• The right saddle height

  • We measure our leg length

  • The right seatpost length

The seat height

The height of the saddle is an important measure for a correct and pleasant use of the unicycle.
If the saddle is too high you will hardly reach the pedals or it might even be impossible to get there. In this case it is almost impossible to use the unicycle. If the saddle is too low the position will be uncomfortable and the load on the knees will be high.

Even if it will be possible to ride, it will be more difficult, uncomfortable and tiring.

But how do you know what seat height is right for you?
You’re at the correct saddle height if, while pedaling your foot reaches the lowest position with the leg not fully extended. That means your leg is straight, but without overextending your knee (the knee is slightly bent). We will call this position “the basic saddle position”.

Then everyone has their preferences. Also the type of route and the tricks you want to perform affect the height of the saddle. However, starting from the basic position, the variations will be of a maximum of 2 or 3 cm. The basic position of the saddle depends on the height and the leg length of the person who will use the unicycle.

The basic position of the saddle for a person is always the same whether using a 12" or a  36" unicycle, a unicycle for speed on track or for mountain unicycling, or a bicycle. Sit down on the saddle, ride and just check that the knee is almost completely extended.

We will therefore say that the "basic saddle position" is the distance between the pedal and the saddle.

To determine this measure just make sure the pedal is pointed down at its lowest position and in line with the seat tube. Then you measure from the centre of the pedal axle to the top of your saddle (about in the middle above the seat tube).
If you don't have a unicycle or a bicycle, you can measure the length of your leg directly. This is a good method to get an approximate result. 

We measure our leg length correctly

HowMeasureLegs-1.jpg
Frame-Leg-Length.jpg

The length of the leg can be measured with the same method applied to measure the height of a person, so it is better to be in two.
Stay with your back and heels to the wall (be sure that your shoulders and heels are really close to the wall).

To measure the leg length you need a "square", we usually use a book with a hardcover.
Put the book between your legs, press it against the wall and push it upwards.
It is easy to make a mistake because we often do not push enough up.
You must almost feel as if you were sitting on the book.
Please leave slowly this position, while your friend is still holding the book.
Do not tilt or move the book as this will cause an inaccurate measurement.
Mark the position above the top of the book on the wall with a pencil.
Measure from the floor to the pencil mark with a measuring tape to get your leg length.

Now that you have determined  your  “basic saddle position” you have to mount the right components to be able to position the saddle in that position.

Adjust your seat height by loosening the pinch bolt where the seatpost slides into the frame.  
Twist the seat to raise or lower the post as needed and then tighten the bolt.
In the mountain unicycle frames the "neck" or vertical tube is 14 cm long.  

The seat post must be inserted on the frame at least 5 or 6 cm.
The difference between seatpost length and the amount inserted determines the range of adjustment of our saddle height (14 cm - 5 or 6 cm = 8 or 9 cm maximum).

But unicycles are made to be used by people of different height, say about 150 cm to 200 cm.
If our frame has a normal neck we have to choose the right seat post length in order to adjust our saddle height correctly.

The lower part of the seat post that is inserted into the frame neck is made of steel or aluminum and can be easily cut with a hand saw. Obviously it’s difficult to extend your seat post once you have cut it, therefore, if you have doubts it’s better to choose a longer seat tube.


Remember that the "minimum leg length" given in our site is the distance between the pedal (in its lowest position) and the saddle. Next to this data you will find the crank used to obtain this measurement.
With shorter cranks, the minimum leg length is also shortened and vice versa.
The leg length must be greater than the B value.
It is important to know the B value (normally expressed in mm) in order to define the right length of your frame (value A).

IMPORTANT: the B value, that may be called "the height of your unicycle" depends also on your style and habit, however, as a rule, the leg length is  1-2 cm greater than the B value. If the B value is greater than your leg length, it will be almost impossible for you to ride the unicycle. If, on the other hand, the B value is much lower, you will be able to ride the unicycle, however with a "more sitting" position. It will be therefore more difficult and tiring.

Now let's do a practical example:
you have measured your leg length applying the method described above.
Let's imagine that your leg length is 81 cm (= 810 mm) and that you are interested in the IRON-MAD EXPERT Freestyle.

Iron-Mad Basic - EXPERT
Saddle Slim, thickness 47mm
From the middle of the hub to the crown - 283 mm
Thickness of the saddle - 47 mm
Minimun leg length
Frame (neck) 310 380 450 520
Cranks - 80 mm 720 790 860 930
Cranks - 90 mm 730 800 870 940
Cranks - 100 mm 740 810 880 950

Before we determine the frame length you need to answer this question:
what kind of cranks would I like to mount?
Let's imagine you want to use 90 mm cranks.
In this case you can use either the 310 mm or the 380 mm frame.
On the other hand, the 450 mm and 520 mm frames are certainly impossible for you to use.

