Exteded legs

Is there a rule to choose seat height?

I ride only road and some gravel during easy XC. I’ve raised my seatpost till maximum leg extension and now I can ride more relaxed with all my weight in the seat, but I feel like I’m slower in balance corrections, mostly accelerating. Now I overlean forward more often leading to UPDs and 1 flying man per hour training.

What’s your choice for seat height for commuting? maximum leg extension or less? How much less? 0.5" could be ok?

I cannot lower the seat right now because a stripped bolt in the seatpost clamp… :o Going to solve it this weekend

For long distance riding, I prefer full extension with the foot of that leg flat (90 degrees). With that said, I ride with the ball of my foot on the pedal and definitely pivot my foot (feet) while riding to use as many muscles as possible for control. Others probably use different technique successfully for long distance riding.

When road riding I keep the seat as high as I would with a bike, but not as high as what they do with freestyle. I like to be able to catch some bumps, like protruding roots on cyclepaths, which we have here. In such cases if the seat is too high, it would be very uncomfortable.
Once you get into muni, it is best to keep a lower seat.

I prefer a little lower…

From looking at your pictures I prefer to have my seat a little lower. Similarly to bicycles, you will likely do better and stress your knees and muscles less with a little more bend in the knee when the pedal is down at dead bottom center.

Many unicyclist will raise seat height to climb and lower to go downhill, especially when the downhill riding includes drops, roots, rocks, etc.

Trainers and PTs usually recommend typical knee-flexion angle between 25 to 35 degrees measured using a goniometer. A good starting angle is 32 degrees. People with posterior knee pain, poor hamstring flexibility, or lower-back pain may need to maintain a lower saddle position (knee angle greater than 32 degrees).

Try google with bicycle saddle height should get you started with an abundance of diagrams to look at.

You might benefit from analyzing the picture below of my ride last Saturday:



I have a road route that is about 12 miles, and I like to have the seat height low enough so I can slip a piece of foam for comfort on the seat while I am riding. I also found that for idling it is convenient to have a little extra reach with the legs should you need it. I usually will keep the seat about 1 inch below maximum height. It’ll also give you a little more clearance when you jump on (free-mount).

There are a few, mostly depending on the type of riding you do.

This might just be a function of your center of mass being a little higher, and your senses getting used to the idea of that longer stretch of your body mass. If so, you’ll get used to it with a little more riding. Or it’s possible your seat may be a little too high, causing you to stretch for the pedals, making your reaction speed a little slower.

Me too. For most Freestyle riding, your surface is very predictable, so you can run maximum height where your feet still have a good reach. But for riding “out in the world”, you will occasionally come across bumps you may not have seen. Hit one of those the wrong way, and it can bounce you off the seat or otherwise make a foot come off a pedal, so I have my seat maybe 1/4-1/2" lower for Road or easy dirt riding. For more technical riding, either on harder trails or crappy roads, I’ll lower the seat more.

I sometimes do this as well, usually on Muni rides with long stretches of climbing or descending. A higher seat on the climb gives you more power. A lower seat on the downhill allows for more fun!

1" lower

Today I’ll test about 1" lower the max in road riding than let you know. Thank you for your help

Based on nothing but the photos in the OP, I’d say your seat may be a tad too high.

The rule for efficient road biking is wear flat shoes, put your heel on the pedal and put the pedal at the bottom of its travel. If your leg is straight but not stretched, that’s about right. Then ride with your ball of the foot on the pedal.

This is a good starting point for road unicycling but there are other considerations, chief among which are:

Shorter cranks (most bikes are on 165-175 mm cranks)

The need to apply back pressure to balance.

Different seat profile and upper body position.

Some unicyclists prefer to have their instep on the pedal.

For road uni, I set the seat according to “the rule” then lower it about a centimetre. After that, I do it by the rule of “what feels right” but even a 5 mm adjustment can be noticeable.

If you ride very short cranks, you may find that the seat needs to be a tad lower relative to the pedal at the bottom of its travel. One disadvantage of short cranks is that you are using a smaller amount of the muscle movement that is available, ad if you concentrate that all at the extended end of the leg movement, it can be tiring and you may find you have less leverage.

The whole point of a QR seat clamp is you can make these small adjustments mid ride to allow for the riding conditions, the terrain, and so on.

The only trouble with this ‘rule’ is that it fails to account for foot size. If you’ve got little pygmy feet your leg will be far too stretched, and if you’ve got giant clown feet you’ll probably end up too bent. It’s a good way to get a very rough guestimate, and (as you said) allows you to start with a baseline and fiddle from there though!

I pretty much just put the seat where I sort of feel like it’ll work, hop on and test it and adjust it until it’s comfortable. I don’t really adjust it according to my terrain, I just go for a happy medium and leave it there :smiley: When I swap crank lengths I just move it up and down by roughly the difference in crank length (So if I go from 114mm to 137mm, I’ll move it about 23-25mm down).