BigMac on Wheels

There are a number of different posts here on the topic of Wheels. Of particular note are the "Tubular vs Clincher" & "Big Boy Wheels.

William

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I think Flydhest here raises an interesting point, is there in fact ANY verticle deflection in a quality built wheel? I'm not a physicist or engineer and thus will not attempt any scientific diatribes based on nonsense thats way beyond my minimal comprehension. I would however suggest that if there were in fact any vertical compression at say road patch area (call it 6:00), would that not require some horizontal expansion at both 3:00 and 9:00 positions? Just a hypothication that I'll leave to far smarter folks than I to debate.

Now from a practical standpoint of personal experience I notice a dramatic difference in feel between certain rims and spoke lacing pattern on front wheels. Sticking with a somewhat apples-apples comp, not deviating to composite rims or spokes and always using sewups only, there is considerable difference in feel between a traditional box section rim and a deeper section aero or "v" rim using identical spokes and spoke lacing. Similarly, there is considerable difference in feel between a radial laced front wheel vs. a traidtional 3x pattern, each wheel using similar rim, hub and spoke guage. Why? Is this a product of vertical compliance? I would suggest it is more likely a case of hf vibration energy dissipation, but that's a non scientific hypothication. Radial lacing and deep section rims use shorter spokes which more efficiently transfer hf frequencies than longer, lower tensioned spokes used in box section, 3x patterns. Does that make any sense? I would further suggest there is little torsional load on front wheel, at least in my expereince even during high speed descents at large lean angles. Why? I do not know scientifically however I tend to run my brake blocks very tight to front rim for better brake response yet do not recall ever experiencing brake block rub under any load on a true rim. Then again I have never spent much time on weight weenie rims like GL280, Fiammes, Assos or similar designs.

Rear wheels are a different beast altogether. These are under tremendous torsional load. I know this because I have experienced brake pad rub on many occasions under heavy sprint or climbing and that's with several mm's of brake block clearence at setup. I would still question the vertical movement hypothication, I have never had brake blocks rub tire side walls for example or a tire rub at forward section of a rear fender indicating a horizontal flex at 3:00 position. Now my real question is why some wheels with poor torsional flex characteristics ride so poorly -- harshly to borrow the phrase used by others. I would offer the original Ksyrium sewup wheel as an example. This wheel felt buzzy and harsh over my normal riding terrain compared to my handbuilt 32/36 3x sewup reference wheels using same sewups at similar measured pressures yet under load it was not difficult to induce enough torsional flex from said Ksyrium to cause brake block rub in rear. I rarely experience similar brake block rub with my 36H 3x handbuilt reference wheel. Was this the product of fat bladed spokes? Massive and deeper section rims? FWIW: I have ridden several examples of this same wheel and each time felt very similar. Among the pre-builts, the Campy Nucleon (now named Neutron) is the smoothest riding sewup wheel ime, and reasonably stiff torsionally with good rider form. The Bontrager Race X-Lite ('02 version sewup) is a bit stiffer torsionally and perhaps a touch less smooth but it too is an excellent DC duty wheelset, ime. I also really like the Hyperon for silky smooth ride and very good torsional stiffness however we're talking a whole different price range which I personally feel is waaaaay beyond reasonable w/o any real gains for anyone short of D1 racers.

I realize this is a deviation from the original posters comments regarding a clincher wheelset which i have no experience with, I just thought Flydhest question regarding vertical rim compliance was an interesting one that seemed to go unaddressed. Then again I did not necessarily answer his hypothication, rather I further muddied the waters with more questions for which I am personally unqualified to answer from a scientific/engineering standpoint.

BTW: Discount ANY and ALL wheel mass claims by most firms, that includes rim mass claims as well. There is no industry standard regarding published wheel masses concerning with or w/o QR's, even when such is specified the claims are often laughable versus actual production examples weighed on properly calibrated scales. Mavic rim weight claims are often 8-10% less than reality, just as an example.

Ride on!

