Given that frames are rarely built ‘square’ any longer (where the top tube measurement is the same as seat tube measurement), this formula is only a starting point. Frame types run the gambit now, as we see more responsive and lighter compact style frames (a shorter seat tube with downward sloping top tube), frames designed with higher head tubes for the recreational rider who may not have the flexibility they once enjoyed in their youth, and then there are time trial and triathlon frames, most with very short head tubes aimed at decreasing that frontal area exposed to the wind.
Another aspect of sizing is the rider. A look at two riders of the same height and build, chances are their fit will be different due to many other factors such as intended use (racing, recreational riding, triathlons, etc), injury history, and flexibility to name a few. This is where working with a professional bike fitter has it many advantages. As in most cases, in the world of bike fitting you get what you pay for. I had one client who came to me with a new bike complaining of knee problems. He began pedaling for me and immediately I saw that his seat height was a good 2 inches too low. I asked him about it and he said the bike shop that did his fit also said the seat was too low but that the seat post was out as far as it would go. It never crossed their minds to change to a longer seat post, which is what I did and solved the rider’s knee problems immediately.
A few years back, VeloNews ran an article entitled - "Five ways to reduce your risk of over-use injury on the bike". That list included the following:
- Professional bike fit
- Strengthen the hips
- Lengthen the hamstrings
- Close the open chain
- Ride, rest, recover
With regards to the first suggestion VeloNews went on to say, in a sport based on such a highly repetitive action—pedaling—the first line of defense against injury is a proper bike fit.
“That is the biggest thing,” said Frank Overton, founder and head coach of FasCat Coaching in Boulder, Colorado. “A good bike fit ensures you’re in the proper position that’s biomechanically not going to cause you any overuse injuries.” Overton pointed to knee, Achilles tendon, back and neck pains as just some of the common discomforts associated with improper bike fit.
Many riders are most prone to overuse injuries during the transition from winter to spring, as the weather improves and six-hour training weeks spent largely indoors swell to 12 hours or more outside on the road. Taylor Phinney (Cannondale Drapac) experienced this firsthand in 2011, seeing minor knee inflammation grow into a case of tendinitis that had him out of top racing form for much of his neo-pro season.
How the bike fitting process should work, beginning with just who should get a bicycle fit?
- A ‘newbie’ who has just upgraded his bike
- Someone rehabbing from an injury and their old position might not be ideal any longer
- Someone who has added new equipment to their bike (like new seat or aerobars)
- A rider experiencing chronic discomfort (saddle sores, numb feet or hands, joint pain, sore back, etc)
- A rider unable to stay in the aerobars for prolonged period of time
I will add one more person who may want to consider a fit. The seasoned athlete who has never had one! You would be surprised by the number of people who think they are riding a properly fitted bicycle but aren’t. Sometimes the changes are small, but even those can lead to big changes in incremental performance, efficiency and overall ride comfort.
