All Mountain

Mountain bike fit: solving the saddle position puzzle

Here’s the deal: we’ve all heard about how important bike fit really is. Magazines go on about the ideal riding position, and bike shops boast about their fancy new bike fitting equipment, which often has its own special spot in the corner of the store. Despite this, the extent to which most riders actually undertake proper bike fit is eyeballing the right seatpost height, and hitting the trail. Whether this is out of not knowing where to start, not caring, or not having ridden a properly fit and adjusted bike, the unfortunate reality is that most riders could be riding more comfortably and efficiently with a few tweaks to their riding position.

A word of caution before using this guide: this shouldn’t come as a big surprise, but bike fit is a pretty personal thing. Different people have different body types, and the same fit suggestions may not work for everybody. This guide is meant to give a solid foundation which will work for most riders, but there is no ‘perfect fit’ which will work for everybody. Try these suggestions out, pay attention to how you feel after making the changes, and feel free to make incremental changes as needed.

Preparation: What you’ll need

• A level
• A tape measure
• A hardcover book
• A pencil
• A calculator
• A string with a weight on the end (a plum line)
• A beer (for celebration of a job well done)

Step One: Get your saddle level

This is the easiest change to make, and can have the biggest impact on your pedaling power. If you’re riding with your seat too low, your legs aren’t getting full extension, and that means that you’re not getting as much power to the pedals as you could. On the flip side, if your seat is too high, you’ll be rocking your hips on the saddle, overextending your knees, and stretching with your ankles, all of which can lead to discomfort.

In order to set the saddle to the correct height, you need to first set the angle of the saddle itself. Using a level (or at very least some careful eyeballing), loosen off the bolts on your seatpost clamp, adjust the saddle to a level position, and re-tighten the clamp. Some seatpost clamps have notches, and some are infinitely adjustable, so just try to get the saddle as level as your style of clamp will allow.

Step Two: Find your ideal seat height 

Now that your saddle is level, the next step is to find out what your ideal saddle height is. For this, get your riding shoes on, and stand with your back to the wall, feet together, and heels touching the wall. Then, put the hardcover book between your legs and square against the wall, and slide it up as high as it will go. Mark the top of the book on the wall with the pencil, and then measure the height from the mark to the floor. Multiply the height you end up with by 0.88, and the result is the correct seat height, measured from the centre of your bottom bracket to the top of your saddle. Set your seat height accordingly, and it’s not a bad idea to put a small mark on your seatpost so you can quickly find the correct height in the future.

Step Three: The fore/aft position 

There’s just one step left to get your saddle in the perfect spot: determining the ideal fore/aft position. Still in your riding shoes, get on the bike and put both feet on the pedals, with the cranks parallel to the ground (it’s helpful to lean against a wall while doing this). Now, dangle the plum line while holding the string from the depression just below the knee cap of your forward leg. Look at where the string falls compared to the pedal axle. If the string falls in front of the axle, move your saddle back in the rails until the string lines up with the axle. Similarly, if the string is falling behind the axle, slide your saddle forwards until it is in line with the axle.

Step Four: Ride, enjoy 

That’s it! Your saddle is set up in the right spot, and your bike is fitting you a world better already. Now get out and ride, pay attention to how it feels, and tweak using small adjustments until you’re feeling great about your bike fit.

© 2008 Two Six Nation.