Is the "pro look" aero, healthy, safe, stupid?

Today,  we are re-visiting a popular story from 2008 when the occurrence of stem slamming was being hotly debated on the local group ride. To get a clearer picture on the positives and negatives, we reached out to a variety of industry heads who we knew had good opinions on the subject. So here it is…

To slam your stem or not to slam your stem? You roll up to a group ride and the first thing the riders do is look at the spacers on your stem. You’d think they would at least check out what you are wearing, helmet, glasses, gloves, but it doesn’t happen. They want to know if your stem is slammed, and if it isn’t you are going to get dropped early and often. Some say it’s worse than the chainring mark on the back of your calf. That mysteriously happens to me fifty percent of the time. Is it really this simple? If you run any spacers at all on your stem you are a novice? Does a slammed stem offer any benefits, and if it does, is it worth the back pain and chiropractor visits? Or is it just a silly status thing that any rational person can get over with a deep breath and a more harmonious relationship with their inner child?

We got in touch with various industry luminaries to find out from them if this stem height and taller head-tube conundrum was just in my head (something about a bruised ego) or if there really was a scientific, bike fit reason to either slam your stem or not.



‘Ten years ago, after I broke my back in a crash, I put my stem up a couple of centimeters. Since then I have progressively put it down and actually think having a lower stem is better for my body than a higher stem. I found with a higher stem my lower back was being used too much and my shoulders and neck were getting too sore and tight. The ideal position should have you sitting on the bike so that you have little weight on the arms/hands and your legs, a solid core, and glutes support to power the body and bike. The best position I have had is the one my dad (a bike builder, racer, randonneur) set me up with as a kid-a classic position, like that of Eddy Merckx-and one I am back with again today. Tristan Hoffmann, our current director at Team High Road, has repositioned many of the riders so that they sit high on the saddle and have their bars low. CSC has also put many of their riders in the same position. It is not only more aerodynamic, but also the position in which the rider can most efficiently get the most power to the pedals while also sitting comfortably for six to seven hours.’

On the trend to run higher stems?

People tend to think it should be more comfortable-which it is when you ride for half an hour a day or sit on a bike in a shop for a few minutes-but during longer rides, and over time, a lower stem is far better. Somewhere someone in America said higher was better, but if you look in the pro peloton there are not too many guys with their bars as high as their saddles sitting upright.

WAYNE STETINA: Shimano/American cycling legend

‘I had raised my bars maybe one or two centimeters over the years for better breathing on the climbs. In the last year, since I’m leaner than ever before, I lowered my bars back down as low as ever. Because I just felt I was sitting up too high in the wind for no benefit. Position has to be comfortable to ride five to seven hours. Every pro is extremely conscious of aerodynamics, but too low and you can’t generate sustained power. With everyone using Power Meters, I suspect it’s fairly scientific experimentation for each individual rider position.

‘Running my stem as low as I can and still breathe with a reasonably flat back seems optimal to me. The road pros all tend to have fairly low bar positions because they are so thin they can still pedal without hitting their thighs into their abdomens. LeMond was among the first to adopt this position. My nephew Peter has the same upper body nearly parallel to the ground while he is on top of the bars climbing. Of course a track position is too extreme for five to seven hours on the bike. Too low and you can’t descend as well either, if you need to be in the drops, and it is a problem for rougher roads.’


‘I run my stem as low as possible. I’ve lowered mine based on experience and a better understanding of how important aerodynamics are. I’ve also lowered it because I now have componentry that is comfortable to shift from the drops and aggressively low positions.

On longer/higher head tubes on bikes?

‘I can’t speak to the trends, I just know personally, and as a 6′ 5″ rider, I prefer the smallest head tube that is comfortable and functional. But I know a number of people just getting into riding where aggressive positions are uncomfortable, and so I think offering people a choice is a perfect solution.’



About five years ago I got fitted by a local high tech tri-geek Serotta fit-certified, USA-certified, Carmichael-certified coach. My position of the cleats on shoes was right on. The saddle height and distance to stem were very close to my original position. He then showed me the actual power increase when the stem was raised while riding on that CompuTrainer. He asked how much time I actually spent in the ‘Drops’ these days? Very enlightening. As the elder statesman in the local group rides at the time, I really did not have to spend that much time at the front on the drops stringing out the whole group. I have had my share of lower back problems over the years going back to 1976 and had learned enough about chiropractic and massage to almost go back to school for a degree in Chiro.

Being old school with the flat-out position with the long 12 or 13 centimeter stem was cool, but those days were going to end sooner or later and now I had total justification for changing-more power!

ANDY PRUITT:  Boulder Center For Sports Medicine

RBA: Tell us about the Specialized Roubaix and the movement of bike companies to design more comfortable, upright bikes with higher stems?

