4 FIND THE RIGHT SIZE
Getting a bike that fits you properly is the most important factor. Geometry and sizing aren’t consistent between brands, so always make sure to check the measurements. Don’t be tempted to compromise on fit just because your mate’s raving about a particular bike. If it isn’t quite right for you – the top tube’s a little short or you can’t get the seat low enough, for example – it’ll affect your fun far more than a fancy paint job or a posh suspension fork.
If this is your first new bike in a while, it might surprise you how much longer they’ve got in recent years. This isn’t because we’ve all suddenly got taller, but because designers have figured out that stretched-out bikes with slacker head angles handle far better at speed. Any initial awkwardness you may feel when trying to manoeuvre a bigger bike around will soon disappear (assuming it’s the right size for you) and you’ll wonder how you ever managed on that cramped little ‘kid’s bike’ you had before.
Traditionally, bikes were sized by seat tube length. This is still an important factor, because you need to ensure you can get the saddle to an efficient height for pedalling, as well as drop it out of the way for descending. However, the advent of long-travel dropper seatposts has permitted bike designers to reduce seat tube lengths. As well as giving more freedom of movement, this allows riders to ‘upsize’ to a larger frame for more length, or vice versa.
Perhaps the most important metric when it comes to how big a bike will feel to ride is its ‘reach’ – the horizontal distance from the centre of the bottom bracket to the centre of the top of the head tube. This measurement gives a good indication of how stretchedout you’ll feel when standing on the pedals. From surveying our team of MBUK and BikeRadar testers, we found the interesting correlation that our ideal reach in millimetres was consistently between 2.6 and 2.7 times our height in centimetres. This calculation should give you a good starting point. Some brands – notably Specialized – have now moved to reach-based sizing.
For more on bike sizes and measurements, see our ‘Geometry Lessons’ feature in MBUK 375.