Where do I put my bike hydration? Part 2: On the hypotenuse.

In part one of this post, we covered rear hydration mounts. Moving forward, we find the most traditional place to store bike hydration: on the downtube and seat tube of your bike frame.

Most road bikes today have water bottle cage mounts on both the downtube and seat tube. Most of us are pretty familiar with those mounts and with the usual aluminum, nylon and carbon cage options that fit them. Triathlon bikes, by contrast, don't always have both sets of bosses. On the old and new carbon tri frames from Cervelo, for instance, the cage mount appears just on the downtube. The Felt DA frames only have mounts on the seat tube. In these cases, only one cage can be conventionally mounted in the front triangle.

The classic P2 frame. Bottle cage bosses appear only on the downtube, at left.

If you're mounting standard bottle cages (or one standard cage) on the downtube/seat tube, you can play the swap game - moving full bottles forward from a rear cage mount, moving empties back. This kind of setup is great if you have to ride long distances carrying your own nutrition (like if the drinks provided on a given race course don't agree with you). Mounting a pair of standard bottles in the front triangle also, by the way, can be the cheapest way to carry hydration on the bike. Cheap cages are cheap, and so are cheap water bottles.

Some triangle-mounted hydration systems incorporate a flexible drinking straw, which can be run up to your aerobars. Speedfil is probably the best-known system of this type. The straw in these cases is largely a matter of convenience, though I've also found that I remember to drink more often when I have a straw right by my mouth. For the aero-minded, the straw also means you don't have to sit up or take a hand off your aerobars to drink.

Felt DA tri bikes come with the TorHans VR aero frame bottle.

As a third option, there is the aero frame bottle. It's not just a bottle for an aerodynamic frame; it's an aerodynamic bottle for an aerodynamic frame. The Profile Design RZ2, X-Lab Aero TT, TorHans VR and Arundel Chrono are all versions of the aero frame bottle. X-Lab claims a 50% reduction in drag if you use their Aero TT instead of a round bottle.

One downside of using an aero frame bottle is that you can only fit one of them on your frame. Even if you have two sets of cage mounts, the aero cage takes up too much space to mount a second bottle. The other significant downside is that you can't switch bottles out during a ride or race. The aero cages will only fit their respective bottles...unless maybe you shove really hard. Some of those race support bottles are pretty flimsy.


Last thoughts on the downtube/seat tube mounts:


I think the only disadvantage to mounting your hydration inside the front triangle - using bottles or systems of whatever form - is the potential increase in aerodynamic drag. Most riders will be familiar with reaching for bottles below them, and the cages aren't really taking up space for anything else. Additionally, as mentioned above, this can be the least expensive way to carry hydration on the bike.

Where do I put my bike hydration? Part One: Look out behind you!

There are many systems now for fitting water bottles onto your bike. We'll take a look here at the broader categories, broken up by bottle location.

First up, and the subject for today's post, is the behind-the-seat option. Most rear bottle mounts will put either one or two standard water bottles at the level of your saddle or just below. The idea is that bottles positioned behind you aren't causing additional drag, because they're sitting in your wind shadow. A lot of people are using the rear bottle mounts for their switch-out bottles. They'll have one or two bottles in an easier-to-reach spot (like in the regular frame-mounted cages), and as they empty each of these bottles, they'll swap it for one of the bottles behind them.

Rear bottle mounts will typically attach in one of three ways. Most commonly, the mount will use brackets to attach to your saddle rails, where the rails slant up toward the back of your saddle. In the event that you use a carbon-railed saddle, you'll probably need some kind of adapter so the brackets don't damage the saddle rails. The brackets will fit pretty much any metal saddle rails.

A pretty standard saddle-rail-mount cage system.

Some mounts will attach to your seatpost. If you have a round seatpost, it's easier to find one of these that will work with your bike. Most tri bikes, and a good many road bikes, now use aero seatposts, so we don't see as many of these as we used to. It's worth noting that there are some seatpost-specific mounts, such as the X-Lab Sonic Wing, which fits only the classic Cervelo P2 and P3 carbon seatposts, and the Delta Sonic, which was designed to fit the new P2, P3 and P5 seatpost.

Delta Sonic - a single cage mount for the new P2/3/5

The X-Lab Sonic Wing mounts only to the classic P2/P3 seatpost

Direct saddle mount for the Cobb Gen2 - mounts one or two cages.

Lastly, there are some saddles that have optional integrated mounts. Cobb and Fizik have both come out with bottle mounts of this kind, Cobb on their Gen2 saddle and Fizik on their new Tritone saddle. These, naturally enough, are some of the easiest bottle mounts to install.



Advantages

Aerodynamics, as mentioned above, is one factor that leads people to use a rear bottle mount. The bottles sit in the turbulence caused by your body, so they add a negligible amount of turbulence themselves.

Just as valid a reason, however, is that bottles mounted behind you don't take up handlebar or frame space. You can use your aerobars to mount more bottle cages or computers, or you can keep the bars clean and clear. Pretty much the same goes for your frame cage mounts. You can use them for other bottle cages or keep them empty for aerodynamic reasons.

Disadvantages

The biggest disadvantage is probably that bottles are harder to reach when they're behind you. This is most troublesome if you only have rear mounted bottles. You'll be reaching behind you every time you drink, and that's not the easiest thing to do when you're in the aerobars (and it's not conducive to drinking much).

