What is the truth behind bike weight? Does it really help THAT much?



PhillP: I hear you. But it stands in stark contrast to the ceramic bearing you are selling in your signature line. :eek:
 
Let's see what has been mentioned already bike weight, rider weight, terrain, aerodynamics.
Anyone mention wattage output to weight/drag ratio?
 
sogood said:
The OP needs to convince himself. So a simple experiment on his turf would allow him to "get to the bottom of it". So why not? All these physics probably doesn't mean very much for the OP.

I think he should find out for himself but there is SO much more involved and different when considering a bike that weighs this or that and also when comparing to his 25 pound Schwinn. Lots more than just weight but that's all bike makers can measure and point to so less weight becomes better when all it really is lighter.
 
JTE83 said:
This is a bit unscientific because I was in different form for these top speeds, and I don't remember the exact weight of my bikes.

Top Speed in the flats no wind sprint & weight of bike -
2004 Cervelo Soloist Team 32.9 mph 17.4 lbs
2005 Kestrel Talon 31.1 mph 18.6 ? lbs
2002 Giant TCR Aero 2 30.2 mph 18.6 lbs
2005 Giant OCR 1 with 2 Jandd Commuter Panniers 29.8 mph 29? lbs

Haven't tried top speed on my best bike - 2006 CF Cervelo Soloist Team with Zipp 404s and Zero Gravitys!
A "bit" unscientific? Totally irrelevant info, I'd say.
 
Tell you what though, some nice skinny tyres make a whole lot of difference. Coming from my hybrid on 40mm to my roadie on 25mm is like floating down the road.

The main reason low weight is an advantage is that its easier to carry it home when you stick it in a pothole and bend the front wheel (thats my experience anyway :D)
 
AngryPenguin said:
The main reason low weight is an advantage is that its easier to carry it home when you stick it in a pothole and bend the front wheel (thats my experience anyway :D)
Yeah, but if you had some solid heavy wheels on, maybe you wouldn't have bent it.
 
artemidorus said:
Yeah, but if you had some solid heavy wheels on, maybe you wouldn't have bent it.
The higher momentum would have collapsed the concrete barrier instead. :p
 
Peter@vecchios said:
I think he should find out for himself but there is SO much more involved and different when considering a bike that weighs this or that and also when comparing to his 25 pound Schwinn. Lots more than just weight but that's all bike makers can measure and point to so less weight becomes better when all it really is lighter.
+1 for your statement ".....less weight becomes better when all it really is is lighter". Weight is easy to measure, so it gets measured and compared, while the important (and hard to achieve) parameters of strength and durability tend to be ignored in buy decisions. After all, weight can be shaved off any part of the bike at little or no cost to the manufacturer. Just make the part thinner and bingo, less weight = more sales.
 
dhk2 said:
+1 for your statement ".....less weight becomes better when all it really is is lighter". Weight is easy to measure, so it gets measured and compared, while the important (and hard to achieve) parameters of strength and durability tend to be ignored in buy decisions. After all, weight can be shaved off any part of the bike at little or no cost to the manufacturer. Just make the part thinner and bingo, less weight = more sales.
I don't think it is just a matter of making a part thinner. Doing just that will make that part a POS, for which nobody would pay for let alone give a premium for. They have to make it durable in addition to making it light for it to be a good sell. But yes, weight is a good marketing ploy, when for the average Joe, it is going to make an insignificant change to the speed on the bike.
 
Travis44 said:
Carbon, titanium, grams and weight shaving: does it really make a difference? Will you really be able to tell the difference between a 16 lb bike and a 17 lb bike? I ride a 25 lb steel Scwhinn, so you can see that I am yet to experience this carbon obsession and such. I always hear people discussing how good a bike is just because of how much it weighs. My question: does it really matter? Does it effect riding on the flats as well as mountains? Or is it just a placebo, something that has a very minor effect but you "think" that your bike is lighter? Please respond, I want to get down to the bottom of this.
Hope your question is getting answered Travis. Just to add my 2 bobs worth for what it's worth, I had a steel, heavy as hell bike, progressed to a lighter aluminium and now ride a carbon with Dura Ace. I just know that when I'm sprinting, with my body up over the bars, and all I can see is the road, the bike doesn't even exist. I have never had that feeling before on any other bike. I have never been able to sprint up the hills around my place before, and the accelleration of this new bike is a blast. It does flex alot more, which I am slowly coming to grips with, and I found out the other day what a cross wind is all about. A tornado wouldn't have moved my steel bike but if you even fart on this one, it gets the wobbles. So now I am hooked on the speed, and aerodynamics, weight and friction are the easiest to fix................. Fitness is a bit harder.
 
Russ Reynolds said:
Hope your question is getting answered Travis. Just to add my 2 bobs worth for what it's worth, I had a steel, heavy as hell bike, progressed to a lighter aluminium and now ride a carbon with Dura Ace. I just know that when I'm sprinting, with my body up over the bars, and all I can see is the road, the bike doesn't even exist. I have never had that feeling before on any other bike. I have never been able to sprint up the hills around my place before, and the accelleration of this new bike is a blast. It does flex alot more, which I am slowly coming to grips with, and I found out the other day what a cross wind is all about. A tornado wouldn't have moved my steel bike but if you even fart on this one, it gets the wobbles. So now I am hooked on the speed, and aerodynamics, weight and friction are the easiest to fix................. Fitness is a bit harder.

