RoadBikeReview.com's Forum Archives - Components
rims, especially bill shook rims (not spam or advert.)(44 posts)
|rims, especially bill shook rims (not spam or advert.)||novice|
Dec 16, 2001 9:22 PM
|According to his website he has a 350 gram 700c rim, and a 420 gram deep section aero rim available. The only aluminum rim I know of that comes close that weight is the one used by nimble on their spyder model (I think), it is supposed to weigh in at 375 grams. I have seen the nimble rim, and was dissapointed. The joint where the rim is normally welded togther was "glued" togther. This created quite a rough junction that looked like it would tear the sh!t out of a set of pads. What I am looking for is info how the seem on the bill shook rims is joined. Is it also "glued"? Essentially what I am looking for is any info on these things. They look great on the website, but will they hold up? Do they have eyelets? Do they have anything? There is a definite lack of technical infomation on these rims out there. Asked around at a few lbs's and was told that they saw them at interbike, but that was it. They just said he is making rims using less material, which he must be, and that quality was a huge question. I am looking into this as I am looking for new set of wheels. They can be race only as I already have a pair of open pro's laced to ultegra hubs, although quite beaten. So I am looking for a durable, for a 140 lbs rider, rim that has a low mass. And I am not looking into zipp's. My other choices besides the shook rims are the velocity aerohead, and possibly the open pro's again.|
Dec 16, 2001 9:28 PM
|you guys are right about the mass quantities of bill shook questions. The reason I am interested is a few guys on the weight weenie mtbr forum are using his ISIS splined bottom brackets. And whilst perusing his sit I happened upon these rims. Seem cool, but I don't want to have to buy new rims within the next year or two because these things crap out on me. Whilst I am asking questions, how about those american classic/bill shook hubs? They too look cool, but 68 grams for the front seems like a durability nightmare.|
Dec 17, 2001 3:16 AM
|I have a pair of the hubs built by A/C with Velocity Aeroheads, about 2,000 miles, and they have been durable (so far). They are 32r/28f with Wheelsmith XL spokes and weigh 1427 grams.|
|rim weight is one of the biggest lies in cycling||nm|
Dec 13, 2001 1:05 PM
|how do you figure that?||novice|
Dec 17, 2001 8:37 AM
|rim weight is 100% rotating mass. the lower the mass of the rim, the lower its moment of inertia. the lower its moment of inertia the less power it takes to spin the wheel. this is according to the simple formula of kinetic energy (rotating) = I(moment of inertia) * omega^2 (radial velocity, expessed in rad/s). as far as i am concerend rim + tyre + tube mass is the most important mass on a bicycle because it is all rotating mass.|
|simple- mfger says 400, actual is 430||nm|
Dec 17, 2001 8:47 AM
|because of manufacturing tolerances...||ohio|
Dec 17, 2001 11:47 AM
|They're not necessarily lying. What they're actually doing is using the rim weight from the first run of rims out of a given tool. Extrusions (used for any tubing and rims, among other things), especially the double and triple cavity ones used for rims, are much more effected by tool wear than, say, forging or CNC machining, because as the tool wears away it allows that much more material left behind over the entire length of the product. Depending on the manufacturer's tolerances, rim weight can more than 10%. The more often they change the tool, the more consistent the rims, the more expensive the rims. I have a feeling this is one of the biggest reasons Mavics are more expensive than others: they change their tools more often (that's a guess. I have no proof).
So if you're a true weight weenie, weight the actual rims at the shop, and pick the lightest ones. Don't go by catalog weights.
As far as shook rims go, I have no knowledge of the rims, but I can say that unless he has created some new stronger alloy (which he hasn't), or he has invented a new rim cross-section (which he hasn't), or knows something that mavic/sun/velocity don't (unlikely) the rims are either heavier than claimed, or unsafe. Last possibility: he trusts his own wheel-building skills enough to use rims that other manufacturers wouldn't, because they don't trust people will have the skill to build them strong enough.
|manufacturing tolerances my @$$ !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!||Rusty McNasty|
Dec 17, 2001 3:22 PM
|OK, if it is "manufacturing tolerances", then why is the rim ALWAYS heavier than advertised??? Has ANYBODY ever found that their rim weighed LESS than was claimed??? If it really is manufacturing tolerances, then you would see as many OVER as UNDER!!!
