View Single Post
Old 12-21-09 | 10:22 AM
  #41  
RFC's Avatar
RFC
Senior Member
 
Joined: Sep 2007
Posts: 4,466
Likes: 24
From: Scottsdale, AZ

Bikes: many

Originally Posted by mtnbke
With low end and high zoot seat posts available up to 400mm getting proper leg extension is pretty much a given for almost any cyclist on almost any size frame.

The frame size, which is a measure of the seat tube, in centimeters, from the crank bolt to the center of the seat tube/top tube junction, is not something to ballpark fit so the cyclist can get proper leg extension. In fact the frame size has really NOTHING to do with leg extension at all, rather frame size determines the ultimate relationship between the handlebars and the saddle. Essentially with a frame that is too small, requiring a longer seatpost, the resulting consequence is that the tops of the handlebars will be farther below saddle height. Frame size is critical to determining the relationship of bars to saddle.

While goofy Technomics high rise stems exist they are definitely not designed for big strong Clydesdale cyclists over 6'5". The average big cyclist can deflect the bottom bracket of any steel frame, and even most oversized aluminum ones, and this with silly little clown 175mm cranks. In a hard effort its entirely reasonable that a bigger cyclist would break the spindly and flexy Nitto Technomics stems right in half. I mounted one on a tandem once and I found the Nitto Technomics stem to be downright scary. Definitely something for the tiny little people, not big Clydesdale cyclists (the context of this thread is someone with a 37" inseam)...

So while there are some goofy things you can do to "fit" a bike that is too small, that is not being the proper platform to dial in stem extension and stem position, none of these so called solutions are ideal. Sure you can use a Nitto Albatross bar to allow a cyclist to ride a bike that has too long of a top tube where even a 2cm stem woud be too long. It puts the rider in a much more comfortable position and essentially makes the top tube shorter. However these tricks require completely changing the personality and handling of the bike. A stable bike with drop bars can be transformed into something that would be frightening to descend on the Albatross bars...

The fact is that most people would do well to understand fundamental bike fit first, and that starts with a properly sized frame.

Lemond was making recommendations for racing style bikes. Most people aren't ever going to enter a race or get a category rating.

In fact the general rule that the bars should be two inches above the saddle, or at a minimum at saddle height would do wonders for the majority of cyclists. Rather than have bikes with drop bars they can NEVER reach, even for the briefest of stints, they would have road bikes with multi position drop bars that they can comfortably ride on the hoods, in the drops, or wherever they want. Set up this way, or randonneur style instead of racer style may not look as aggressive, but its not about what the bike looks like but how it rides. Set up this way the cyclist will not have neck pain to look up the road or even into the sky, they won't have wrist pain, back pain, etc.

The bike pictured in this thread with the six to seven inch drop to the top of the bars, let alone to the drops couldn't be a more perfect example of someone who just doesn't understand bike fit. That cyclist may be used to riding the bike set up that way, but that's only because they probably have never ridden a properly fit bike in their lives.

Nothing is more stupid looking than a roadie who can't get off the hoods. Again the average cyclist rides frames that are least 2cm and probably more like 5cm too small for them.

The thing is that everyone knows someone with a higher end road bike that hangs in the garage. The person bought the bike thinking they would get into cycling. They don't ride the bike, and probably can't even articulate why, but it has something to do with "not really liking cycling." In reality some wanna be poseur racer kid at the local bike shop probably helped them "fit" the bike and walked them out the door with something that doomed their cycling experiment before it even started. The person will probably never think critically enough to challenge the information that they were given that the bike they were sold "fits" and so they just assume that cycling is just uncomfortable in general, or that just their neck, back, and wrists hurt. This in only reinforced by looking at all the foolish roadies riding around perched on the hoods of too small bikes.

The funny thing is that there really isn't any significant advantage over an aggressive below saddle stem position. Not in the range of two inches above saddle height to two inches below saddle height. The amount of energy a big cyclist has to expend to push air out of the way of his 6'5" (and up) body isn't go to change measurably based on such a minute adjustment. We're not talking all out UCI time trial efforts here, but just the leisurely pace of a local competitive group ride or even charity centuries, or double centuries.

Trust me a properly set up bike makes ALL the difference in the world. I love my touring Cannondale (68.5cm or 27" frame) that shows only a fistful of post. I have a 98cm cycling inseam and standover clearance is not 'comfortable'. However, you don't fit a bike by standing with your feet on the ground, but actually riding it. Sadly so many people, and hacks at bicycle shops don't understand that. I've got hundreds of miles on bikes that were too small and set up with riser stems and 400mm seatposts (and these were 63cm frames) and there is just no comparison to a bike that actually is the right size to begin with.