Hello to all and with this quote I may add this is my first post on this forum. Been a voyuer for quite a while. This post just about sums me up. I just got back from the LBS where I placed a deposit on a Cervelo r3sl. I've had more bikes than I can count but never owned a aluminum road bike till 15 months ago, a Raliegh Cadent 1. Nice bike comfortable, stiff, everything works and at 23 pounds it was the lightest I've ever had. Can't wait to try this new carbon Cervelo I bought, wow! It's gonna cost me around 5k all built and at first I was gonna settle on any good deal I could find for 2k but the more I researched the more I discovered it would take at least another grand on top of 2k to get into that 16 pound bike I see and dream about. Will it make a difference maybe not but I do enjoy the concept of a bike disapearing beneath me. I also think the the premium for quality, I mean race quality factors in stiffness and areo, with that comes high price. The lightness is helping me to stay interested in cycling. Always liked it for practicality but now it's become a bit of a hobby/sport. :p
 
Problem with light and stiff bikes is that the feel disappears quickly as you get used to it. Then it's that old slog up the hill. You need to have a heavier and mushier training bike to remind you the difference.
 
sogood said:
Problem with light and stiff bikes is that the feel disappears quickly as you get used to it. Then it's that old slog up the hill. You need to have a heavier and mushier training bike to remind you the difference.

Well I do have a trek 4300sl mountainbike running on Ritchey 26 by 1.4 comp slicks. It also comes equipped with topeak cargo rack and a bungeed milk crate plus the suspension fork. Bike has to be about 34 pounds easy, mushy as heck and serves as my occasional commuter to and from work. 26 miles round trip. My best time yet one way 13 miles in 45 min. Can't wait to try that on the Cervelo.
 
sogood said:
PhillP: I hear you. But it stands in stark contrast to the ceramic bearing you are selling in your signature line. :eek:
Peter@vecchios said:
Doooohhh!!!
I hear what your saying, but it does actually support what I said.

I'd love a fancy bike, but can't afford it. I managed to find a way to sell the bearings at upto 1/3 the price you would pay else where, so in turn making some of the wiz bang stuff more within reach. If I could sell you a new Colnago at 1/3 the price (and still make a profit) I'd be doing that too!!!
 
You guys are having a nice scrap. My turn.

The performance of a bike is made up by getting the right balance between a number of factors;
- Fit to body
- Comfort
- Ability to transfer your energy into forward motion
- Handling
- Reliability
- etc etc.

There is not a lot of point of saving 200g off the frame if it means a loss of lateral stiffness, however if you can design a frame that gives you same qualities as the old frame and is 200g lighter, then you have 200g less to carry over the mountain.

Should also point out that something like 65% of the effort goes into pushing air off our bodys. Want to go faster? lower your handlebars.

And for many of us, the best place to reduce weight is to reduce our fat levels. 5kg of fat loss is a lot cheaper to loose than 5kg worth of bike.
 
Phill P said:
I hear what your saying, but it does actually support what I said.
I know. It's actually good to know that you are satisfying a particular demand in the market place. :)
 
mikesbytes said:
You guys are having a nice scrap. My turn.

There is not a lot of point of saving 200g off the frame if it means a loss of lateral stiffness, however if you can design a frame that gives you same qualities as the old frame and is 200g lighter, then you have 200g less to carry over the mountain.
The original poster's question is on the effect of 9lb (4kg) or 36% bike weight reduction on, amongst all things, climbing. Not 200g.
 
Russ Reynolds said:
Hope your question is getting answered Travis. Just to add my 2 bobs worth for what it's worth, I had a steel, heavy as hell bike, progressed to a lighter aluminium and now ride a carbon with Dura Ace. I just know that when I'm sprinting, with my body up over the bars, and all I can see is the road, the bike doesn't even exist. I have never had that feeling before on any other bike. I have never been able to sprint up the hills around my place before, and the accelleration of this new bike is a blast. It does flex alot more, which I am slowly coming to grips with, and I found out the other day what a cross wind is all about. A tornado wouldn't have moved my steel bike but if you even fart on this one, it gets the wobbles. So now I am hooked on the speed, and aerodynamics, weight and friction are the easiest to fix................. Fitness is a bit harder.

That post put a smile on my face. Sitting in an all-day workshop in a stuffy office, sneaking a look on here to try and stop from falling asleep.
I'm no physics expert and have never ridden an ultra-light, throughbred race machine. I did switch from a brick-heavy lugged steel frame to a much lighter model recently giving me a weight reduction of about 1kg in bike weight. There is certainly a noticeable difference on the climbs. On the steeper sections I always used to feel like there was a little goblin hanging on to my seat stays pulling me backwards. It really did feel like I was fighting against a force pulling in the opposite direction, which I suppose, in a sense, I was.
The new bike has none of that. It's not like I'm cruising up mountains all of a sudden but when the climbing gets tough I feel my new machine is neutral rather than a negative effect on my momentum. It feels like the effort in my legs is proportionately reflected in my speed. That probably makes no sense in physics terms but I think you might know what I mean in terms of perception.
 
Lighter is definitely better. I've got a bad back and low weight helps a lot when tossing a bike onto the rook rack. :D

/k
 

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