Andy: It’s pretty simple: there are riders out there over 30 years old! It’s the same reason Porsche builds a Cayenne, and BMW builds an X5. They are comfortable but able to go really fast. The whole idea for the Roubaix was for that long comfortable ride; you can ride it on Saturday morning and still be able to feel good Saturday night. At the same time it is raced in the one-day classics. Half the Gerolstetiner team was racing the Roubaix. The trend, for a while, was get low, get low, but the truth is always in the middle.

RBA: How do the longer head tube bikes affect fitting?

Andy: In bike fitting, the torso angle for racing is 45 degrees from the top of the bars, and maybe 35 degrees in the drops. So, we can get people on a Roubaix with a level stem to those torso angles. If they were on a Tarmac they would have a positive rise stem.

RBA: We’ve talked to a few racers, or stem-slamming proponents, who claim the lower position is optimal?

Andy: Most people you’ve talked to are not bike fit experts. Ultimately, the bicycle needs to look like the rider. We evaluate the rider’s strengths, flexibilities, desired cycling experience. If riders don’t meet the physical criteria of a low stem/bar combo, they shouldn’t be in that position. And the age of the average rider is going up, so ithe bell curve of people needing a more ample head tube is also on the rise. When I proposed the Roubaix to Specialized, we increased the head tube height, which gave us that stable ride and the position we were after. I’ve got a Tarmac and a Roubaix, with a level stem on my Roubaix, ten-degree positive rise on my Tarmac. If I’m going out for an hour ride with the boys, I take the Tarmac. If it’s a four- to six-hour ride, I’m going to take the ample-headtube Roubaix. It’s really about high-level bike fitters analyzing their customer’s need.

RBA: Do you suggest people lower their stem once they get more fit, or more experienced on the bike?

Andy: Flexibility and low back strength has to be a big part of it. The more and more serious you become about the sport, which has to include working on your core strength, then yes, you can lower your stem. The bike fit needs to look like the rider; if the rider’s look has changed, the bike can change. Just to put the stem down, because that’s the way some 20-year-old Italian racer has it, doesn’t work. Fit is dynamic and individual.

RBA: What trends do you see in your work?

Andy: The trend we are working on is making more people comfortable on bicycles. When I first started consulting, or at a bike design meeting, I would look around the room, and there were always 20- to 30-year-old racers designing the next race bike. That’s fine, but if we are trying to save the world and get people out of cars and onto bikes, we need a product that appeals to not necessarily the racers; there are always going to be the flagship models and you’ve got to have those. To me it’s about getting more people on bikes, and if it works out, like in the Roubaix’s case, that they end up being raceable, all the better.

MICHAEL SYLVESTER:  Creator of the Serrota Fit System

RBA: Care to weigh in on the To Slam or Not-to-Slam question?

Michael: Sure. Right now, if you stand up, try and touch the ground with the palms of your hands. Can you? What if I put a hundred dollar bill on the ground. Could you then do it? My guess is no. So how can you be in the position on the bike? We need to get the cycling community to start thinking about the biomechanics, because we all want to have jobs! If we start fitting people responsibly, the bikes come out of the garage and people ride more. If you are trying to emulate racers, but don’t have the body to go there, it doesn’t work.

RBA: Can you explain the flexibility factor?

Michael: I was trained by a bunch of physical therapists and yoga instructors and come from a long history of racing. I’ve never owned a car and have been fitting for 20 years. I’ve used every system I can think of. It’s really all about fitting psychology, learning to listen to what the person says about where they want to go. Do they have the flexibility, what about their body would not allow them to be in that lower position, etc? Because we live in modern times, we tend to sit in chairs, drive, fly in airplanes, work at computers, and spend a lot of time in positions that do not help the movement of our bodies. As a result of this our overall flexibility has lessened, and so bike companies are now building bikes with higher headtubes, because it works for many people.

RBA: You are passionate about bike fitting?

Michael: I am. I want to say to you that the more we can get bike fit into mainstream thought, the better. When the bike community starts accepting a better-aligned position and if an average 23-year-old man or woman realizes bike fitting is an essential part of their cycling consciousness, we will be getting somewhere. Because the body has certain ranges of motion that it works well in, we must adapt the bicycle to the body, not the other way around. I have seen a trend with the fittings that I have done which has allowed the body to move and ride in an efficient way, and often, this is a higher position than many of the bikes have been designed for.

RBA: So is the stem-slamming concept just all ego?

