Once only a consideration for road cyclists and time trialists, a bike fit is becoming increasingly common among mountain bikers. But why now?
The benefits for mountain bikers were always there: A good fit will simply make pushing harder – whether attacking climbs or jumping off cliffs – easier.
More cyclists are riding both on the road and on the trails, which explains the knowledge / experience transfer. But a more significant reason for the growing interest is that the mountain bikers – especially those living in flatter countries – are now more often feeling the need for a bike fit. Many are experiencing cramps, tight quadriceps and hand numbness like never before. What has changed? The answer lies in the geometries many new mountain bikes share? They are ever longer and slacker. Short stem on a long top tube and a slack head tube may be good for moving the rider’s mass to the centre of the bike. But then you will also read reviewers praising the very steep seat tubes for getting you up those climbs!
Well, you just read a description of bike perfectly suited for a bike park in the UK where you only ride (or walk) up long 15% climbs and then bomb them down with no flat sections in between! Those steep seat tube angles will be well appreciated for keeping your centre of gravity balanced over the bike while climbing. On the descents there is no seat tube anyway, it is dropped in!
What happens when gradients are much closer to zero? Now your centre of gravity is way forward on the bike, your hands are carrying your weight and your quadriceps are doing most of the pedalling work. You will be using them up before you reach those steep climbs, which are so short that you ride them up standing anyway!
With cross-country bikes beginning to look more like the trail bikes this issue is becoming a bigger concern. For those living in a flat country anyway…