Were the 1980 and 1996 records on different Islands…and did John Howard in 1980 run SIGNIFICANTLY slower than Thomas Hellriegel did in 1996. A better comparison would be to compare riders in the same race. LVL road a slack Road bike (either a Giant or Colnago) that year and still rode ~ 4:30 and ran like the wind.
Ok, so the main thrust of the 2003 Kona survey is that bikes are getting steeper, not shallower. Also, a majority of the pros, including the 1st place male and female, ride steep.
“Of the 1631 bikes we counted this year, 851 rode seat angles of 76 degrees or steeper, and 780 rode 75 degrees or shallower.”
If you did the math, you would see that 851 is actually 52.2% of the field, a 5.5% increase over 46.7% in 2002.
“So, yes there is a trend. Every year less Kona competitors go steep.”
Your evidence does not support this.
“The steep is slowly going out”
The Kona survey does not support this.
“The steep is slowly going out, until it will be used by some people who make an informed decision and have data that showed them that it works for them”
This makes no sense at all. What were you trying to say?
John Howard in 1980 run SIGNIFICANTLY slower than Thomas
John’s time split (run) was 04:13:36
(even slower than myself).
But it shows that by selecting names you can carefully select cases that support your argument.
The race was run on Oahu in 1980. Only 108 competitors. Wasn’t still really a race back then compared to today. Was more just about finishing. Dave Scott won over all for his first win in 9:24:33. His splits were 51:00-5:03-3:50. Howard set the bike split at 4:28 which remains as the third fastest. Howard came back to win over all in 1981 when the race was moved to Kona for the first time.
Have you ever published peer reviewed scientific literature??
No science paper should ever be taken as gospel since:
- It is impossible to draw conclusions relevant to the masses, unless you test the masses since every human is a different unique dynamic biomechanical/physiological system
- It is extremely difficult to close out ALL extraneous factors bar those you wish to study especially when utilising testing equipment.
Scientific papers indicate nothing more than trends of varying degress of robustness (robustness being governed by statistical validity). It’s relevance to you is driven by your likeness to subject somatotype, physiological make up, flexibility, strength etc… la de da de da.
Would have thought the above points were bloody obvious to someone trying to make such erudite points!!
Just because its a “double blind” 1000 subject 2 year timelined study doesn’t mean it’s the whole truth and nothing but the truth…
Effects of bicycle frame ergonomics on triathlon 10-km running performance.
Garside I, Doran DA.
Effect of variation in seat tube angle at different seat heights on submaximal cycling performance in man.
Price D, Donne B.
Department of Anatomy, Trinity College Dublin, Ireland.
Cardiorespiratory responses to seat-tube angle variation during steady-state cycling.
Heil DP, Wilcox AR, Quinn CM.
Department of Exercise and Sport Science, Oregon State University, Corvallis 97331, USA.
This is all nice and good. But do theose studies take into account individual differences in the riders built (femur/tibia ratio), their flexibility etc.?
I do not think so. You can generalize as much as you want, but I bet that the test-subjects do not represent the average distribution of physiological properties you would expect in a population.
Luckily we have the choice to adapt our riding style to our own needs and requirements. Not everybody is doing better on the same setup. This studies do not prove this and such a conclusion would be wrong. They just suggest that that specific test group (ridiculously small) may do.
I am not average and I would therefor never accept an experiment, whose start-up parameters do not represent me and my “geometry”. I am able to conduct my own experiment and draw my own conclusions.
Why? Because I know that I am built different than the “average Joe” and that I am not representing the small group of “elite runners” sampled for these experiments.
Easy as that,
How about this one.
Multivariable optimization of cycling biomechanics.
Gonzalez H, Hull ML.
Department of Mechanical Engineering, University of California, Davis 95616.
