Reducing front wheel weight

[PhilDawson8270]

Many race cars have a large engine and car mechanics and racers are still trying to reduce the weight and mass of the components around that engine.

There is nothing wrong with having a V8 engine rather that a V4. Taking one's weight all the way down to the engine the size of a lawn mower would be no way to power a car. While gains can be made with weight reduction to the engine, gains can also be made by keeping the engine the same size or mass and increasing it's power.

They spend massive amounts of time, and money, trying to develop lighter engines that produce similar power. In the cycling world, this is called dieting, and training.

 

[TomAndrew91]

Any aggression is purely inferred, not implied. You asked a question, I gave you a simple, honest, straightforward answer. You may not like it, but it remains the same, whether I put fancy embellishments on it or not.
There's a bit of history to this debate and perhaps you could have spent a little time researching it here because it is a frequently-asked question. ... MOD EDIT
We've done the physics here, I've quantified the differences, we've had an intelligent and robust debate about it, yet some people will always walk away saying that they can feel the difference even if physics shows otherwise. With new wheels their bikes steer more positively, is more responsive and attracts more members of the opposite sex. Yet, when you ask them to quantify such vague concepts they will bluster and say that if the rest of the world can't feel it it doesn't mean they can't, etc etc.
Joffey's answer was perhaps a bit kinder than mine but read between the lines - it will make no difference.

Since you are new here I'll repeat the truth about wheels for you.

1) Weight saved on wheels is no different from weight saved anywhere else on the bike.
2) No matter where on the wheel the weight is saved, it makes the same as weight saved anywhere else on the bike.
3) Aero wheels will save you a couple of seconds over a 40k time trial if, and here's the crux - if you can cycle fast enough so that aero drag is significant. Since you are a self-confessed newbie, you don't qualify for those benefits.
4) Some people will say that the pro's use fancy wheels and therefore it is good for you. Pros ride fast, have free wheels at their disposal and get paid to emblaze sponsor names on wheels designed primarily to look like rolling billboards. This doesn't make them beneficial to you unless someone pays you to make their name go round and round.
5) Heavy wheels take longer to spin up but the energy is not wasted. When you coast, they return the favour. There is no energy lost.
6) A bit of weight saving will make it every so slightly easier to climb but you have to put it in perspective. 500g off a 90kg package is insignificant. Further, us humans can't detect small speed differences. If the wheel (or the 2l Coca Cola bottle on your frame) is slightly heavier, then you will simply cycle a teeny bit faster. You won't feel better or worse for it.
7) Aero wheels are ironically, heavy by definition.
8) Aero wheels are not durable like wheels with alu rims and 32 spokes.
9) People who spend lots of money on wheels will always, yes always, post-rationalize it. None of them retain perspective after spending so much money.
10) Your thoughts on front wheels vs rear wheels have no scientific reason to be valid. Weight is weight, whether you tow it with a trailer or carry it in your pocket or pack it all into a unicycle's only wheel.
11) If you want to see the maths on this, search for F=MA on this forum, there's a long debate there somewhere with all the irrefutable sums and lots of lapdog who claim they're exempt from the laws of nature.

Go for a ride, drink a beer and find new places for your bike to take you to.

Thank you for explaining this all to me. I feel like this is a topic you are very passionate about and much like the dear members of the "Flat Earth Society" do your utmost to convince others of your cause and look down on the "non-believers". I am therefore aware that there is probably little point in entering a debate, but nonetheless feel it is important to respond given the effort you have gone to.

1) You say there are lots of lapdogs claiming to be exempt from the laws of nature. However, points 1,2 (albeit they are the same), 3 are clearly formed through your own version of the laws of nature. Rotational acceleration is different to straight line acceleration (as mentioned by @Profpointy above) therefore it goes against the laws of physics to say that there is no difference.

2) Why do F1 teams spend so much money saving weight on their cars? They carry 100kg of fuel at the start. The longer the race the quicker their lap times as they burn off the fuel and (guess what) reduce weight.

3) There is air resistance at all speeds. There will be aero efficiencies at all speeds, it may be offset by the increased weight at lower speeds, but there will still be efficiency from having an aerodynamic wheel.

4) I am a new to this. It doesn't mean I am 90kg+ who cannot cycle fast. Maybe you were when you started, but it will not be the case for everyone.

What I will concede is that spending ridiculous amounts of money on a lighter/ aerodynamic bike might not be the best way to spend your money, but this is entirely up to the person spending the money. However, you cannot say that people won't feel the difference of these items as that is just not true (why do pro's ditch water bottles before a big climb?). You appear to be accusing @Justinslow of pretending he can feel the differences to justify the cost however I imagine he does notice the change and indeed the laws of physics dictates that he should.

