Bike Fitting Fundamentals: A Case Study with Dylan Cooper

It’s Saturday morning and the familiar smell of glove funk and chain lube is wafting in the air. You’re out on your local ride feeling indestructible. Unfortunately you come to realise that you are not. Frustratingly it’s not your fitness that gives out but that recurring injury that has plagued you for what feels like as long as you can remember. Personally at this point I’d be justifying a more expensive bike for myself as an investment in my health. However the first three bikes didn’t change the issue, why would the next? You may have spent thousands of dollars on your dream bike, why not make sure the bike fits you and more importantly that you fit the bike. Not only will you be more comfortable and efficient on the bike, but it also less likely to get injured.

Dylan Cooper at Port to Port MTB 2016.

Have you thought about paying some attention to that ache and visiting your local therapist with a good knowledge of cycling biomechanics?

At this point, I should probably disclose that I work as Physiotherapist at Sport & Spinal Physiotherapy in Canberra and have a particular interest in bike fitting. I’ve seen many broken and battered bodies ranging from the elite to the highly recreation. Mountain bikers certainly provide some of the most interesting stories as to how they ended up with that stiff knee, broken shoulder or achey back. Unfortunately the mere act of pedalling a bike is highly repetitive and restrictive on the body. There aren’t too many sports where you are fixed at the feet, pelvis and hands then ask your poor body to repeat the same movement thousands upon thousands of times. Not to mention the odd loss of skin.

There are a few things you can do to make that Saturday morning ride more comfortable and enjoyable. The first seems like the most obvious. Have you thought about paying some attention to that ache and visiting your local therapist with a good knowledge of cycling biomechanics?

If the problem only occurs whilst riding then it is safe to say the bike has something to do with it. Once again don’t go blaming the new 27.5” carbon fibre dually that you just bought, it could still be your body that needs fixing to allow you to use the bike to its full potential.

Even veterans of the sport can improve their bike fit.

Recently I had the pleasure of working with Dylan Cooper from Trek Racing Australia to help solve a few of his long term aches and pains and get the most out of his bike. Before even looking at bike position and pedalling technique we like to run through a full musculoskeletal screening to check muscle length, joint range of motion, pelvic alignment, key muscle strength and motor control. Then there are structural components to check such as foot abnormalities and leg length differences. When it comes to feeling great whilst riding it is just as important for the body to be able to cope with a cycling position, as much as the bike being the correct fit for the body. Having said that there are some adjustments you can experiment with yourself.

Saddle height is crucial, even if you’re on a trail or Enduro bike with a dropper post. It’s handy to measure and recored your ideal height, so you can quickly get the set up correct if something slips, breaks or needs replacing. 

Saddle Height

Saddle height is one of the most important measurements on the bike. Too high and the pelvis will roll side to side on the saddle, and potentially aggravate the lower back. Too low and there is significantly more compressive forces going through the patella-femoral joints (kneecap joints), as well as decreasing overall pedalling efficiency. The correct height is a happy balance between staying steady on the saddle and getting the correct amount of knee extension to maximise drive through the pedals.

Measuring ankle angles to re-check seat height.

Being a very technically minded rider, Dylan had his saddle height near spot on. The only adjustments that needed to be made was a mild increase in height and the packing out of a cleat to compensate for a slight leg length difference. This allowed Dylan to gain better and more consistent contact with the pedal at the bottom of the pedal stroke.

Dylan’s Comment:

“I’d messed around with saddle height for years, but wasn’t ever 100% confident with it. Having Simon confirm it was correct was reassuring and also meant if I didn’t feel right on the bike it was probably due to another set up issue. Having things measured and noted down also” helps. Now when I get my bikes each season I can just refer to those measurements and know they’re correct.

The knee cap should be over the axle of the pedal in the 3 o’clock position for optimal fore/aft position.

Saddle Fore aft position

Fore aft position of the saddle has an effect on the how your body creates power. Too far forward and the thigh muscles become dominant and potentially cause knee pain. Too far back and you may compromise your ability to push through the pedals or end up in a position unfavourable to the lower back. Ideally the posterior surface of the knee cap should be over the pedal axle when the pedal is at “3 O’clock” in the pedal stroke with your ankle at its usual angle at this point of the pedal stroke. Once again Dylan wasn’t too far off the mark here and didn’t have any real low back or knee complaints.

