does frame weight matter?

[Climb01742]

over the last couple of days, there have been a number of posts pointing out that fina estampas are heavy and saying that that wasn't a good thing. so how much does a frame's weight really matter? my answer might have been different before i got a merckx MX Leader. holding that puppy, weight matters. riding it and weight doesn't. same is true for a fina, at least in my opinion. few folks have built more frames for racers than eddy and dario. serotta's aren't exactly featherweights, yet they are fast. i'd cast my vote for the weight of a frame as being an overrated aspect. even as someone who loves to climb. me losing five pounds would help me climb more than a frame losing one pound. ;)

[David Kirk]

I have to say that I agree with you. Bike weight can't be looked at in a vacuum. It's the whole package weight and the power to weight ratio that is the big deal.

If you weigh 190lbs. and the bike weighs 18lbs.the complete package that you are powering up that hill is 208lbs. If you knock off a pound from the frame you've reduced the package weight to 207lbs. This is a big change in frame weight but a very small change in the package weight. A good thing but as a percentage not a very big deal and it has little effect on the power/weight ratio.

Now the complicated part.......what if a heavier frame is more efficient that a lighter one? Not due to fit of course......lets say they fit exactly the same. I'm talking about having the amount of frame flex optimized for the weight of the rider and the type of rider they are. If the heavier frame happens to better at allowing us to get our power and the way we produce it to the ground it will be faster.

Now all that being said.....this doesn't apply to rotating weight. Reducing rotating weight is the the wholly grail. this not only applys to wheels but to shoes, pedals etc. I think shoe weight is one of the places people tend to forget.

anyway......back to work.

Dave

[Ray]

For high end racers on hilly courses, I think frame weight matters. There are plenty of calculators that show the difference 2 pounds makes on a climb of a given length and grade at a given power output. For long, tough climbs, its enough to matter in a race. I would guess for the level that most of us ride at (and I *KNOW* for the level that I ride at), it's pretty meaningless. In terms of the FEEL of the bike, I believe that geometry makes a much bigger difference than weight. I've had lighter bikes ride heavier than heavier bikes and heavier bikes that feel as light and responsive as anything I've ever ridden. If you timed me riding up the Gavia, I'm sure I'd be slightly faster on the lighter bike, but we're talking HOURS here anyway, so whats a minute or two difference in that context :)

-Ray

[dave thompson]

I agree with Dave Kirk; that frame weight is only a part of the whole equation. A very good example would be my Kirk Terraplane compared to my (ex)Litespeed Tuscany. Both essentially set up with the same components (except the Kirk had wheels made with Phil Wood hubs while the Litespeed had wheels with Dura Ace hubs), the Kirk weighed 21.75 and the Litespeed weighed 19.5, on the same scale. Both bikes were set up with basically the same fit, saddle/bar height, setback, reach etc. The Litespeed was a pig compared to the Kirk. It was sluggish in the climbs, didn't seem to respond to pedal pressure as quickly and overall seemed to have a slow feel.

Perhaps for pros' and riders of exceptional abilities frame weight would matter. However for mere mortals like me, based on my experiences, I would say the frame weight is a minor player in the greater scheme of bicycling.

[gt6267a]

I'm talking about having the amount of frame flex optimized for the weight of the rider and the type of rider they are.

this to me is a very interesting topic. if mr. kirk or others have the inclination to talk about frame flexing and the BENEFIT this has to a bicycle. I am all ears.

thanks,
k

[Ozz]

Frame weight only really matters if you are racing....and then, it really only when the road starts to tilt upwards.

Aren't most time trial and track bikes fairly heavy?

Even at elite racing, I think you are probably splitting hairs when looking at frame weight. All the bikes are pretty close in weight. How the rider feels on a given day, tactics, and help from teammates probably have more impact on who gets to the top of the hill first, than 8 oz of frame weight.

For me (and for most of us, I think), I prefer beating my time up to the top of my favorite climb faster on the same bike I rode last week, rather than a new, fancy carbon-helium combo bike. Then I know it is me, and not the bike making the difference.

:beer:

[djg]

It's not that weight is irrelevant, it's just that the whole context counts. In addition to efficient power transfer, we might just consider things like stability on descents (not all superlight "climbing frames" descend the way you might like, and if they don't that can cost you time or your butt or both) and cornering and the anti-fatigue value of comfort.