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Zap:

Now you've really got me scratching me head. Are you suggesting a rim diameter, or circumfrence if you prefer, decreases as we tension wheel during build process? This cannot be true, a circle could not shrink in diameter and still be a circle, no? Now if a rim were delivered out of round, yes its shape would change during build-up (to round and true of course) but honestly only the really bad rims are typically delivered out of round to any considerable degree. Now I suppose if you secured a wheel in a stand and pushed very firmly downward on rim its possible to acheive a very infinitesimile amount of vertical compliance but honestly this wreaks of non-real world testing techniques. Certainly a wheel with tyre mounted and inflated to 100-110psi would never realize such a load excepting for event of crash or severe pothole experience. Under 'normal' circumstances, air volume in tire and tire sidewall flex dissipates any vertical loads encountered loooong before any realized vertical wheel compliance, no? I suspect most of the wire-on riders would suffer a rather severe pinch flat long before any vertical wheel compliance would be exhibitted in actual riding experience, heck i'd probably blowout the tire casing of my sewup before such a severe load were encountered to cause such a wheel deflection. Its my understanding that as we tension spokes, the spoke itself elongates, there is in fact no deflection or change in rim circumfrence. To further illustrate this, 14g. spokes require less feel to acheive tension while smaller guage and butted spokes seem to take more patience, at least ime. Just my completely non-scientifically trained viewpoint.

Ride on!

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Zap response:

BigMac,

Now you bring up another interesting dynamic. But to answer your first question, no the rim will not shrink in diameter. It will change shape verticaly or laterally.

Tire pressure puts an incredible amount of pressure on the wheel. So with the wheel just sitting there with 100-140psi, there is a lot of force at play already. More force than with you sitting on the wheel. Now add the additional force of a wheel striking a pot hole with a 180lbs rider.

You are right that it is easier to build a wheel with 14g spokes. Conventional bladed spokes are easy too. It's a bear using revo or ti spokes because these spokes stretch more than straight 14 g spokes. But those thin/stretchy spoked wheels do ride nice

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At your mass, assuming of course you are not hitting every pothole and rock in sight or using these wheels to double for 'cross duty, 32H should be fine if built correctly. Yes Campy 9/10 has worse dish than Shimano, but not THAT much worse...heck they both build with terrible dish. There are better rim choices, but I know plenty of folks bigger than you using same setup getting much better results. BTW: unlike a previous poster, its the drive-side that takes bulk of load, not non-drive due to the terrible dish. I would NEVER send wheels off to be built elsewhere, but that's just me. I have nothing against the mail order guys, its just a local guy who can service any problems that may arise such as in your case is a far better choice. Joe does build fine wheels but w/o peer? Not hardly. He wasn't even the best in town when he was shlepping his wares in Bay Area several years back...no offense but there are LOTS of skilled wheelsmiths throughout US, simply no reason to send mailorder. If you do live near Joe, then he would be a wonderful choice for a fine wheel. otherwise call around to local bike clubs, there should be 1 or 2 local wheelsmiths to serve your needs.

To deal with the problems you are experiencing, much more info is needed. You do not mention spoke breakage, only trueing, nipple and rim eyelet issues, true?. Are these alloy nipples by chance? If so, this is your primary culprit, ALWAYS use brass in rear. Alloy nipples loosen, stretch, strip, corrode, sheer..... What is respective lacing l/r(drive, non-drive). What spoke choice? Same throughout or differential l/r? If you rebuild wheel w/14g straight laced 3x on drive and butted 14g laced 2x on left using only brass nipples and properly tensioned, you should eliminate any problems you are experiencing. Tension should be rechecked at first 100-200 miles, otherwise they should be fine for at least 2500 miles before any trueing issues.

If you are interested in the ultimate bomb-proof setup, get a Bontrager Aurora OSB rim in rear. Assymetrically drilled, MUCH better quality than the Velocity/Ritchey rim at a bargain $39USD retail. These are available in 32 and 36H drillings. Choose 32H to retain existing hub, same lacing, spoke guage and brass nipples as above. You will however have a noticably stiffer wheel torsionally, in fact the left spoke tension will be nearly identical to right side. Good luck.

Ride on!

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Hoover:

Using an assymetric drilled rear rim like the Velocity is certainly a better choice for the King hub, but using a C/S hub with assymetric rear rim is even better yet. The "Jerk" is spot on with his assessment of King hubs, they are WAAAAAY overpriced and poorly designed. Not to sound crass but I believe the kids would call these poser hubs, no?

You are far better off using an Ultegra hub, your wallet will remain considerably more plentiful which in my book is always a fine thing. If you absolutely, positively must spend money on 'bike jewelery' hubs, at least buy well engineered ones. Sounds like you are running a Shimano drivetrain thus you may choose Phil Wood hubs, they do not offer a Campy spline mode and. Yes they are stronger and better engineered than anything Shimano with a flange design that will result in better spoke tension balance. Honestly, unless you are really big and very hard on wheels, this is an excercise in overindulgence. The White Ind hubs are also superb, sharing nearly identical flange design as Phil, they are however even pricier though a few grams lighter as well -- if you believe lightweight hubs contribute anything on an unsuspended bicycle.

