Strida Wheel Sizes Explained

Strida Wheel Sizes Explained

Prompted by a customer’s phone call one morning I decided to write this post on Strida Wheel Sizes.  The customer had just received his new Strida EVO with 18 inch wheels. He had never owned or seen a Strida in person before and when he received his new Strida he measured the wheels. He was concerned that I had sent him the wrong wheels. This is where things can get confusing.  If you measure the Strida 18 inch wheels you will find they are actually 14.5 inches in diameter to the outside of the rim.  The Strida 16 inch wheels are 12.5 inches. The tires do have 18 x 1.35 and 16 x 1.5 printed on them.

So why is this?

Also printed on the Strida tires and every other bike tire is the ISO measurement.  The first number is the width of the tire and the second the diameter of the inside of the tire in millimeters. The Strida 18 inch tire is 35 x 355 and the Strida 16 inch tire is 50 x 305. This is a size you can depend on. Some tires like the Schwalbe Big Apple tire will have a greater outside diameter than the Strida tires but the inside tire diameter of 305 mm is the same.

This page and tire sizing chart by Sheldon Brown helps explain the conversion factor between 16 and 18 inch size tires and their ISO equivalents. I have to assume the reason we got off track in using Imperial measurements with bicycle tire sizes is complicated. Canada is a country that switched from Imperial measurements to metric in my lifetime. I have seen first hand the difficulties and confusion that can develop. An example is we drive our cars in kilometers per hour, we fuel up in liters, but we commonly still calculate our fuel economy in miles per gallon! We pay for our groceries by weight in grams and kilograms but often purchase and think in price per pound.

In Canada marketing may partly explain this situation, this may also be the situation with bicycle tires. I ask you, would you rather ride a bike with 18 inch tires or 355 mm rims?

Is the Strida Bike Wheel Size misleading?

I did check the Strida.com site to see again how they describe the Strida bike’s wheel size. It was the first time I noticed that they don’t use the word inches, only 16 and 18 wheels!

I don’t think this is unique to Strida bikes. A quick search on the net of folding bikes looking for wheel or tire sizes and you will see what I mean.