So you want to be a bike fitter, then take it from a true pro!
What's Real? What's Imitation? What's behind it all?
Cycling knowledge is often based on myth and riddled with misinformation. This is especially true when it comes to bike fitting. We’ve all gotten some advice based on the 'eyeball' method, plumb lines, or my favorite, the broom-between-crotch technique. So, when I was fit for my road and TT bikes recently by Craig Upton, the current Central Park TT record holder, I wanted to get to the bottom of all the bike-fitting mumbo-jumbo. Here is the result of my fit conversations with him, and some shots of a fit session he did with Jaime Garcia.
NYVC So many fitters are either the highest ranking employee of a bike shop, or an experienced rider with a 'good eye'. I assumed you were the latter until I heard about the science behind your system. Can you talk about some of the research that went into your theory of fit?
CU The research behind the Wobble-Naught system is huge. It involved a group of incredibly qualified people, ranging from a medical team for biomechanics, CAD guys, sEMG and some incredible anatomy guys to make it work. The sEMG is amazing. It basically shows us how much energy each muscle is firing with, so you see how effective your pedal stroke is in each position on the bike. After coming up with the solution that made sense to them, they took it to the Wenzel coaching group (who founded the Saturn juggernaut) to make sure it worked in the real world of bike racing.
The fitting system is based upon measuring and fitting the bike to your skeleton. If you think about it, your skeleton is the structural part of your body, therefore it should make sense that your bike be fitted structurally solid to your skeleton. This is different to other fitting systems which base their positions on muscular flexibility. A fit based upon flexibility will produce a different fit depending on the time of day you get fitted. In the morning when you’re not warmed up your position will end up shorter than in the afternoon.
After positioning the skeleton to the bike, the next trick is to get your muscles working in their most efficient manner. This requires the muscles to be positioned in their relaxed position as we know that a stretched muscle can’t fire. As an example try holding your fist out at arm’s length and lifting a friend’s little finger to the ceiling. You can't do it. But if you bend your arm into its relaxed position, you are now able to lift a lot of weight towards the ceiling.
NYVC Is that why you take such different measurements, like finding the hip socket instead of measuring the inseam (thanks for not making me jam another stick up my crotch), and measuring knee thickness?
@##=#<1,l>@##=#CU Yes, no two people are the same size/shape. For example my pelvic bone is a different size to yours, and to my wife's, etc. So I measure the exact pivot point (your hip joint) rather then the inseam, and then take some calculation with regards to your pelvic bone. If your hip joint is lower in your pelvic bone than mine perhaps we should have different saddle heights, even though our inseams could easily be the same length.
NYVC Almost everyone who visits you gets their saddle raised. I was fitted with the Guimard formula of .883 of inseam length, which is a full 25mm lower than your height. What accounts for the difference?
CU It's true most people that visit me get a raise, and to be honest I'm not completely sure why nobody gets a high enough saddle to start with. I think perhaps people are nervous about hurting their knees (being a common cycling complaint) and think it's safer to have a lower saddle. In actual fact, it's the other way around. A low saddle will almost always cause knee problems. I also think the difference is that I am measuring from your hip joint exactly, the actual pivot point when you cycle rather than the traditional inseam. The research we did when producing the fit system discovered that 1cm up or down did dramatic things to your VO2 power output. We also discovered that you can develop more torque when the saddle is slightly higher than traditional methods, resulting in more power while seated. This follows into the ‘cross setup, where you need to remain seated to keep traction, yet need torque to climb hills. Unlike a road bike where you stand, on a ‘cross bike (or MTB) you need to sit, and keep the back wheel from spinning.
NYVC That's interesting. I'd think you'd want a slightly lower 'cross saddle height to avoid painful remount accidents. You're saying that 'cross saddle height should be the same as road?
CU I'm actually saying the cross height is higher than the road. You just need to practice remounting to save on ugly accidents. The theory is you need more torque than usual seated, because this is how all the climbing is done and you can't come out of the saddle to develop the torque as road cyclists do, because you’ll lose traction.
NYVC While we're on the topic of seat height, most people advocate making changes in small increments. You make the change and that's that. I was surprised that I needed no adjustment period and felt no pain, even though it was a massive change. It's as if you're saying 'this is the right position and you should get into it asap'.
