigue-inducing effects of both accelerating, decelerating and compensating for gyroscopic effect probably leaves the rider with lighter wheels (bike) in a better physical state, therefore able to go faster further with his (her) given limited resources. (throws two cents on the bandwagon before it rolls over him..)
Start thinking about the change in weight from the perspective of total weight; bike+rider+kit...
..you have to accelerate all of it, so a reduction of 760 grammes from ?100 kgs...
Ignoring the discussion if the effect of saving rotating weight makes a significant difference or not...
.......................................................................................................................................................................................
...and even the article referred to by crikey mentioned that rotational weight becomes more significant under acceleration. Off-roaders tend to accelerate quite a bit compared to roadies, right?! So what might not be significant in some circumstances might be (more) significant for the OP's endurance race. While at the same time the wiki article stated that the measurable difference is not huge and can hardly be felt. 😐
So - really - make of it what you want or what you do indeed [i]feel[/i]!
.......................................................................................................................................................................................
...so ignoring that discussion for a moment - what I really don't get are these repeated remarks on 'rather loosing body weight and getting fit than spending money on parts'. Yes?! So what? Is this some sort of advisory board for naughty bikers? Bike watchers? Wouldn't we and shouldn't we all lose a few pounds? But was it the question? No, it wasn't!
You could also always argue that one should just race for fun, enjoy the camaraderie and not worry about weight advantages at all...
...but that wasn't the actual question! 🙂
.......................................................................................................................................................................................
Back to the actual topic: I can feel it! I am a believer! And I am so so happy with my light-ish wheels (and tyres and tubes) as a result of this. It makes me fly! 😛
That's the whole point though - it is only 760g but given the frequency of the accelerations etc, any saving is going to make some positive difference over the course of an endurance race - which I believe was where all this came in? 🙂
Ultimately what's more fun, buying spangly new bike bits or going on a diet?
Exactly!
Crikey (and all other "disbelievers" for that matter),
1.
which scenario would you personally prefer:
a) (crikey minus 1 kilo) plus crikey's bike
b) crikey plus (crikey's bike minus 1 kilo)
c) "bah, it doesn't make a significant difference anyway, I don't want any weight saving at all"
2.
Should you prefer a) I'd be curious to understand why.
Should you also prefer scenario b) where would you want the weight to be saved?
If you go for c) you'll probably state that it's a function of weight loss divided by money loss times training time in relation to grmpfmpfblah...
Personally - and given the financial resources at the time - I would always go for b) (hock plus (hock's bike minus 1 kilo)) because it [i]feels[/i] like a huge difference when my bike is suddenly almost 10% lighter while it doesn't [i]feel[/i] like a huge difference when I am 1.2% lighter.
I mean, am I the only one who sees a difference in the unit that is being moved around (the bike) and the unit that moves around (me). A light bike just [i]feels[/i] great!
And I'd still argue the same principle is true for the rotational mass: there are units that just need to be moved along (e.g. the frame) and there are units which have to be spun up AND moved along.
We could also open a thread on unsuspended vs. suspended weight by the way... 🙂
Read [url= http://www.pinkbike.com/news/Santa-Cruz-and-Enve-Carbon-Interbike-2011.html ]this[/url] article, nothing scientific.
And this about them switching to carbon rims
Roskopp cites multiple benefits of the carbon hoops for the team, including carbon fibre’s memory – its ability to bounce back from a bend rather than deform – the material's help in resisting flats, wheel stiffness and lower rotating weight.
Now ask yourself why they are trying to reduce weight on a downhill bike.
Si - go & see Darren & Jonathan @ Strada. FRM/BOR rims are in.
Let's leave my suspenders out of it eh..? 😯
I put lighter wheels on a bike some time ago and I 'FELT' a huge difference.....
So I don't care as to the actual proved difference, (which I don't think is quantifiable in feel terms anyway) I was very pleased with the result. 🙂
After all look at all the different bikes and components available, it isn't possible to use formulae to see how each rides !
