Category Archives: Saddle fit

Myth Busting & Tips from Team Sky’s Head Physio

Custom Saddles, Bike Fitting, Training, Coaching Tips
Phil Burt – Head Physio at Team Sky and British Cycling

Phil Burt, Head Physio at British Cycling (BC) and Team Sky, has been working with the world’s top cyclists for nearly a decade, and he has committed his learning and experience to paper in his new book, Bike Fit. There is a great deal of cause & effect analysis in the book, and his perspective and experience have led to a number of cycling’s “facts” being turned up as myths.

I went to his presentation in London last night.   In to discussing the book, he presented highlights from recent academic research into cycling physiology, which further busted some long held “truths” and introduced some great new training tips. Finally, he shared a few stories from working with folks like Bradley Wiggins, Chris Froome and Mark Cavendish over the years. Here are highlights from Phil’s presentation.

  • Marginal gains are irrelevant until you get your own weight and fitness where they need to be.  In 2010 Bradley Wiggins had every benefit BC and Sky sports science could provide at the Tour de France, but he wasn’t fit enough.  After that, Team Sky made a rule – no salary payment for any rider until all their month’s power meter data had been uploaded.
  • 70% of the R&D budget for Sky/BC goes into aerodynamics.  Above 18mph, 80% plus of energy expended goes into pushing you through air, so that’s where they’re finding the best return on investment.
  • BC has designed their own women’s saddles, as standard models were creating major soft tissue damage on many of the women riders.  (If you’re having an issue, we can help )
  • Proper resistance (weight) training also increases endurance, but you have to commit to it throughout the year, not just during a two month “off season”.  The focus is on functional strength for cyclists, by the way, not building biceps.
  • There is no “correct” crank length, as there is no appreciable difference in power output between 150 – 180mm cranks
  • There is NO difference in muscle group recruitment between 80 – 120 rpm with your cadence
  • There is NO benefit, and even a loss of efficiency, in pulling up with your hamstrings during your pedal stroke.
  • Speedplay are the most “knee friendly” pedals
  • There was an epidemic of knee problems at Sky/BC when another pedal manufacturer made a small (and un-announced) increase in the spring tension in their cleats
  • Bradley Wiggins suffers for his success.  He may look smooth on his time trial bike, but that position is NOT comfortable.
  • Saddle Fit is the single most important element of a Time Trial fit.  If you cannot hold the aero position for the full race, what’s the point?  Discomfort on the saddle is the primary reason people get out of their tuck.
  • The most common cycling injuries he works with are knees, back and neck, in that order
  • It is NOT true that knees should track directly up and down viewed from the front.  If they do, fine.  But as long as you’re not having any pain, don’t try to fix it.  Every knee has its own bio mechanics, so only alter the knee movement if there is knee pain.
  • Wiggins’ recent advice to neo-pros going to high altitude training camp, “Bring your own porn boys, there’s no internet at the hotel”

Are you average? 3 reasons why bike fits get it wrong

Many bike fitters get it exactly wrong by simply relying upon the precise measurements of their fitting systems and fitting guidelines from the manufacturer. Here are 3 reasons why they often get it wrong based on our case studies.

before and after1. Saddle fit is ignored. You can place a rider in their ideal position for 5 minutes but will they stay there for 5 hours? This rider suffered from neck and shoulder pain. It’s easy to see on the left she is riding with straight & stiff arms and her shoulders are in her ears. However, the traditional fix, a shorter stem to reduce reach, won’t address the fundamental problem.

Pressure map nose heavyHer arms are straight and locked in order to rotate her hips and push herself up off the nose of her saddle, which is causing discomfort.  This saddle pressure map shows how the majority of pressure is on the nose of the saddle.

In order to get the rider comfortable in a position they could sustain on the bike, we had to change the saddle and move the saddle forward.  Again, traditional thinking is that moving the saddle forward will automatically move the rider’s position forward.  If fact, many riders will actually move back on their saddle to keep the same position of their knee relative to the pedal spindle.  In this case, we were able to get the rider comfortable on her saddle, and then the straight arms and hunched shoulders were eliminated.

Polar Chart comparison2. Historic injuries.  While measurements of leg lengths and flexibility may show a rider to be be symmetrical, those with historic injuries may sub-consciously compromise their position on the bike in order to protect the old problem.  You can see in the upper diagram (a Wattbike power “polar chart”), this rider had significantly less power on the right pedal stroke than they did on the left, and there was an alarming dip in power part way through the down stroke on the right leg, which is the flattening of the curve between 1:00 and 2:00.