No, it's lying, pure and simple.
|i've seen rims under manufacturer spec||novice|
Dec 17, 2001 5:19 PM
|i've seen both mavic x517 and bontrager valient mtb rims under the spec. check this out http://forums13.consumerreview.com/crforum?viewall@@.ee99edb this is under the maufactorer spec.
And you would think that you would see as many below, but the spec weight is not an average of rims, it is usually the lightest they made. This means that if you see a rim under spec, it is truly a rarity.
|is this the kind of thing...||gtx|
Dec 17, 2001 5:35 PM
|that keeps weight weenies awake at night?|
|no just laywers...||esq|
Dec 18, 2001 5:42 AM
|ever hear of truth in advertising?|
|manufacturing tolerances my @$$ !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!||Woof the dog|
Dec 20, 2001 9:23 AM
|if you go to www.damonrinard.com and then go to a page of component weights (there's a link there), you may see, I think, that some rims are actually lighter by some grams than the advertized. Not sure though.
Woof, I like light, but not too light rims dog.
Dec 20, 2001 9:53 AM
|If you actually read and understood his post you'd know why extrusions tend to be heavier as time goes on. Since you didn't I'll make it really simple for you. Alloy rims are extruded, that is they are forced through a die under high pressure. There is a lot of friction involved and material actaully gets worn off of the die making it larger. A larger die means a larger extrusion, which in turn is heavier. It's no suprise that a mfr. will weight the extrusions at the beginning of the life of a die and see the weight drift upwards. At some point the decision has to be made to scrap the die - and this costs money. What you were thinking of was a white noise type of random (normal) statistical distribution - which is not the case. |
You should engage your mind before the keyboard.
|Does that make it right?????||Rusty McNasty|
Dec 20, 2001 12:57 PM
|If Mr. Schnook is going to advertise his rims as weighing xxx grams, I'd be damn pissed if mine weighed 40g more! Any honest manufacturer would at least figure what the weight of a rim at the end of the die life will be, and average the weight for the run. The weight could then be advertised as weighing xxx grams (+ or - yy grams). This would be proper.|
Dec 21, 2001 10:38 AM
|I guess that makes you pissed at the entire bicycle industry. Do you really think he's going to do that when the rest of the industry does it the other way and lose sales to weight weenies? You going to sue Mavic for false advertising? Their wheels consistently weigh more than advertised. |
The end of the life of the die is a very subjective thing and is driven by business decissions as much as technical considerations. You can bet your bottom bracket that the teams get first run stuff while the general consumer gets what comes after.
My real beef was with you using all caps and lots of !!!!'s and being totally wrong. You come off like a reactionary wet hen.
|You come off like a reactionary wet hen.||haha|
Dec 21, 2001 11:13 AM
|FUNNY! AND YOU DON'T???|
Dec 17, 2001 8:47 AM
|It is one of the most important weights on a bicycle. Which is why manufacturers have the greatest incentive to lie about the weight, or at least, creatively report the weight.
Past antics have included things like weighing rims without the eyelets, or making 24" rims and reporting that weight.
Furthermore, with clincher rims, due to their manufacturing process, the first rim off the die will be up to 30% lighter than the last rim off the die. Of course, most companies report the weight of the first, and conveniently ignore that only one customer will get this rim. The only honest way to do it, is to report an average weight, preferably with a standard deviation- some do the avg, but I've never seen a standard deviation listed.
Dec 18, 2001 7:06 AM
"...Furthermore, with clincher rims, due to their manufacturing process, the first rim off the die will be up to 30% lighter than the last rim off the die."
Just curious how you came upon this definitive information? Do you have inside information provided by a rim manufacture?
