A Different Take on x/y

  • By coachimfit
  • 10 Aug, 2015

Making Centre of Mass displacement an integral part of bike fit

A good fit is as much about body angles on the bike as it is about body displacement. How your weight gets displaced along the wheelbase and where your center of mass lies in relation to the bottom bracket is every bit as important as what your hip and knee angles are. In fact, I could easily argue that weight displacement is more important as it this factor that determines how the bike is going to handle out on the road.


The sad truth is, a decent fitter can arrive at the appropriate body angles on a virtually infinite array of bike sizes. Saddle height, saddle fore-aft and stem length can all be adjusted to "make" a bike fit the rider. IF your definition of fit stops at body angles. Mine does not.

The way I see fit, there is a pair of x-y parameters that ultimately determine proper rider position. Saddle height and saddle nose to center of handle bar. Now, these are not to be confused with the more commonly understood x-y measurements of stack and reach, although they are related. Stack and reach refer only to bike dimensions. What I'm focused on has more to do with rider position.

Saddle height obviously determines knee angle. Saddle nose to bar center determines hip angle. Yes, I'm oversimplifying a bit, but hopefully you get the idea. What I want to focus on mostly here is the cockpit reach or saddle nose to bar center measurement. Say your optimal hip angle occurs with a cockpit reach of 66cm. By combining top tube and stem lengths you can see that it is possible to arrive at that magic 66cm number in a wide variety of ways. At extremes, you could have a 60cm top tube with a 6cm stem, or a 54cm top tube with a 12cm stem. And yes, I am oversimplifying again. Work with me. So we have a bunch of different ways of arriving at that magic cockpit reach and hip angle. Do you suppose all of those options are going to handle the same out on the road? Not a chance.

You need to think of your stem as your steering axis. A short stem creates a very twitchy, fast to respond steering input. Some people like this, many don't and I consider it to be a very unsafe way of riding. The shorter your stem, the more likely you are to lose control in bumpy and uneven surface conditions and the more likely you are to over-steer in an emergency situation. The longer the stem, the more controlled and stable the steering response. But again, you can go too far and create a bike that is sluggish and completely unresponsive. In my humble opinion the ideal generally lies somewhere between a 10 and 12 cm stem. Any shorter and I consider the bike too big, any longer and I consider the bike too small. Now there are always extremes. Cippolini used to ride a custom 15cm stem on a very small bike. He did this because the smaller frame was lighter and stiffer, and the longer stem gave him optimal control when he was throwing the bike around underneath him in the sprint. I can imagine he would have a serious loss of control in those violent sprints if he were riding even a modest 12cm stem. So ultimately where you lie on the scale comes down to your riding style, your range of motion and your biomechanics. A good fitter will understand this and take all of it into account when performing your fit.

But wait, there's more! That ratio of top tube to stem length impacts the overall geometry of the bike as well, which also impact it's handling on the road. Stock bikes are built proportionally. A shorter top tube creates a shorter head tube, longer top tubes require taller head tubes. So where you end up on the horizontal plane has a huge impact on where you end up on the vertical plane. This has the greatest impact on people with long inseams and short torso's. That short torso requires a shorter top tube length than your overall height would indicate, but those long legs cause a problem. Long legs means tall saddle height. Short torso means short top tube for short cockpit reach. But, short top tube means smaller frame and a shorter head tube, which can then create too great a drop from saddle to handlebar, causing a massive shift in your COM over the bottom bracket. Essentially, it can pitch you too far forward, put too much weight on your hands and have your COM too high above not only the BB but the frame in general. This can create a very top heavy and weight forward bike that will climb poorly and descend dangerously.

Twice in the last month I've seen bikes that were sold based solely on rider height and both times they were the wrong size and geometry. Sometimes these people need a custom bike and sometimes they can work with a stock bike. But it may not be the bike they "wanted". When your body is disproportionate, you have to go with what works. Fortunately, not all size 54cm frames are created equal. Every company has their own ideas about what a particular size means and they all have their own ideas about how their bikes should ride. So armed with the proper knowledge and tools, it is usually possible to find a stock bike with a geometry that can be tweaked for the individual riders needs. And when I can't, custom is my recommendation.