Original pressure mapIn order to diagnose this asymmetry in power output, we used the saddle pressure map to understand how the rider was sitting on their saddle.  It turned out they were rotated anti-clockwise, and they had more pressure on the left side of the saddle.

Using a “shark” saddle, which forces the rider to sit straight on their saddle through the use of a “fin” at the back, we eliminated the dip in the power they generated with their right leg (see the lower Wattbike polar chart, above).

The rider was completely unaware they were not straight on the saddle and unaware they had a power asymmetry.  They had, however, disclosed in the pre-fit discussion they had an historic injury of the right knee.  Subconsciously, they had adjusted their position to “protect” that knee.  They are now riding with a Shark saddle to ensure they are straight on the saddle, which addresses the dip in power, and they are working to strengthen the right leg to reduce the total power difference.

3. Your body changes,so your fit needs to change.  Our bodies are wonderfully adaptable.  We change in response to stimulus.  For example, training that stresses our muscles results in the body adding mitochondria to supply energy to the muscles more efficiently.  The body also increases capillary density to bring more blood to muscles, and we understand these changes as “getting fitter”.

Unfortunately, our bodies also adapt in negative ways.  If you work at a desk 8 – 10 hours a day hunched over a computer, your body will adapt to that stimulus.  So, a bike fit for a 50 year old office worker new to cycling should be VERY different to the fit for a 24 year old amateur racer working in a bike shop to support their racing habit.  Where is the “average” between these two profiles?

old versus young

If you have a bike fit when you are just starting serious cycling, that fit may no longer be correct for you after you’ve trained for six months.  Your body has changed.  You’ve gotten stronger, and the balance between your muscles has altered.  For example, if your quads are stronger relative to your hamstrings than they were, then your ideal seat height may be different.  Think of your bike fit as dynamic, not a one-off static event.

How will a professional Bike Fit improve my cycling?

Bike Fit, KOPS, Bike Fitting
Knee over Pedal Spindle

When you’re comfortable on the bike, you’ll ride with more power and confidence, but the top benefit of a quality bike fit is avoiding injury.

You turn you legs over around 10,000 times every time you ride two hours, so cycling can be a recipe for repetitive strain injuries.  All three contact points (pedals, saddle and handlebars) can be adjusted to find YOUR ideal fit and avoid the most common cycling injuries. 

Knees, lower back, feet/ankles wrists, shoulders and hips are the most common areas for injury.  Pre-existing problems, such as poor flexibility, previous injuries, leg length imbalance, collapsed arches, can be accommodated through your bike fit if they are correctly diagnosed and understood. 

Andy Pruitt wrote the definitive book on bike fit, “Complete Medical Guide to Cyclists”, and here are his top three rules.

  1. Make the bike fit the body, don’t make the body fit the bike:  While improvements can be made in flexibility over time, it’s vital to make the bike fit you and not the other way around. Importantly, it’s not just the bike, the angle of your cleats and the arch support provided by your shoe affect the tracking of your knee, and the top injury among cyclists is patellar tendinitis, the inflammation of the tendon structure supporting the knee cap.
  2. Dynamic bike fit is better than static bike fit:  When you are pedaling, your are constantly moving on the bike. As you pedal the angle of your foot changes throughout your pedal stroke.  Can you replicate the exact angle at the bottom of your pedal stroke when you static on the bike?  Angle measurements taken while your sitting motionless can vary dramatically with those taken while you’re pedaling.
  3. Remember the fit window.  What works for a svelte 25 year old professional cyclist with a physio and masseuse may not work for you.  Systems that fit you to a prescribed set of angles do not take into account critical variables, such as previous injuries, flexibility and the natural orientation of your feet (straight ahead, toe in or toe out).  As a result, their recommendations are not sufficiently customised for you.

We can also you find the ideal balance between aerodynamics and comfort.  Michael Hutchinson, author of Faster and winner of over 50 national titles explains, “Most of the drag comes from the rider, not the bike, and just because were fashioned by evolution for every purpose other than aerodynamics, doesn’t mean you don’t have to make the best of it”  

AerodynamicsThere is little point putting you into your most aerodynamic position, however, if you are unable to breathe properly and lose 20% of your power and endurance.  By adjusting your position and simultaneously measuring your power output and heart rate, we can objectively determine a balance point.

If aerodynamics are particularly important to reach your goals, we can experiment with more aggressive positions and give you body a chance to adapt to a new position over a period of weeks before measuring your power output again.