Ask me anything speed round

Ask me anything speed round

My friend Colin sent a bunch of questions, some of which I can't answer but might be able to give some info on. We'll do it in sort of a lightning round format. His questions (some of which have been slightly modified) are in italics.

Tire inserts (cush core) - Have you tried them? Seems like an ok idea, a ton of pain in the ass factor, probably not going to save your rims if you really crush a rock. While on this topic, ever try Slime tubes with sealant in them? These are the sort of pool noodle looking things that you insert into your tires to prevent snakebite flats and prevent rim damage. I haven't tried them, as I don't do the kind of riding I think they're appropriate for. They sell an XC kit and even a CX kit, but they must do 90% of their sales to the full face helmet set. It seems like a big thing among those guys. Any users out there?
I've never tried Slime tubes but when I used tubulars in cross I sometimes put sealant in them. The biggest thing I noticed was the if I let the tires go flat and sit there, the tubes would glue shut. It probably works with latex tubes, definitely doesn't with butyl tubes. 
Rotor alignment - Your disc shims are all well and good but have you noticed rotor alignment is actually affected by mms based on the tightness of your QR--and even the torque on your thru axle? First, our shims are a heck of a lot better than well and good, but we'll leave that to the side for a second. How much you torque your axle/QR does have a slight effect. You can also see this with your rear derailleur. Most hubs with bearing preload adjustment don't completely isolate the axle/QR torque from the hub compression (White Industries is the only one I know of that has bearing preload adjustment that isolates axle/QR compression) and that is another avenue for slight variability. In practice, if you get everything set up with axle/QR torque applied (as though you're ready to ride) and then apply nearly the same axle/QR torque whenever you reinstall your wheel, you should be good to go. 
Musings on cross - I'm all ears any time you have a point to make, like the fact that getting fast over the barriers might save you 0.5 sec x 2 per lap x 7 laps but cornering better might save you 0.2 sec x 1,000 per lap x 7 laps. Go work on your turns. Go work on your turns. The best years I had in cross and mountain biking (which were not all that good in the absolute sense) were when I worked a lot on turns. Remember this - it's not how fast you go into the turn, it's how fast you come out. Improving your turns means coming into the turn a little faster and coming out a lot faster. Coming out a lot faster has a double benefit - the first is that you're going faster. The second is all the pedaling energy you save by not having to reaccelerate the bike as much out of the turn. That second part is massive. I remember reading an interview with Matthieu van der Poel where he said mountain bike racing was "easy" compared to cross because you're not accelerating from a dead stop out of every corner. Barriers for show, corners for dough. 
Show us the data - You do some of this already but it's always interesting. What's been your sales mix? What is surprising? What are you surprised that doesn't sell? We have about 4500 "regular" SKUs. A lot of those are color variants, and still more are lacing (spoke count) variants, so this so called data is tough to get at. Mike mentioned in a recent email that Hotfoot 29er wheels were our biggest seller year to date, which was the first time a mountain bike product has led sales since forever. 
Our carbon disc wheels have been the category that's led for the last couple of years. The category encompasses a lot of wheels so it's sort of cheating, but the preorder orders are such a heavy part of the month. It's not unusual for preorders to be 1/3 of a month's sales, and in the winter they're over half of our sales. 
Disc wheel sales now far outstrip rim brake wheel sales. That happened a while ago and I don't see a rim brake resurgence but you never know.
White Industries has always been kind of dominant in hub sales, but I9 has inched closer every year for the last three. It's noisy after that, those two dominate. 
HED are the main choice for alloy rims, by more than a little bit. They're an easy choice to make. 
Power loss due to measurement (or sound) - Has anyone ever tried to put a number on what you sacrifice to compress a piezoelectric sensor in your crank or hub or whatever? Maybe it's minuscule but it's always bothered me. The sound of pawls clicking over always just sounds like friction to me although at that point I guess you're not freewheeling and marginal resistance is probably not your thing. Zipp makes the Cognition hubs which avoid contact between the hub shell and cassette body while coasting, and shockingly they don't put a watt savings figure on it. Onyx is the only hub we sell that does this sort of thing, and I hope to get a better answer from the guy we work with there on this and a while bunch of other questions soon (the plan is for an "in their own words" series featuring some of our suppliers).
Some hubs tone down their points of engagement between road and mountain bike hubs. King and I9 are the main ones I can think of. This is reflective of a few things - one, that quick engagement is massively more important on mtb than road; two, that excessively loud hubs are more likely to get you knifed in the face on a group road ride than on a mountain bike ride; and three that there probably is some drag worth losing that's caused by engagement noise, and if it ain't helping you out (which it is not on road) then you might as well tone it down.
MTB tire size - I'm doing a long MTB marathon race but don't want to buy an XC bike so am doing it on my 27.5" hardtail. What am I really giving up by not using a 29er. Obviously rolling resistance, contact patch, blah blah blah but I find both diameters to be pretty arbitrary and not very different. Is there such a thing as truly "optimal"? This is more of a "let me Google that for you" deal as I certainly can't answer better than these places have. 
Partnerships - I don't know how big the handmade / custom / small-batch etc. bike frame market is but it always kills me when you see a photo of this steel thing for like $8,000 with Chris King galore and then like Zipp or Enve wheels. You ever thought about partnering with OEM frame builders? It's tough sledding if you want to do that. We quickly investigated and rejected it. The boutique builders rely on the margins from components and particularly wheel sales as an important part of their margin mix. Their margin on a set of Zipp or Enve wheels, even with the extra layer of supply chain in there, is way more than ours is on any set of wheels. So if we gave them all of our margin, they'd still be behind and we'd be working for free. The big brands put splashy logos on and gets lots of visibility out of these things - you notice it, for example. Fundamentally, our product is our service, and that doesn't lend itself to capturing benefit out of that type of deal, so it's not worth us taking a hit for. We're solely focused on building the best wheels you're ever going to own for the people who find us. We like to root for the smaller builders, and there's probably big big overlap between our customers at least in terms of mindset, but the business mechanics of it are a square peg and a round hole.
Hopefully you live in a place that still lets you exercise outside because it is way too nice today to not be going for a bike ride. 


