Road Cycling - Different perspective on bike weight

Technology has brought us to the point where 16 lb bikes are fairly common. It's likely that advances in materials science will, over time, bring down the weight of frames, wheels, and even drivetrains. But is this always a good thing? Even assuming the structural integrity of new lightweight materials, I can think of cases where more weight would be desirable. For long rides over flat terrrain, for example, more weight in the wheel rims would provide extra gyroscopic stability and less wind buffeting. If there isn't a lot of acceleratin/deceleration going on, weight isn't a limiting factor in top end speed; in fact, extra rotating mass in the rim/tire area would help maintain that top end speed. For us non-racers, it makes a lot of sense to look at the type of riding we will be doing, and the actual weight distribution between frame, wheels, etc. Obviously, the pros will pursue even the slightest weight advantage, but this has limited relevance to most cyclists out there.

I see us going to better grades of carbon in teh future, nod not just this laminated cloth taht is in use currently. I'm talking the same grade and manufacturing process that goes into formula1 cars, and McLarens. Their design gives one of the best results..a composite that is stronger than aluminum, yet lighter.

But, that grade carbon plus that process right now is stupid costly. I think a bikc fork made that way would cost the manufacturer a couple thousand alone....imagine the cost we sould see after manufacturer mark up...

If that's good or not...I have no clue. I do see how touring folks will often prefer steel,and I do thinkmetal frames will always be around.

You do have to be careful, most ultralight bikes have a 180 pound rider limit, that should tell you something about it's longevity. Also anything that is converted or bought with the sole mindset of racing, be it cars, motorcycles, bicycles, etc, will not last as long in the real world. A standard 4 cylinder Acura RSX 160hp engine will last about 150,000 miles, but take the wanabe racer who drops $10,000 (in Los Angeles that would be cheap!) to hype that same engine to 300hp and suddenly the engine goes to about 40,000 miles! I've seen 650hp Acura 4 cylinders and their engine life was about 10,000 miles!! The point here is that the more radical you get to either go faster and or get lighter the shorter the life expentancy of that product will be. You don't get to have it both ways...sorry! If your not a sponsered racer or independently wealthy then consider getting a bike that is in the "normal" weight range of 18.5 to 20 pound range;hHeavier wheels with more spokes will also weigh more but last longer; and as an added bonus you pay less for the heavier stuff.

Really if light weight is a real concern why not lose that weight from your own physical make-up given that you could lose some pounds. What's wrong with a 20 lb. bike. It's all about the ride, the one you are enjoying on the bike that you have anyways.

Ah yes, weight vs strength is a debate that is raging in every racing sport. But I look at it this way, thats why there are weight regulations for cycling and other forms of racing. Becuase if there was no weight restriction then frames would be designed for one time X mile use, and then the team would throw it away. Also the gear that comes from racing makes its way to the public (most of the time) and personally I really dont want to pay 10K for a carbon frame that is the "heaviest" carbon frame.

All I'm really saying is that weight is not too much of an issue as long as weight restrictions are in place. Thats my .02

I just bought and rode for the first time (yesterday) my new Lemond Zurich. That bike comes in around 20 lbs I'm guessing (haven't weighed it). It is an absolute rocketship compared to the 88 Trek 400 I was on.

BUT, when I was shopping I looked at alot of bikes and made a decision based on riding style, cost, life expectancy (the bike not mine), etc. I didn't like the feel of 16-17 lb bikes...too light if you ask me. I want a nice, managable ride for the long haul. I plan on having this bike for many years to come.

If I was racing and truly concerned with weight (come on every roadie likes to tinker and shave a few grams here and there) I'd be chasing the lightest thing out there. Fuji makes the team superlight and recommends you don't ride the wheelset unless you're racing. What a waste, spend $2,200 on a new bike to be light and plunk down $800 more for a set of daily wheels which incidentally make your light bike heavier.