We could also open a thread on unsuspended vs. suspended weight by the way...
There is no need, I have already provided a link with a formula showing that a pound on the wheels equals two pound on the frame.
Edit: quick question
Two riders, same terrain, wind speed, identical fitness, body mass, muscle mass etc
One has a bike that weighs 30lbs
The other has a bike weighing 25lbs
Who will be quicker over 10 miles?
Hi skywalker,
my "suspended/unsuspended" was more about handling than efficiency. That's why I suggested a new thread. While dreading another outrage. 😕
Regarding your quick question:
I don't think that - at least initially - the "insignificant" brigade doubted the effect of weight savings as such. The main point was whether it's significantly beneficial to save a given weight at the wheels or e.g. the frame, wasn't it?
So high-jacking your quick question - if I may - it could come down to:
Two MTB riders, same terrain, i.e. quite technical XC course with up/down and technical passages, identical fitness, body mass, muscle mass etc
Both bikes weigh 25lbs and have the same spec, apart from
- Bike A has a 1.5kg frame (though same stiffness etc.) and 2.0kg wheel set
- Bike B has a 2.0kg frame and a 1.5kg wheel set (again same stiffness etc.)
Who will be quicker over 10 miles?
What are the 10 miles and how are they ridden? Of course the lighter bike will be faster, what is under disagreement is by how much.
Read this article, nothing scientific.
And this about them switching to carbon rims
If it's not scientific it's not worth reading.
Can anyone explain the science of fun to me?
I'd hope we're all capable of admitting when we get it wrong...
Congratulations - it's just that it's rare enough on STW for it to be remarkable - especially for somebody who gets so passionate about the viewpoint they hold as you.
For all those asking "which is faster" - well clearly all other things being equal, the lighter bike is, we're just arguing about how significant that is in a world where everything isn't equal. I should point out that I have a lighter full-sus than all but a handful on here, but the most significant advantages to that are when I'm carrying not riding (which in a former life I used to do quite a bit of in races).
No idea about the science but I noticed a significant difference loosing about 500g from one wheelset to another.
I'll liken it to the feeling when you've ridden a muddy trail and some mud builds on the side of the tyre (the stuff on the tread has flung off so nothing that would impact on rolling resistance). You hit some hard pack and feel that extra rotating mass in terms of slower steering and acceleration and it feels harder work especially up hill.
Erm, guys, this is about 500g on bike wheels. Aren't we over reacting?
You new here?
You're not like this on the other channel [img] 
[/img].
Lizzy just saw this and was like "what on earth are they arguing about, has someone had a fight?".
I can be like this there if you like ❓
Is Lizzie new to the internet?
Well I can feel a difference between heavy and light tyres, tell me clever STW folk that know all.....is it in my head?
no one is saying that, try reading the thread.
Rotating mass in bicycle wheels has an insignificant effect, however often the myth is repeated.
If anyone can show it makes a difference, rather than claiming it does, I'm open to having my opinion changed.
cynic-al - Member
TBF crikey me sober chum, so does non-rotating weight.
To me that says you were.
I'll tell you what, saving 500g on wheels is boring. You lot need to get out more.
skywalker, I know it's yours (and others') failure to get my point that's kept this thread alive, here's a chance to read some of the thread you seem to have missed, so you can let it go now?
cynic-al - MemberMy points are 1. losing weight doesn't make you significantly faster than the proportion of weight loss to overall weight on the climbs only...2. weight loss to wheels may make a little more difference, but not the 3x referred to in 1 touted in magazine articles...despite 3. your bike "feeling way faster" etc.
In other words, a mass on the tire has twice the kinetic energy of a non-rotating mass on the bike. There is a kernel of truth in the old saying that "A pound off the wheels = 2 pounds off the frame."
Keep reading that til you understand it.
OP.. my 2p. Lighter wheels are a proven car-park bike-test winning tactic. They are noticed as soon as you try to accelerate. But much of the 'lighter is better' physics is more applicable to a track or road bike, MTBs are very different and although the physics doesn't change, there are other factors that reduce the importance of lighter wheels on MTBs. ie the rougher the course, the less light + thin rims make sense.