Michael: Maynard Hershon attended one of my fitting classes and wrote a piece called, ‘Like A Dork On A Bike,’ which is worth mentioning here. After a bike-fit session with me, he wrote: ‘I took my bar-raising hard. I felt as if I was finally coming face-to-face with being old, inflexible and hopelessly unathletic. I imagined myself showing up for rides in front of Caf‚ Paraiso with my bars above saddle level.’

RBA: Where is the bike fit industry headed?

Michael: In general, I think the industry is beginning to see that we do have guidelines as to what hurts the body and what helps the body in terms of alignment-ask any physical therapist. I believe we have used paint-by-number formulas in the past, and now we are beginning to take the time to work with people and really listen to the issues, and address them using knowledge from more of a medical background.

Cinelli’s 1A stem remains one of the most iconic stems ever made.

RIC HJERTBERG: Historical Perspective

‘A deep riding position reached its extreme in the early ’80s with new aerodynamic ideas. Even leisure riders had little option but to follow the trend to uncomfortable but efficient postures. Recently, more attention has been paid to the needs of some overlooked niches (women, older riders, etc.) and alternatives entered the market. As the industry ran out of customers who swallow fashion unquestioningly, it’s been noticed that women outnumber men and mature riders are buying more bikes than younger riders are.

An overreaction is typical of herd behavior, and many varying positions have become available on high-performance bikes. From the competition point of view, this trend seems to have gone too far. Competitors are not changing in the way the market does. So, it’s a good time to review the costs and benefits of back angle:

(1) The most natural posture is upright. An ergonomic office chair or standing provides this. Any departure needs a rationale.

(2) For pedaling in circles, upright posture favors quadriceps and disadvantages the glutes/hamstrings. This is fine for low intensity and long duration, because quads have the most bulk and best circulation. However, for peak efforts, the more muscle groups that are engaged, the more power. Leaning forward enables the glutes and hamstrings to contribute, so riders feel stronger. So, leaning forward permits more power for bursts.

(3) An upright back puts more weight on the rear wheel, unless the wheelbase is stretched, which makes a long, slow, awkward bike. A minimal wheelbase is preferable. For handling, two-wheel vehicles want fairly equal weight distribution. Sit upright (90 degrees, measured from hips to shoulders, ignoring back arc) and it’s about 30:70 (front:rear). Lean forward to a comfortable 45 degrees and it’s 40:60. Lean further forward to a sporty 30 degrees and it will approach 47:53, thought by some to be a golden ratio. Here you have few speed wobbles and a front wheel that resists washing out in corners. Yet there’s not so much weight forward to limit deceleration (lifting the rear wheel).

(4) Leaning forward reduces frontal area which makes cooling more of a challenge but lowers wind resistance-a serious factor at the high speeds of competition.

(5) Most healthy adults report few chronic pains in neck, back, or arms with leaning angles of 35 to 45 degrees. So a posture with a good balance of benefits is available to most. This helps explain why leisure riding on racing bikes is popular.

This has been my experience:

(1) I’ve raised my stem substantially over the past ten years as I adjust to lower back stiffness. I have several disk herniations from accidents in the past. At this point, my bars (top surface) are only 2 to 3cm below saddle (top surface). If I were undamaged, that would be 5 to 8cm.

(2) Higher stems favor folks like me and, conveniently, neophytes with more office chair than bike racing experience. Unfortunately, too many women’s specific bikes are offering these upright postures. However, women are generally more capable than men of low riding postures, even as novices. So that trend has gone much too far.
As far as science goes, physics hasn’t changed. A 30-degree posture was typical for competition for the first 100 years; look closely at Coppi or Anquetil. Aerodynamic awareness has driven us to sacrifice comfort and muscle health a bit in favor of lower wind resistance. However, the speeds at   which those postures really deliver are higher than most any training, endurance, or triathlon session. So weekend warriors with such postures are fashion/marketing influenced.

(3) Lower position has a minute effect on handling, and so does lower bottom bracket height. A rider may notice such a trade-off but, ultimately, races aren’t won with handling, and good riders can out-corner everyone with the worst handling bike. Handling, within the range found among most road bikes, is not the performance factor (as in the automotive world) that most suppose. It’s more a matter of preference, like clothing fabrics and fit.

(4) Among pro team mechanics, the consensus is that this upright trend has gone too far, especially with bikes whose super-tall head tubes prevent low positions.

Every rider needs to be aware that his/her back angle is an option. Absent an orthopedic consideration, that angle matches a riding objective. For leisure riders, 60 degrees may prove ideal. For athletic oriented training, 45 degrees is probably enough. A competition minded rider will likely want 30 degrees. And an actual competitor with high-level aspirations will be in the ten-degree range. In the best of all worlds, fitting begins with this angle. Then, a bicycle is built below this posture, proportioned to support the contact points and deliver handling appropriate to the ride.

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