For rims, get to your local Trek/Lemond shop and order a set of Bontrager rims. The Aurora is name of 20mm width clincher rim. It is available assymetric drilled, just like the Velocity, only its uses a FAAAAR more reliable MIG welded joint and is $20-30 less $$! $39 retail for the best clincher rim ever...if only they offered a sewup rim of same design.

Ride on!

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Tubular vs Clincher:

I do not know if there has been an emperical study performed that would prove sewups have lower rolling resistance than wire-on, but it is a fact. Speak with engineers at Continental, who produce high quality versions of each design used by pro's worldwide, they will tell you sewups are lower rolling resistance, at least in theory. Places where ultimate speed is the only criteria, velodrome racing for example, only use sewups. It does have something to do with casing design and friction losses due to the loose tube, this is one of the supposed benefits of the new tubeless clinchers. For practical terms, anyone around this forum, including yours truly, is not going to be even fractionally faster based on tire design choice, at least in straightline racing.

If you were however to include high speed descents in your riding regimen, I do believe the sewups will be faster for most aggressive riders due to much improved handling response, feel and performance(grip). I also suspect any triathletes competing over most long courses could gain considerable time using faster rolling sewups as used by every elite triathalete and professional road racer over long TT events.

For most stage events, pro teams generally prefer sewups for 2 reasons, performance and servicability. In reality, the field is nearly even at this years TdF due primarily to Michelin being the largest professional sponsor. All Michelin support contracts REQUIRE teams to use clinchers a minimum of 50% of total miles, some teams much higher. Michelin does not produce sewups however teams are allowed to contract for mock-up sewups that employ cosmetic features of Michelin clinchers, namely logos and tread colors. Yes, pinch-flat prevention, low rolling resistance, handling performance are all important factors but perhaps the biggest factor in choosing sewups among pro teams is ability of wheel to continue to be ridden when flatted while race support attempts to get to rider. If a puncture occurs with a clincher, the wheel can rarely be ridden safely thus rider often must wait helplessly at roadside till a race support vehicle can get to him for assistance. This can mean minutes, not seconds and has often occurred thus far in this years Tour.

On this very forum this topic has often been rehashed with the identical arguments. There are in fact fans in both camps, perhaps a few may even convert to clinchers with soon introduction of Mavic-Michelin road tubeless design. I would not dismiss either design w/o a full hands-on demo of each under your normal riding conditions. The difference in feel is considerable, as is installation and servicabilty. Use whatever works and feels best to you and your needs. Heck whatever gets people on their bikes more often is ALWAYS the best choice. Debating rolling resistance is synonymous with debating whether smooth or file tread offers better performance...it just don't matter.

Ride on!

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Big Boy Wheels:

William:

I am not your size and probably considerably older and less skilled. I am however a very muscular 6'2" 230lbs. My first suggestion would be to avoid Mavic K's, with all due respect to the gentleman who suggested them. K's are simply not designed for anyone our size, they will self-destruct in under 1000 miles. The cracking eyelets have been a long standing issue with many alloy rims using SS eyelets, the Mavic K's seem to suffer this more than most but honestly most similarly designed rims can have these problems and in many instances it does not effect structural integrity of wheel. The K's however lack torsional stiffness of a big guy wheel, I can easily produce enough flex to cause rear brake pad rub during in saddle climbing, out of saddle sprints are far worse often accompanied by loud popping, creaking and several spoke failures. Mind you, my expiences are with the sewup version but in most cases these are torsionally stiffer than the wire-on versions.

For prebuilt wheels, I'd follow Sr Jerk's suggestion of Bontrager Race X-Lite sewup. Great wheel, low dish, sewup, great customer support. The Campy Nucleon (aka Neutron) sewup olso features assyemtric rim/reduced dish design however its slightly lower torsional stiffness and customer support pales in comparison to Trek(Bontrager's parent). Sounds like you may be a wire-on/clincher guy, I won't hold that against you but would suggest sewups for best performance, handling, feel and strength. For clincher prebuilts, I'd suggest the Campy Eurus followed by Bontrager Race Lite. The Eurus has worderful torsional stiffness that beats out even the great Race X-Lite sewups. The Race-Lite clincher is lower priced clincher only version of X-Lite offering same performance and 2 extra rear spokes plus Trek support.