Relying on a biomechanical model of the lower limb which treats the leg-bicycle system as a five-bar linkage constrained to plane motion, a cost function derived from the joint moments developed during cycling is computed. At constant average power of 200 W, the effect of five variables on the cost function is studied. The five variables are pedalling rate, crank arm length, seat tube angle, seat height, and longitudinal foot position on the pedal. A sensitivity analysis of each of the five variables shows that pedalling rate is the most sensitive, followed by the crank arm length, seat tube angle, seat height, and longitudinal foot position on the pedal (the least sensitive). Based on Powell’s method, a multivariable optimization search is made for the combination of variable values which minimize the cost function. For a rider of average anthropometry (height 1.78 m, weight 72.5 kg), a pedalling rate of 115 rev min-1, crank arm length of 0.140 m, seat tube angle of 76 degrees, seat height plus crank arm length equal to 97% of trochanteric leg length, and longitudinal foot position on the pedal equal to 54% of foot length correspond to the cost function global minimum. The effect of anthropometric parameter variations is also examined and these variations influence the results significantly. The optimal crank arm length, seat height, and longitudinal foot position on the pedal increase as the size of rider increases whereas the optimal cadence and seat tube angle decrease as the rider’s size increases. The dependence of optimization results on anthropometric parameters emphasizes the importance of tailoring bicycle equipment to the anthropometry of the individual.
PMID: 2625415
Agreed, it obviously will have affect on the swim.
And steep angles doesn’t automatically mean a slower bike. But going steeper CAN slow you down on the bike if you go past where your body “wants” (in a biomechanical sense) to be . If you close off your hips too much, you can put yourself in a weaker muscular position, and if you close off your midsection/chest too much, you can reduce your ability to breathe as effectively. All of which can happen if you ride too steep. You can ride too steep (just as you can ride too aero if other areas of performance start to suffer as a result of trying to reduce drag.)
My point is that if your legs are fresher such that you run 1% faster, but because you have exceeded where your body is optimal for biking, you are 2% slower biking, that is no good.
That was all I was trying to say. That a 78deg bike is not by definition “slower” for biking than a 73deg bike, but it may be for some people, even if it keeps their legs fresher for the run. And if you tell people that steeper=faster running as a hard & fast rule, there are people who will read that and try a steeper seat angle that is past where they should be riding, especially if they only steepen their angle without changing fit on the rest of the bike (new stem, change bar position, etc.)
I ride 75.5. Am I steep or shallow? “76 degrees or steeper… 75 degrees or shallower…” What about us in the middle?
You’re sheep… or stallow… something like that.
This is the most intelligent thing that has been written in a while… Maybe that is why these guys did the study?
“The optimal crank arm length, seat height, and longitudinal foot position on the pedal increase as the size of rider increases whereas the optimal cadence and seat tube angle decrease as the rider’s size increases. The dependence of optimization results on anthropometric parameters emphasizes the importance of tailoring bicycle equipment to the anthropometry of the individual.”
IMPORTANCE OF TAILORING BICYCLE EQUIPMENT TO THE ANTRHOPOMETRY OF THE INDIVIDUAL.
Ride steep if your body biomechinically says steep (while in the aero position), ride shallow if it it says shallow. Ride sheep or stallow if you are me.
One more question. Let’s say you have two guys, both 5’7", with all identical bone measurements and muscle composition, but one wears size 8 shoes vs the other guy at 9.5. Would the guy with the longer feet ride slacker. Let’s say the size 8 guy is riding 78, would the 9.5 guy ride 76.5 or so ? In this case the big foot guy also uses a stem approximately 1.5 cm shorter. Or does the long foot guy ride with a higher seat height and raise his bars a spacer or so…or is it a combination of both ? I don’t see much in the literature about the effect of foot size on optimal seat angle, but I would think that the bigger your foot, the slacker you would go.
If “all identical bone measurements and muscle composition” are the same, then they should be wearing the same size shoe 'cause the feet are made of bones. Tell that one guy to stop wearing bigger shoes than he needs… Just kidding.
The problem with “shoe size” as a factor is that shoe size is determined to a large extent by arch location/height/etc. The overall length of the shoe is not as critical as where your arch is supported. I wear a size 11, and while a 10 1/2 is not really much smaller, and an 11 1/2 is not really much bigger (only 1/8" per size), the shift in arch location makes them really uncomfortable in some shoes. So even a difference of 1 1/2 sizes might not mean that their feet are actually 1 1/2 sizes different.
If you combine this with the fact that length of toes also impacts shoe size, but would not affect cleat placement, you run into another problem. If a guy has really long toes, his cleats will be farther back (relative to the front of the shoe) than a guy with the same size foot but who has shorter toes, since we want to align the cleat under the ball of the foot (technically I think it is the second metatarsal head…).