It seems strange to me that a manufacture would let their tooling wear to the point where they are getting 30% weight variation. I have personely witnessed true CAD/CAM aluminum extrusion dies being produced. The entire die production only took a few minuets. No doubt a large company like Mavic would have similar tooling capabilities. I would venture to guess that they have a maintanence process to change these dies on a regular interval. Considering the ease of producing these dies, why let them go to the point of getting 30% variation? Very strange.
Dec 18, 2001 8:38 AM
|I was told this by the Mavic service center, when I called them to complain for a customer who's clincher Heliums weighed about 20% more than they should have. His answer was something to the effect of: "our tolerences allow for the weight to go as high as 30%, so you're guy is lucky to have them only be 20% too heavy." That wasn't quite how the customer saw it...Granted, this was in the Helium era, which was ~4 years ago.|
Dec 18, 2001 9:23 AM
|that means a rim that is supposed to weight 400gm might weight 520! seem like a bit of a stretch to me|
|I can't help it...||TJeanloz|
Dec 18, 2001 9:28 AM
|Maybe the Mavic guy was trying to cover himself and make the rim I had not look so bad? I don't know. 30% is the number they gave me, and my jaw dropped when I heard it too.|
|Sounds like Mavic bs||Nessism|
Dec 18, 2001 10:58 AM
|Sounds like Mavic passed some more questionable information along to cover their a$$ regarding their over weight Heliums. Also realize that production weight tolerances for a wheel set will be higher than for any one of the components considered seperately.
It seems impossible that Mavic would allow rim weights to vary 30% within the same part number. The rim dimensions would have to grow significantly for this to happen. Also consider that the sidewall machining process would remove any extra material from the sidewall that the worn extrusion die left behind. Ten percent, or 40 grams for a 400 gram rim, sounds more like a reasonable range.
|i think this only matters during acceleration||surf|
Dec 17, 2001 11:46 AM
|and also in deceleration (nm)||mclements|
Dec 20, 2001 9:31 AM
|Oh boy, here's a can of worms.||jw25|
Dec 17, 2001 12:21 PM
|I have no knowledge of the Shook rims, other than website info. They're supposedly made of a new alloy, which helps explain the lower weight, but I'd worry about cracking around the spoke holes and effects of high inflation pressures. |
I also have to keep reminding myself that rim weight is only a factor during acceleration, and a minor one during climbing. Anywhere else, it's pretty moot. Sorry folks, but that implies the same thing for tires. I think a lot of the effect is psychological, anyway. You put a light set of "race" wheels on the bike, so you know it must be faster. That should start the flame wars.
If you really want them, you're going to be a guinea pig, or else wait a year, and see how the testers this year fared. I want to believe in them, mostly because he offers a 16 hole version at a reasonable price, so I could rebuild my Cosmics, but it's almost too good to be true.
The hubs, on the other hand, seem like the real thing. I just built a set up, and they are light! Bearings aren't bad - the front spins forever, and the rear should get better as the seals break in. They've been around for a year or two, so there's a decent number of reviews to go by, and most seem good. I built them up with CXP-33's , though, even though they're 470 grams claimed.
Of the rims you mention, I'd go with the Velocities. They've been around, American Classic uses them in their prebuilt wheels (as do Velomax, Cane Creek, and others), and they're pretty darn light. At 140 lbs, you could go AC hubs, 28 spokes (something nice like Revolutions or Sapim Lasers) to Aeroheads, and have some impressively light wheels that should last, and won't break the bank. Actually, American Classic's prices for prebuilts are pretty good, it might be worth going that route, and just checking tension and true yourself.
I hope this is helpful - there's a lot of info out there, and it can get hard to sort through the hype sometimes.
Dec 17, 2001 2:06 PM
|I can do the calculations on this, but a wheel requires power (read: kinetic energy) to keep it spinning, even at a constant speed. It might not be that signifact, I have towork out the calculations still, but I can tell you that the less you weigh with you bike, the greater degree of significance this would have to where your power is going. This is because the power you exert while riding goes to spin all rotating parts and then push you and your bike through time and space.