Moreover, even where weight counts, it shouldn't be overstated. In training and rec riding and many racing contexts, a half a pound just doesn't matter. Even in those racing contexts where it might really matter, it is what it is. If you start with a fina estampa you cannot make your bike five pounds lighter by trading frames, because a fina doesn't weigh five pounds and when it comes to competitors, there's nothing that weighs nothing anyway. You can probably save half a pound and maybe--maybe--a pound (remember, holding all other relevant factors equal). Saving half a pound is just saving half a pound--a marginal improvement in serious climbing at the limit of ability. That marginal improvement needs to be traded against other factors, supposing all else is not identical, and might or might not translate into a difference that matters in the context of the race.

I've never owned a fina and I've only ever ridden one Pegoretti (and that was briefly and it was a Marcelo, not a fina). But for a slug like me, the "extra" weight of a fina couldn't possibly matter. Even if I get a sudden boon in free time and dust off that old Cat 3 license, it still won't matter. For somebody, sometime, it might. Just not for me.

[jerk]

it matters. for the courses and applications for which the fina esatmpa was made it can not nor should it be any lighter than it is. a light weight climbing bike will feel "tinier" and not as snappy or as comfortable in a criterium or a relativly flat road race. that's why dario makes the cckmp too!
the fact of the matter is the reason why modern race bikes are made of aluminum and carbon is because it is impossible to make a race bike as light and as stiff out of anyother material. the fina is a great deal lighter than a similar performing bicycle made out of either ti or steel...eg a merckx mx leader or an oversized serotta ti.

[Climb01742]

the cckmp is the one peg i've ridden that i really didn't like. the U2 really buzzes. dario's heavier frames ride better, IMBO (in my butt's opinion :p )

[oracle]

yes - if all else is equal as stated above, then most simply stated, anytime the equation is watts/mass vs. watts/aerodynamics, then it is a big deal.

oracle

[William]

Frame flex is an interesting thing. My first road bike was a 60 cm (I think) Fuji Roubaix that I retrofitted for my size. That thing would flex like a mofo but it felt fast. It seemed to have the right kind of response (Flex) that complimented my power. I got a lot of jeers from bike snobs riding that bike until I started regularly beating them on it (the best form of revenge). The bike came to an abrupt demise on the last turn of a crit in a mass pile-up when someone decided to planted a pedal. I rode a few other frames that flexed almost as much after that but they didn’t feel the same. When I had my Serotta built the flex was certainly minimized and at first the bike felt slower to me. I was used to a certain amount of feedback from the frame that I wasn’t getting from the Serotta (Basically it was doing what I wanted it to). The thing was, it felt slower, but the clock said otherwise. Not by a huge amount, but it was on the average a bit faster (and a heck of a lot better ride). The Serotta was a heavier bike for sure but the extra pound or so didn’t make much of a difference.
I guess the point to my ramble is that it might be possible to have an optimum amount of flex that is in sync with your strength, weight, body type, and pedal style that allows a smooth flow of power from you to the pavement. Or you can go the other way and get a stiffer frame. That’s easier (and less expensive) then trying a bunch of different frames to find one that flexes “in tune” with you.

Disclaimer:
I’m not a scientist and I don’t play one on T.V.

William

BTW, I remember holding my Serotta frame in one hand, and a teammates Klien in the other. Both were the same size, but his was a heck of a lot lighter than mine. But on the road it didn’t seem to make him appreciable faster. As others have mentioned, body and rotational weight are better places to start shedding weight than frames.

Food for thought.

[dave thompson]

I'm talking about having the amount of frame flex optimized for the weight of the rider and the type of rider they are.

this to me is a very interesting topic. if mr. kirk or others have the inclination to talk about frame flexing and the BENEFIT this has to a bicycle. I am all ears.

thanks,
k
See Dave Kirk's 'treatise' on flex here: http://www.kirkframeworks.com/Flex.htm

[shinomaster]

it matters to me..I only weigh 144lbs and am more of a spinning clinber type..and I find that my cannondale just takes off faster under me. Less effort is required to move it.

My Atlanta is more like a truck. Slow to get started and accelerate with my limited power output. It's great for a flat road ride but I feel held back when climbing a 3 mile mountain on it..
If I were a power rider like Erik Zabel I'm sure the Atlanta would work much better for me.

[Matt Barkley]

Weight does matter - but not for most of us on this forum it seems. I do believe heavier bikes tend to smooth out the road a bit and give a more solid feeling by nature of their greater mass. Lighter bikes will climb long steep stuff more efficiently if they have at least reasonable stiffness...