Thanks all for your responses, appreciate the help.

Tom

 

[Fab Foodie]

What a Moser and his super heavy rear wheel for the hour record .... Why not put that mass on the frame instead ....

 

[TomAndrew91]

What I find interesting is the bit about the rear wheel having unconventional sizing. Can you elaborate on that a bit?

Its not actually that unconventional. I have a 126mm rear dropout (1980s road bike) and found a rear wheel that fits without having to bend the frame. If I replaced it then imagine my chain line would probably move and it might be difficult to alter another wheel to fit. Having said that, despite @Yellow Saddle 's reservations its probably worth doing as the wheels on their on (no tyres or tubes) weight 3kg so can easily take off a full kilo there

 

[Yellow Saddle]

What a Moser and his super heavy rear wheel for the hour record .... Why not put that mass on the frame instead ....

Because it does not matter where the weight is. In the hour you are maintaining a reasonably constant speed (as most of us actually do on most of our rides) so the placement of the weight does not matter.

 

[TomAndrew91]

I know that they don't make "huge" difference.
I know that they make "some"difference
I know that they make me faster.
I know they may not make you faster.
If the OP is happy with that then why not?

Summed up far more concisely than me!

 

[Fab Foodie]

Because it does not matter where the weight is. In the hour you are maintaining a reasonably constant speed (as most of us actually do on most of our rides) so the placement of the weight does not matter.

So why then make a special wheel when you could have simply added some lead into the frame?

 

[Yellow Saddle]

So why then make a special wheel when you could have simply added some lead into the frame?

I think you misunderstand me. The weight is not necessary. It was simply a consequence of the large wheel. Had the wheel been smaller, it would have been lighter but they would not have added weight elsewhere. The weight of a bike in this type of contest is irrelevant within reason. To keep a heavy bike going at a constant speed or a light bike going a the same speed requires the same energy. At the speeds they're going it is all about aero dynamics. The only time a bike's weight comes into play as at the time from standstill to accelerating up to speed. This is done extremely slowly due to our weak engines. We accelerate like slugs. Next time you are out on your bike have a look and see how long it takes you to get up to 30 kph. At this rate, a bit of weight here or there just doesn't make a difference and certainly no difference in the spinning up of the "flywheel" (wheels).

Moser's bike design wasn't based on any valid science. You'll see that subsequent faster bikes were kinda traditional in wheel size and geometry. He didn't break the record because of the design, he broke the record because his bike's aerodynamics were within spec and he trained correctly and could switch off pain.

 

[TomAndrew91]

I think you misunderstand me. The weight is not necessary. It was simply a consequence of the large wheel. Had the wheel been smaller, it would have been lighter but they would not have added weight elsewhere. The weight of a bike in this type of contest is irrelevant within reason. To keep a heavy bike going at a constant speed or a light bike going a the same speed requires the same energy. At the speeds they're going it is all about aero dynamics. The only time a bike's weight comes into play as at the time from standstill to accelerating up to speed. This is done extremely slowly due to our weak engines. We accelerate like slugs. Next time you are out on your bike have a look and see how long it takes you to get up to 30 kph. At this rate, a bit of weight here or there just doesn't make a difference and certainly no difference in the spinning up of the "flywheel" (wheels).

Moser's bike design wasn't based on any valid science. You'll see that subsequent faster bikes were kinda traditional in wheel size and geometry. He didn't break the record because of the design, he broke the record because his bike's aerodynamics were within spec and he trained correctly and could switch off pain.

http://www.reynoldscycling.com/uploads/RZR_no6_Level_Speed.pdf

 

[Yellow Saddle]

Thank you for explaining this all to me. I feel like this is a topic you are very passionate about and much like the dear members of the "Flat Earth Society" do your utmost to convince others of your cause and look down on the "non-believers".

I am therefore aware that there is probably little point in entering a debate, but nonetheless feel it is important to respond given the effort you have gone to.

I don't look down on non-believers. I despair at their inability to debate based on facts. Why is there little point in debating me? Because I may come back with facts? Either debate or not. It seems you have chosen the former.

1) You say there are lots of lapdogs claiming to be exempt from the laws of nature. However, points 1,2 (albeit they are the same), 3 are clearly formed through your own version of the laws of nature. Rotational acceleration is different to straight line acceleration (as mentioned by @Profpointy above) therefore it goes against the laws of physics to say that there is no difference.

