How Are Bikes Measured?

The basic measurement of bike size is taken from the length of the seatube  (The frame tube that runs up from the bottom bracket shell to the intersection of the top tube and seat stays and into the top of which the seat post inserts.). This is measured in inches on mountain bikes and in centimeters on road bikes. Mountain bikes are designed around a smaller diameter wheel and a lower frame to give them handling characteristics useful for the trail. A good rule of thumb is that your mountain bike should be three inches smaller than your road bike.

What's My Size?

For a mountain bike, if you stand flat footed over a bike straddling the top tube between the seat and the handlebars, look for about three to four inches of room between your crotch and the
toptube. If the bike will be used exclusively on the road as little as two inches is alright, but if you're a hardcore mountainbiker, up to five inches of standover clearance may be okay.

For road bikes we're looking for one inch of clearance, and for hybrids or cross bikes, about two.

Is That All There Is To It?

No, it's not. As the seatube measurement changes to accommodate different leg lengths, a bike's frame size also changes horizontally along the "toptube" to accommodate corresponding upper body measurements. Complications derive from the fact that we all correspond a little bit differently. In general, women tend to have longer legs than men, while men have longer torsos and arms than women. For some women this can mean going with a smaller frame size than the standover test might indicate in order to reduce the forward reach to the handlebars. Some men have the opposite complication and may need to go with a larger frame to give them enough room for their upper body. The picture gets a bit murkier when you start talking about individual preferences. Some folks may want an upright posture and some may feel comfortable
in a more forward position. If you are still unclear as to the right size bike for you, maybe it's time to do some test riding and while you're doing it to get some expert input from our sales staff.

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