A guy who is an 9.5 instead of an 8 wears shoes that are 3/8 of an inch bigger if relative foot proportions are the same (1 full size = 1/4 of an inch). Let’s say that of that 3/8 of an inch is evenly distributed throughout his foot. Now let’s generalize and say he has “average” feet (and I don’t know enough about feet to know what is average, so I’ll measure my own feet). The ball of my foot occurs 2/3 of the way down my foot. So let’s say that means that the guy with bigger feet has his cleat aligned 1/4 of an inch further forward (since the heel-to-ball section is 2/3 longer). 1/4" longer feet wouldn’t seem to really drastically affect seat-tube angle.
I’ve tried (so far unsuccessfully to figure out how this would affect his geometry). On the one hand, it makes me think that you would have to move the seat forward to achieve the same relative knee-to-pedal-spindle position as for Mr. 8Foot, meaning the seat-angle would be steeper. But at the same time, he clearly has a longer lever arm within the linkage of levers (leg/foot/pedal/crank), which would make it seem that he would ride slacker (and at a slightly lower cadence). Any thoughts? Anyone else want to take a stab?? Did I produce anything of value with this post?
The information is far from perfect, but:
- The 4 peer-reviewed studies mentioned in this thread support a steep seat tube angle for triathlon.
- The race performance of steep and shallow biking triathletes is mixed.
- The anecdotal evidence offered by the forum members is mixed.
- A steep seat tube angle allows the rider to rotate shoulders down and hips up and forward for a more aero position while maintaining an open hip angle for power.
Therefore, I’ll be shopping for a steep geometry bike as my first major purchase for this sport. (#s 1 and 4 > #s 2 and 3)
Steep = good. Too steep = bad. That is why I am stallow or sheep. Trader, just make sure the bike fits you. Cervelo is nice because of the reversi seatpost.
Rapster, I’m the guy 5’7" with 9.5 foot size, and I never seem to get comfortable riding at 78 or greater but seem to be OK at 77 or slacker. Any steeper than 77 and I am pedaling squares and I can’t use my hamstrings well for some reason or another. My anecdotal evidence with a sample size of 1 with 25 years of biking and 20 years of tris, suggeests larger shoe size = slight slacker seat position and slightly higher seat height then the corresponding guy with the same inseam and smaller foot size.
So when I bought a tribike, I bought a relatively “slack” 76 degree seat tube Guru trilite, which seems to centre me around where I want to naturally be without having to jack the seat to far foraward or back (thus affecting bike handling characteristics). There is no science to this, but whenever I try to ride >77 I am slower based on numerous race splits. I run equally fast off the bike at 74, 77 or 79. When I ride steeper, my first few kilometers are faster, but when I ride slacker, the final half of my 10K run is faster, since the running muscles may have been used a bit less. Again, anecdotal evidence based on a sample size of 1.
If I look at the top pros at Hawaii, no one is riding super steep anymore (>80). Most are in the 76-78 range.
There has been a great deal of technical information dispensed on this thread about what is better. What I know from 20+ years of cycling and triathlon training and racing, and please note this is personal and anecdotal, but backed up by a modest amount of success, is that there is a certain “sweet spot”, that you can find where power, comfort and effciency all seem to come together. This will be different for different riders - some steep, some shallow, some in- between. Dan himself, I think has talked about this “sweet spot” in the past and steep or shallow, it is the place you want to find. I have found mine - found it many years ago. However, it’s not constant and it does change as fitness changes and as our bodies change as we get older. I think that’s why bike fitting is part science( do these calculations and you get this set-up) and part art( look at the rider and understand where the rider is at) to get the best fit.
WRT the reversible seat post thing. It affects the top tube length, so while a bike may fit perfectly at 78 degrees, it may be too long at 75 degrees. Have the fitter make the call on the approximate STA first, then pick the appropriate frame.
umm… as someone who competes at a decent draft legal national level, its because road bikes handle better for the crit type riding that draft legal races have, tri bikes are slow in corners, and fairly unstable ridden with drops. Its also illegal to have aerobars with bar end shifters, you also can’t have unbridged aerobars extending past the front shifters, however I have my seat around 74 degrees, and some of the elites at nationals had theirs up around 75-76… but no-one rides super steep.
- david