Weight! Does it really matter?

[chris667]

It only matters if you're at a standard where other people are prepared to pay for your bikes.

For general use, it's no difference at all, although a better quality machine is generally nicer to use than a bad one.

 

[yenrod]

> Weight! Does it really matter?

In my opinion (weight of the bike) is a 50/50 matter on the flat yet, obviously uphill it'll have an effect..the lighter the bike the better..BUT strength for a given weight of rider is a big FACTOR...I'm having a frame built up and had a tubeset recommended for my weight..which made me feel a bit sidelined though I know it'll be strong or should be.

 

[SoulOnIce]

I can't be bothered to repeat all what I've already said months ago, so here's a link to a site that explains all.

http://www.analyticcycling.com/ForcesPower_Page.html

Wow - nice one. For maths geeks like me it's always interesting to see the models

 

[johnr]

I start my daily commute with a couple of miles uphill, the second mile pretty stiff. It might be psychological, but I notice significant differences when I'm carrying stuff to work. I'd add that the ride after pumping up the tyres and lubricating the chain also seems noticably nippier too.

But all in all, it's the direction of the driving wind which is the main determinant of performance.

 

[jimboalee]

It's not like you to not be bothered jimbo...

Had a chicken cooking and I could smell it.

 

[Crankarm]

It's not exactly rocket science. If you want to go faster you have to increase your power to weight ratio. Stop eating cakes, buns, crisps and pizzas. Lose a few kgs and build up your power and stamina. A ligher bike is reducing the amount of weight you have to move so again better a light bike than a tank. Plus they are much more enjoyable to ride.

 

[scook94]

What would be classed as "heavy" for a bike these days?

 

[dodgy]

It's the accumulation of incremental weight benefits that really show up on a bike. I doubt if anyone can feel the difference if they change a saddle for a heavier or lighter one. I've never bothered changing components to save weight (with the exception of wheels), I wait for a new bike rather than upgrade.
My winter bike is a Giant TCR2 with full mudguards, it always feels so much slower than my carbon Dolan. This is because it is (slower), in Sporttracks I can see the trends when I compare my performance on each bike, there's a roughly 4lbs difference between them. But I had a niggling suspicion that the handling, performance and feel of the slower bike was down to the wheels on it. So I swapped the wheels from my Dolan (Mavic Aksium 2006 wheels on the TCR2) onto the TCR2 and the difference was amazing! It felt almost like I was on the Dolan.
So now when I read that wheel 'X' felt better than wheel 'Y' in a magazine bike test, I no longer scoff at it. The weight of my Dolan wheelset is about 1600g and the TCR2 wheels are closer to 2000g, that 400g of rotating weight can sure be felt, trust me.

 

[Cubist]

I can understand the weight of the bike being a factor if it was a huge difference, but, and Jimbolea may be able to help me out with this one (my working life consists of hitting people, not maths)

I weigh about 100kg. It takes a lot of energy to haul my carcase anywhere, but if I am then hauling a bike with me, (or am I using the bike to do the hauling) a kg of weight added to the bike is only one percent of the total package. WIll there be a significant difference between say a 9kg bike or a 12 kg bike, all other factors being equal?

I suppose part of it is that of that 100kg body weight, a significant percentage is actually providing the power to drive the package, but then that has more to do with strength and fitness rather than just weight.

 

[Steve Austin]

Cubist. yes. a 12kg bike will have heavier wheels, as has been said propelling heavy wheels make a huge difference to any bike.
All riders will benefit from the lightest bike they can afford. Magnus backstedt rode a very light bike, and he was a big lad.

I've got several road bikes. heaviest about 25lb, lightest 15lb. I know which is easier to pedal up hills and for long distances

 

[knapdog]

I've got several road bikes. heaviest about 25lb, lightest 15lb. I know which is easier to pedal up hills and for long distances

In relation to above quote where you believe the lighter bike will be faster, again, I wonder, what if there are two people of equal fitness cycling over a given distance. One weighs in the region of 100kg on the 15lb bike and the other weighs around 70kg on the 25lb bike. Which one will fare better? You've all given great replies to my post but I'm still a little perplexed and will repeat my initial post query: Do we carry the bike or does the bike carry us?

 

[Cubist]

In relation to above quote where you believe the lighter bike will be faster, again, I wonder, what if there are two people of equal fitness cycling over a given distance. One weighs in the region of 100kg on the 15lb bike and the other weighs around 70kg on the 25lb bike. Which one will fare better? You've all given great replies to my post but I'm still a little perplexed and will repeat my initial post query: Do we carry the bike or does the bike carry us?

