Watching any professional cyclist race at a high level, especially in disciplines like mountain biking, the bike appears as merely an extension of their body. We all have different heights, bone lengths, joint angles, muscle strengths and weaknesses. The difference between a good bike fit, and one where the bike feels like an extension of your body may only be a few millimetres here and there, but once you’ve had a biomechanical expert fit your bike to your unique and quirky body the difference is night and day. Try honing these easy setup parameters first:
1. SEAT HEIGHT
Too often I see the seat way too low slung on the frame, usually because the person is attending my clinic for knee pain. Whether it is road, track, mountain bike (or even penny farthing), the knees have a certain range where they develop maximum power. For a person of regular proportion, with the proper length cranks, the knee should finish up at 25-35deg bend with the foot at the bottom of the pedal stroke. A quick check while riding is to unclip your shoe, put your heel in the middle of the pedal, and continue riding. The unclipped leg should almost be locking out at the knee at the bottom of each stroke, meaning that when clipped in it finished in that 25-35deg butter zone. Try raising or lowering the seat a few mm at a time to get this balance right. See my article HERE, for more info. Ideally you should have the knee measured through the pedal stroke with slow-mo video and an experienced bike-fitter as the foot angle and other factors can also influence the knee range.
2. SADDLE FORE/AFT POSITION ON RAILS
This can have quite a dramatic influence on knee and lower back loading during riding. Sliding the seat forward pushes the hips and legs further forward, changing the joint angle and muscle recruitment patterns. Classically the kneecap sits just anterior to the pedal axle with the leading leg at 3pm on the crank rotation. You can however make similar power and save your patella tendons by making sure the kneecap is directly above the pedal axle at this 3pm position. Try hanging a plumb-bob off the leading kneecap in this position. It should hang directly over the pedal axle.
3. SEAT TILT
This is one of the most overlooked, but important issues with bike setup for most cyclists clocking over 200km per week. I have written an entire blog article about this HERE, but the short of it is, bloodflow to very important areas is compromised with long skinny seats, and made even worse if they are tilted back (front higher than rear). I suggest resting your bike on level ground and getting the saddle horizontal as a good starting point. If you plan to ride lots of hills, the seat should then be tilted forward by up to 3-5deg or as comfortable.
4. CLEAT POSITION
On most cycling shoes, the cleat position on the bottom of the shoes usually has a few options in terms of forwards/backwards position, as well as twist left and right. I usually recommend setting the cleats further towards the front of the shoes initially, with the cleat set in a fairly neutral angle. If there is any foot numbness, plantarfascia or Achilles issues, setting them further back may help.
5. HANDLEBAR HEIGHT
There is a bit of variability for this in terms of the type of riding eg, Triathlon vs. road vs. mountain bike. There are also considerations in terms of pelvic tilt and lumbar spine flexibility. A nice starting point for road bikes is the bars should be between 1-4 inches lower than the saddle with the bike upright on flat ground. The rest depends on lots of other factors that benefit from consultation with an expert. Having the bars much higher than the seat is not a ‘comfort position’, it is a BAD position.
6. STEM LENGTH
A longer stem takes the handlebars further forward in front of the steering fork. This has the advantage of stretching out the torso and shoulders, but may increase the body weight going through the arms. Try adopting a ‘racing’ position on the drops while riding, and look at the axle of the front wheel. If the handlebars completely obscure the view of the axle, then the stem length is probably close to perfect. There are other small considerations including the rise angle and starting height of the stem, both of which can be assessed by an experienced hand.
There are of course a lot of other factors to consider such as crank length, frame size, handlebar width etc, but these are a little harder (and more expensive) to experiment with, so best to discuss these with an expert.
Once you’ve got your bike setup totally dialled, the next step is to figure out where improvements can be made to the body, to make it more efficient with cycling. The human body is anatomically designed to walk, run, throw, and climb, not to ride bikes. To improve performance and reduce risk of injury, slow-motion analysis with an expert physiotherapist or cycling coach can identify areas for improvement, and prescribe the right stretches and exercises.
