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FEATURED BUILD - Pacenti SL25 with WI CLD and CX-Rays.

Pacenti is rolling a new rim for 2017 but we can't imagine why. The SL25 has been a deserved customer favorite since it launched. Save $100 while our inventory lasts.

 

 

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Friday
Feb242017

Race Ya To The Top

We've been moving the shop this week (pics when it's done, it's still a raging disaster), which proves that you never know how much crap you have until you have to move it. The move came at the right time during the inventory cycle but the wrong time of the wheel box cycle, and moving a few hundred empty boxes is such a joy. But the new place is great, in a cool historic building which we share with a clock maker/repairer, an art gallery, and an architecture firm. There's a neat energy of creation and craft there, which I've found inspiring. Plus we're on a cobbled street so if that doesn't give us "street cred" (see what I did there?) I don't know what would.

Nothing says "street cred" like a street with cred.

Without wishing to relitigate carbon (seriously), it's easy to observe both a race to the bottom and a race to the top in that market. I use this purely as a foil for my main point. If you'd like to spend more than $3000 on a set of wheels, the market is rich with options. You also now have plenty of options if you'd like to spend $600 on a set of carbon wheels. I have my doubts as to what's actually in a $600 set of "carbon" wheels, but we'll take it as face value. $2000 now seems decidedly mid-market. Perhaps there will be a resurgent rush to the middle?

The interesting contrast comes with what's going on in alloy. Bike marketing within the performance sphere is completely dependent on pro racing. The funny thing there being that the tubular wheels that the pros race on are far more different than their clincher stablemates which everyone who buys wheels uses than Brand X's tubulars are from Brand Y's tubulars. Or than Brand X's clinchers are from Brand Y's clinchers. But one thing you know for sure is that you ain't seeing any alloy wheels on a Pro Tour team. So the traditional marketing realm really has no place for them.

Despite that, innovation and compelling new product abound in alloy. I'm intrigued by this new set from DT, which despite a higher price point seems like a really neat product. While it's expensive in context, without having seen them or riddent them, they at least seem to give you some nice value for your spend. And they look cool as what. I don't love Mavic products in general - it's just a different philosophy to mine - but their Exalith stuff is cool. HED does some neat black metal, Fulcrum/Campagnolo do it... And it's not just about legitimately durable black brake tracks (although let's face it, that's a HUGE resistance point to alloys) - there seems to be an identifiable move toward companies making an earnest effort at putting out something other than a "let's just dress up whatever thing we're dumping into the OEM market and call our alloy product box checked off" alloy wheel product. 

It was really really recently that if you wanted a premium component (which is to say "not pre-built into a factory wheel set") alloy rim, HED was the only game. They're still a GREAT game, we love when we get orders with HED rims if for no other reason than it just says someone's interested in buying a quality product in what's been an underappreciated category. But Easton's rims give HED's an awfully, awfully close run in terms of refinement, fit, and finish. And those are just two examples in what's somewhat recently become an exceedingly "not boring" category, in very short order. 

Without going into too many details, my one prediction for 2017 (and I just wrote an email to a vendor a few minutes ago claiming that forecasting 2017 seems more like pure gambling than any previous year has) is that there will be hot competition in the premium alloy segment when we see 2018 products launch. 

 

 

Tuesday
Feb142017

Meaningful Differentiation

The one convention we have left to cover following last week's wind tunnel test is the "how many seconds will I save or spend in the mythical 40k TT by making any of the above choices?" Since the results so clearly deserve a different take on it than what's been presented in the past, we're going to express it in terms of distance rather than time. 

Our last wind tunnel trip really has the big guys sweatingUsing a 303 instead of a Kinlin XR31T/FSW3 or an AForce Al33/RFSW3 will put you 40mm (we originally said .4mm - Mike carried the 2 wrong somewhere earlier, and an eagle-eyed commenter caught it) ahead after 40k. The construct here is that the 303 is ridden at a power that makes the rider go 25 mph, and the others ride at that same power. The FLO30 and HED Belgium+ are a couple of bike lengths behind. That's it, and that's the extent of our summary report there.  

Maybe we just magically picked the 5 wheels where this would occur? Maybe our distribution (which again, is something of a distribution of distributions) is a bit off? We can't help but concluding that if you choose any good, modern wheel of some moderate depth and width, you're putting yourself at no aerodynamic disadvantage with the (possible) exception of in high level TT competition. 

There are some other differentiators, though. One is rolling resistance. Your rims don't make any real difference there, but your tubes might. And latex tubes have been shown (note that I didn't use the word "proven" since some of you are already screaming "but that's not a real world test!!!!") to have lower rolling resistance than butyl tubes, and the delta is bigger than the aero gap seen in our test. And rolling resistance doesn't decrease when you draft. If you use butyl tubes, there's a range of rolling resistance there, too (same link as above).

