23 Feb 2016


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.

Inside Leg
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!

Handlebars also come in a range of shapes and sizes – including the SL-K Compact here

The best thing to do is read each manufacturers’ own sizing guide. In reality, two ‘52cm’ bikes (for instance) can vary hugely, so don’t assume you know your size because it was right on another manufacturer’s frame. Instead, compare seat tube, top tube and reach measurements.

Women’s frames
Women also have the option of ‘women’s specific’ designs, but in truth not every woman will benefit. The theory behind them is that, in general, women have longer legs and shorter torsos than a man of equal height. So women’s specific bikes have shorter top tubes and narrower bars, plus saddles shaped for female anatomy. They’re generally available in smaller sizes, too, and may have shorter cranks.

If you’re long-legged and under around 165cm, it’s definitely worth looking at women’s specific designs. If you’re much taller, or long in the body, you can probably choose between the two.

It’s always wise to get the right frame size first time – and remember there are a world of cockpit upgrades for fine-tuning position as you develop flexibility and riding style.