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AC – Sure, you have to learn how not to have a disaster, and you need to get comfortable with barriers at speed.. But losing a group because you’re even 1 second slower on barriers (and it’s kind of hard to be that bad relative to where you ride in your race) is hard, but losing 3 seconds twice in turning sections and thus dropping your group isn’t quite as difficult.

Thanks for the insight into the noodle. I can’t see mass uptake in “sane people” riding but stranger things have happened.

UPDATE TO CHRIS’S COMMENT – He wasn’t able to find savings data from Zipp. My intuition tells me that 10w is credible at high speeds (maybe somewhere above 35mph) but not at lower speeds. Fortunately we should get another answer about that from a good source soon.


re cross, I think it’s also important to note that the risk of getting it wrong when bunnyhopping a barrier is a lot more than the seconds saved, where the risk of not executing improved cornering skill is more like going the same speed as before. So higher return, lower risk – seems like an obvious choice to me.

I have a Vittoria tire insert in the rear of a ti AM hardtail. I think the idea has merit, but weight matters. Cushcores are too heavy IMO (without having tried one). The Vittoria/Pepi’s Tire Noodle type helps keep the ride firm with low pressure, and makes it feasible to ride a flat in. I’ve had no problems with mine. OTOH, the last two rides have been on a bike without the tire noodle, and I can’t say I missed it or found it lacking in anyway.


Hey Chris – That would be awesome, thanks.


Hi Dave. I recall reading somewhere that the Cognition hub saves 10w. If you want me to fact check I can.


Paul – He must have bought the bike used? We’ve certainly never sold a set to Cervelo.


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