Bicycle Tire Terms And Concepts Part 2 of 2
All right then here is the other part I promised! Will just cover a few more areas that are important and hopefully will help you make the right choices when looking for the correct tires for your cycling needs.
Choosing the correct size, this is in most cases pretty easy, however there are a few size that you will have to dig a little deeper to make sure you getting the correct tires size for your rim. For example the 20″ tire is one of of those sizes that have a two different sizes. It may say 20 x 1.5 but knowing the other size that is on the side of the tire will help make sure you get the correct size. The other size is called the ISO or ETRTO (European Tyre and Rim Technical Organization)
So this is what it would look like, notice the 3 digit part of the ISO number, it tell the size of the bead in millimeters and the two digit number tells the width of the tire in millimeters:
20 x 1.5 = 47-406
20 x 1.75 = 47-451
Some tires you will see tubular tires labeled as 27″ or 28″ they are same size. The most common size are26″ 559 ISO, 700c 622 ISO, 27″ 630 ISO the 29′er 622 ISO same as the 700c however you would not want to mount a 29′er on a 700c road bike rim because of the width of the rim will change how the tire rides and could create a few safety issues.
A few other things I would consider would be the:
- Puncture protection qualities of the tires which are often made of a harder nylon type of layer that make the tire much more puncture resistant. Most racing/training tires would have a thinner layer that creates a balance of performance and protection at the same time. Many of the Hybrid and Touring tires will have a much more thinker puncture barrier and of course that makes for a very durable tire.
- TPI (Threads Per Inch) in most cases the more the TPI the more expensive the tires some are made from a cotton base and most are made from a nylon base. For example high end Vittoria Open Corsa EVO’s, Challange, VeloFlex tires are made from a cotton casing and have some of the highest TPI and I have found them to be the most supple and best riding quality. I am not picking sides here, this is just what me experience has been after logging 10s of thousands of miles on the road. With that being said Vittoira does make many neylon TPI based tires, along with Schwalbe, Continental, Vredestein, Michelin to name just a few and their top tires also ride super great as well.
- Tire Pressure! now here is very interesting topic that should be a post in it self, so I may visit this in the future But in a nut shell it breaks down like this. So you think you a skinner tire with high pressure (psi) is going to be a faster??? well the studies are show hands down that a wider tires with less psi is going to be faster every time.
There are a of course a few acceptations and for the sake of time I will not focus on these. I have been riding 700 x 23 most of cycling years, this pas year however I have made the switch to the 700 x 25 and here is my take. The truth is I can’t tell if I am faster but I will tell you I do not fell any slower and the rider quality is awesome. Once you get over the psychological aspects of looking down a the wider tire and ignore your sup-consonance mind playing games with you! You may never go back to a 700 x 23 tire again.
The theory is that the forward elliptical motion creates a thinner tire patch when it hits the road because of wideness and psi together allow the tire to do this. The other factor and I think this is a big one for sure; most roads are not perfectly smooth like a track or a newly paved road, their for on rougher roads the tires that are wider and have lower psi keep your bike/tires from bouncing off the pavement. So what this adds up to is your tires are doing more inches per revolution, which means faster. I know of an elite master rider out west that tested this theory and he said he gained 1-2 miles per hour faster with a wider tire with lover psi then the thinner and higher psi tires. Bottom line it is worth a try!
