I was having a discussion with Steve Hogg who runs the cyclefit centre in Sydney about tri bike positions and seat angles greater than 75 degrees. He's been in the business for 18+ years and has fit a lot of professional cyclists and triathletes (a lot of world champions too). He also fit me on my road bike.
Here are his thoughts, it's very different to what a lot of people post here about ideal positioning, etc.
"The bike leg of an ironman is disproportionately long, and as such directly affects the outcome of your race. You must ride a competitive time and still be able to run freely off the bike. Many people find this difficult. Most modern bike frames have seat angles that position riders too far forward. Additionally, very few aerobars on the market are adjustable enough to allow you to reach them without comrpomising your seat position.
When you sit too far forward on the bike you overload your quadriceps. One of the quads the rectus femoris, is a hip flexor and attaches to the illium or uppe rpelvis. Functionally it is linked to another hip flexor, the iliopsoas group of muscles, which attach to the five lumber vertebrae in the lower back. In simple terms this means that if you hammer your quads, you'll hammer your lower back. In extreme cases the lower back will go into a spasm on the bike. In less extreme cases the effects of this hip flexor overload are not appparent until you get off the bike and try and stand up for a run. What then happens is that the hamstring tightness as well as sore quads and lower back prevents the athlete from striding out early in the run. When you overuse and tighten a muscle group, its opposing muscle group tends to switch off or relax. Those overloaded hip flexors tend to cause just that reaction in the major hip extensor, the glutes.
The glutes and hamstrings play a huge part in maintaining pelvic stability and provide a counter-balancing pull on the rear of the pelvis. With the glutes relaxed, the hamstrings, which are a postural muscle group, have nowhere to hide and have to assume the full load of opposing the anterior (forward) tilt of the pelvis caused by tight hip flexors. That is why many triathletes have tight hamstrings off the bike during an ironman.
Many times I have read in triathlon magazines well intentioned but poorly informed people assuming that tight hamstrings in the run means that the muscle group had been over-used on the bike. And that, therefore, moving the seat forward would lessen the load on the hamstrings. This is potentially dangerous advice and results from basic misunderstanding of the mechanics involved.
Aerodynmaics is a hugely overrated factor in triathlon. If you can put good pressure on the pedals, utilise the full range of upper leg musculature, breathe to your fullest capacity and have a relaxed uper body AND be aerodynamic then fine. My experience is that many people sacrifice one or more of these requirements to achieve an aerodynamic position. To their detriment. To do all of the above and be aero requires flexibility in excess of what most ironmen and ironwomen possess.
Forward position can be made to work. This has been demostrated too many times at the highest level of competition to argue to the contrary. Atheltes vary tremendously. Forward position leads to structural problems because of resultant muscle imbalances. How long it takes for problems caused by forward position to manifest themselves can be anywhere from ten minutes to ten years. The big variables being how lucky you are gentically as to your predisposition to particular problems and how much time and effort you put into maintaining your structural health.
Ironman racing is one of the few mass participation sports that imposes a training load normally undertaken by professionals in other sports. Ten to fourteen sessions per week are not uncommon. Where an elite athlete differs from the rest of us is that they are sponsored and/or full time. This means that after a heavy training session the full timer can rest, sleep, have a massage, an ultrasound session, see the physio or whatever. In contrast, the part timer showers and goes off to work after a similar session.
As a result, part timers miss out on that body maintenance to a greater or lesser degree and so should adopt a bike position that is kinder to their body. That means sitting firmly on ischiums (sit bones) rather than the perineum, gentials, elbows and hands.
Triathlon should enhance your life and improve your health. The mere practice of the sport should not create injury time bombs at some future date. Forward position will do this, slowly or quickly, depending in individual make-up, training load undertaken and amount of time spent on body maintenance. Even elite athletes are not immune. Watch an event and see how many athletes run with a pronounced anterior pelvic tilt and buttocks projecting rearwards and you will see problems such as I have described in the making.
So how far back should a given person sit? The answer to that varies as much as people do. We recommend seat angles of between 70.5 and 74.5 degrees. Such is the variation in humantiy. Seat position is the major factor in injury free performance but is part of the package. Cleat and bar positions have to suit a given seat position. Get one part of the equation wrong and you will not perform to your optimum."
If you want to discuss with Steve, he can be contacted via http://www.cyclefitcentre.com
The article he wrote is a lot longer than this, and has a few case studies. It's definitely worth reading.