For the last year or so I've been riding XC on the heaviest wheels I've ever used and I'm riding faster than I have done for a long time. (training effect? maybe but not really!) I found this suprising, but there's some points that explain it -
Light wheels accelerate to a set speed in a set time with less power input. But once at that speed they have less intertia and are decelerated over bumps more easily.
So you spin em up to speed and think 'wow, fast bike' but you need to keep putting that effort in to maintain speed. A heavier wheel feels slower initially, but once rolling it should maintain speed more easily. One may well balance out the other. A bit like frame flex or the 26" vs 29" debates, it all comes down to the fact there's no such thing as free energy, energy put in is just dissipated in different ways and we just want to use it effectively.
The other factor is that a heavier wheel is often due to a wider rim, and in my case also a UST tyre. Low pressure tyres on wide rims mean lower rolling resistance off-road, as well as grip and float that help maximise the momentum of the heavier wheel.
Combine this low rolling resistance and high momentum of these wheels and I can understand why they 'feel fast' despite being heavy. Your muscles quickly gain or lose strength based on the regular efforts you put in, so you get used to accelerating heavier wheels pretty quickly anyway.
Lighter wheels are good if all other elements are equal, but it's not the most important factor. It's the most easily measured and 'sold as a benefit' factor though.
In your case for endurance events I'd go for something light, while being happy to trade 50-80g a rim for a wider section and the ability use a lower pressure tubeless tyre. Comfort and efficiency count for more the longer you ride. Pacenti's new TL28 rims (28mm width) are very light for the size and are tubeless ready.
skywalker - Member
Keep reading that til you understand it.
I understood it the first time I read it, shame you couldn't even link to it 🙄
Why not use our brains? What you (and the article) ignore is, as ever, the relevant detail.
1. the effect of conservation of energy which means that the heavier wheel gives more energy back and takes longer to slow down when the bike decelerates (like the F1 KE system) and 2. that formula accounts for pure acceleration only - one does not spend an mtb race constantly accelerating.
You and I don't know the extent of these effects...when I ride/race I am able to keep what I consider a fairly constant speed...and it's established that at a constant speed weight at the rim has the same effect as non rotating weight.
Until someone's attached an accurate acceleromter (sp) to a bike we'll never know who's right.
Here's my take on things, based on races I used to do...80kg + 10kg bike, losing 500gm of (non rotating!*) weight = 0.55%, say I spend 70% of my race climbing, my time will be 0.385% quicker, which over 90m equates to 0.347% = 20 seconds
* We don't have the info to do rotating, but even on your wiki formula, which is way too high as it ignores significant factors, that's 40 seconds.
When I was racing (masters, the tightest category in Scotland) it would be pretty much unheard of for 2 places to be separated by 20-40 seconds, and it would be interesting to see what times separate riders in 12 hour events.
Finally I would say it's pretty rare for anyone who's serious about racing, and therefore finishing in the higher and more tightly packed positions, to be able to save 500gm off their wheels or bike affordably!
Keep reading that til you understand it.
Aw bless, gone quiet, probably bed-time.
You still going on 🙄
Ha ha, bored now you don't understand?
I got bored of you ages ago mate.
Making up your own theories based on nothing, nice.....
Even better!
You'd have some credibility if you even tried to debunk what I've said, but you can't.
Best thread outcome for a while! 😀
Can't and can't be bothered are slightly different.
Talking to you is like trying to teach a child that doesn't want to learn, pointless.
Ha ha it gets better
[img] 
[/img]
Skywalker, you've proposed that you are a physics wizz, but seem incapable of dealing with any of the questions asked.
Give your mum a kiss and get off to bed now, there's a good lad.
*high fives*
If you read that link from beginning to end you wouldn't be asking such stupid questions and you would realise that you don't actually have a valid argument. You are just making yourselves look stupid by thinking you know what you are on about.