PJ

We Clydesdales have been saying that for years...
I weigh about 220 when I'm in great shape, which is not now, and I've had trouble every time I've tried to save much weight. Wheels below 36 spokes fall apart, and wheels with fewer than 32 spokes fall apart right away. Frames flex, handlebars and stems bend and occasionally crack, cranks work loose, even saddles will collapse. This is a sport dominated by 140-pound riders, and even some experienced mechanics don't understand the load an extra 100 pounds brings with it.
Solution for me so far has been an Atlantis, from Rivendell (www.rivbike.com), with 36-spoke Rhyno Lite wheels and a Brooks B-17 saddle. I dunno what it weighs--25 pounds, maybe more--but it's comfortable and strong and I spend my time riding instead of wrenching.

What about buckyballs? It's a new (3rd) form of carbon that the discoverer got a Nobel Prize for. It's 20 times stronger than diamond. Assuming it's the same mass as steel (which it isn't) and that diamond is twice as strong a steel (it's much more than that), you would have a bike 40 times lighter than the present limit, using buckyballs. Only trouble is, they've not made more than a few molecules of the stuff, so it might take the budget of NASA to make a bike out of it. But who knows in 50 years? It boggles the mind. We could have an entire bike weighing in at 200 grammes and absolutely indestructible.

But how brittle are buckyballs? If they are very brittle, then it won't be safe for bicycle use. In most cases strength comes in the form or brittleness.

Diamonds are exactly that way...You really don't even cut a diamond...you jsut hit it in the right angle, and the crystalline structure and brittleness do the rest. Of course the diamond is so brittle that hitting it along hte wrong angle can destroy it...so it's not as easy as it sounds.

Well, 'common sense' and 'consumerism' seem to be polar opposites sometimes. Personally, my steel bike is 18.1lbs and the only thing purchased with a weight consideration is the wheels. For me to get down to 16lbs or whatever...the cost is ridiculous. I weight 200lbs, and 2lbs ( 1% of my weight ) is nothing - I swing by that much on a daily basis. I wouldn't notice a 1% weight saving. Even for a 100lb tiny woman cyclist....it's still only 2% difference.

I think the great irony is people's obsession with high performance/short lifespan 'racing' componentry, when the majority of cyclists really don't even race or even really benefit from spending the big bucks to lose 2-3lbs from their bike.

But anyway, the ultimate frame would be one constructed through nanotechnology, that would be constructed/deconstructed as you ride, depending on where the frame was experiencing the most stress, adjusting for terrain, chainging body weight, power output etc.

In the meantime, oh boy, I love my 18lb steel roadie. :)

What about buckyballs?

Nanotube CF shows great promise as well and they've advanced that material further than buckyballs.



Graphite Crystal = Diamond
CF Std. = Typical standard carbon fibre
MWNT = Multi-Wall Nano-Tubes
SWNT = Single-Wall Nano-Tubes

Graph CF MWNT SWNT Steel
Crystal Std.
-----------------------------------------------------------------------------
Tensile Str. - GPa 100 3-7 300-600 300-1500 0.4
Elastic Mod. - GPa 1000 200-800 500-1000 1000-5000 200
Specific Str.- GPa 50 2-4 200-300 150-750 0.05
Specific Mod. - GPa 500 100-400 250-500 500-2500 26
Strain-Failure - % 10 1-3 20-40 20-40 25

What about buckyballs? It's a new (3rd) form of carbon that the discoverer got a Nobel Prize for. It's 20 times stronger than diamond. Assuming it's the same mass as steel (which it isn't) and that diamond is twice as strong a steel (it's much more than that), you would have a bike 40 times lighter than the present limit, using buckyballs. Only trouble is, they've not made more than a few molecules of the stuff, so it might take the budget of NASA to make a bike out of it. But who knows in 50 years? It boggles the mind. We could have an entire bike weighing in at 200 grammes and absolutely indestructible.


1234567890 10 is B.S. or B.F. ( a concept)
Buckmaster Fuller.
Builder, not discovered. Invented using natural models and adapting.

How are Buckmaster Fuller geo mol's gonna help bikes other than supa tires?
Psi distribution on surface geodesics are not applicable to tubular designs| or are they?
(BF's atomic level geodesic molecules, man made B-balls) are bouncers? A motion molecule.

The lightness only is applicable when the object is massive.

Geodesics are\ are not B-balls.

Tell me more, I'm not sure of the diff or the subject.