CU This is a tricky one. Yes I try to get people into the correct position asap. I find most people can do it straight away. The theory is that it is where your body is most stable/relaxed and comfortable, so it should want to sit in the new position. Occasionally I get people who are so inflexible (in either body or mind) that I need to adjust them slowly, then the solution is a target rather than "this is your new position". I fit a bunch of pro's earlier in the year at the end of their training camp – they had problems because they had just ridden 800 miles in 8 days, so the new position was a slow adjustment. But I find in general, most people can go straight to it.
NYVC So, were the pro’s all too low as well?
CU Actually they were a mix, I think in general they were too low as it was a team of flat race riders. They had decided that they couldn’t climb, so they were going to race on the flats. In actual fact with their new position, they could climb and had a well rounded season.
NYVC Now to the front end. What are the general principles you use in setting the front end?
CU One thing to remember here is that the front end is about the length of your spine and arms. You should not move the saddle to get the body length you are looking for. We always set the saddle first, which puts the engine in the right place. Then we think about the front end. Firstly we set the length up so the muscles of the body are relaxed, as before if you stretch them out they won’t be able to work for you. We also want the length to be just right, so as you are able to sit with a straight back.
NYVC It seems like you generally drop the bars, and sometimes shorten the stem. First of all, is that correct, and if so, why?
CU I don't know if there is a trend of what happens with the front end. I do get the feeling that people don't lower their handlebars enough because they are worried about flexibility or lack of it. What most people don't realize is that flexibility is not as much of an issue as they think. The trick is rotating the hips forward. So part of the reason I get a lower handlebar height is to encourage hip rotation. We have found with the hips rotated further forward, the muscles in the quads fire better.
NYVC When I was spec'ing my Seven I had to practically arm wrestle them to keep the head tube short. They insisted that you get more power with a more upright position. If they got their way I would've had a headtube so long that the lowest possible handlebar position would've been about 2 cm above your recommended height.
CU I don't know what they are thinking there. Or what they have used to prove this claim. If you developed more power with a higher handlebar height, why would TT bikes, pursuits and sprinters have dramatically low handlebar heights?
NYVC Speaking of TT bikes, what are the fundamental differences between TT fit and road fit?
@##=#<2,r>@##=#CU The TT fit is slightly different to the road position because of the different body position to aid in aerodynamics. The first thing is to roll the body forward in to the aero position first displayed by Greg Lemond in the Tour de France. There have been many studies done proving the aerodynamic benefits of this position. When in this position you have to be aware of what happens to your skeleton. Rolling your body forward and down rotates your hips further forward and results in a higher hip position. This means you require a higher saddle height. One of the tricks is getting the reach at the right distance. The aim here is to get as comfortable as possible, because more comfort equals more power. The most comfortable reach is when the top half of your arm is almost vertical. When this position is achieved the bone in the upper portion of your arm supports your body weight, resulting in less stress in your upper body – less stress and energy used in the upper body means more power to the pedals.
NYVC Do you mean lower hip position? A higher hip position would seem to require a lower saddle to compensate.
CU I mean when you rotate forward, your hip joint moves up because of the shape of the pelvic bone. Therefore your saddle needs to be higher to support the pelvic bone at this new height, it also has to do with the different angle your pelvis now hits the saddle.
NYVC I got the feeling that unlike the road position, there's a lot of room to play around with in a TT position. You could alter the STA, bar height, stem length quite a bit and still get good positions.
CU The TT position appears to have more adjustment or more room for interpretation because of the process in setting the front end. Rather than go with calculated numbers, I like to line the person up with the laser, because you're really limited to one position while riding a TT. It's nice to see the person in the position for a while to make sure they don't wiggle around too much. The actual room for adjustment is about the same.
NYVC So it's actually fairly rigid, but done more visually than mathematically?
@##=#<3,l>@##=#CU That's correct - Interestingly the TT position is not that different to a road position. After getting your legs in the most efficient position on the road bike, why would we change it for a TT setup? Basically the changes compensate for the aero front end. Also in the front end setup, the biggest mistake I see is people trying to get their elbows too close together for obvious aero advantages. The problem here is that it means the shoulders are placed under stress to hold your body up. If you slide your elbows out so the upper portion of your arm is vertical, the bone structure holds the weight and your muscles are relaxed. It is worth noting, that in most cases this position leaves the elbows inside your hip line, so there is basically no aero disadvantage. A great example is David Millar winning the ITT Champs last year. See how wide his aero bars are.
NYVC The fore/aft position of the arms is based on that same principle as well, right? Using the skeleton to support upper body weight instead of muscles?
