Has anyone been able to build up a pair of REAL sub 1350 gram wheels with what's available? Seems that using Chris King hubs 112g front + 264g rear + IRD cadence front 385g + 385g rear + Sapim CX-ray or DT Revolution + 200 grams = 1346 grams? I've contacted IRD asking if they'd sell me a pair of undrilled rims and it seems that this might work. These will be pure climbing wheels and with my weight of 128 lbs will this setup work? Wheels will be 18 front radial and 24 half radial/2x drive. I've heard some good things about Rolf Elan wheels but what the heck-this might be more fun. Any reply would be appreciate.

First, those rims are slightly heavier than 385 so you're going to need lighter hubs. Second, I have doubts such a light low profile rim will make for a sufficiently strong build considering such a low spoke count. Third, check Spocalc for bracing angles. The rear spoke pattern you've chosen might not be optimal for your hub/rim combination.

My lightest clincher build is:

Tune MIG 70 front hub 75g
Tune MAG 190 rear hub 191g
DT RR 1.1 28h 419g
DT RR 1.1 28h 421g
Sapim CX-Ray + nipples 280g

(laced 3x)

total: 1386g

It's quite a sturdy set suitable for everyday use. Stiff and almost 200 grams lighter than K-SL wheels. I've done about 1000K on these so far on mostly smooth roads but have also ridden them on some medium pave. They're still as true as the day I built them.

those rims are slightly heavier than 385

Mine came under 385, can't remember the exact weight (wrote it down though) but from memory they were 378 each.

chris king hubs are amazing but don't come in less than 28 holes. at least that's what they tell me when i call them up at the shop. great hubs though.

Build your wheels with some solid hubs and decent weight low profile rims like Open Pros or DT RR 1.1's and you'll see no appreciable difference in climbing between these wheels and wheels using Mickey Mouse weight weenie hubs that save a couple grams. Chris King hubs are not all that light either. Their advertised weight does not include skewers. The ad weights of Campy and Shimano road hubs include skewers. Throw on any sensible set of steel skewer weight to CK hubs and you'll see you pay a lot for very little weight savings over other hubs. A 1350 gram wheelset getting most of its weight savings from trick weight weenie hubs and spokes isn't gonna get you up the hill any bit appreciably faster than a heavier wheelset using the same rims, a few more spkes and heavier hubs. A few grams saved of hub weight means next to nothing in climbing.

According to pretty solid math weight saved for climbing = weight saved. It doesn't matter where it comes from because inertia forces are simply too small to consider.

If you really want light-weight hubs, try these:

http://www.soul-kozak.com/

I believe you can buy them through Mike Garcia (who can build a great wheel and would be a good resource for this kind of venture) at:

http://www.oddsandendos.com/

- khill

According to pretty solid math weight saved for climbing = weight saved. It doesn't matter where it comes from because inertia forces are simply too small to consider.

From an inertia, specifically change in inertia, lighter hubs really won't impact acceleration of the bike that much. Their mass is located too close to the axis of rotation to be a major player in the acceleration game. BUT what most people don't get or what people forget when talking about such things is that unlike the theoretical models where acceleration is constant, velocity is constant, cadence is constant, power is constant, and so on......the real life application of the numbers has two BIG differences: first, the efficiency between riders is gonna be different, which means the less efficient "model" will end up on the short end, and second, the human pedaling doesn't have some infinites source of energy. So while over short periods of time, near the beginning of a climb, you might be able to make crude theoretical approximations. At some point in the climb, the finite energy resources will start decreasing all the theoretical elements: acceleration, velocity, cadence, etc.

AND the theory misses and even bigger factor: if you are jazzed about new kit or feel you look better or just think you'll prolly be faster........you are more likely to be faster. Motivation is a great thing.

When the theoretical elements decrease won't changes in inertia become even less of a factor?

When the theoretical elements decrease won't changes in inertia become even less of a factor?

It's not that inertia is less of a factor. It's just that while inertia is important to minimize changes in acceleration as you climb, you also have to remember that energy expenditure is of increased importance in the real world, since an infinite energy reserve is assumed in the other theoretical models that people suggest. As for your question, for a rider as the energy resource gets low, low moments of inertia become more important, since that rider will have less energy to spend changing his accelration (thus, his velocity and inertia) with each pedal stroke.

A 200 gram savings (on the bike, you, your water bottle, your tool kit, your wheels) on a 6% grade is going to save you something like 8 seconds an hour. Very significant if you're in the Tour de France. Not so significant otherwise. It has nothing to do with rotational kinetic energy, cadence, inertia, and very little to do with speed. It's just about lifting weight against gravity and the power required to do that. Not a "theoretical model" - it's called Newtonian physics. Most would consider Newtonian physics to be proven fact.

A 200 gram savings (on the bike, you, your water bottle, your tool kit, your wheels) on a 6% grade is going to save you something like 8 seconds an hour. Very significant if you're in the Tour de France. Not so significant otherwise. It has nothing to do with rotational kinetic energy, cadence, inertia, and very little to do with speed. It's just about lifting weight against gravity and the power required to do that. Not a "theoretical model" - it's called Newtonian physics. Most would consider Newtonian physics to be proven fact.