And as far manufacturers lieing about rim weights, that doesn't make the mass of the rim any less significant. It still matters, it just means that you have to do some research on on how far off the manufacturor is off in its estimate of rim mass. From what I have seen, the mass of the aerohead rim is a little above 400 grams. http://damonrinard.com/weights.htm#clincherrims
yeah, so I am still looking for a light rim. Any suggestions? As of right now, I am heavily leaning towards the velocity rims, but I would like to know some info on those. Do they have eyelets or just holes drilled in them?
|Physics novice too?||Kerry Irons|
Dec 17, 2001 5:05 PM
|I'm sorry to burst your bubble, but kinetic energy is something that is increased or decreased when velocity changes. When a system is at constant speed, KE is constant, and therefore no additional energy is consumed or released as a result of the KE component. The energy required to keep a wheel spinning is bearing friction and aerodynamic drag, it has ABSOLUTELY NOTHING to do with KE. The only place that rim/tire weight have special meaning is when you accelerate. When climbing a hill, the weight savings of light wheels is the same as the weight savings of not carrying a multi-tool in your seat pack. The ONLY place that light wheels have any significant impact in cycling (as compared to non-rotating weight) is when you are constantly accelerating and braking - a crit.|
|KE is not constant||novice|
Dec 17, 2001 5:31 PM
|This is because of the friction between the tyre and the road, tyre and tube, every bearing, and the air. Air resistance is especially important for wheels as the top of a wheel travels through the air at twice the speed of the bike. If kinetic energy was constant it would imply that these resistances do not exist. But they do.
Beside that point I am scheduled to race a few crits this spring. Therefore this is a fairly important matter for me.
|Do the math?||Kerry Irons|
Dec 18, 2001 5:50 PM
|KE = 1/2mv^2 (one half of the mass times the square of the velocity). If velocity is constant, then KE is constant, therefore no additional energy is required once the wheel is up to speed. The energy required to get a bike and rider from point A to point B is the friction and air drag losses plus any change in KE and PE (potential energy change due to change in elevation). On flat ground at constant speed, there is no change in PE or KE, and therefore no additional energy required as a result. Once the wheel is spun up to speed, that's it. It's hard for me to understand how you can be so emphatic about this, when you don't clearly understand the physics.|
|Is there such a thing as rotating weight?||koala|
Dec 17, 2001 6:33 PM
|I thought it was inertia when rotating and weight when static. You can tell physics class was a while ago.|
|technically it is rotating mass.||novice|
Dec 17, 2001 11:57 PM
|The action of rotating a mass creates a moment of inertia about the center of gravity of the mass.|
Dec 18, 2001 1:13 PM
|... while we are being technical: ANY given mass has a specific moment of inertia about ANY given pivot point. The mass doesn't create the moment, and it does not have to be about the center of mass (or "gravity"). AND, as stated before a moment of inertia and rotational acceleration are analogous (but not equal) to mass and linear acceleration. It is also true that wheel rotation comes into play for braking and accelrating but not for maintaining a constant velocity (except for the issue of air resistance of the spokes, which is NOT an inertia issue).
However there is an additional issue, and that is the gyroscopic inertia of a wheel, which effects it's ability to move laterally, or pivot about an axis IN the plane of the wheel (turning the fork moves the front wheel in both of these manners at the same time). Since you're front wheel actually turns very little and very slowly in most road riding this makes little difference. However in crits, there ARE times when you actively steer the front end, or saw the bike side to side when sprinting, so again, light-weight helps for crits.
Dec 20, 2001 12:53 PM
|A mass a rest has a moment of inertia, just like it has a CG - it's not "created" by rotation. It is a property that exists on it's own and requires no action. Does a higher value of rotation create a higher moment of inertia? Nope. |
The only difference between a rotating weight and a rotating mass is the gravitational constant. In the English system pound mass and pound weight are freely interchanged. Not too many people quote mass in "slugs" the unit for mass in the English system.
