Written by Steve Hogg
We could call this article, ‘Pelvic Stability As The Basis For Bicycle Position.’ However, that sounds a bit dry. How about I call it, ‘Why Jan Ullrich Slides Forward On The Seat and Subsequently Gets Dropped By Lance Armstrong In The Mountains.’ That’s a bit lengthy perhaps, but much more interesting. I will come back to Jan later as a case study in how not to sit on a bike. This will be a regular series about this complex subject (in as much as business and family commitments allow). Ideally, it should be read in conjunction with the articles by Andrew Richards that regular readers of Bicycling Australia would have already noted over the past few issues. Andrew’s series will be dealing more with background information about cycling biomechanics and I will be dealing more with practical applications. There will be some overlap, but each article by Andrew or me will make sense separately, but more sense together.
Perhaps I should mention why this series of articles is necessary at all. In my view the bottom line is that all the information about positioning that I have read over the last 25 years, in books, magazines and coaching manuals is totally inaccurate. Furthermore, this information has been the cause of many injuries to susceptible people.
Basis of Opinions
A little history will be necessary to explain how I came to be of this opinion. I first became interested in bicycles more than 25 years ago. At the time, I had some debilitating knee, ankle, hip and shoulder injuries as a legacy of playing contact sports without having the physique for it.
I thought at the time that a bicycle would be an ideal impact free way of regaining fitness, so I purchased an expensive one. However, riding it made most of my injuries hurt more! I returned to the bike shop, told them the story and asked for help. They looked at me on the bike, made some adjustments, and sent me on my way. The result was that I was feeling no better. I bought books and magazines about cycling and, at a later date, coaching manuals. The positioning information gathered from these sources could be summarised as:
- Seat height is leg length (inseam) multiplied by 1.09 including crank length or by 0.883 plus crank length.
- Seat setback is such that the tibial tuberosity (bump below the knee) is over the pedal axle centre with the crank arm at 3 o’clock.
- Foot position on the pedal should be such that the first metatarsal joint (ball of the foot) should be centred over the pedal axle with a level foot and crank arm at 3 o’clock.
- Various contradictory ways to determine reach to the bars and handlebar height.
It seemed curious to me that differences in proportion, flexibility or pedalling technique made no difference to these norms. However, the same information was so pervasive and widespread that I, like many others, assumed that it must be correct. I applied this information to my own case.
The result for me was worse pain. Eventually I worked out a position that seemed okay in that nothing hurt too badly. However, I did not discount the info that I had read because all the sources seemed to be in agreement. Rather, I supposed that given my injuries, the information was not meant to apply to me.
Fast forward to 13 years ago. I find myself the proprietor of a bicycle shop. I was selling quite a few expensive bikes with only the vaguest notion of how to set up the people riding them. I set about educating myself to find answers. This is harder than it sounds as the first three or four years in the shop had taught me that the commonly published and/or proprietary methods were useless. However, despite this I was making slow steady progress until I met a bloke in Melbourne named John Kennedy.
John had a unique way of looking at people on a bike and taught me the rudiments of that method. Without meeting John Kennedy, I may never have progressed further and this article may never have been written or, best case, it would have taken me an extra five years to get on top of the subject of positioning.
Why does this method work? Excuse me if this sounds like an advertisement. John and I between us, have positioned something like 14,000 riders, ranging from world champions, Olympic and Paralympic medallists, national and state champions to people with severe disabilities. This has been across all branches of cycling and triathlon and it has all been based on money back if not happy with the result. I stress this because, nothing works better as an incentive to learning one’s profession thoroughly and quickly, as having to confront one’s mistakes and hand over the cash. So, without further ado, I will start at the most basic and fundamental point.
Platform For Pushing
The secret to success in any athletic endeavour is to have a stable pelvis. No matter what talent, skill or natural ability you have, without a stable pelvis, the athlete will never reach their full potential. This is beyond argument and agreed with by every biomechanist, sports health professional, physiotherapist, chiropractor, osteopath or similar. You may be a good athlete without ideal pelvic stability, but you will never reach your full potential. This is because athletes without it will have to enlist inappropriate musculature to try to gain stability and they are subsequently less efficient in whatever actions their sport requires.
Let us look at cycling. Pelvic stability can be gained in two basic ways. One of these is inherently efficient and the other inherently inefficient. I will start with method one, which I will call the Ideal Method.
Any cyclist needs a solid platform from which to push the pedals. Ideally, this is achieved passively by sitting firmly on the ischiums or ‘sit bones’ at the base of the pelvis in such a way that the hip flexors and hip extensors are being used in harmony and equilibrium. This is important because these are opposing muscle groups and if one group is being overused, it will tend to destabilise the pelvis.
For instance, the further forward a rider sits in relation to the pedals, the more they are forced to use their quadriceps. Quadriceps are extensors (straighteners) of the knee. However, one of the quads, the rectus femoris, attaches to the ilium or front of the upper pelvis and is also a hip flexor. Furthermore, it is functionally linked with the ilio-psoas (Iliacus and Psoas Major), which in turn attaches separately to each of the five lumbar vertebrae in the lower back.
