23 Feb 2016
HOW TO CHOOSE THE RIGHT ROAD FRAME SIZE
Bike fit is absolutely vital. Get it right and you’ll barely notice the machine beneath you; get it wrong and you risk discomfort, fatigue, recurrent injuries and poor handling. Frame size is, of course, right at the heart of proper fit. While some bikes are simply sized Small, Medium, Large and so on, traditional road bike sizing is in centimeters. It refers to the length of the seat tube: 56cm, for instance.
Riders come in all shapes and sizes – whatever your size, getting the right frame is the important first step, as the Lampre-Merida team know
It’s a decent rule-of-thumb guide, but there’s a bit more to it than that. Not so much more that you should get lost in the details – there’s plenty of conflicting advice out there – but enough that it pays to find out what you’re looking for. There are three main things to consider: your height, your inside leg, and your reach.
Your height is obvious, and dictates the rough size of the frame you need. However, it doesn’t take into account whether you have relatively long or short legs or arms.
Your inside leg matters because it dictates the standover you need. When straddling the bike (both feet on the ground, with the frame between your legs), it’s a good idea to have a 2.5-5cm gap between your crotch and the top tube.
Your reach maybe short or long (depending on your inside leg), and your flexibility further affects what’s comfy or sustainable for you. If you can’t touch your toes, you’ll probably be happier on a slightly shorter frame (and with a taller front end) than stretched out on something racy.
If you find your height dumps you between recommended sizes, measure your arm span. If it’s greater than your height, go for the bigger (longer) frame. If it’s less, go for the smaller (shorter) one.
Of course, plenty of small adjustments to fit can be made with inline or layback seatposts, longer or shorter stems and bars with varying widths and drops. In fact, these adjustments are vital for fine-tuning the fit of any bike. Even adjusting the stack height – changing the number of spacers under the bars – can make a huge difference to comfort. It’s vital, however, that all these adjustments are made on a frame that’s correctly sized in the first place!