Have you bothered to look up the formulas I posted where I think you'll find that I understand acceleration, be it a wheel or a lump? No difference means that the effect is so small that it is negligible. I've quantified negligible and published a way where you can plug your own figures into the formula and figure out the level of importance to you. You said you are a novice, which has context. It implies that you are not interested in time trialling or do not compete at a high level. It implies that you are still finding your feet. It implies that your biggest improvements will come from training and dieting, not new wheels. It implies that you can achieve most (99%) of your improvement without spending money on equipment.

2) Why do F1 teams spend so much money saving weight on their cars? They carry 100kg of fuel at the start. The longer the race the quicker their lap times as they burn off the fuel and (guess what) reduce weight.

Do you really want me to draw parallels between F1 racing and pootling along on a bicycle? I suggest you draw up the list of similarities and then we can discuss it.

3) There is air resistance at all speeds. There will be aero efficiencies at all speeds, it may be offset by the increased weight at lower speeds, but there will still be efficiency from having an aerodynamic wheel.

Yes, but air drag increases with velocity cubed. It is exponential and at low speeds the improvements are negligible. If you want to be more aero, lower your handlebards, get clip-ons and wear skin-tight smooth lycra from top toe toe with seams strategically placed to prevent turbulence and increase laminar flow. Removing two spokes from a wheel and making the rim a bit deeper is farting against thunder. Put your money where your mouth is and get your body aero first.

4) I am a new to this. It doesn't mean I am 90kg+ who cannot cycle fast. Maybe you were when you started, but it will not be the case for everyone.

We'll, are you a 62kg ectomorph with less than 6% body fat, a high VO2 max and the right psychological make-up for TT-ing? If so, get aero wheels. Also move your front brake to behind the fork, the rear brake to under the BB, ram the rear wheel right into a curve in the seat tube, hide all cables and put white lycra booties over your shoes. Then, for that last 0.1% difference, get fancy wheels. I suggest you go to www.analyticalcycling.com and have a look at the difference various components make. You'll see that wheels isn't top of the pile.

What I will concede is that spending ridiculous amounts of money on a lighter/ aerodynamic bike might not be the best way to spend your money, but this is entirely up to the person spending the money. However, you cannot say that people won't feel the difference of these items as that is just not true (why do pro's ditch water bottles before a big climb?). You appear to be accusing @Justinslow of pretending he can feel the differences to justify the cost however I imagine he does notice the change and indeed the laws of physics dictates that he should.

Thanks all for your responses, appreciate the help.

Tom

Yes, it is entirely up to you how you spend your money but your question was "what difference will there be" not "should I buy this because I have money and I feel like it, or not?" Don't throw down red herrings. I never said you should not buy what you want. I don't argue about emotion.

They can't feel the difference because on paper the difference is clear - very, very small, There is no way wheels make "steering more responsive" and "I can feel I'm accelerating faster". That is all in the mind. I've challenged people to blind tests but they won't bite because they can feel the difference and continue lying to themselves. They bluster. I challenge you to tell the difference in "feel" of a 20 second improvement on a 40km time trial. Humans are poor at gauging time. We are even worse at gauging speed and totally useless at gauging acceleration in tiny doses.
My challenge to the deep-section and fast-wheel crowd stands: Quantify and explain responsiveness. Tell me how much faster your think you accelerate. Tell me when you think you accelerate during a ride. Tell me how much slower over a given course you think you are because of X handicap on Y wheels.

 

[Klassikbike]

Changed wheels on my XC MTB.
Before 2.3kg wheelset, now 1.4kg.
Changed Suspension from 1.5Kg down to 0.947KG Lauf Fork
Am I faster than before? Probably not.
Do I accelerate and climb faster? Marginally Yes.
Does every single ride feel a lot more fun and make me smile a lot more than before? Yes absolutely.

Changing to better, less rolling resistance and lighter tires helped in all these points too.

If you have the money to spend, sure spend it on lighter better wheels and tires.

 

[2IT]

But I don't understand where this fits into the argument that mass saved on wheels make a significant difference or not. What don't I understand here?

Let me try again.

Weight that is not engine - is one of the better places to look at reducing weight.

With the human engine, one can get to the point of power loss when trying to reduce weight. Anorexia is an extreme example. Feeling weak below a certain weight is more common. There are some skinny riders that are not that good going uphill or in the flats and I would probably be one of them.

 

[Justinslow]

View: http://youtu.be/le_LSWfGJUo

Interesting video comparing bike weights on a climb.

 

[Yellow Saddle]

Let me try again.

Weight that is not engine - is one of the better places to look at reducing weight.

