Hopefully by now you’ve figured out which category (pro, race or sportive) of road bike you fall into and you’ve narrowed your bike selection down to a few likely-looking models that have caught your eye and fall within your price range. But regardless of category and manufacturer, you still need to know the correct size bike for you.

While an experienced rider may have a firm grasp on frame geometry, for new or inexperienced riders, the first port of call should be their local bike shop. A good bike shop owner or experienced member of staff would have been, quite literally, sizing you up from when you first expressed an interest in purchasing a new road bike. He or she should have weighed-up any obvious disparity of shorter or longer legs against your short or long back as part of their job. It’s also in their interest to take the time to get you on the right style and size bike as they will want you as a long-term customer.

Good bike shop staff will also know their brands, the foibles of each bike model that they stock, and therefore which bike model might best suit your needs and body shape. Just as importantly, they will have listened to what you have to say. Tell them you are looking at doing your first sportive later in the year and they should be showing you a selection of sportive bikes. If they try to sell you a bike right off the start line of the Tour de France there should be little warning bells going off in your head.

Standover height

Going back to the fundamentals of bike fitting – inside leg, standover height and reach – and the bike shop owner should by now have you straddling a bike. This is where your inside leg measurement and standover height come in: there should be at least an inch (25mm) of room between your crotch and the toptube, this is an important safety feature for when you step off the bike, and for comfort if you find yourself straddling the top tube when you didn’t intend to (compact frames with a sloping toptube, like the Giant TCR, are increasingly common, so there may be more standover height).

The next step might be to fit the bike into a turbo trainer and the front wheel into a riser block to bring the bike level. The saddle is adjusted to be flat and at a neutral point across the middle of the seatpost ready to be adjusted fore and aft and tilted if necessary. To get the most efficient pedaling position, your leg must have a soft angle to it when the pedal is at the bottom of each stroke (normally achieved by having a straight leg when you have put your heel on the pedal with the crank in the six o’clock position). At this point the bike shop staff member may come along with a plum-line and check that the front of your knee is in line with the pedal axle when the cranks are parallel to the ground.

It’s worth noting at this point that manufactures as a rule build their road bikes with corresponding components that are relative to the size of the bike. Smaller frames have shorter crank arms (170mm), shorter stem lengths (90 or 100mm) and narrower handlebars (400mm). Likewise, a large frame of 58cm and upwards will probably be fitted with longer and wider components to complement and balance-out the rider’s dimensions for greater comfort and control. The stem and handlebar can be changed fairly easily to provide marginal adjustments to reach, comfort and handling, but if things become too extreme in length or width, then you’re probably on the wrong size bike to start with. To give yourself the best chance of a proper fitting, try and wear the clothes that you would normally cycle in, including shoes. This, of course, is an opportune time to get a great deal from said bike shop.

By this point in time you may feel comfortable with how the bike feels in terms of saddle height and standover height, but this is, at the minimum, a three-way equation, so it’s time to consider reach.