Dylan’s Comment:

“This is another one I always played around with, especially when saddles change shape and length each year. Having this measured accurately gave me the confidence to commit to my set up.”

Checking cleat position and float.

Cleat position

Cleats can be trickier to get the positioning right on. The simplest way I can explain cleat position is aim for the middle of the balls of the foot. If in doubt go with what feels comfortable and stable. It’s in this region that Dylan’s kryptonite began. Dylan complained of having long term pain on the outer border of the foot, particularly down long descents where there was a lot of pressure through the feet. He has experimented with a multiple pairs of shoes and orthotics however the problem has remained.

On assessing Dylan’s feet, I was quietly happy that he hadn’t been blessed with perfect genetics. Let’s face it, it wouldn’t be fair on the less cardiovasulcularly gifted riders such as myself. He had an abnormal foot type where his big toe joint had dropped and was causing his forefoot to roll outwards leading to excessive pressure on the lateral border of the foot. Dylan also had excessively pronated feet (flat arches) which pushed his knee towards the top tube during his pedal stroke. It should be mentioned here, that excessively pronated feet unlocks the midfoot axis and hence one doesn’t have a rigid lever to push on the pedals. Hence with a mobile pronated foot, one loses energy in the transfer of power to the pedal.

Assessing forefoot position for optimal pedal contact and potential foot pain

Again, cycling is a bugger for showing up any biomechanical flaws. Carbon fibre cycling shoes with little give can potentially make for a very uncomfortable riding experience. To fix the problem, we made a pair of customized orthotics for Dylan designed to allow even pressure through the balls of the feet to compensate for his dropped big toe as well as provide adequate arch support to control the excessive pronation. This helped alleviate the foot pain and created a more stable platform for pushing through the pedal. It also enabled Dylan to keep his knee in line with the pedals rather than tipping towards the top tube, meaning a more efficient pedal stroke.

As part of the fit process, Dylan’s left vs right leg power was assessed.

As an adjunct to this remedy Dylan was also taught gluteal (buttock muscle) stabilising exercises in the cycling position. The gluteal muscles are important for cyclists as they are the main stabilisers for the hip joint. Without good gluteal function the knee can have a tendency to go in and out during the pedal stroke rather than straight up and down. This can potentially cause pain or injury to the knee, as well as decreased pedalling efficiency.

Dylan’s Comment:

“The corrections in my feet and focusing on specific glute strengthening exercises has been the biggest revelation. I’ve put up with excruciating pain in my feet for most of my cycling career, especially in the heat. And I’d tried almost everything to fix the issue. But in the end I gave up. Having this sorted out in one sweep was amazing. And, combined with glute strengthening I can notice the difference in power and efficiency.”

Again, knowing your measurements helps. The seat/bar distance is something we pay more attention to on the road, but it’s important on the mountain bike too, particularly if you’re spending long periods of time in the saddle during a marathon race for instance.

Stem length and position

The front end of the bike is mostly about comfort and control. Handlebars too close to a rider can create issues through lower back. Too far away often leads to neck issues. On a road bike an aerodynamic body position needs to be taken into account, however not so low as to compromise back position or pedalling efficiency. On the mountain bike it is safe to say that aerodynamics isn’t as big a priority. I certainly haven’t seen anyone descending Mt Stromlo on aero bars lately.

Headstem length, handlebar height, handlebar width and brake position are very much a personal preference depending on riding style. It is useful to keep in mind what effect each change has on your back position if you plan on riding up the hill as well as down. Keeping the lower back in a neutral posture by maintaining the natural slight inward curve of the spine allows the leg muscles to drive from the most stable base, and generally feels a lot more comfortable several hours into a long day in the saddle. Dylan, much like many of the elite level cyclists, was running a very aggressively low handlebar position to allow for excellent cornering and climbing control. With good core strength and muscle flexibility he could hold this position easily without compromising his low back posture.