I have morals when it comes to fitting, and I will never just "make" a bike fit. If I don't believe it's going to handle well and safely on the road, I'll shut down the fit and work on finding the client a bike that will.


IMFIT Athletic Performance Studio

By coachimfit 15 Aug, 2015

Greetings and salutations faithful IMFIT followers. I hope everyone has been having an awesome summer so far. I just got back from an awesome week in Mont Tremblant checking out the Ironman event. Always, always a very inspiring day. I had the chance to put some time in on the bike on some truly amazing and scenic roads. Time that also served to show me just how much bike specific fitness I've lost in the last couple of years spent with a greater focus on my clients fitness than my own. It was at that point that I decided it was truly time to get my own butt back in the kind of shape it used to be. I know how to do it...I've got countless client PB's, podiums and improved test results to show that I've created a training formula that truly works, and that is completely adaptable to each clients needs. Time to put that to work for me!

All I needed was a starting point. That starting point was some Metabolic Testing to figure out what my current heart rate zones are, where my Threshold is and how strong (or not) my aerobic system is.

Well! That was a humbling morning. A little physical history on little 'ol moi. At my peak about four years ago I had a Peak VO2 of 63ml/kg/min. My max heart rate was 198, Anaerobic Threshold was 172 and my Aerobic Endurance Threshold or Aerobic Base was 155 and I was burning 55% fat calories.

Ya. Not any more. Current data as of this past Thursday has me at a Peak VO2 of 36ml/kg/min, peak heart rate of 140, AT of 132 and AeT/AB of 114. In short, I'm couch potato fit! And yes, I'm trying to maintain a sense of humour about this. That's my bike fitness. My run fitness is slightly better. VO2 isn't much better, but my AT is in the 140's and my AB is at 131.

I am not the man I used to be. But here's the thing. Because I spent so long training at those levels back in the day, my body and my brain are both conditioned to feel that effort level. My brain especially is conditioned to look down at my heart rate monitor and see certain numbers and that is part of my problem. Up until I tested myself last week, I had been riding and running to feel. Problem is, that feel was all wrong. I know now (and new deep down at the time) that I was pushing too hard.

How could I tell? I was too tired after my rides and runs, recovery was taking too long. I was super hungry and craving bad things. I was sore a lot, more sore than I should have been for what I wanted to be doing with my training. And most importantly, I wasn't losing any weight. All of those things add up to tell me as a coach that the training is too intense, too anaerobic in nature. As a coach it's very easy for me to see that in one of my athletes. As the athlete, it's harder to admit that I need to go easier than I used to be able to. But now that I have the cold hard test results staring at me, there's no more denying it. No more doing what I used to do just cause it's what I used to do. My body has changed. My training sweet spot has changed. If I want to see the kind of improvement in myself that I get out of so many of my clients then I have to drop the pride, accept and believe in the results and train smart.

And that's what I've been doing for the past week since doing the testing. Result? I've already dropped two pounds with no change to diet. I'm not as tired after my training sessions, I'm not as hungry through the day and I don't have the cravings post workout that I was getting before.

Believe me, it's tough to spin easy enough around Halton Hills to keep my heart rate under 120. Really hard. I'm spending a lot of time doing loops around the neighbourhoods to avoid the bigger hills right now. It is incredibly humbling but I have a goal and I have a plan to get there. I don't want to waste any time in getting there either so I've made the same commitment to my training that I ask of my clients. Don't waste any time. No garbage miles. I've got the results, I know where my sweet spots are. I know that every minute I spend going easy right now will equal awesome minutes going hard in a few months time. I just need patience and focus right now.