Sure assuming that some very important variables remain constant. I've said nothing that violates theory behind Newtonian physics: I've only re-posed the question that people usually pose in terms of a lot more real world variables. That 8 second difference you calculate cannot be accurate unless you can specifically characterize the person in question. And for what it's worth, in the end I wasn't necessarily referring to some time difference. For some rider, how far they go might be more important, or how they feel when they get "there" might be more important. In those terms, a given person just might go farther, feel better when they get to the top of the climb, or once at the top of the climb, they might have energy to get back to where they came from.

As for the assertion that it's all about working against gravity and the power required to do that: of course. I didn't say any different. What I was asserting was that, first by thermodynamic law, no machine, such as the human body, can by 100% efficient. That machine's efficiency will determine what amount of work it can do, given a certain power output or given a specifc finite energy source. If you would feel better if I instead said energy spent per unit time (power), so be it. If you'd like me to say something in terms of lifting weight against gravity (work), fine, I can do that. But that doesn't change the fact that you're still talking about energy (in this case, doing work to increase the potential energy of the bike/rider system and to put/store energy in rotating extended objects.).

Again, I didn't put forth anything contrary to physics. I had suggested that a change in the mass of a hub would have less of an effect on inertia, specifically rotatational inertia. And I said that in the real world, there were other factors to consider that might be of greater consequence.....like the limited energy reserve of a given rider.

Finally, there's nothing in physics that explicitly quantifies how a person will "feel" at any point in a ride: there's no variable for "feel" in a Hamiltonian, in the Lagrangian, or any other expression of energy. Feel is part physics, part psyche, and maybe part self-delusion. And how we "feel" at a given point in a ride and how we are able to make ourselves perform with that "feel" is really what the questions like this are all about. They're part physics, but no wholly physics. And while in physics, we physicists like to express problems as nice, tidy systems that ignore certain variables, the reality is that these variables can have a significant impact on the problem and cause the real solution to be quite different than the modled solution.

American Classic hubs are available in the drillings you're after, and they're only 58 g front/220 g rear. The IRD rims are certainly the best ones for your project. It's certainly doable, whatever the case.

If I'm not mistaken, when this topic comes up, you frequently make what seem to be vague references to "real world" issues that those using "theories" in models with which you seem to disagree. Yet, the stuff you bring up (how a rider feels, etc.) are not what is in question. The question is how much power is required to accomplish a given task under different circumstances. Is there any chance you could clearly articulate why these calculations are not applicable to simple cases like riding on the flats against the wind or climbing a hill?

If I'm not mistaken, when this topic comes up, you frequently make what seem to be vague references to "real world" issues that those using "theories" in models with which you seem to disagree. Yet, the stuff you bring up (how a rider feels, etc.) are not what is in question. The question is how much power is required to accomplish a given task under different circumstances. Is there any chance you could clearly articulate why these calculations are not applicable to simple cases like riding on the flats against the wind or climbing a hill?

No he will not clear it up or explain it. Because if he were forced to explain the incredibly minute differences in performance which minor weight savings at the hub results in it would be laughable.

Likewise Divwe says its solid math, yet does he provide any "simple and solid" clarifications or examples of exactly how much performance is affected by a couple grams saved at the hub. No. Just the earth shattering revelation that solid math says any weight saved helps climbing, wow, musta gone to MIT to come up with that brilliant observation! If he were to provide some "solid and simple" mathematical numbers it would be pretty "simple" to realize how incredibly little hub weight changes affect performance. Pretty simple and solid huh?? Well maybe not for some.

If you really want light-weight hubs, try these:

http://www.soul-kozak.com/

I believe you can buy them through Mike Garcia (who can build a great wheel and would be a good resource for this kind of venture) at:

http://www.oddsandendos.com/

- khill

what about American classics? There only a few grams off pre hub.

I just ordered a set from Dave Thomas. Arrowhead rims w/ AC(20) front hub and Tune(28) rear, claimed weight is 1355. We'll see in a few weeks. Kind of concerned about durability, but at 140 lbs I think I'' be OK. Only one of my normal routes is on rough roads. Only had one conversation with him so far, but he was great to deal with.

I just ordered a set from Dave Thomas. Arrowhead rims w/ AC(20) front hub and Tune(28) rear, claimed weight is 1355. We'll see in a few weeks. Kind of concerned about durability, but at 140 lbs I think I'' be OK. Only one of my normal routes is on rough roads. Only had one conversation with him so far, but he was great to deal with.

Great choice. I have two wheelsets from Dave. I use them all the time on both bikes. One is an older Aerolite wheelset I have been using a couple years. The other is the same one you ordered. Mine came in at 1346g. I've had the chance to ride them on three occasions now. They're wonderful. You'll be very pleased. I've no concerns about durability for them (I weigh 158-160). Top notch builder. Enjoy them.