Fitting a stem measuring device to assess the best possible handlebar position.

For many of the cyclists that I meet a headstem too long can lead to poor upper back and shoulder position. If the handlebars are too far away the natural response is to push the shoulder blades forward to maximise the length of the arms. Riders will also often shorten the headstem in response to low back pain however sometimes this is counterproductive. By shortening the reach it can be like pushing two ends of a piece of bamboo closer together. The result can be more bend and more low back pain. Conversely the same can occur if the handlebars are too low as riders with poor flexibility will be forced to bend more through the back to reach the handlebars. We usually use a sizing stem which allows observation of posture whilst pedalling in many headstem degrees of drop, raise and length.

This shot is of Dylan’s Trek Superfly 100 from 2015, but you can certainly see that aggressive front end position he prefers.

Dylan’s Comment:

“I definitely run a low and long position, mainly to keep stretched out and have more range to ‘work’ the bike with. Too many riders assume a higher and shorter cockpit set up is better for descending, unweighing the front end too much and not keeping their body weight balanced between both wheels. This is a key thing to get right if you want to handle a bike well, but also avoid back pain.”

Sorting out orthotics to alleviate foot pain. This also allows better contact and power transfer through the pedal.
Sorting out orthotics to alleviate foot pain. This also allows better contact and power transfer through the pedal.

Brakes and shifters

Ok so most of you have figured out already that braking with 4 fingers doesn’t feel good. However for those of you new to mountain biking the brakes needs to be adjusted such that you are only using your index finger. To maximise your braking capacity the curved tip of the brake lever shoulder be lined up with the index finger. Play with the reach adjustment where possible to maximise the comfort levels. Once the brakes are set the shifters are adjusted to where it feels most comfortable and accessible.

Having your brake lever positioned so that stress is reduced on your tendons and muscles will reduce the risk of arm pump.

Attention also needs to be paid to the angle of the wrist. Hand and finger musculature works much more efficiently when the wrist is in a neutral position, which on a mountain bike is as if you were punching the handlebars. Too much angle at the wrist forwards or backwards can lead to impingement or tendon injuries, and is far more likely to increase the dreaded arm pump.

Dylan’s Comment:

“This is such an important, but neglected, aspect of setting yourself up on a mountain bike. A lot of people I know run their levers way too high and it forces them to compensate with other parts of their body.”

Where do you start?

If you do decide to experiment with different positions I suggest you make small changes at a time. Allow your body to adapt and respond to your new and hopefully improved setup. If in doubt there is no harm in asking for help. Getting your position right on the bike is much easier with a second set of eyes watching from angles that you may only achieve whilst riding past a photographer in a race. If you are anything like my friends you’ll be more preoccupied with striking the best cornering pose than holding the perfect pedalling posture. In that case why not go get a bike fit.

There’s nothing more frustrating than watching someone ride a bike worth more than my car with a horrible seat position or headstem that just isn’t right for them

There’s nothing more frustrating than watching someone ride a bike worth more than my car with a horrible seat position or headstem that just isn’t right for them. Personally I would highly recommend a physiotherapist with bike fitting experience as there is often as many problems that need solving on the body as there are on the bike. You may be needlessly putting up with problems that can be easily fixed and make your riding experience so much more enjoyable.

About the Author:

Simon Davis works is a senior physiotherapist at Sport & Spinal Physiotherapy in Canberra. He is an avid mountain biker and has a special interest in treating cycling related injuries and correcting lower limb biomechanical issues. He regularly performs bike fitting assessments for all cyclists from weekend warriors to the elite level professional rider.

About the Rider:

Dylan races for Trek Racing Australia and has nearly 20 years of racing experience. He’s won countless national series races and represented Australia at the World Championships 7 times, as well as many World Cups. As well as 10 years of skills coaching experience, Dylan has raced internationally for years and won across various disciplines, including cross country, marathon, short track, road, and enduro. He’s passionate about getting people into this great sport and loves seeing people improve.

It appears you're using an old version of Internet Explorer which is no longer supported, for safer and optimum browsing experience please upgrade your browser.