As I ride around and spot other cyclists, I look at them, too. And I’ve noticed, like my friends did, that there are a lot of too-low seats out there. I see too-high ones once in awhile. But the low ones are easier to spot and more common, I think.
Too low a seat is a problem because it can cause knee pain, or even injury, fairly quickly, especially if you climb hills or push the pace. It also reduces your pedaling efficiency, since you aren’t able to use the full power of your legs. And, as the seat drops, the distance to the handlebars changes, possibly causing back or neck discomfort or pain as well.
Tip: When winter approaches, you may be planning to ride indoors on a trainer. It’s even more important to have the right seat height on a trainer because you’re more likely to sit in one position for extended periods, which can lead to injury faster if your seat’s not right.
Know your seat height
The easiest way to be prepared to check your seat height is to mark it or memorize it. That way, you can routinely check your seat with a tape measure or look at your mark. Some riders put a wrap of electrical tape around the seatpost to mark it. Black electrical tape blends in well with many seatposts and can hardly be seen. It’s also there if you ever need it for any on-the-road repair. But if tape clashes with your seatpost, or you simply don’t want a piece of tape junking up your baby’s looks, a line or dot from a Sharpie marker will last a long time, too.
I also memorize my seat height measurement, taking it from the top of the seat to the center of the bottom bracket. These two reference points are relatively easy to measure from.
Tip: Because I’d like to have a permanent mark, too, I know it’s tempting to want to scratch or notch your seatpost to mark it. But don’t do it because it will likely damage your seatpost and may even cause it to break. Maybe you’re lucky, though, and exactly four fingers fit beneath the seat. Something like that would be a nice gauge if it works for you.
Resetting your seat height
If your seatpost is marked or you know the measurement, it’s simple to raise it if you’re home with your tools. If you notice it on a ride, as long as you have the right wrench and have it marked, you can raise it right there. If you only know the measurement and don’t carry a small tape measure, you can ballpark it with the steps that follow, or look for an old mark since a post that has been in one spot for a while usually leaves some line or blemish on it.
Tip: Hopefully, when you try to raise your seat it will move easily. To prevent a seatpost from freezing, make sure it’s lubricated. If it’s steel or aluminum, use grease. For carbon seatposts and frames use what’s called “carbon assembly paste,” which is made just for carbon and has grit in it because plain grease would allow the post to slip. Be careful not to overtighten carbon seatposts.
Finding the right seat height
If you’re not sure exactly where your seat was, here’s an easy way to find the optimum height. Do it on a trainer or indoors in a doorway and have a friend or your spouse help. Put on your cycling shorts and shoes, mount your bike in the trainer or place your bike in the doorway, get on and hold onto the doorjamb to support yourself. Have your helper stand behind.
To find seat height, place your heels on the pedals and pedal backwards. You’ve found the optimum seat height when your legs are completely extended at the bottoms of the pedal strokes with your heels on the pedals. Have your helper watch for rocking hips, the sign that the seat is too high. Now, when you’re actually pedaling, you’ll have the perfect bend in your knees.
This is a great way to find a starting position. If it feels too low or high, adjust the seat up or down — but only slightly — to fine-tune the adjustment.
Tip: There are many high-falutin’ calculations you can perform to figure out your seat height, but this simple legs-fully-extended-with-the-heels-on-the-pedals method is quick, easy and almost always very close to perfect.
Jim Langley is RBR’s Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter. Jim’s streak of consecutive cycling days has reached more than 8,000. Click to read Jim’s full bio.