It deals with everything you need to know.
Edit: Plus there is the analytic cycling site if you are still having trouble figuring it out.
I'll tell you once more, then off to bed you young scamp.
Small changes in wheel weight and rotating weight are insignificant in bicycle performance. When you accelerate your wheels you also have to accelerate your bike, your camelback, your helmet and most importantly, you.
This is easy to demonstrate; if you don't accelerate all these things, you will leave them behind.
Go and look at the article you quoted, and see what it says about lightweight wheels, then apply this to the real world.
And don't forget to brush your teeth.
If you're so clever and I'm so wrong it would take no time to destroy my arguments...but you've not advanced anything other than references to your article...which concludes against you from what I can see.
...you could do it tomorrow morning break time?
What am I supposed to be proving exactly?
That lighter wheels accelerate faster, handle better, stop quicker, and let your suspension work more efficiently.
Whereas heavier wheels accelerate slower, handle worse, stop slower, and cause your suspension to work less efficiently.
Do you expect me to show you all that in formulas?
And please stop trying to be offensive, it doesn't suit you 😆
y time will be 0.385% quicker, which over 90m equates to 0.347% = 20 seconds
Doing the maths on this, that means 90m (metres?) originally took you 96 minutes?? (0.347% of 96 minutes is 20 seconds)?
🙁
Skywalker...You're telling me I'm wrong without explaining why. Your last post shows you don't even understand my point, no matter how simply I make it. That's enough for me, you lose.
H...90 minutes.
Lighter wheels accelerate faster, we already agree on that right?
They handle better because of the reduced gyroscopic effect. You can notice this by simply putting on slightly lighter tires!
They stop quicker for the same reason they accelerate quicker.
They cause your suspension to work more efficiently because the suspensions job is to keep the wheel in contact with the ground. The wheel is forever being bounced up and down by rocks/roots/bumps etc. The heavier the wheel, the more work the suspension has to do to keep in contact with the ground. The less unsprung weight it has to deal with, the better it can do its job.
All this combined makes saving weight on your wheels worth while.
Not really much to argue about is there?
Gotta laugh at smart ass Al's change of stance, it was only last year he was saying:
Look up moment of inertia.If acceleration didnt matter then you wouldn't know the difference between a light and heavy bike
do try harder!
LOL you are arguing this without even understanding the physics?
Let me help you. I'm not saying it's significant - just that gram for gram you'll feel weight loss more at the rim/tyre than static weightyou're probably trolling anyway.
Most of your factual points are correct...you've also expressed a few opinions which are subjective and so incapable of being proved either wrong nor right.
But that's not really against what crikey and I were saying, so you've changed your point 🙄
Being offensive suits you BTW...and it appears to be all you've got.
Run along now!
Nice selective quote these Doug, the older thread is actually a year old, and in it I even say the difference in time/speed is insignificant - my present position.
Flattered you're spending time on it tho...haterz gon' hate...
Be nice if you could contribute something to the thread other than attempts to bring of down...says all about you and nowt about me.
Most of your factual points are correct...you've also expressed a few opinions which are subjective and so incapable of being proved either wrong nor right.
No, they are all correct and can be proven so by simple physics.
But that's not really against what crikey and I were saying, so you've changed your point
I haven't changed my point, I was originally saying that you were wrong for saying this;
Rotating mass in bicycle wheels has an insignificant effect, however often the myth is repeated.
If anyone can show it makes a difference, rather than claiming it does, I'm open to having my opinion changed.
TBF crikey me sober chum, so does non-rotating weight.
And
Being offensive suits you BTW...and it appears to be all you've got.
I haven't been offensive, you two were the ones being childish and resorting to insults.
Run along now 😆
skywalker
...All this combined makes saving weight on your wheels worth while
...is subjective. Problem is, so was my "insignificant" tho you chose to ignore my re-phrasing of my point.
Even then it's all about degree and other factors which affect the simple formula in your wiki article (and even it later concede's that's balls...funny you've nothing to say about those eh?