If you want to get technical you need to aquire the knowldege first - something you've overlooked.
|or going up and down a series of small hills.||dzrider|
Dec 18, 2001 6:55 AM
|As one who never races this is the situation where I notice lighter wheels. Getting back up to speed is much quicker and easier after I top one of the many little hills that make up so much of the riding in central Connecticut.|
|Conservation of energy||Kerry Irons|
Dec 18, 2001 6:21 PM
|When your bike slows down, you get back the KE that you put into spinning up your wheels. Lighter anything makes climbing easier, but lighter wheels are not special relative to any other weight savings. In a crit, you put energy into spinning up the wheels, and then you turn it into heat when you hit the brakes. You never get that energy back. But your wheels are small flywheels - if they are heavy they take more energy to spin up, and they give more energy back when they slow down. Lighter wheels take less effort to spin up and give back less when slowing down. The effect cancels.|
Dec 18, 2001 7:20 PM
|The rotating mass, as well as the aerodynamics, of a wheel are more important than other weight savings/areodynamics. This is because not only do you have to push the mass of wheel forward, you also have to spin it. The reason aerodynamics are more important is because the top of the wheel is travelling through the air at twice the velocity of the bike.|
|Once again, DO THE MATH!||Kerry Irons|
Dec 19, 2001 6:38 PM
|"This is because not only do you have to push the mass of wheel forward, you also have to spin it"
You keep repeating this statement over and over but the simple physics do not support it. Spinning up a wheel takes roughly twice as much effort as accelerating the same (non-rotating) mass to the same speed. Once that is done, there is no difference whether the mass is rotating or not. The ONLY time it makes a difference is when you accelerate. The math that proves this is overpoweringly simple. What's not to get?
|if I can butt in here||Dog|
Dec 20, 2001 9:19 AM
|While the math is very simple, reality isn't that simple. As someone noted, actual bike riding requires numerous accelerations, whether they be from intersections, corners, falling back in a paceline and catching up (if you don't do it right), surges in races, blasting up hills, slowing inadvertently and then getting back up to speed, rough roads, etc. The causes are nearly infinite. So, I don't think simple math reflects the "real world" very well. No one rides that steadily, unless you are talking about a flat, straight, timetrial. Plus, the kinetic energy is not returned anywhere near 100%. Every time you brake or corner, you are scrubbing off energy that is lost to heat.
On the other side of the balance, I don't think drag numbers for wheels reflect real riding, either. Anyone who's ridden a deep section rim in gusting cross winds will attest that you can spend a whole lot of energy, and not just in your legs, keeping the bike on path. Some drag numbers for apparently aero wheels become fairly high at some wind angles. Plus, the drag numbers, at least when given in terms force, likely don't reflect realistic speeds most riders on this forum experience. I know I can't timetrial at 30 mph (well, no more than about 10 seconds). There is a huge difference in drag between 20 mph and 30 mph, and many riders actually average in the 15 mph neighborhood.
I think there is one fairly obvious solution. Try to maximize both in a compromise for the "real world" riding that you do, and possibly having different wheels for different events or conditions.
The over all "best" compromise of a high performance wheel I can see is the Zipp 303 tubular. It's about 40mm deep, which combined with the tire gives a pretty good aspect ratio. They aren't overwhelming in cross winds. At around 1250 grams a set, they are lighter than most wheels noted for their lightness. Their spoke count is mediocre, and I don't think they are bladed, so they aren't ideal there. But, I think they are a great over all compromise for a high performance wheel. Can't choose between light and aero? Get both.
