Bikes: always carry a rubber.

If you look at the triathlon world there is a strong undercurrent of geek running through many athletes. It shows itself in how we analyze data, heart rate stats, calories, and wattage output. But nowhere does it show itself more than in matters bike. If the internet burned down tomorrow and had to be restored from backups, you can bet that first up would be porn sites, second would be a viagra spammer, and third would be a bike blog. I’d go so far as to say that bike porn would be up faster than a computer parts catalog, and within hours someone would be comparing the gram difference of pedal systems. I like to eat elephants in small pieces, so I’m going to go all the way back to the simplest piece upon which the Roman Empire dominated the known world: the wheel.

And not to put too fine a point on it, I sure as shit am not going to reinvent the wheel here. This article is my way of opening Pandora’s box for the new rider. I have to be careful in these lands, as the bike trolls will eviscerate me for giving bad information, omitting details, or inserting editorial preference.

A bike wheel is typically built from a hub, rim, is supported by spokes, and fitted with rubber tires. These tires usually contain an inflatable tube. On the rear wheel, the gear cassette attaches to the outside of the wheel which engages the chain mechanism. The cassette is part of the components of the bike and will not be covered in this article. Mostly so I can relax and avoid sniper fire from Campagnolo loyalists.

The hub contains an internal rotating mechanism aided by encased ball bearings.
The rim creates the circumference of the wheel.
The spokes radiate from the hub to the rim providing the internal structure and stability. Spokes can be round or bladed for aerodynamic purposes.
Some racing wheels do not have spokes, but instead have a solid disk.
There are different kinds of tires and tubes specific to type of bike, type of event, and preference of rider.

Whew. That was close. Nothing offensive in there, I don’t think. Hopefully I’m boring the serious bike nerds and they’ll move on to better targets.

A good set of wheels can cost anywhere from $250 all the way past $1500. This depends on material, quality of build, and purpose. Hand built wheels can be put together by a maker for around $400+, and the nice part of custom wheels is picking your preferred hub, spoke count, spoke style, and rim material. Each of these will affect rolling performance and wattage output. Most inexpensive wheels are machine-built overseas, and their quality can vary. Serious bike enthusiasts say you haven’t really lived until you’ve built up your own wheel, which means knowing how to “true” the thing so it spins perfectly. Then you put your body weight on it and roll for a few hours in heavy traffic, trusting your life to your skills. No, thanks. I support globalization enough to get me halfway decent over-the-counter wheels for day-to-day racing, and then I’ll buy American-made Zipp wheels for racing. Even with that there are huge variables in each area, enough to keep me busy with product research for weeks.

When my wheels disintegrated and I had to replace them I purchased inexpensive but decent quality Mavic Aksium race wheels. They were heavier than my Korso wheels that came with my bike, but the hub was of better quality and the overall strength was noticeably better. This translated into a smoother rolling ride, with less vibration transmitted to my arms, but an increased demand for wattage output to push the heavier material. Had I spent more I could have purchased lighter, stronger wheels which would have bought me more speed. However, I plan on purchasing a tri bike in the next year and I felt my lunch money was better spent on solid replacements, with the money saved going into the piggy bank for better race wheels later on the tri bike.

Disk wheels and deep rim depth wheels provide aerodynamic benefits for time trial and triathlon racing. They are lightweight and offer the rider the ability to slice through the wind with significantly decreased drag. However, if you plan on racing or riding anywhere with cross wind a disk wheel will kill you. Even a deep rim can create an unstable platter in hairy cross wind, so while there can be savings with these awesome wheels you can also die. I have to admit that there is a high intimidation factor in being passed by people whose bikes make a distinct “whump whump whump” sound as they fly by. If you’re willing to trade wobble for scaring other riders, go deep dish my friend.

Tires will significantly impact wheel performance. A greater man than I, Sheldon Brown, has a MUST READ article about tires and a sizing guide.

To paraphrase Brown’s article, there are essentially two types of tires: clinchers and tubulars. Clinchers are a U-shaped tire that hugs the wheel rim encircling an inflatable, replaceable inner tube. Tubulars are an encased system that require a specific rim style. Most road and tri bikes use clinchers, and there’s enough subset information on types of material, tread, and inflation pressure to keep anyone researching for days.

For even more intense reading, I suggest doing some research on rolling resistance. This is the area of testing that shows how different weight and material tires will degrade your overall speed on the bike. For those considering shaving off seconds from their time, I suggest listening to the Tri Talk podcast discussing rolling resistance of different tire brands. In the show archive, he also discusses the rolling resistance concept but it looks like it’s been removed from the site and is only available as a purchased download. Slowtwitch.com has an article set discussing the rolling resistance of different tire types as well.

On a practical note, if you use clinchers and you’re going to go for long rides of dozens of miles it’s a good idea to carry two replacement tubes and a method of inflating them. Chances are you won’t need to replace your tire if when you get a flat you take the time to inspect the tire for damage or puncture. While a wheel out of true will kill your ride because it will wobble and rub against your brakes, a flat tire can be fixed (with practice) in under ten minutes. Methods of inflation are usually a small bike pump attached to your frame, or if you are concerned with weight and aerodynamics, a CO2 inflation system costs about $15 and does a good job of rapidly inflating the tube. The CO2 system takes practice – I wasted my first cartridge when I didn’t thread it properly into the device and it discharged into my hand all at once (it was like being 13 again). I was glad I had the bike pump with me to inflate the tube. In an effort to lighten my bike I have removed the bike pump so now I am dependent on CO2 cartridges. If I get too depressed at being slower than everyone, I can always do whip-its.

My ride kit includes: 2 spare tubes, 2 CO2 cartridges and inflation tool, and tire levers (to remove the tire from the rim).

If you go to a bike shop make sure you know the size of your wheel, measured in centimeters, and the type of tire on your wheel to purchase replacement tubes. Sheldon Brown’s article will offer clear guidance on sizing, and the misleading labels that can cause problems on the road. It’s also well worth your while to practice replacing your tube before you are stuck on the side of the road messing around with it in bike gloves and spandex. Lastly, if you’re going to use a CO2 system, practice using it as well. The threaded cartridge can be tricky and if you’re an idiot like me, your first use will be explosively educational.

Hopefully I’ve provided a starter guide to beginning your research into wheels, tires, and tubes. Now let the bike trolls club me to death for being wrong about everything.

Advertisements

3 responses to “Bikes: always carry a rubber.

  1. If weight and balance are so important in wheels, what happens to w&b when the rider’s body changes in weight and muscle distribution? Do you have to compensate for body changes if your equipment is calibrated so finely?

  2. Good question. It’s probably wise to visit the bike fitter after a substantial amount of body and bike changes. It’s up to each person to define what “substantial” means, but after clocking a couple thousand miles on the bike when something is of you’ll know.

  3. Wow! It seems like bicycles provide their owners with copious opportunities to spend time on the Internet rather than riding. This article provides valuable information for lazy fat-asses like me who want to fool ourselves into fitness by pretending to be athletic without actually performing any strenuous activity. My only complaint: not enough links to other places to read about tires rather than going through the effort of causing them to rotate.

    There are shirts and patches available to display your brand loyalties, right? Fortunately, another thing to research.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s