Of course you have been offensive...calling someone "stupid" isn't?...and you've been obnoxious from the start.
Oh well...at least I know what to expect of my first day volunteering in primary tomorrow...
Oh and Duggie...nothing to say? 🙄
This thread is great!
I would rather have light wheels if I could afford it end off! The only thing I would put it down to is how much stick I give my wheels. For and Enduro I would stick the lightest wheels my wallet could afford. Save weight on all the parts. It always comes down to money balls to the science.
Al you are wrong, face it.
I have said [i]nothing[/i] that can't be backed up by physics.
Lighter wheels are worth while, for the points I outlined up there ^
If you don't believe me, buy the heaviest tires you can find, and some of the lightest ones, and see how much better your bike rides with the lighter ones.
Have fun tomorrow, being surrounded by 30 people of higher intelligence.
Nighty night, don't let the bed bugs bite 😆
[img] 
[/img]
LOL...you still don't even get it!
Anyway....why are you 2 so obsessed with putting me down? Did you get mixed up in the crossfire of some flame a thon?
Minnows like you really shouldn't try to mix it with the big hitters until at least your voice has broken.
Al and Crikey:
a fairy comes along and you have a free wish to have either taken 500g from your wheels or from you frame. With no other than the weight effect. So no more or less flexibility, durability etc.
What would you choose?
LOL...you still don't even get it!
No grandad, you still don't get it. You must have forgotten to take your alzheimer's medication for the past few days because you seem to have forgotten what you are even arguing about.
Anyway....why are you 2 so obsessed with putting me down? Did you get mixed up in the crossfire of some flame a thon?
You started it old boy, I have only been giving as good as I was getting.
It seems that when you don't have the answer to the undeniable facts, you resort to petty name calling.
Minnows like you really shouldn't try to mix it with the big hitters until at least your voice has broken.
Calling yourself a big hitter 😆 it gets better and better. Not only are you confused by simple physics, you have to resort to blowing your own trumpet because no one will do it for you.
😆
[img] 
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[i]Al and Crikey:
a fairy comes along and you have a free wish to have either taken 500g from your wheels or from you frame. With no other than the weight effect. So no more or less flexibility, durability etc.
What would you choose?[/i]
It would make no difference where you lost the weight from.
How much faster are you with a full water bottle or an empty one?
How much effect does losing 500g from a total weight of 100 kg make you?
A big wee is about 250 mls; how much faster are you after having a wee?
You are assuming that changing the weight of your wheels will have a greater effect than changing weight elsewhere, please explain why.
You are assuming that changing the weight of your wheels will have a greater effect than changing weight elsewhere, please explain why.
It would make no difference where you lost the weight from.
Err, yes it does.
I explained all the reasons up there ^, if you care to read them again it would stop everyone repeating themselves.
Also the analytic cycling website has models and graphs which clearly show the benefits of lighter wheels in different situations.
What they don't take into account though is the effect lighter wheels have on suspension performance, handling and braking.
If you add up all these benefits, you will find saving weight at the wheels is worthwhile.
[i]Err, yes it does[/i]
Theoretically, there is a very very very small effect. In the real world? No.
[i]The miracle of light wheels (compared to saving weight anywhere else in the bike/rider system) is hard to see.[/i]
This is a quote from the article that [b]you[/b] are using to support your theory that [i]you will find saving weight at the wheels is worthwhile.[/i]
Let me spell this out for you; the source for your theory says that your theory is [b]not correct[/b].
See?
No.
Like I said, you two are only looking at the effect on accelerating and maintaining speed. If you look at the whole picture (accelerating, braking, handling and suspension performance) it is significantly worthwhile.
Why do you think manufacturers try so hard to reduce the sprung and unsprung weight of downhill bikes? If you and Al were right, they would build heavier bikes to keep momentum, but like I said you are not looking at the whole picture.
Edit: That quote is taken out of context, read the whole thing FFS.
Plus it isn't taking into consideration braking, suspension and handling.