Tires make a difference too. Much bigger than wheel aerodynamics. Just yesterday, I read some guy on a forum that he could clearly feel the difference when he switched to his carbon clinchers versus his other wheels that have Gatorskins on them. He didn't say what tires were on his carbon clinchers, but it's not at all unlikely that there was a 20w difference in the tires he's using - so OF COURSE he can feel it. And this is likely to be the "noise" in the usual anecdotal comments like this. Our guess is that people had always put the garden hose tires on the alloy training wheels, with fast tires on the carbon race wheels. Now that people are sharing great info on rolling resistance and people are paying more attention to it, it's likely that the tires were making the difference, yet people blamed it on the wheels. Isolate your variables.

So, within wheels, what does make a difference?

Looks make a difference. I mean let's face it, carbon looks pretty freaking cool. If carbon happened to be really ugly, would people use it? If you dig deeper or shallower wheels, that's going to make a difference to you. We've plainly stated before and will plainly state again right now that getting a Special Edition matte finish on our XR31Ts exponentially increased our enthusiasm for what was otherwise already an easy rim to love. And then there's the whole "ceramic coated Al33s sold out in 4 days" thing. So go with it, and don't feel guilty about it.

If Victoria's Secret had a wheels catalog...Price makes a difference. You could pay for an entire season of race or gran fondo/century entry fees (with enough left over to buy fresh tires all year long) with the price gap between FSW3s and 303s. Having money left over to not think twice about saying yes to an event you want to do makes a difference. You can put a Powertap into a set of RFSW3s and still save most of a grand from a lot of carbons. Training with power helps you make a difference. 

Handling makes a difference. Not getting blown around in crosswinds makes a big difference. Tire set up and cornering makes a big difference (never forget that the impetus behind the Rail series was width more than anything else). Having a front wheel that holds a line makes a difference.

Weight makes a difference. I'll get skewered for saying that, but "light and stiff" are the two most popular answers when we ask people what they're looking for in a set of wheels. They often exist on competing curves, so getting the right mix of both is a compromise, but we're able to do it with PLENTY of builds. 

Hubs make a big difference. We've said it for years and years - buy hubs first. You won't roll any faster out of the box with fancy hubs, but good hubs will see you through several sets of rims - rims are a wear item, hubs don't have to be. 

And finally, build quality makes a huge difference. When you install your wheels they should be silent, round, and true, with nice even tension on the spokes. And they should stay that way for a good long time. If the builder has spent some effort helping you discover what mix of components will work best for your use, you should be able to ride them for a long long time without doing much more than keeping them clean (WITHOUT using a pressure washer!!). 

Good thing I wore my kevlar underoos today because I have a feeling we'll take some heat for such heresy. 

Friday
Feb102017

Wind Tunnel Testing the Al33, XR31T(FSW3), and others, Part 2

Yesterday's was a quick post to show the basic results. Today's post will explain the Angle of Attack distribution that we've used, and fill in some of the finer details on the test. 

The test occurred at A2 Wind Tunnel in North Carolina. A2, along with the San Diego Low Speed Wind Tunnel, is one of the two default standard, publicly accessible wind tunnels in the US. If you want credible aerodynamics data, A2 is a an outsanding place to get it. No one from November was at A2, we Skyped in during the test. The test is a very standard one - 30mph test wind speed, temperature and pressure are normalized. We used a 23c sized (Continental's chosen descriptor) Continental GP4000sII tire, inflated to the wind tunnel standard 100psi. The alloy wheels used a tube with a 48mm valve stem while the Zipp used a 60mm valve stem, so valve stem protrusion was normalized as closely as possible. Other details of the builds have been detailed before

The standard test sweep is to go from 0* to 20* angle of attack, or yaw angle, in 2.5* increments. This is enough resolution to give an accurate representation of how the wheels perform through any statistically significant wind situation you will encounter. Wheels were tested alone, front wheel only. There are already some rattles of "this is irrelevant because it doesn't account for frame and fork" pushback on this. Simply, testing wheels standalone has decisively proven to have outstanding transfer to their performance in a bike system, and it's impossible to test with the range of bikes/forks/situations to satisfy everyone. The validity of this test's scope is established legislation, which you are free to relitigate as you wish, but it's not something we'll engage in arguing. 

Al33 in the tunnel at A2

Wind speed is 30mph. This is the standard test speed as it's been established to give the cleanest data. You can scale with software to produce results for more or less air speed, but the shape of the curves doesn't change - a wheel that's a laggard at 30mph doesn't become a star at 20, it stays a laggard. But since the effects of air resistance increase so quickly with air speed, the differences between wheels get compressed at lower air speeds.If you want to do the quick and dirty calculations on watts versus grams of drag versus time in the mythical 40k TT, here's the teacher's edition: using the 30mph parameter, 10g of drag roughly equals 1 watt, and 1 watt roughly equals 3 seconds in the mythical 40k. Not good enough for real science, but good enough to become a hyper-aware wheel consumer. 