With the human engine, one can get to the point of power loss when trying to reduce weight. Anorexia is an extreme example. Feeling weak below a certain weight is more common. There are some skinny riders that are not that good going uphill or in the flats and I would probably be one of them.

Well, getting to that point would be silly now, would it? However, you would have to go way, way beyond skinny before power loss is the result. As your weight drops your power to weight ration increases. Human engines are good places to save weight and in general, there's more to save there than anywhere else on the bike. Many people can drop 10kg without adverse health effects.

Our old friend Michael Rasmusen below seemed to do well on the hills and on the flats.

 

[TomAndrew91]

I don't look down on non-believers. I despair at their inability to debate based on facts. Why is there little point in debating me? Because I may come back with facts? Either debate or not. It seems you have chosen the former.



Have you bothered to look up the formulas I posted where I think you'll find that I understand acceleration, be it a wheel or a lump? No difference means that the effect is so small that it is negligible. I've quantified negligible and published a way where you can plug your own figures into the formula and figure out the level of importance to you. You said you are a novice, which has context. It implies that you are not interested in time trialling or do not compete at a high level. It implies that you are still finding your feet. It implies that your biggest improvements will come from training and dieting, not new wheels. It implies that you can achieve most (99%) of your improvement without spending money on equipment.


Do you really want me to draw parallels between F1 racing and pootling along on a bicycle? I suggest you draw up the list of similarities and then we can discuss it.


Yes, but air drag increases with velocity cubed. It is exponential and at low speeds the improvements are negligible. If you want to be more aero, lower your handlebards, get clip-ons and wear skin-tight smooth lycra from top toe toe with seams strategically placed to prevent turbulence and increase laminar flow. Removing two spokes from a wheel and making the rim a bit deeper is farting against thunder. Put your money where your mouth is and get your body aero first.

We'll, are you a 62kg ectomorph with less than 6% body fat, a high VO2 max and the right psychological make-up for TT-ing? If so, get aero wheels. Also move your front brake to behind the fork, the rear brake to under the BB, ram the rear wheel right into a curve in the seat tube, hide all cables and put white lycra booties over your shoes. Then, for that last 0.1% difference, get fancy wheels. I suggest you go to www.analyticalcycling.com and have a look at the difference various components make. You'll see that wheels isn't top of the pile.



Yes, it is entirely up to you how you spend your money but your question was "what difference will there be" not "should I buy this because I have money and I feel like it, or not?" Don't throw down red herrings. I never said you should not buy what you want. I don't argue about emotion.

They can't feel the difference because on paper the difference is clear - very, very small, There is no way wheels make "steering more responsive" and "I can feel I'm accelerating faster". That is all in the mind. I've challenged people to blind tests but they won't bite because they can feel the difference and continue lying to themselves. They bluster. I challenge you to tell the difference in "feel" of a 20 second improvement on a 40km time trial. Humans are poor at gauging time. We are even worse at gauging speed and totally useless at gauging acceleration in tiny doses.
My challenge to the deep-section and fast-wheel crowd stands: Quantify and explain responsiveness. Tell me how much faster your think you accelerate. Tell me when you think you accelerate during a ride. Tell me how much slower over a given course you think you are because of X handicap on Y wheels.

There appears to be little point as having looked at your points across various threads I don't believe much would be gained from entering into a debate with you. Your comments are one sided, you never accept someone else's opinion and its very much a case of your way or the highway.

Whilst I do not doubt your cycling or mechanical expertise, your grasp of physics I do. Moving a heavier object takes more force and more effort than a smaller one. Therefore a lighter bike will be easier to accelerate and will have a higher top speed.

F1 cars follow the same laws of physics as a bike. Therefore it is reasonable to use them as an example. However, if you don't like comparing to F1 cars, then why not road cars. Arial Atoms are faster than all cars with comparable power. Their reduced weight being the key difference.

I think what your argument boils down to is that you wont necessarily feel a difference of 500g reduction. Whilst this is an opinion and some will notice some wont, you cannot argue with the following facts as they are proven by the laws of physics.

Will a lighter bike accelerate faster: YES
Will a lighter bike be quicker: YES
Is it better to save weight on wheels or frame: Due to the additional rotational forces under acceleration, wheels.

Therefore I think it boils down to whether or not you personally can accept that someone will feel a difference. I for one believe you will. If you don't, that's great but please don't start saying that they wont make a tangible difference. As they will.

Either way, I have my answer from helpful people like @Justinslow @Klassikbike @Fab Foodie among others, so unless you can demonstrate that the laws of physics have changed since I studied them at school, higher education and university, then I'm not sure this debate is worth my time.