Climb,
Very, very interesting.... I miss my CCKMP for a couple or reasons... Three that come to mind are: its light-weight, its springy - snappyness (especially when climbing), and its comfort - OVER the Fina Estampa!!! FUNNY and intersting!!
The Fina is great - really as all (and I) have already said. Drop me a line or email about your ride report on the CCK.... - Matt

[vaxn8r]

It matters. You guys are deceiving yourselves if you think it doesn't. Maybe if you are in a noncompetitive riding situation, or you live in Florida you want whatever you like the best. Heavier frames can feel more solid, connected, stable etc. People like those qualities in a frame. It deosn't mean light weight frames can't come close or duplicate those traits AND get you up a climb faster.

I think it's funny that some are comparing a heavy "efficient" bike to a lightweight "innefficient" bike. Like it's a black and white issue. What if the light weight bike is really efficient? Then which do you choose?

We all have our personal experiences. I live in the hills. That's where the races and training rides are out here and weight matters a ton (so to speak). I love riding my Atlanta but it is a penalty on every incline and every flat out acceleration compared with the boys on their 16 lb aluminum bikes. OTOH, on my Tetra Pro, I don't get near as fatigued at the end of a hard 60-70 mile ride with lots of climbs and changes of pace. I'm in the mix on my Calfee. I'm hanging on with the Serotta...unless it's flat of course.

It matters a lot.

[shinomaster]

ha ha the Vax knows of what he speaks!

[csb]

hell yes it matters + so does size

think in terms of backpacks +/or suitcases.

[David Kirk]

I also agree with Vax.......it's just that I feel that just being lighter doesn't make a frame better, or even faster. I feel strongly that the bike should be the correct stiffness for the rider.

If, as Vax stated, two frames are both the correct fit and stiffness for the rider then yes, of course the lighter one will be faster.

The tough part, as far as I'm concerned, is finding a light weight bike that has the proper amount of flex for the rider. If you weight 180 - 200 lbs then I think it's not too bad. If you weigh 150lbs. then it becomes tougher. I think this is due to the fact that most very light bikes are either aluminum or carbon. It's very hard to build an aluminum bike that will flex the proper amount and last more than a season. Carbon is much harder to generalize......all carbon is not created equal due to the dramatic differences in lay-up and % resin.

Anyway....it's dinner time. I just got back in from a ride and need to eat NOW.

Dave

[slowgoing]

I don't think it matters. It's other factors that make a difference.

A few years back I had a Kestrel 200SCi and upgraded it to a 200EMS. They had exactly the same dimensions. Went from 3.2 pounds down to 2.6 pounds for the frame. I couldn't detect one iota of difference between the two frames, even when climbing. I should have saved my money.

[Climb01742]

as david kirk said, it's complicated. my ghisallo is as light or lighter than any frame made. yes, it climbs very well. up to a point. it flexes like crazy. at the first acceleration of a climb, that flex works for me. but then the excessive flex begins to work against me, or at least eats up power. my cckmp is damn light too. but for me, how and where it flexes, and its buzzy ride, compromise its climbing effectiveness for me. now we get to my IF ti crown jewel. its light-ish...heavier than either the ghisallo or the cckmp...but lighter than many frames. but the folks at IF perfectly dialed in the right amount of stiffness/flex and maybe more importantly, dialed it in in exactly the right places for my style: bit more flex in the BB, nice and stiff in the TT/headtube. so for me, the heaviest of these three frames is the best climber by far. so while weight is a factor, in my experience, its not the most important factor.

[Roy E. Munson]

How does one determine that the frame is flexing and not the components?

And a general question - what does one qualify as something worthy to test a bikes climbing ability - a 10 foot bump, any mile+ hill, anything that is not pan flat or downhill?

[Too Tall]

Not for me. I have no talent and no lungs. BUT, I'd really look good on an uber-fly weight bike so there you have it a good reason ;)

[dbrk]

As a guy who routinely rides "heavy" bikes, such as full fendered and lighted Singers, Mariposa, and other audax-stylers, I never actually notice that these bikes are far more weighty than the featherweight Hampsten/Parlee Z1 or the Carrera Giove (an al/carbon blend). My C40 was likely lighter than anything other than the Fondriest I had but neither rode to my satisfaction, climbing, descending or seated. That's just me.

I am willing to give up something in pure climbing for descending. If climbing is cycling's offering to the deeper satisfaction of accomplishment, then descending is it's pure gift of freedom as speedy fun. I measure the quality of a bike almost exclusively by its power to instill ease, comfort, and pure joy in descending. That C40, for example, wanted far too much attention for my liking, just too requiring of attention. The MX Leader may be the best descending bike I've ever been on, akin of course to dropping anchor on a First Rate.

