Size matters (but not how you may think)
“What size am I”? That’s a common question many of our customers ask. Oftentimes it’s their very first one, and rightly so because choosing a bike that fits is hugely important. A wide range of available sizes is one of the things that separates quality bikes from £100 supermarket ‘bargains’, so the right one is definitely out there for you. The problem is that buying a bike based on size is like buying a suit based on waist measurement alone and ignoring your chest, collar, arm and inside leg. ‘Size’ doesn’t tell you much.
I’m 6ft 2”, and my first serious road bike was a 60cm Genesis Equilibrium. I loved it, but the bars always felt really low. A year after purchase, I was sent on Trek’s Bike Fitting course, and found out that the Equilibrium actually has a pretty low bar position. By the end of the course, I decided I needed to be much more upright, so I looked around at my alternatives. After examining geometry charts and spec sheets, I decided on a Cannondale Synapse, but instead of going up a size, I actually went down, because the 58cm Synapse is actually bigger than the 60cm Equilibrium in every relevant way. And this is not uncommon. There is actually no tube on a Genesis Equilibrium that is 60cm!
The first problem is that the listed sizes often aren’t measurements of the same dimension. Different brands think of sizes in different ways.
There’s no shortage of sizing advice available online, particularly from big-box online retailers. Their prerogative is to over-simplify the fitting process. They offer you all the information they can about their product, because they don’t know very much about you, or how you will relate to the product. It’s your responsibility to figure that out! So they’ll typically ask for your height and inside leg measurement and hey presto, “here’s the right size Brand X Sportive Machine for you”, and they are right, to an extent, just as 60cm is the right size Equilibrium for me. It’s just an awful fit!
The second problem is that the listed size doesn’t tell you anything about the handlebar position, which is probably more relevant to your purchase than your saddle height, because it is far less adjustable. .
The complex truth that online retailers don’t want you to understand is that core strength, flexibility, relative limb/torso dimensions and intended use all influence what size/fit bike you should choose. It’s absolutely not just about your inside leg and height. The good news is that for most casual riders, you can trust your instincts (and our staff’s guidance) and make a purchase after taking some test rides on different bikes.
For enthusiasts, particularly those riding longer distances, consider getting a bike fit from either myself in Birmingham or Denver in London. We can use the information gleaned from that process to recommend which brands, models and sizes to shortlist, and which to rule out. We possess the knowledge and experience to look beyond marketing hype and decode geometry charts to find a bike that suits you!
Posted on 30th Apr 2012