Austin Tri-Cyclist Blog

Tuesday, January 27, 2015

Living with Latex

by Jack Mott

A lot of cyclists still swear by tubulars, claiming they offer improved performance and comfort. A common way to describe the difference between tubulars and clinchers is that tubulars are "more luxurious." While that nebulous feeling is quite real, it's not for the reason you might think. The better ride is not a result of the tire being glued to the wheel, but rather the latex tubes that are sewed up inside the tire.    

In our previous article on road bike tires, we touched on the benefits of latex tubes. Because of their flexible, supple material properties, latex tubes improve both comfort and rolling resistance by a substantial amount over a normal butyl tube. Careful testing by Tom Anhalt has shown a power savings of around 3-4 watts per tire at 25mph, along with better comfort and handling. A good clincher tire with a latex tube can offer the same or better rolling resistance and comfort as a tubular.

But as always, there's a downside. First, latex tubes leak air faster. You will need to pump up your tire every day. Not a huge issue for racing purposes, perhaps, but a bit of a hassle for training. They also leak Co2 even faster, making latex unsuitable for use in a flat kit.

The biggest issue, however, is that latex tubes are a pain to install. Most people who have switched from butyl to latex have blown up a tube or two before either giving up or mastering the process. The good news is that once you do get them installed perfectly, they can actually be more flat resistant than normal tubes, and they work much better with sealant. Below, we outline the steps you can take to make the learning process go smoother:

Why is latex so tricky to install?
  1. If there are any installation problems the tubes will fail very quickly. If a spoke hole is exposed, they will blow through it very soon, whereas butyl might last a few weeks. If they are pinched between the tire and wheel, they will blow, whereas butyl might survive for a few days.
  2. Latex tubes are both sticky and extremely supple, which makes it very likely that a bit will end up outside the tire when you first put them into the tire and mount the tire on the wheel.
  3. Because they get sticky and leak air after a day or two, latex tubes can often move rim strips around over time as they deflate and re-inflate, causing spoke holes to become exposed.

How to solve these problems:
Stan's Rim Tape
The inevitable tube peeking out on the first try
  1. Use Stan's No Tubes rim tape (two layers), in the proper width for your wheels. Stan's tape is sticky on the inside and extremely smooth and glossy on the outside. This prevents latex tubes from sticking to it and moving it around. Pick a width that fills the inside of your rim perfectly and you will be safe from exposed spoke holes. Use two layers to prevent deep dimples over the spoke holes. Most shops will stock a few rolls of this in different widths.
  2. After initially getting the tire mounted, use your thumbs to press the tire bead inward and check for any latex tube peeking outside of the tire. Check both sides! If you see some tube peeking out, you can usually massage it back in with your thumbs, or use a tire lever to pull the bead out and the tube will get back inside
  3. Pump a tiny bit of air into the tube, and then do step #2 again.
  4. Tubes usually ship with a bit of talcum powder on them when new. If your tube is old, put it in a ziploc bag with some baby powder and shake it up. This will make the tube less sticky and install a bit easier.
  5. Because latex is so supple, it doesn't matter how thick it is. A thick latex tube is just as fast as a thin one, and a little more resistant to installation mistakes. So use brands like Vittoria, which are a bit thicker.  
With a little bit of care and knowledge you can reap the big energy savings of Latex tubes without the stress and risk of flats. Enjoy the watts!

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