If you would like to use custom handbuilt wheels, the options are fewer but the results will be significantly less $$ and potentially stronger rear wheels. Unfortunately, there is not a sufficiently strong sewup rim readily imported in 'States thus I would again reiterate the suggestion for the Race X-Lite prebuilt wheelset as my top choice for sewup wheels. For handbuilt clinchers, the Bontrager Aurora assymetric rim is the best clincher rim available anywhere. Nice alloy rim, welded joint and assyemtric 32H drilling for reduced dish. Lace'em up with Campy or Shimano hubs and they should need very minimal servicing or care for 5k miles at the very least. If you needed any extra assurance, Phil Wood (Shimano spline only) or White Ind (Campy or Shimano spline) hubs are also available in several drilling patterns and feature flange designs which will further reduce spoke tension imbalances in rear wheels. Mind you these are considerably more $$ than C/S hubs and probably overkill for your needs (highly recommended for loaded touring uses however) but it is an option. Avoid King, Edco and several other "lightweight" hubs, they actually increase wheel dish due to poor flange designs, bad news for big guys like you and I. I would also suggest a straight 14g driveside spoke 3x lacing -- a very good friend of mine similar in size and fitness to you(he recently retired from NFL as TE) used DT's butted 13/14g spokes on driveside and his wheels are absolutely bombproof. For leftside (non-drive) rear use a butted 14/15g spoke with 2x lacing, the spoke length and tension left-right will be almost completely equal which results in a VERY strong, durable and torsionally stiff rear wheel. Best of luck.

Ride on!

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Big Boy Wheels cont...

William:

I'm not really looking to "convince" you to change your ways, I merely suggest you try a quality sewup and let the experience do the convincing. During my frequent travels i often ride loaner bikes and I can assure you the minute I take the initial pedal stroke and just the slightest nudge on the bars, I can identify whether the bike I am riding has clinchers or sewups. If its clinchers I just do not enjoy the experience of riding nearly as much.

I would like to correct a misnomer you seemed to have acquired regarding sewups, clinchers are FAR more prone to roll-off than a sewup. Pro's still use sewups predominantly, by a very wide margin. In fact, many teams and vendors go to great lengths to disguise a sewup to appear like the sponsors' clincher tire for marketing-sponsorship reasons. Why are sewups the pro's tire of choice? Reduced rolling resistance, ride quality and cornering ability are important but somewhat minor factors from race support standpoint. The primary reason is that when a clincher punctures, it flats in under 30 seconds and is basically unrideable. If one was to be descending at high speeds, a puncture could very likely cause a roll-off and very severe crash. Conversely, short of a blown casing, a sewup puncture will cause a very slow leak allowing the rider to continue racing for several minutes while race support vehicle can provide wheel replacement assistance. This alone can save 2 or more minutes for a single rider. A sewup is in fact glued to the rim but that is actually a supplemental retention system. The primary retention is the tires inflation pressure. Unlike a wire-on where the higher the psi, the greater the pressure on bead and casing to prevent dismount, a sewup actually increases it grip on rim as psi increases.

If you're worried about glue softening due to brake induced heat build-up, the easiest response is to improve your descending skills such that you will not need to brake as often. You should basically never use a rim brake enough to cause excessive heat build up in racing or hard training conditions, this is only a concern for loaded touring bike riders. Not good enough? If front brake begins to feel soft or fade due to said heat build up, use a H2O bottle and apply 2-3 light, steady squirts at backside of forkcrown.

Joseba's roll-off was in fact a sewup however it is my understanding from 2 of the now former Once mechanics that the tire in question had flatted prior to the roll-off. This is based on some unscientific video review but primarily a close examination of the tire in question which had a severely punctured casing when examined. Interestingly (or frighteningly as it were), Joseba does not recall much of the actual events leading to his crash.

Enough about sewups v clinchers, the modern clincher is infinitely better than the clinchers of old and if you're happy with'em, no problem. Find a local wheelsmith and have them lace up a set using the Bontrager assyemtric rim in rear, you should have trouble free wheels for many thousands of miles. I would encourage you to use a local wheelsmith only. I would personally never recommend any mail order/online wheelsmith to anyone, but for someone your size it would be even more critical. Big guys like you are hard on all wheels, no matter the quality of build. An occasional tweak or trueing is to be expected, many local wheelsmiths will either not touch a wheel they did not build or will charge a very high fee for any adjustments and offer no warranty for said work. If its a good local wheelsmith, they will provide spoke repairs/replacements at no charge along with any adjustments on wheels they have originally built. Check with local cycling clubs for the referrals, there is usually 1 or 2 local wheelsmiths who's name and reputation exceeds all others. If you are located in SF BayArea, the best wheelsmith is in Berkeley, I'll be happy to give you his name if you require.

Ride on!