I have found that discussing saddle height with triathletes is like discussing politics or religion. It can be a controversial subject with many diverse opinions! It seems everyone agrees that saddle height is important, not only for performance gains, but for injury prevention. Too low will not generate full power and too high can lead to knee and back strain.
There are several schools of thought on how to determine saddle height. The first, and probably the simplest, is to get your bike on a trainer, get on and place your heel (without shoes) onto the pedal. Adjust your saddle height until your leg is fully extended while the heel is on the pedal. This is a good way to get a general measurement of your saddle height. Some recommend you do this with bike shoes on, some recommend without. I’m sure that without bike shoes it is more accurate since the heel thickness varies with cycling shoes. While this measurement is widely used by recreational athletes, serious cyclists rarely use this method exclusively.
Another popular method is based on a ratio of your inseam length. In 1978, Claude Genzling measured cyclist’s height and saddle height in the Tour de France and concluded that a saddle height should be .885 of your inseam length. Don’t use your pant size inseam to determine your inseam length. Stand barefoot up against a wall, take a book and place it snugly under your crotch, and mark the top of the book with a pencil on the wall. Measure this mark to the floor, and multiply it by .885. For example, if your measured inseam was exactly 32 inches, your saddle height should be 28.33 inches. Now, from which points on the bike do you determine what that 28.33 inches is? Well it’s from the center of the bottom bracket to the center of the saddle where your crotch will be resting on the saddle. By the way, the bottom bracket is the axis on which your cranks rotate. This is a popular method, but there are 3 potential drawbacks. First, is that this method does not consider your crank length. Longer cranks would obviously more fully extend your leg at the bottom of the stroke. Second, this method does not factor in shoe thickness or even cleat thickness. I suppose you could measure your inseam while wearing your shoes and cleats, but this would probably negate the accuracy of the measurement.
A third method is to base saddle height on the angle at which the knee is bent when fully extended in the stroke. This angle should be between 25 and 30 degrees. This has become more and more popular as the best method to determine saddle height, but it can also be hard to measure without a set of complex tools that include a giant protractor to measure knee angle.
Finally, what I consider to be the best method is to get professionally fitted. It does cost some money (around $100) but it is well worth it. I specifically endorse the FIST system developed by Dan Empfield of Slowtwitch.com. There are many FIST certified bike fitters around the country and you can go to slowtwitch.com to find one in your area. In addition to many other points of measurement, the FIST system uses the knee angle method to determine saddle height.
A couple of other points on saddle height, you can also use the method of trial and error. It’s too high if you’re rocking at high cadence. It’s also too high if you can’t catch the stroke in single leg drill. Saddle height is definitely something you should give some thought to as it can greatly impact your performance in practice and race situations.
David Warden is a 3-time USAT All American and Elite Coach with Joe Friel’s TrainingBible coaching. His work has been published in Triathlete and USA Triathlon Life magazines. He is the former Vice-Chair of the USAT Rocky Mountain Region, and the host and producer of the #1 triathlon podcast, Tri Talk and part owner of www.powertri.com.