The other major disadvantage is the likelihood of ejecting a bottle, perhaps without knowing it until later. Since they're positioned behind the saddle, rear mounted bottles experience more vertical travel than you do each time you hit a bump or pothole in the road. If the cages aren't holding on tightly, the bottles (usually the ones with a pound and a half of water or sports drink inside) will fly out. To combat this, the wise rider uses a cage with lots of grip (X-Lab Gorilla Cages were designed expressly for this purpose), and angles the cages a bit backward, if possible. Angling the cages means that, in a bumpy situation, the bottles' upward velocity will throw them partly against the side of the cages instead of directly out the mouth of the cage.




Next week we'll look at frame cage options: the standard, the aero and the oversize!

Open Water Goggles

When you're swimming open water, you can pretty much use whatever goggles you want. If the goggles are comfortable and keep water out, that's a pretty legitimate pair. There are a few things, however, that make a set of goggles nicer to use outside.

• Lens size: Open water style goggles, as opposed to pool goggles, have wider lenses, which make it easier to see landmarks and course buoys, especially when you're just glancing up to sight. 
• Seal: Similarly, the gaskets around the lens contact a larger portion of your face, which creates a more secure seal. That means your goggles can take a harder hit (whether from a wave or another swimmer's heel) without losing their seal.
• Tint: You can get clear open water goggles, but if the sun is in the wrong place (like directly in front of you), a tinted or reflective or even polarized lens will help with visibility. I find dark lenses helpful for morning swims and evening swims when the sun is on the horizon. It seems like you're always having to look directly into the glare when you sight or, worse, every time you breathe to one side.

Most all of the usual guidelines apply when you're picking a pair of open water goggles. Look for a secure seal, make sure the nose piece (which is generally not adjustable on open water goggles) isn't too wide or too narrow for your eye spacing. Manufacturers usually make goggles in a couple different widths to accommodate narrow to wide faces. Try the goggles on with the strap to make sure that the gaskets are a good shape and size for your eye sockets. I've worn some pretty uncool-looking goggles...in public...because they were the most comfortable ones I owned at the time.

Happy New Year! And why should I bother replacing my chain?

What happens if you don't replace your chain when it wears out?

Good question. I can give personal testimony (as many people probably can) regarding the consequences of unchecked chain wear. I won't go into much fine detail about how chain wear happens. Sheldon Brown, among others, has described the process well, if you're curious. Instead, I'll mostly stick to describing the practical results of using a chain that has clung to life too long.

While you're riding, your chain is repeatedly flexing under pressure as it passes around your cassette and chainrings. Where each link flexes, there is a chain pin and a bushing. Those are the parts that wear out, getting looser and sloppier, increasing the distance from chain pin to chain pin (or from bushing to bushing). Since the bushings are the contact points between your chain and your cassette and chainrings, the chainring and cassette teeth will begin wearing out along with your chain. A worn-out chain will grind away the contact edge of each tooth, eventually leaving your most-used gears looking like circles of sharp shark fins. Cassette teeth generally wear out more quickly than chainring teeth, since they end up contacting the chain more times per pedal revolution.

Normal looking teeth on a cassette.

Same cassette, more heavily used teeth. Shark fins!

Now, the important part, and usually the reason today's question is even asked, is that your chain and cassette end up wearing out in tandem if you never replace your chain. If you do replace your chain before it's worn past a certain point, the cassette will hardly show any wear at all. A new chain will mesh fine with the cassette teeth and all will be well. If you do not replace your chain in a timely manner, then your chain will grind your cassette teeth into a pattern and spacing to match its now-slightly-larger link spacing. That's when the shark fins appear. At this point, a new chain will not mesh well. The hollowed-out tooth shape and spacing will cause a new chain to slip forward over your old cassette teeth with a clunk or a bang when you push on your pedals. This happens particularly when you're starting from a stop (especially uphill, especially when you're in the biggest hurry). In this case, you will have to replace your chain and cassette at the same time.

So why not run the chain and cassette to death together? Does the cost of replacing a chain and cassette once per year (let's say) end up being any less expensive than replacing a chain two to three times per year? Sometimes. It does depend on the quality of the chain and cassette, but it also depends on how much other damage the chain is doing.

Your chainrings will wear out more slowly than your cassette, but they will eventually wear out in the same way and need to be replaced. In that time, your shifting will get sloppier as the carefully engineered teeth of your cassette and chainrings change shape, and you'll start feeling some mushiness when you push on your pedals, because the chain isn't engaging solidly with each gear tooth. Also, the chainrings will slip beneath the chain once their teeth are sufficiently worn, which feels similar to the clunk/bang from the new chain/old cassette situation.

Back before I knew that chains could wear out, I rode my commuter bike until the only gears that worked were the two easiest ones. Which meant that I had worn out most of the gears of my cassette, then I had worn out my large chainring, then my middle chainring. So I had the small chainring (good thing I had a triple at the time) and whatever I hadn't used much in the back. It had taken a while for the first gears to go, but as a chain gets more worn, the damage happens more quickly, so by the end of that episode I was noticing differences in my shifting and in how mushy my drivetrain felt even from one week to the next.

Replacing your chain is partly a matter of money. From the standpoint of cost, it usually does make better sense to replace the chain more frequently, before other parts go bad. If it doesn't seem to make financial sense, consider it a quality of life thing. It's nice to ride with parts that work well. Much nicer than riding with mushy gears or finicky shifting.