But to the point, imho, a properly designed bike makes you forget the weight unless you are a racer in which case speed, comfort, and riding in painful exertions are not only the principal but sometimes the sole purposes. Serotta has never marketed a bike because of it's weight. Serottas have never been lightweights in comparison to other designs and materials because Serotta has understood that weight as the _primary_ criterion in design is a misplaced notion. My lightest steel bike, btw, is a Rivendell built for fun and fast...and today's ride.

dbrk

[Climb01742]

douglas, ditto on the mx leader being an awesome descender. even i, the world's biggest wuss, loves bombing down on the eddy. its wheelbase and fork rake aid in that, too, don't they? remember in dr. strangelove, when the cowboy pilot rides a missile out of the bombay doors and whoops it up? that how descending on the eddy feels. a bit safer though. :rolleyes:

[William]

I can only speak from my own experience. In most cases, I don’t think the difference of a pound or so makes much difference. As someone who carries 80 – 100 lbs. More than the average rider, a difference of a pound or so means absolutely nothing to me. When I was living and training/racing in Oregon, we had any type of climb you could want right on our doorstep. Rolling, short & steep, long gradual grinders, and major climbs. When smaller guys who I raced and rode with (and against) switched from steel to Ti or carbon frames, they didn’t all of a sudden become Marco Pantani (RIP) on the climbs and drop everyone. Conversly, when I went to my Serotta which was heavier, I wasn’t all of a sudden getting blown out the back on the climbs. They couldn’t drop me on anything but the very steepest climbs before they switched (in which case I would catch them on the decent), and still couldn’t after.
In pack racing and criteriums, small variations of weight is not a huge factor. I think when you get to individual time trials, a fraction of a second is a much bigger deal. You can’t suck someones wheel, or take turns at the front to conserve energy. In that case a small variation in weight becomes a little bigger factor.

Now remember, I’m only talking small differences in weight of higher end bikes. If I was to jump on a solid steel tubed bike, and you were on your wonder light Ti-Carbon-Helium frame that weighed about 25-30 lbs. Less, then we can start talking about differences in weight (on the climbs).

That's just my opinion. :)

William

[BigMac]

One of the biggest misconceptions I hear from folks on street and even on this forum is somehow saving 3 to maybe even 5lbs using the latest plastic or alloy bike. If we consider an average 56cm frame beginning with lugged construction using butted ht steel tubing and yes a lugged steel fork that would likely be the absolute heaviest 'racing' frame available, no? I think you would find the average mass for such an animal to be 5.5lbs. Now keeping sizing identical but substituting a butted Ti tubed frame and composite fork, heck let's consider the Legend/F2 combo since that's likely among the heaviest available. The gross frame weight for said combo is likely 4lbs +/- 100grams -- 3lb frame, 1lb fork). Now the typical composite frame/fork combo in same size (make it Trek, Colnago, Parlee or what have you) would be 3.5lbs -- 2.5lb frame, 1lb fork. The lightest aluminum and handful of composites from Giant, Lightweight or C'Dale further pare that weight to just over 2lb frame plus the 1 lb fork, call it 3lbs. So reality using like for like is really 2.5lb mass differential from lightest to heaviest, a bit more in larger sizes although most flyweight frames are downright scary descenders in larger sizes, a bit less mass differential in smaller sizes. So the question is whether a maximum of 2.5lb frame mass differential means anything climbing the steepest of mountains.

I tend to agree with Dave Kirk, from a purely emperical standpoint frame mass has very little bearing on anything. I like his example of watts/mass wherein mass is described as a whole package of rider, bike and accessories, it is afterall the whole package which must be hauled up the mountain.

The problem however comes when we consider that mass located between the ears. The mind is an amazingly powerful and persuasive entity. It matters not whether we are talking about a boardroom presentation, a sales presentation, effort on a ballfield or cycling up Mt Ventoux, if one's outlook is focussed on success the chances for success are DRAMATICALLY greater than if one's mind were not focussed on success. What does this have to do with frame weight and climbing? If one believes they are faster on a light bike, they probably will be.