There's gotta be a "both" style answer to this. Without the bike we can't go very fast. With the right bike we can (well, some of us can). Therefore the bike is a machine which makes us go faster. The machine must be efficient, in other words it must be worth our while expending the energy to get the bike AND us moving faster than if we didn't have the bike at all.

Logically that therefore means that there must be a balance point where any heavier, and the effort of making the bike move would outweigh the benefits, in other words it was so heavy we might as well walk anyway. The wrong side of that line is where the bike is so heavy we would be better off without it.

The other side of that line is that for a given amount of effort, we will benefit from riding the bike. That benefit will, for a large part of any graphic curve, show that as the bike gets lighter, so the benefits of riding it increase. That increasing benefit curve MUST however change. Once we get in and amongst the modern frames, I cannot believe that a identically geared pair of bikes, one weighing 8kg and one weighing 10kg will perform very much differently were they to be ridden by the same rider, on the same gradient. That benefit curve must flatten off, where to gain the same percentage benefit as you would at the beginning you will have to lose an impossible amount of weight from the bike



All things being equal however, and I will take some convincing that losing 30% of the weight of my rear derailleur will actually benefit me to the tune of the £799 that CRC want for it.

 

[jimboalee]

There's gotta be a "both" style answer to this. Without the bike we can't go very fast. With the right bike we can (well, some of us can). Therefore the bike is a machine which makes us go faster. The machine must be efficient, in other words it must be worth our while expending the energy to get the bike AND us moving faster than if we didn't have the bike at all.

Logically that therefore means that there must be a balance point where any heavier, and the effort of making the bike move would outweigh the benefits, in other words it was so heavy we might as well walk anyway. The wrong side of that line is where the bike is so heavy we would be better off without it.

The other side of that line is that for a given amount of effort, we will benefit from riding the bike. That benefit will, for a large part of any graphic curve, show that as the bike gets lighter, so the benefits of riding it increase. That increasing benefit curve MUST however change. Once we get in and amongst the modern frames, I cannot believe that a identically geared pair of bikes, one weighing 8kg and one weighing 10kg will perform very much differently were they to be ridden by the same rider, on the same gradient. That benefit curve must flatten off, where to gain the same percentage benefit as you would at the beginning you will have to lose an impossible amount of weight from the bike



All things being equal however, and I will take some convincing that losing 30% of the weight of my rear derailleur will actually benefit me to the tune of the £799 that CRC want for it.

Don't start talking about 'graphic curves', they are two dirty words around here....

 

[jimboalee]

There's gotta be a "both" style answer to this. Without the bike we can't go very fast. With the right bike we can (well, some of us can). Therefore the bike is a machine which makes us go faster. The machine must be efficient, in other words it must be worth our while expending the energy to get the bike AND us moving faster than if we didn't have the bike at all.

Logically that therefore means that there must be a balance point where any heavier, and the effort of making the bike move would outweigh the benefits, in other words it was so heavy we might as well walk anyway. The wrong side of that line is where the bike is so heavy we would be better off without it.

The other side of that line is that for a given amount of effort, we will benefit from riding the bike. That benefit will, for a large part of any graphic curve, show that as the bike gets lighter, so the benefits of riding it increase. That increasing benefit curve MUST however change. Once we get in and amongst the modern frames, I cannot believe that a identically geared pair of bikes, one weighing 8kg and one weighing 10kg will perform very much differently were they to be ridden by the same rider, on the same gradient. That benefit curve must flatten off, where to gain the same percentage benefit as you would at the beginning you will have to lose an impossible amount of weight from the bike



All things being equal however, and I will take some convincing that losing 30% of the weight of my rear derailleur will actually benefit me to the tune of the £799 that CRC want for it.

An experiment.

Put two 1 litre bottles of water on your 8kg bike. Start riding up a constant gradient hill.
Half way up, throw both bottles of water over the hedge.

Feel what happens.

 

[Cubist]

An experiment.

Put two 1 litre bottles of water on your 8kg bike. Start riding up a constant gradient hill.
Half way up, throw both bottles of water over the hedge.

Feel what happens.

Are they biodegradable? I think your experiments sound irresponsible!

But how can 2% of the total package make such a difference? That's what I was asking. And I think the OP was heading that way as well.