I'll be testing every four weeks or so for the next few months as I expect my body will respond quickly to the proper training and I don't want to waste any time with fitness plateaus. As I continue following up on my fitness I will continue to post here to let you all know how it's going.

As always, thanks for reading and happy training!

By coachimfit 10 Aug, 2015

One of my favourite cycling films is a documentary called Overcoming. It follows Team CSC as they prepare for the 2004 Tour de France. It's a great behind the scenes look at what goes on in the world of professional cycling. One part that really stuck with me was a brief commentary from the team director Bjarne Riis. He was talking about maintaining the bicycles, how one of his favourite things as a racer was to tinker with his bike, making sure all the bolts were tightened just so. He talked about how you screw them in just right, but sometimes you go a quarter turn too far and the bolt snaps. But, he says...how do you know how far you can tighten a bolt if you never break one in the process?

It's an interesting question, and I think you all know he's not really talking about breaking bolts. No, what he's really talking about is breaking cyclists. Which is exactly what I want to talk about today. The Break...

Before I go any farther I want to make one thing clear. This is NOT for everybody. If you are a middle to back of the pack athlete and more importantly are happy to be there, just taking part and challenging yourself then this isn't for you. This is for the athlete who wants to move up, wants to set PR's, wants to push the limits of what he or she can handle and ultimately for those who want to win. As a coach, it's this latter group of athletes that I will deliberately attempt to break at some point during a season, because exactly as Mr. Riis said...how do I (and they) know just how far they can go unless they go too far every now and then?

There are two types of break in the athletic world. The Training Break and the Race Break. I'm going to focus on the Training Break for this instalment.

The Training Break is quite simple to understand. At some point during a macro build cycle I make the choice to push my athlete to what I think will be their limit. The training gets picked up an extra notch, I ask for more power, faster paces and/or longer distances than they are used to. But not too much more than they are used to. I don't want them to fail right off the mark. That doesn't teach anybody anything. Instead, I make them just hard enough that as a stand alone workout, each session is achievable. It takes just about everything they've got, and leaves them exhausted when they are done, but they are achievable on their own. It's the cumulative effect of a three week build cycle of progressively harder and harder workouts that causes the break to happen. If I did my job right, somewhere in that third week the muscles have had enough and just can't fire the way they should, the way they were firing even a mere week ago. It's a workout that the athlete has to shut down and walk away from. If that happens, I've succeeded. I've pushed my athlete to a new level of training intensity and from that point onward I will know exactly how far I can take them without breaking them. I know exactly how much I can tighten the screw. Effective training is very much about pushing limits, placing stresses on the body and then allowing the body to compensate for those stresses with proper rest and recovery to get stronger and better deal with that stress the next time it comes along. Once an athlete has broken in training I'll be better able to optimize those training stresses by pushing to just below the breaking point and then bringing them back to a happy place with a mix of active and passive recovery. Optimize the stress, optimize the recovery, maximize the training benefit.

Now, there's a little more to it than that. There is something else I'm looking to learn and teach in this process. You see, I don't tell my athlete when I'm pushing them to break. If I did, one of two things would happen. Either they would be afraid of breaking and not execute the workouts 100% which means they probably won't break. Or, if they do push through and break, they will be mentally prepared for it and move on from it easily. And this ruins the second part of the process. In breaking an athlete during training I'm looking to see how they handle a "failure" both mentally and emotionally. I need to know what they are made of, how they handle set backs. No matter how fit and strong you are, not every competition is going to go to plan. By learning how to deal with a setback in training they are better able to handle setbacks during the race season. This part requires a lot of feedback between coach and athlete. Once they have broken and rest and recovery kick in, it's very important to keep the line of communication open so I can assess how they are dealing with it, and help them understand how and why it happened. Most are frustrated at first, I let them talk and work through that with a little guidance from me. Once I see where they are headed mentally I talk them through my thought process and how/why I pushed them that hard. I help them understand that not only is it ok that they broke, but that it was totally expected. If they can come to grips with that concept, that not only is it ok to break, but that sometimes it's actually expected, then they are on the road to being better able to handle things when and if the Race Break occurs.