Now we calculate the right seatpost length

Below the formula to know how long the seatpost should be:
your leg length - minimum leg length + 15 cm.
Example:
your leg length = 82cm.
The minimum leg length stated for the mountain unicycle I want to buy is 75cm.
The formula will be:

82 - 75 = 7  + 15 = 22 cm

In this case the 20 cm seat post is fine because I will only have to raise it by 2 cm.
Remember that in a mountain unicycle the seat post can be raised from its fully inserted position by a maximum of 9 cm.

Another example:
my friend Sandro is 195 cm and has a 93 cm leg length.
The calculation will then be:

93 - 75 = 18  + 15 = 33 cm

In this case the 30 cm seat post is fine because Sandro will only have to raise it by 3 cm.

Special cases:

Your leg length is 80 cm.
The unicycle minimun leg length is 75 mm:

80 – 75 = 5 + 15 = 20 cm

In this case the 20 cm seat post could be fine but if I wanted to lower the saddle even by just 1 cm (in order to perform some specific tricks or to be more comfortable) I can't do it without cutting the seat tube a little.

Another example:
your leg length is 89 cm.
The unicycle you are interested in has a minimun leg length of 75 mm:

89 – 75 = 14 + 15 = 29 cm

In this case the 30 cm seat post is too long but the 20 cm seat post is too short because I would have to raise it by 9 cm which is the maximum measure and if I want to raise it again by 1 cm I will not be able to do it because I risk breaking the frame.

In doubtful cases, choose the longer seat tube and enter your leg length in the order notes asking to shorten the seat tube to your size.

The table "minimum leg length" 

Iron-Mad Basic
Saddle Comfort, thickness 62mm
From the middle of the hub to the crown - 283mm
Thickness of the saddle - 62mm
Minimun leg length
Frame (neck) 310 380 450 520
Cranks - 89mm 745 815 885 955
Cranks - 100mm 755 825 895 965
Iron-Mad Basic
Saddle SLIM, thickness 47mm
From the middle of the hub to the crown - 283mm
Thickness of the saddle - 47mm
Minimun leg length
Frame (neck) 310 380 450 520
Cranks - 89mm 730 800 870 940
Cranks - 100mm 740 810 880 950
Iron-Mad Basic - ELITE
Saddle SLIM, thickness 47mm
From the middle of the hub to the crown - 283mm
Thickness of the saddle - 62mm
Minimun leg length
Frame (neck) 310 380 450 520
Cranks - 89mm 730 800 870 940
Iron-Mad - EXPERT
Saddle Slim, thickness 47mm
From the middle of the hub to the crown - 283mm
Thickness of the saddle - 47mm
Minimun leg length
Frame (neck) 310 380 450 520
Cranks - 80mm 720 790 860 930
Cranks - 90mm 730 800 870 940
Cranks - 100mm 740 810 880 950
Mad4One Freestyle - 100 - cotterless hub
Saddle Slim, thickness 47mm
From the middle of the hub to the crown - 286mm
Thickness of the saddle - 47mm
Minimun leg length
Frame (neck) 310 380 450 500
Cranks - 89mm 732 802 872 922
Cranks - 100mm 743 813 883 933
Cranks - 114mm 757 827 897 947
Mad4One Freestyle - 90 - hub ISIS
Saddle Slim, thickness 47mm
From the middle of the hub to the crown - 276mm
Thickness of the saddle - 47mm
Minimun leg length
Frame (neck) 310 380 450 500
Cranks - 80mm 713 783 853 903
Cranks - 90mm 723 793 863 913
Cranks - 100mm 733 803 873 923
Mad4One Freestyle - 100 - hub ISIS
Saddle Slim, thickness 47mm
From the middle of the hub to the crown - 286mm
Thickness of the saddle - 47mm
Minimun leg length
Frame (neck) 310 380 450 500
Cranks - 80mm 723 793 863 913
Cranks - 90mm 733 803 873 923
Cranks - 100mm 743 813 883 933
PowerSquare Flat - hub ISIS
Saddle Slim, thickness 47mm
From the middle of the hub to the crown - 290mm
Thickness of the saddle - 47mm
Minimun leg length
Frame (neck) 210 270 330
Cranks - 100mm 647 707 767
Cranks - 103mm 650 710 770
Cranks - 110mm 657 717 777
Cranks - 125mm 672 732 792
Cranks - 135mm 682 742 802