I would be interested to hear other peoples thoughts on this, especially given the number of people commenting on rider positions in this forum.
Here are his thoughts, it's very different to what a lot of people post here about ideal positioning, etc.
"The bike leg of an ironman is disproportionately long, and as such directly affects the outcome of your race. You must ride a competitive time and still be able to run freely off the bike. Many people find this difficult. Most modern bike frames have seat angles that position riders too far forward. Additionally, very few aerobars on the market are adjustable enough to allow you to reach them without comrpomising your seat position.
When you sit too far forward on the bike you overload your quadriceps. One of the quads the rectus femoris, is a hip flexor and attaches to the illium or uppe rpelvis. Functionally it is linked to another hip flexor, the iliopsoas group of muscles, which attach to the five lumber vertebrae in the lower back. In simple terms this means that if you hammer your quads, you'll hammer your lower back. In extreme cases the lower back will go into a spasm on the bike. In less extreme cases the effects of this hip flexor overload are not appparent until you get off the bike and try and stand up for a run. What then happens is that the hamstring tightness as well as sore quads and lower back prevents the athlete from striding out early in the run. When you overuse and tighten a muscle group, its opposing muscle group tends to switch off or relax. Those overloaded hip flexors tend to cause just that reaction in the major hip extensor, the glutes.
The glutes and hamstrings play a huge part in maintaining pelvic stability and provide a counter-balancing pull on the rear of the pelvis. With the glutes relaxed, the hamstrings, which are a postural muscle group, have nowhere to hide and have to assume the full load of opposing the anterior (forward) tilt of the pelvis caused by tight hip flexors. That is why many triathletes have tight hamstrings off the bike during an ironman.
Many times I have read in triathlon magazines well intentioned but poorly informed people assuming that tight hamstrings in the run means that the muscle group had been over-used on the bike. And that, therefore, moving the seat forward would lessen the load on the hamstrings. This is potentially dangerous advice and results from basic misunderstanding of the mechanics involved.
Aerodynmaics is a hugely overrated factor in triathlon. If you can put good pressure on the pedals, utilise the full range of upper leg musculature, breathe to your fullest capacity and have a relaxed uper body AND be aerodynamic then fine. My experience is that many people sacrifice one or more of these requirements to achieve an aerodynamic position. To their detriment. To do all of the above and be aero requires flexibility in excess of what most ironmen and ironwomen possess.
Forward position can be made to work. This has been demostrated too many times at the highest level of competition to argue to the contrary. Atheltes vary tremendously. Forward position leads to structural problems because of resultant muscle imbalances. How long it takes for problems caused by forward position to manifest themselves can be anywhere from ten minutes to ten years. The big variables being how lucky you are gentically as to your predisposition to particular problems and how much time and effort you put into maintaining your structural health.
Ironman racing is one of the few mass participation sports that imposes a training load normally undertaken by professionals in other sports. Ten to fourteen sessions per week are not uncommon. Where an elite athlete differs from the rest of us is that they are sponsored and/or full time. This means that after a heavy training session the full timer can rest, sleep, have a massage, an ultrasound session, see the physio or whatever. In contrast, the part timer showers and goes off to work after a similar session.
As a result, part timers miss out on that body maintenance to a greater or lesser degree and so should adopt a bike position that is kinder to their body. That means sitting firmly on ischiums (sit bones) rather than the perineum, gentials, elbows and hands.
Triathlon should enhance your life and improve your health. The mere practice of the sport should not create injury time bombs at some future date. Forward position will do this, slowly or quickly, depending in individual make-up, training load undertaken and amount of time spent on body maintenance. Even elite athletes are not immune. Watch an event and see how many athletes run with a pronounced anterior pelvic tilt and buttocks projecting rearwards and you will see problems such as I have described in the making.
So how far back should a given person sit? The answer to that varies as much as people do. We recommend seat angles of between 70.5 and 74.5 degrees. Such is the variation in humantiy. Seat position is the major factor in injury free performance but is part of the package. Cleat and bar positions have to suit a given seat position. Get one part of the equation wrong and you will not perform to your optimum."
If you want to discuss with Steve, he can be contacted via http://www.cyclefitcentre.com
The article he wrote is a lot longer than this, and has a few case studies. It's definitely worth reading.
I would be interested to hear other peoples thoughts on this, especially given the number of people commenting on rider positions in this forum.