Which will be the topic of my next instalment.

As always, thanks for reading and happy training!

By coachimfit 10 Aug, 2015

Good day and thanks for checking in. I know my next topic is supposed to be a continuation of my discussion of breaking in training and racing but I wanted to divert for a moment and talk quickly about supplements.

I get asked fairly frequently what my views are on supplements and nutritional products. These questions tend to come from two camps. My athletes, and sales reps trying to sell me on their version of the latest and greatest product to hit the market. Mostly due to an increase in queries from the second camp, I feel it's time I put my thoughts on record.

I always welcome this question from my athletes, but it's a hard one to answer. I'm a firm believer that what works for one person isn't always going to work for another. We all have different tolerances, needs, tastes and sensitivities. All I can do is tell them what has worked for me in the past, and what seems to really be working well for other athletes and encourage them to experiment on their own to find what works for them.

Overall though, it should be noted that I'm not a very big fan of processed nutritional products. I don't believe we are supposed to be getting our vitamins and minerals from powders, pills and drops. I firmly believe that if you eat a truly healthy, balanced diet comprised mostly of whole, real foods, you're going to get everything you need. Granted, athletes do need to supplement their caloric and nutritional needs during training and competition but I believe that too can be accomplished through real, natural foods. As a quick example, when I'm training in the heat and need additional electrolytes and minerals I use a mixture of coconut water, plain water, lemon and either agave nectar or honey for flavour. Coconut water is truly nature's sports drink. When it comes to needing calories on the bike, I make my own energy bars and gels. There are a multitude of sources out there for recipes. One of my favourites is The Thrive Diet by Brendan Brazier. He's got some great recipes at the back of the book for home made, natural bars and gels. Yes, it takes a bit more work than stopping off at the running store on your way home, but it is a far more satisfying snack when you know exactly what is in it.

Which leads me to the second camp. I know there are a lot of coaches out there who sell nutritional products on the side to supplement their income. I don't really blame them. Coaching isn't exactly a business you get into to get rich! But for all I've said above, that business model just doesn't register with my moral compass. I take great pride in being neutral on a wide range of products. By not selling anything it leaves me free to recommend what I feel is best for each individual client. That goes from bikes, to running shoes, to cycling jackets to indoor trainers to food. If I'm making a buck by selling X, I may hesitate to recommend Y even though I know it's the better option. I want to be free to recommend what I think will be the most effective product for that client in that situation.

But beyond that, I just flat out have issues with the nutritional products industry. I don't think it's right to isolate vitamins and minerals into pills, powders and drops. I believe that nutrition is a holistic endeavour and that a particular food is made up of its particular nutrients, in those particular quantities for a reason. When we isolate these nutrients I believe we are messing with the balance of nature and risking harms that we don't even know about yet.

I also don't believe the industry really needs to exist. If it weren't for the fast food/processed food industry we wouldn't really need to buy nutrients in a bottle. Processed foods may be calorie dense (in fact the argument could be made that many of them are too dense!) but many of them get the nutritional quality processed right out of them by the time they make it store shelves. I think it's kind of ironic that many eat these processed foods in part because they are cheap, but then go out and spend good money on supplements to get what they can't from the cheap processed foods. When you add up the crappy food and the pills/drops/powders I wonder if it wouldn't have been cheaper to just buy the real, whole foods in the first place?

Now don't go thinking I'm all preachy and perfect! Far from it. I do enjoy the odd fast food meal. I try my best to live by the 80/20 rule. 80% good stuff, 20% crap that happens to unfortunately taste really good!

As for supplements, only two things on a regular basis. A vegetarian protein powder for my smoothies and oil of oregano as an immune booster when I think I may feel a cold coming on.

So, those are my thoughts. Please take them with a grain of natural sea salt and experiment on your own to find what balance works best for you.


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