Something we included in yesterday's chart that we've previously omitted are the blue bars showing the amount of time you're likely to spend encountering any given wind angle. How we arrived at this distribution needs explaining.

It had been an established convention that 10* was THE heavyweight angle, likely because Zipp's collateral always placed such heavy importance on 10* in particular, and the 10* to 20* range in general. When they give a time savings figure, it is computed at 10* as the only angle. However, the world has long since moved past "because I said so" as an acceptable premise, and Trek and Flo have both gone to the trouble of doing actual data collection in real world situations, and come up with distributions that show that lower angles are actually vastly more prevalent. In fact 10* is shown to be largely irrelevant.

We've linked a few hours of quality technical reading there, but the abstract is this: at real world riding speeds and in real world conditions, this is what you see. The Flo data is very plainly presented in percentages, and you'll notice that if you add the percentages up they don't equal 100% - that's because 0 to 20* doesn't encompass every situation encountered. You have a bunch of small data points going out from >20*. The Trek data is harder to break down, but break it down we did. 

The frequencies we show are a straight average of those three data sets - Flo's gathered data, Trek's data from the Ironman AZ course, and Trek's data from the quite windy Ironman Hawaii course. Anyone can argue with our methodology on this, but we think that this is the most robust, relevant, defensible distribution available. And for what it's worth, Hawaii distributed a bit differently, being very exposed and windy, but the Flo and Arizona data matched very well, and Hawaii really wasn't that different.

We are not asking you to believe anything on faith. Every bit of what's been done and how it's been done are available to you here and in the links. As none of these rims is our own or available exclusively through us, we derive no benefit from the data leaning one way or another, or shading the data in any way. This entire exercise to to provide the wheel market with good information to become educated about wheel aerodyamics. 

More in subsequent posts, but I've run long as is, so that's it for now. 

Thursday
Feb092017

Wind Tunnel Testing the Al33, XR31T(FSW3), and other alloys

This blog, and series, will be a way more difficult story to tell than I'd thought it would be. 

What we'd expected was that the Zipp 303 reference wheel would be that shade faster at the heavily prevalent and thus more important narrow angles of attack (aka yaw angles), and then extend that lead out into the angles that occur with much less frequency. What actually happened was that the Al33 (our RFSW3 wheelset's rim) and the Kinlin XR31T (that we use in the FSW3) both performed better than the 303 at the most prevalent low yaw angles, starting to cede a bit at around 7.5* and going on from there.

 

When you do a test like this, you get a lot of data, and it takes a while to chew and digest it. What we present here is just a first, very broad, pass at things. 

The blue vertical bars that you see in the graph are the amount of time the average cyclist is likely to spend encountering each wind angle during a ride. We will offer a very complete explanation of that in the next blog. 

For now, we're just trying to wrap our heads around this, and make good on all the teasing that we've done. Sorry for that, hope it was worth it. 

Enjoy

Wednesday
Feb082017

BYO Hubs in RFSW3

The particularly eagle-eyed among you may have noticed two "I'll send you my hubs" options in the hub pulldown options for RFSW3 builds. That's right, you can send us your hubs and we'll build them into a set of RFSW3s for you.

Some of Dave's cache of "I can't throw that out, no way!" stuff

A lot of you are probably like us, with a stash of stuff that seems too good and too useful to get rid of, but somehow you never get around to actually putting any of it to good use. Maybe you've got a set of wheels where the rims are worn out or dented or you crashed them or spokes started braking or whatever. Maybe the rims failed prematurely but the hubs still have plenty of life. You might have a set of wheels that came with your bike but they've got kind of crappy rims and spokes so you never used them. We've had a bunch of people contact us with these very situations, and we're very happy to help.

It does require some extra work for us, in that we have to manage incoming packages, assess the hubs (if we think you're better off not reusing them, we'll tell you), clean them up, measure them, blah blah blah, so we can't make it a bonanza of cost savings, but if you've got a set of hubs that's in good shape it's definitely worth doing. We've differentiated the price on straight pull hubs a bit because they're harder to measure and work with, but we expect there are a lot of LOT of almost-never-used take off wheel sets hanging in garages and basements and sheds that are perfect candidates for this. 

We're also building out a partial build service in the Custom section where you can add different components a la carte and have us assemble them for you. And yes, we'll be offering Al33 rims for sale as stand alone rims, we just haven't yet heard what if any MAP policies or whatever there will be, so we can't post that yet. 

It's sort of funny how excited I am about tomorrow's test. I am truly a geek.