I have no substantiated test data to support my opinion, then again neither does anybody else as it would be nearly impossible to develop a true test vehicle to actually prove any weight benefit theories. I would however submit that if we considered an "average" 10km ascent that featured an average gradient of 6% and were able to eleiminate variables such as fit, rider psyche, nutritional anomilies, etc, the 2.5lb lighter bike would at the very most account for a 2-3 second reduction in time, basically meaningless for recreational purposes. If the rider were an extremely fit pro-level climber with extraordinarily high power-weight ratio, that time may climb to 10 seconds, max. In professional racing that may be quite significant but I also believe it to be somewhat optomistic for even the best climbers. The big difference however would be for the average weekend warrior-type who spends every waking moment considering how he/she can save an extra 5 grams and every disposable penny and then some accomplishing said weight reduction. For this individual, the bike mass is of little consequence in their results, rather they are so compelled to believe they will be faster that they are better able to put forth the effort that could save 30 seconds, maybe even substantially more.

In the end it does not matter what some testing or theories suggest, if the latest whiz-bang flyweight gizmo makes you ride harder and more often, indulge away. Just get out and ride with your best effort.

Ride on!

[David Kirk]

word up!

[csb]

my old SL tubed nova sucks at being pumped up hills,
its heavy, it always feels like i'm dragging a bag of
sand around on tour. it has a hidden bag of stones that
goes kachunk over every road seam.
it does adore going down a gravity fed ramp, it has a
substantial wheel base, and a pretty curvy fork, the
kind our fingerlakes friend pines over ( it is nice).
it just feels heavy + sluggish, hence it dont get out much anymore.

as BigMac says whatever makes it fun and
gets you out there riding great, even if its all just un-scientific perception.
i tend to agree with dave k + BigMac conscerning the weight of the overall package,
but heres where i differ _ i FEEL the weight of the bike when climbing, seated
and standing, the more weight the more annoying. i KNOW having extra
lard on my body makes it harder going also, but the weight i'm swinging
around underneath me is far more apparent. i cant stand those under
the seat tool scrotums for the same un-scientific reason.


i keep it because it is a nicely made, in general good handling bike,
just not for a lots of hills ride.

[Dr. Doofus]

Big Mac understands....

At the most, you're talking 2.5 pounds in the frame/fork...and 2 pounds makes a difference...but not a huge one. Your own body weight fluctuates by 2 pounds in a day. 2 pounds is a filled water bottle. 2 pounds is the chunk of wood that fills the space where one would expect W's brain to be. Sometimes the doc is two pounds lighter after a chocolate-python dookie. He and I digress....

Now, three or four pounds is a huge difference under any circumstances, but to get a 16 pound bike, you have to start cutting weight where it matters, namely in those large bits with rubber on them that go round that some call...wheels.

My CSi is a 19 pound bike, with Open Pros. Some of his buds with their Al-you-min-eee-um bikes have 18, 17 pound bikes, with Open Pros. Some have 16 pound bikes that don't ride too well on the roads around here, because they're running Ksyriums, or Race-X-Lights...but put those wheels on the CSi, and the Doc and I have an 18 pound bike.


The Doc can stay with the local Cat 2/3 morons becuase he was once a 2/3 moron himself, and even on his heavy Corsa 0.1, 370 watts at LT, at 71 kilos, is still faster than the average bear...although the doc and I should really put some Lightweights on the Corsa, as a tribute to Herr Jerk.


The Doc repeats this mantra: Unless you're getting paid, shut up about 2-pound weight differences. Even on long climbs. Its not your bike. Pass the Krylon, I need a whiff.

[Climb01742]

now...just to complicate matters further...in a completely angels dancing on the head of a pin sort of way...consider energy efficency. in last months cycling plus, there was an article on magnus backstedt (sp?). he said he's always breaking frames. if i remember correctly, he said at his peak, he can produce something insane like 1800 watts!!!! he also said something even more interesting. flexy frames he's ridden could eat up to 250 watts of his power. i mention it because of something i've experienced. riding up the same hills, same equipment except for the frame, i've had two very different experiences on my ghisallo and mx leader. ghisallo is very light but flexy. mx heavy but efficient. granted, without a powertrap like magnus uses, this is all subjective but the flex penalty of the ghisallo mitigates its weight benefit, while the efficiency benefit of the mx mitigates its weight penalty. on a short steep climb, give me the ghisallo. but on a long, steady climb, i'll take the mx. maybe a part of it, even a big part, is mental as bigmac says, but on a long, steady tough climb, efficiency seems to matter most. harkening back to mr kirk's wisdom, it is complicated.

[terry b]

Does frame weight matter? - I think the simple answer is "no." Up to a certain point (10 pounds perhaps?) the math does not seem to support bike weight loss as a means to gaining significant time (significant for most of us anyway.)

