By Georgena Terry
Q: How much does a cyclist’s flexibility factor into your bicycle design?
A: Before a customer purchases a bike from me, I ask her to complete a questionnaire that covers everything from measurements of herself and her current bike, her cycling aspirations and her flexibility. If you’ve followed the evolution of fitting techniques, you’ll know that flexibility is becoming as important as an inseam measurement for setting up a properly fitting bicycle.
Achieving a “neutral” or flat back position can be difficult if the hamstrings are tight. These muscles attach to the pelvis at the ischial tuberosities (sit bones) and behind the knee joint. If they’re tight, they pull down on the pelvis, causing it to rotate back. On the bike, this often leads to a rounded back, which can cause neck pain from rotating the head up to watch the road. The upside is that rotating the pelvis back reduces pressure on the sensitive “bits” that land on the front of the saddle.
It’s easy to see how a rider who is flexible can have an advantage over a rider who is not as flexible, since the former will be able to get into a lower and longer position on the bike. In this position, the rider is more aerodynamic and can generate more power than a rider sitting upright. The pelvis rotates forward, allowing the spine to settle into a neutral position, reducing the possibility of low back pain. The downside is that there is more pressure from the saddle on the rider’s crotch.
Jo McRae, a trainer in the U.K., distinguishes between the “upper” and “lower” hamstrings. She maintains that as a cyclist pedals, the upper part of the hamstring, which connects to the pelvis, is stretched more than the lower end of the hamstring at the knee. [Bike Fit Blog Part Deux, http://jomcrae.co.uk/bike-fit-blog-part-deux/.] As a result of this dynamic motion, the upper end of the hamstring tends to be more flexible than the lower end. Specific stretching exercises are needed to address that area.
The correct saddle height can be determined through a variety of formulas:
- Lemond method: Set the saddle height at 88.3% of the inseam length. Measure from the centre of the bottom bracket to the top of the saddle.
- Hanley method: Set the saddle height at 109% of the inseam. Measure from the centre of the pedal spindle to the top of the saddle.
- Place the heel of the foot on the pedal when it’s at the bottom of the pedal stroke. Set the saddle to the height at which the knee is locked.
- Measure the angle between the lower and upper leg at the knee at the bottom of the pedal stroke. Most experts agree it should be between 145º and 155º.
Hamstring flexibility, or lack of it, affects saddle height. A rider who has tight hamstrings might not feel comfortable with the saddle at the high end of the range, but this can be addressed by stretching to improve hamstring flexibility.
Flexibility has an important role to play in how the bicycle can be set up most effectively for you. In the end, it’s up to you to decide what the proper trade-offs are between comfort and power.
Georgena will answer your questions about bike-fit, bike-frames, saddles, and bike-maintenance. So don’t be shy. Take advantage of her knowledge and decades of experience to get answers to any questions you have about bicycles. Email me at [email protected].
When Georgena Terry first started designing bicycles, over 30 years ago, there were no women-specific bikes. Many female cyclists were forced to put up with neck, and shoulder pain, and other physical problems that came from riding bicycles that didn’t fit them. Georgena Terry changed that. Looking at anatomical differences between men and women, such as body mass and body strength, she began designing bike frames that optimized comfort and performance for female cyclists, with special attention to women under 5’2”.
Working out of her basement in Rochester, NY, Georgena first designed bikes for herself, then for her cycling friends. In 1985, she sparked a revolution in the cycling industry by launching Terry Precision Cycling, selling custom-built, high-quality steel frame bikes for women. Larger cycling companies sat up and took notice. Eventually following her lead, they developed their own brand of women-specific bicycles, clothing, saddles and accessories.
Today, Georgena continues her passion, designing and building custom steel bikes for women cyclists of all sizes. Contact her at georgenaterry.com
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