Dec 20, 2001 12:46 PM
|Here's the deal - the guy keeps bringing up kinetic energy, both linear and rotational, then freeely starts mixing in losses like friction and aerodynamic drag not recognizing that there is a systematic and discplined way to go about the analysis. Ultimately he doesn't know enough to understand that the energy is always there via conservation and that the losses occur no matter what. Kerry keeps bringing up the reality of conservation of energy, which is a really big deal if you want to understand anything, and has made the point that if you do the math (and it's very simple) one would understand. Essentially you have a poet tossing around terms that he doesn't understand and is unwilling to either listen or use his brain to increase his understanding. As to what his point is it is not clear. It sounds like he wants to make sure he has an advantage in some upcoming crit races not realizing that there will be guys on "inferior" equipment that will blow him away b/c they trained and skipped this discussion. |
If you don't believe that the math and numbers explain everything that is going on then we're lost as a people and have no business flying airplanes and sending men into space. This stuff is really child's play. What makes it difficult is trying to have a discussion with people who have huge differences in background. That and the fact that there is so much misleading marketing hype when it comes to aerodynamic issues that the average joe doesn't know what to think, nor does he have the tools to make the judgement.
Bottom line: buy the lightest wheels that you can afford and will meet your criteria. Everyone has slightly different takes on what this means so there is more than one answer.
|but over simplified?||Dog|
Dec 20, 2001 1:02 PM
|I think these concepts are pretty simple; it's just that reality is not that simple. Take some wheel test data and then try to predict what would be fastest over a 100 mile hilly course. I think it would be about as simple and accurate as predicting the weather three years from now. Sure, we can confidently say that it will likely be colder in December than it will be in July in Kansas City, Missouri, but try to predict the temp or rainfall for the day? Can't do it with any degree of confidence. That's my point, that's all.
Oh, and I agree with your point about all this being academic. The motor wins races. The only counter-point is that equipment choices actually matter more to the weaker riders than the strong, sort of contrary to common belief, I'd imagine.
|but over simplified?||grzy|
Dec 21, 2001 10:31 AM
|Well, what you're talking about is the experimental results in real world conditions. As you pointed out there are lots of other variables that make things a lot more complex than the theory suggests. To that I totally agree - it's long been recognized as a problem. What it really points out is that the technical specifications of the wheel and bearings can be measured and well understood, but there are much larger factors at work. This flies in the face of so much advertising hype that wheel XXX is Y% faster in a wind tunnel test with such and such a cross wind angle and therfore you should buy it. The real world is far more dynamic. What is known is that if something has an advantage for some reason in the lab it will not suddenly go away in the real world, but it may not be that important in comparison to other issues. |
Ultimately the original poster kept dropping technical buzz words with no understanding of their meaning or significance. While a particular advantage may benefit a weaker rider more you can't get away from the fact that the weaker rider is still weak. It's pretty common for people to start obsessing about their equipment and forget to go ride. He seemed to imply that if he got just the right wheels he might be victorious in his crit races. At the front of any pack all of the riders' equipment is spot-on and the better rider rules the day. You can't win with a flat tire.
Ultimately I think there is a lot of value in understanding the underlying principles, but it's pretty easy to miss the forrest for the trees. Anyone can take a 1st year physics course and increase their understanding, but it takes more experience to understand the tradeoffs and the whole idea behind the order of magnitude. Throwing in the frictional forces and aerodynamics is not a casual thing. Understanding the tradeoffs doesn't come naturally and there is a lot of misinformation out in the cycling press. The whole concept of "no free lunch" eludes many people.
|another rim choice||novice|
Dec 17, 2001 2:33 PM
|browsing around on the net I just found the sun ringle website. From it I see a few rims that I could use, the assault, me14a and the venus. Anyone have any info on these things. They have eyelets, which is nice to know. But are they true to their post masses for these rims?
|sun venus||gary b|
Dec 17, 2001 3:03 PM
|I had a set of the Sun Pro Race wheels made with Venus rims. The eyelets started pulling out of the rims within a month and the new set (warranty replacement took 6 months) were already pulling out when I received them.
I rebuilt the hubs into Mavic Open Pros and never looked back.
|sun venus||Woof the dog|
Dec 20, 2001 9:18 AM
|my venus rims filled up with water, especially the back one in pouring rain. Hmmmm