However, one of the attributes we all consider and discuss is bicycle weight. Perhaps that concern is academic, but like it or not, it is one of the questions that is nearly always asked when someone solicits opinions here in the ether. So when those questions arise, weight answers are going to be provided.

Personally, while I know that lighter is not going to make me faster, I still try to build light bikes because I like the way they feel when ridden. For me it's very simple, lighter = a more spry bike under my hands. Yet lighter does not mean everything I ride weighs 15 pounds. I have bikes out in my bike house that range from 16 to 21 pounds. I'm the same speed on all of them. The 16 pound bike feels sprier than the 21 pound bike, but I like both of them. While there are other 20 pound bikes that feel like pigs, I've never found a 16 pound bike that does. Very simple.

Since I seem to be the one Fina owner who has a different opinion about that bike's merits, I'll use it in comparison and ask this question - if the heavier bike brings nothing special to the table, in comparison to an equally performing lighter bike, why would you bother with the heavier one?

I have a Kirk and I have a Fina. Both equipped with Chorus and all the same components. The Kirk weighs 18.5 pounds (I asked Dave to build it as light as possible) and the Fina weighs 19.8 pounds.

Since ride is the one thing we are mutually concerned with here's my comparison - the Kirk is in a different universe. There is no comparision whatsoever. I know that the other Fina owners on this forum consider their bikes to offer a ride equal to that of steel, that however has not been my experience. My Fina has a pretty plain ride, not superior to any of the other aluminum bikes I own, and generally not equal to that given by my steel bikes. On my one bad stretch of road, it still beats me up.

Longevity is another area where we often consider aluminum at a disadvantage to other metals. Who knows whether my Fina will have the same lifetime. I have enough bikes that they'll likely never get more than 500 miles a year. Lets call that one a tie.

Beauty - both are gorgeous.

Stiffness and "raceworthyness" - I weigh 154 pounds and I don't race, I don't give a rip about either.

Cost - the same.

So, we now have a 19.8 pound bike compared to an 18.5 pound bike. The lighter bike rides much, much better and is about equal in performance, beauty and lifetime. If I had to choose one, the answer seems pretty darn obvious. Even if they weighed exactly the same, the answer is still obvious, beacuse the ride is better. But let's say that the ride is exactly identical - no detectable difference. The weight is the only variable, which one would you choose?

My question is therefore - why bother with a heavier bike unless it brings something extraordinary to the table?

[vaxn8r]

Doc, you are entertaining and funny. I wish I was either one. "Unless you're getting paid, shut up about 2-pound weight differences. Even on long climbs. Its not your bike. Pass the Krylon, I need a whiff." These are true enough words. You've raced and satisfied your ego. But is everyone else on this forum supposed to do the same because you did?

Terry b put it perfectly for me: "My question is therefore - why bother with a heavier bike unless it brings something extraordinary to the table?"

For me, I know what works and what gives me the results I want. If Doc thinks I'm bogus because of that, well, I agree, to a certain degree I am bogus because of that. But I know what makes me go and a lighter bike makes me go faster. Fortunately I don't need to go faster all the time. That's why I still own the Atlanta and the old Merkx. All good bikes bring something unique to the table. I suppose that's why many of us have so many of them.

[shinomaster]

doc. I doubt K's drop a pound of weight off your rig..as they only weigh a couple hunderd grams less than regular wheels..

Ok, my cannondale frame weighs 2.8 lbs and the carbon fork weighs 390 grams. My atlana must weigh at least five+ pounds because it feels like it has surplus military depleted uranium in the rear of the thing, and the Kinisis fork must weigh 600 grams with its steel steerer tube.

My atlanta with Neutron wheels weighs 20.5 lbs with chorus parts.
My Caad 4 weighs 17.75 lbs with the neutron wheels and record parts. About three pounds of bike weight difference.

All I know is that I can get up to the top of my regular mile long climb in a larger gear while accelerating on my Beer can. On my atlanta I feel more slow, and like I have a hangover or something.

Some of the difference is the responsiveness of the frame, but I know some is the weight too..I weigh very little so a few pounds is noticable to me and my pinto engine. I do the climb all the time and with my eyes closed I could tell which is the faster bike. It was very noticable when I first got the joyful Caad 4..

"so let it be written , so let it be done"

[mso]

Yes Frame wieght makes a difference. If you're a superlight climber and can not afford to lose body weight then YES a light weight frame makes a difference. Get the that bike down to 16 lbs and fly up the hills and you won't compromise stability down.