CU That's right. Use the skeleton to help support the body. There is also a trick in the fore/aft position of the elbows. If you can get the upper portion of your arm close to the same angle as the steerer tube, you'll have an easier time steering the bike while in the aero position. Again this saves some energy while riding.
NYVC That's a really trick concept. Just so intuitively obvious. Between that and having my head a little further back I definitely noticed that the bike tracked very easily. Now, a dedicated TT frame compensates for the forward weight shift. Do you fit people differently when they do a quick conversion of their road bike for a TT?
CU I use the same basic concepts of stacking the skeleton. But there is less movement available on the Road bike to TT bike quick adjustment, so it tends to be finding a solution that the person can do easily themselves, and that gets them into a position that works.
NYVC One quick question for triathletes. Most triathletes ride steeper STA's than roadies, supposedly to save their legs for the run. You told me the exact opposite: move the saddle back to save the hamstrings. What gives?
CU Yes most triathletes have it backwards. A forward seat angle engages the hamstrings more when pedaling, and running is all about hamstrings. I'm not really sure how triathletes came to the forward seat angle, perhaps they thought it was more aerodynamic, but I am sure they didn't test which muscles are being used in different seat positions.
NYVC Now I’m all confused. The conventional wisdom is that tri’s ride steep for the run, and roadies ride shallow because they spend so much time on road bikes, and to conform to UCI rules. Barring any other considerations (running, UCI rules, comfort level), do you believe there’s an ideal STA for TT’s?
CU We believe the ideal seat angle for TT’s is 76 degrees. This puts the legs and body into the most powerful and efficient position. Your frame doesn’t have to be at 76 degrees though. With the aid of the laser I have, I can line any position up as if the seat tube was 76.
NYVC One more question before we leave the bike. You mentioned something about women specific saddles and rocking hips. Can you go over that again?
CU Women’s saddles tend to be wider than men’s saddles, which in theory makes sense, as women tend to be wider in the hips than men. The problem is that most women’s saddles are just too wide for their hip joints, the pivot points. So what happens is that they end up having to rock over each side of the saddle to be able to push the pedals.
@##=#<4,r>@##=#NYVC Ok, now that the bike is set up, on to the cleats. You were digging around the ball of the foot. What was that all about?
CU The trick is to find the Sesamoids, which are little bones in the ball of your foot, then place the cleat just off those so as to avoid hotspots in the shoes.
NYVC That pedaling fix you gave me is along the lines of 'don't use muscles that don't make you faster' as well. It's the best tip I've ever gotten and I'm surprised I never heard it or read it anywhere.
CU I think people are stuck in the ways of repeating what they have heard. It's not until you sit down and think about what you are trying to achieve that you realize where and when to pedal. We manage to prove this theory via sEMG technology. By using equipment that measure when and how much each muscle in the leg fires it became obvious that most people only use a couple of muscles while pedaling, and not the ones they really want to.
NYVC You showed me that I was using my calves, which was totally unnecessary. The funny thing is that I'd frequently cramp up in my calves. As far as using more muscles, is that related to proper knee alignment so that you're using both sides of your legs?
CU Yes, knee alignment helps use both sides of the leg. The most common issue we see is people pedaling with their knees over the top tube. With such a knee in pedal style the rider is only really using their VMO (the big muscle beside the knee on the inside) and don't use the VLO which is the largest muscle in the leg. Also rotating the hip further forward helps the other two muscles in the quadriceps group fire.
NYVC That’s where the Sole insoles come in, right? It really helped me straighten my knees out.
CU The soles will certainly help, but are not a total alignment fix. They are great at supporting the arch in your foot, which wants to collapse with every pedal stroke you take. The problem with the super high tech cycling shoes we buy is that the inner sole, or the piece between you and the technology, is nothing more than a piece of paper.
NYVC I feel as though this was an episode of Mythbusters. It’s scary how much accepted cycling knowledge is based on a house of cards. It’s even scarier how I was a stooge to every one of them.
CU Myth-busting – I often think that is what we are doing with this system. We are using high technology to prove without any doubt or guessing what the correct position on the bike is, and the best way to use it (pedal). So much of cycling is old wives’ tales, it’s just we choose to believe some of it as law. I mean, I’ve heard many times that the old guys would ride 100 miles with one water bottle to get used to it, to toughen them up. But none of us listen to that one. I think a lot of bike position and pedal technique is the same thing.
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