Wow not one reply was on topic, is that some kind of record?
Yes weight will increase inertia and won't affect flatlanders much, it does affect mountain folk though, as the mass of the bike must be lifted uphill. Moving the same mass, rather than adding more, toward the rims would be an option for storing some energy as well as increasing the gyroscopic effect without weight penalty, however it would not help to maintain speed top speed, it would only help to maintain speed longer while coasting or upon reaching the bottom of a long hill or to help buffer speed on multiple very short hills (anything short enough to coast up).

Both my mtb and roady weigh in at a trim 30 pounds, the mtb was 32lb when new(and on step from top of da line) and the roady is just old, I just bought it and almost immediatly tore it apart for some regreasing, but my fancy special grease hasn't come in at the auto parts store yet. The road bike is noticably faster on the flats though.
Anyway its front wheel, without tire, is 1,400 grams of non aero, 36 spoke, cromed, wonderment. Haven't had a chance to do a full ride yet, but soon- real soon.

Hmmm...I usually drop 20-35 pounds between the end of one winter and the start of the next. That's about the weight of 1-2 entire bikes! I couldn't purchase that amount of weight reduction on a bike for any amount...

I ride with a Camelbak, so I don't need my water bottles. I've begun filling them with pennies (about 25 lbs worth) and duct taping them into the holders. Voila! It's great for strength training. Especially on the hills. And I love the look on people's faces when I tell them what that clinking noise is...

When I take them off for races, I bet I'll feel like a rocketship!

I suspect that the ultimate engineering material for frames, when we can produce it in quantity , will be "weblon".

Clydesdales have their problems, but spare a though for us 130lbs whippets. All of our cycling equipment is over-engineered for someone twice our weight. How light could you go for a lightweight rider who is not a power athlete, doesnt race, but can handle a bike properly ?

Good discussion. If nanotechnology was electrical, you'd risk it shorting or going out of commision at some point, wouldn't you? It would need to be fed as well so would you have to smear some "food" on the frame before a long ride? With buckyballs being created at a molecular level, wouldn't the grain be workable, the same way carbon fibre can be weaved?
Just asking

1234567890 10 is B.S. or B.F. ( a concept)
Buckmaster Fuller.
Builder, not discovered. Invented using natural models and adapting.

How are Buckmaster Fuller geo mol's gonna help bikes other than supa tires?
Psi distribution on surface geodesics are not applicable to tubular designs| or are they?
(BF's atomic level geodesic molecules, man made B-balls) are bouncers? A motion molecule.

The lightness only is applicable when the object is massive.

Geodesics are\ are not B-balls.

Tell me more, I'm not sure of the diff or the subject.

Is English your second language or are you somehow related to Freddy Parr?

I remember watching a late night BBC2 program with the inventor of buckyballs and he talked about them in relation to being suitable for heavy engineering tasks. The designers of the space elevator are now able to put their ideas thru some sort of funding models, because they plan to use b/balls to build it. This would be an elevator linked on the ground and gravitationally linked at the top in a geostationary orbit. Essentially, centrifugal force would ensure it's stability. Now, if a material is suitable for building that, it's certainly ok to build a bike. I believe your analysis of b\balls may be in relation to the present state of technology. I suppose it's like the Tachyon (spelling ok?) only less so.
;)

A friend of mine has Callaway Corvet with some type of magneseum wheel. He had to go to steel wheels becouse the pot holes in nyc already cracked one. You can't lose weight without losing some strength.

Nanotube CF shows great promise as well and they've advanced that material further than buckyballs.



Graphite Crystal = Diamond
CF Std. = Typical standard carbon fibre
MWNT = Multi-Wall Nano-Tubes
SWNT = Single-Wall Nano-Tubes

Graph CF MWNT SWNT Steel
Crystal Std.
-----------------------------------------------------------------------------
Tensile Str. - GPa 100 3-7 300-600 300-1500 0.4
Elastic Mod. - GPa 1000 200-800 500-1000 1000-5000 200
Specific Str.- GPa 50 2-4 200-300 150-750 0.05
Specific Mod. - GPa 500 100-400 250-500 500-2500 26
Strain-Failure - % 10 1-3 20-40 20-40 25

Multi-Wall Nano Tubes? Wza Nano-tube? Looks good...Please translate the chart also.