Ride your tri bike race wheels pretty much all the time, even in training, especially if you have aggressively deep wheels. That's one thing I hope we've established in the first two installments of this series, which I hope will serve as a nuts-and-bolts how-to for you on the issue of wheels, and preparing to race aboard them.

Choose your wheels based on what it is you're capable of riding in the aero position. That's the next thing I hope we've established. Deeper wheels are faster than less deep wheels, on average (yes, there are specific instances, at specific yaws, when less deep wheels are faster, but on average deep is better than shallow). However, deeper wheels become slower once you're riding those deeper wheels with your hands on the pursuits. If you hair out and are forced come up out of the aero position, you just blew the advantage of deep wheels.

So, choose wheels to buy — or to ride on race day — that you'll be able to ride in the aero position for the entire bike ride, excepting those moments when you'll be out of the aero position regardless of the wheels you choose (braking, cornering and so forth).

I wrote about the 2 kinds of presta valves: removable cores versus fixed cores. What should you use? Doesn't matter that much on the face of it, all things equal. Personal preference. I can make a case for each. But one style becomes preferable to the other once you start to consider the kinds of wheels you'll be racing — deep dish, disc, mismatched wheels — and once we discuss the use of a sealant, and we'll talk about these things below. Further, as we'll see, there's a good case to be made for both kinds of extensions on your bike, on your wheels, on your spares, each kind of valve extension specific to its best use.

Just realize if you want the core to extend outside the deep rim, you'll need the kind with a removable core, and you'll need an extender that's threaded both ends, so that the extender sits in between the valve stem and the valve core. This is a pretty good system, but if you ride a disc in the rear and you have your spare tubes all set up with extenders, you're screwed if you use this kind of extender, because you can't shorten the stem length to disc-opening-size just by taking the extender off. If this is your situation you're better off using the kind where you leave the core right where it was originally installed and you put the extender over it. Then, it works great for your front deep rim, but if you get a rear flat you thread off the extender and now it's ready for your disc wheel.

However, there's a bit more to the calculus. Are you riding latex or butyl tubes, and are you using a sealant? Slowtwitch tech editor Greg Kopecky gives some very sound advice: carry butyl tubes with you as spares, because they're much easier to mount in a hurry. Sealant? Yes, you bet. Why not? The only problem with sealant, in my experience, is that after awhile it begins to foul the presta valve. So I don't typically ride with sealant in training. But I'll put sealant in the tube the week of the race, say, 3 or 4 rides out from the race, those few rides needed to make sure everything's honky dory before race time. If it's an important race I'm going to put new tires on the bike at that same time. The wheels get a makeover about a week prior to race day. Then after the race I'll continue to ride the new set up until the sealant fouls the valve — if that happens — and if it does happen then I'll replace the tube but not put sealant in it. Until the week before the next race. If you ride with sealant all the time I recommend you invest in a few spare presta valve cores. You can just buy the cores. Stans sells them. A presta valve core looks like this pic above, and if it's a removable core this is what the core looks like. If your clincher tube has a fixed core, you'll never see this little doohickey, because you can't remove it.

If you put sealant in your tires, two things you should consider. First, consider moseying over to Kopecky's sealant test which should give you a pretty good idea what to use and not use in both butyl and latex tubes. Second, if you do use sealant this should inform your choice of presta valve style (removable or fixed core). You can put sealant into a presta valve without taking the core out first, but only certain injector kinds, which limits the method and brands you can use. Also, if you have a fouled valve you can't remove the core and swap in a new one. Me, I would not race a latex tube without sealant.

So, you always use a tube with a removable core if you use sealant? Yes, if i'm riding a pair of deep wheels. If I'm riding a deep in the front and a disc in the rear, I'll still use this kind of tube because it's easier to get the sealant into the tube, and because I can change a fouled core. But if I'm riding a disc I can't use the kind of valve extender that sits in between the valve stem and the core because, while I need a valve extender on my spare tube for the front, I need to take the extender off for the disc. So I've got to use the kind of extender that just sits atop the valve core, so that I can unscrew it from my spare tube if I've got a flat on my disc.

And, again, you have to think strategically about the stem length, and pump head, if you're riding a disc. Both Challenge and Vittoria make latex tubes that are about 50mm long and some complain that this is too long for a lot of discs. It's hard to get a pump head in there. But these are the leading makers of latex tubes which means you'll have to deal with these valve lengths. So you get yourself a Silca head with a thread-on crack pipe and that fits in there nicely. For fixing flats on the road get yourself a Lezyne or XLab or similar low-profile CO2 inflator head that sneaks right in that hole cut into your disc for valve access.

If I was not riding a disc I'd probably opt for the removable core type extender so that I could have that presta core available to me outside the rim, so that I can easily change the core if the core is fouled by sealant. Jordan Rapp has clearly thought all of this through. When I asked him what he does he said:

I use the removable core type valve extenders on my tires. But, on my spare, I use the regular over-the-valve type extender, which is easy to put on/take off (I pre-wrap the valve stem with Teflon tape and just carry an extender with my spare tube). That way, the same spare works for both disc and non-disc. 

In other words, what you race with and what you have as a spare — extender-wise — do not need to be the same. Removable cores are clearly better for racing. And an over-the-valve extender is clearly better for spares. 

Then there's the question of where to put your spare tubes and inflators. If it's a Speed Concept, it's the Draft Box, pictured above. This is a brilliant solution. The new SC's Draft Box is bigger than the original one. I can carry 2 tubes, 3 cartridges, a multitool, and inflator, with room to spare. The only problem, the lid pops off sometimes when I'm riding, so I keep a length of plumber's tape overtop, so that the lid never dislodges.

On other bikes I favor hydration systems for carrying spare tire paraphernalia, and these are pictured above. On my Felt DA I have a Torhans frame bottle, but I don't use it for drinking, I use it for storing spare tubes and cartridges. All my hydration is up front, at the aerobars. Failing anything else I use Xlab Pods with a rear hydration mount or a seat tube bottle cage. This is the Mezzo Pod pictured behind the seat, and I hate anything that sticks up higher than the top of the saddle, both for aerodynamics and because I don't want anything to catch my leg as I'm hiking it over the saddle. So, I'd opt for the smaller Mini Pod, or I'd mount the cage lower if I'm using the Mezzo Pod.

Jordan rides with a SciCon phantom 230 bag behind the saddle (pictured above) and this has his flat changing paraphernalia. "I found in my wind tunnel testing that the SciCon phantom 230 bag actually improves aerodynamics (saves about a watt). That's what I race/train with." Who besides Jordan would wind tunnel test his behind-the-saddle bag?