What this means in practice is that sitting too far forward and overusing the quads pulls the top of the pelvis and the lower back forward. The way our nervous system works means that those dominant hip flexors ‘switch off’ the glutes in a neural sense. This in turn means that the pelvis becomes unstable and that solid and stable platform for pushing the pedals is not attainable.
However, if the scenario just described can be balanced by the counter balancing pull of the gluteus maximus and hamstrings, then the pelvis will be stable. The simple explanation is to visualise the pelvis as an upright sheet of steel. A strong chain is attached to the rear of the sheet and is pulling backwards (the hip extensors). Another strong chain is attached to the front and is pulling forwards (the hip flexors). If these chains are equal in tension, the steel sheet remains upright. If one is stronger than the other, the sheet falls over.
So, what I am saying is this, the most efficient way to achieve that stable pelvis is to use these opposing muscle groups in such a way that they counterbalance each other, maximise pressure on the pedals and achieve optimal performance. This is achieved simply and easily by having your bicycle seat in the right place – I will get to this later.
The Jan Ullrich Method
Now let us look at the second method of achieving pelvic stability. I have called it the Jan Ullrich method of pelvic stability. As I watched the 2001 Tour de France, I couldn’t help but notice how, in the mountains, Ullrich would slide forward on the seat. He also does it on his time trial bike when he is really nailing it. So do many other pros. Why? Because they receive poor advice on position and consequently sit too far forward. I will explain.
When a rider sits too far forward whilst pedalling under heavy load, the pelvis becomes unstable. I have already explained this. Pelvic stability has to be regained somehow if the power is to be generated, although I doubt that any pro thinks of it in these terms. If sitting too far forward, the only way to gain that stable platform is to grip the handle bar tightly and contract the muscles in the arms, shoulders and upper and lower back. This muscular tension and consequent locking of the back stabilises the pelvis but causes the rider to shorten up noticeably.
Now, the handlebars and seat are fixed points, they will not move. So the rider has to move forward on the saddle to reach the bars while enlisting a lot of musculature (arms, shoulders and back) that has little or nothing to do with propelling a bike from the seated position. Paradoxically a rider siting too far forward, has to move even further forward under significant load. This extraneous musculature has to fed with blood and oxygen. In other words, heartbeats that could be going to the legs is going to the upper body, robbing those same legs that propel the bike.
Have a look at the accompanying photo of Ullrich. Note the death grip on the brake hoods. Note the tension in the arms and back. If you videotaped the Tour, go and look and note how he is sitting noticeably forward on the seat. In so doing, Ullrich loses two ways. The first is the previously explained inefficient method of power generation. The second is that as he moves forward on the seat, he limits the degrees of arc through which he can exert force on the pedals.
The further forward he sits on the seat, the further the crank arm must travel forward before he can get his foot behind it to push it forward and down (see Figure 2). This also increases the size of the dead spot where little or no force can be applied either side of top and bottom dead centre. Not to mention the concurrent ‘switching off’ of the glutes-the major hip extensor and largest muscle in the body.
The crux of my argument is this. Visualise Figure 2 as a pair of clock faces. Because the rider titled Ideal A has his seat positioned correctly, he can get power on from about 12.45 to about 7.00. Ideal A is able to push forward over top dead centre and pull back through bottom dead centre. This means importantly, that the phase of each leg in the Zone of Power overlaps the other. This in turn means greater power output because Ideal A cannot push harder but he can certainly push longer and with little or no `lull’ between pedal strokes.
Contrast this with Ullrich B. The poor bloke not only has to enlist more musculature because of poor seating position leading to inherent pelvic instability, hut he can only push the pedals through a shorter zone of power with each leg. This leaves a pronounced ‘lull’ between pedal strokes until the other leg comes over the top to about 1.30 to 1.45, only to run out of steam at 6.00.
Don’t feel sorry for Jan. Feel sorry for yourself because most people reading this will probably be propelling their bikes by the Ullrich B method. Push – lull, push – lull, push – lull. When riding on the flat, inertia and momentum mask this effect. However, up a hill or into a strong headwind, it is noticeable and the only remedy is to pedal a low gear uncomfortably fast or, like Ullrich, slug away in a big gear.
Why is this technique of Ullrich B so prevalent? Because modern mass-produced bicycles, even the most expensive ones, are designed around unit cost, not human bodies. However, that is a story in itself, which I will tackle in detail later in this series.
As to Jan Ullrich, I take my hat off to him. He does not have much going for him in a positional sense, but his engine is so big and will to succeed so strong that he still rides the legs off most of his competition albeit in an inefficient and screwed up way. What an athlete!
As to Lance Armstrong, he sits on a bike a lot better than Jan-not perfectly, but much closer to the mark. If Jan wants to beat Lance then he had better start reading Bicycling Australia or listen to someone who thinks similarly.
You think I am joking? No I am not. Let’s quantify the differences in power output between the Ideal A and Ullrich B methods, together with other things I will teach you about bike position. A 10-25% greater output at the same heart rate is typical. That should be a big enough carrot to keep your attention in future issues.