Again, frame size is there to get the handlebars in the right position, not to give you leg extension. If you try to "fit" a bike that is too small (or large) bad things happen...

As a rule ride the largest conventional (non-sloping or non-compact) geometry bike you can stand over (comfortably on your man bits or even uncomfortably). Everything else will fall into place in terms of bar height and extension from there. Even outlier body types with long or short torsos can be easily fit using the range of standard length stems (7cm to 15cm) on a properly fitting bike.

Its ALL about handlebar height and position, and the leg extension is just a signalling device of that ultimate ideal position.

Lemond saying a two inch drop, or Sloane arguing for saddle height bars, or even set up not to race randonneur style is a far cry from the pics and examples posted here which should be poster examples of bikes that impromperly fit and what NOT to do.

Nobody and I mean NOBODY is "best fit" on a bike with a six to a seven inch drop from saddle to the top of the bars. That there is someone confused on what fit means, and what they have set up ain't it, "road experience" or not...
Much good thought and many astute points here, particularly when it comes to: 1) the relevance of bike size to HT height and the irrelevance of bike size to saddle/seatpost height; and 2) fit for novice cyclists. I agree with much of this regarding cycling and general fit. However, you make a couple of points/assumptions with which I disagree:

1) There are many different body styles out there (like yours) and fit is a personal issue. That's why bikes come with adjustable seat posts and different stem lengths. The three primary components of the cyclist's body correspond to the primary bike fit components (funny how that works). Thus, leg length to seat height, body length to top tube length, and arm length to stem length and handlebar height.

2) I believe this concept of fit is an important starting place. For example, I have long legs, short torso, long arms, which translates into tall seat, shorter TT, medium to long stem (110 to 130). Reapply the "formula" for a rider with short legs, long torso, short arms.

3) My bikes are my Leggos. I reconfigure and experiment. Like many here, I have bikes in a range of TT sizes: 52 (cyclocross) to 56. Part of this is due to the fact that C&V collecting does not generally allow you to pick your custom size. Even so, as I said above, each is setup with my standard cockpit, as are my more modern bikes. With the 56's, I still have at least 6" of seatpost. With the smallest frame I have 7.5".

4) Bike size is not a fashion issue, but is related to performance and feel. I posted the small Ironman as an example of the smaller end of my comfort zone. BTW, the seat to bar drop is 5". Yes, a larger size is more comfortable. Yes, it does take me a while to stretch and warm up to being in the drops. And when I do, I'm in the drops 50% of the time. I don't want to ride a Century on this bike, but for a fast 25-30 miles at dusk around the Air Park, it's a rocket and a lot of fun. Kind of a lock and load experience.

For me, big bikes above my preferred range are, frankly, clunky. And, I have no interest in riding a bike so large that I have to lean it over when I stop in order to avoid racking my pelvic bone. The TT only has one real purpose: to create one side of a stiff triangle. With perfect materials, a better design would be a V-shaped frame without a TT. For me, TT height is only relevant as to how it dictates HT height. But I think you made that point.

5) Fitness has a lot to do with fit: flexibility, abdominal and upper body strength, and body mass (i.e., fat). In the spirit of the holidays, I will try to avoid being pedantic here except to present a challenge to all. While you are watching football ad nauseum over the holidays, every day, get off the couch and on to the floor in front of the TV and do 20 minutes of slow, but progressive and aggressive stretching. Push to the edge of your comfort zone, hold, repeat. After two weeks of stretching, see how you feel about bike fit.

6) No one is telling anyone that they should be aero. Sit as high as you want. Nobody cares. However, from engineering and performance standpoints, aerodynamics are crucial to cycling. The incremental impact may seem small going from top bar to hoods to drops to aerobar. But consider this. When I go from the hoods to the drops, I pick up about a 5% increase in speed. When I go from the hoods to an aerobar, I pick up about a 10% increase. Any time you increase the efficiency of an already well-designed machine by 5-10%, you have made a very significant improvement in performance. If you were to experiment with more aero positions, I am confident you would see increased speed due to decreased aero profile. With your size, you may even have more to gain.

But, now it's time to get some real work done.

Happy Holidays, All.
RFC is offline  
Reply