After having defined the frame size, you need to know which wheel size can be mounted on that frame.
The Mad4One muni frame is available in 3 different sizes: Small (S), Medium (M) and Large (L).
The URC muni frame is available in 4 different sizes: Extra Small (XS), Small (S), Medium (M) e Large (L).
Here's the wheel size, and thus also the size of the tire, that each frame can mount:

Frame Mad4One - Aluminum


Frame Size S 

Wheel size 24" mounts tires up to 24" x 3.00
Wheel size 26" mounts tires up to 26" x 2.60

Frame Size M   

Wheel size 26" mounts tires up to 26" x 3.00
Wheel size 27.5" mounts tires up to 27.5" x 3.25
Wheel size 28" mounts tires up to 29" x 2.50

Frame Size L

Wheel size 24" mounts tires up to 24" x 4.00
Wheel size 26" mounts tires up to 26" x 4.00
Wheel size 27.5" mounts tires up to 27.5" x 3.80
Wheel size 28" mounts tires up to 29" x 3.25 *
Wheel size 32" mounts tires up to 32" x 2.25

Frame for 36" wheel

On this frame you can mount 36"x2.25 tires

Once we have mounted our FAT tire the clearance keeps wide and this provides excellent control of your muni even on muddy terrain.

The height of the frame, together with the length of the cranks, is the dimension to consider when you decide the size of the unicycle based on your min. inseam length.

Below the frame height:

  • MAD4ONE - S = 49,5 cm
  • MAD4ONE - M = 53 cm
  • MAD4ONE - L = 55 cm

Thickness of the saddle: approx. 6,5 cm.

  • MAD4ONE - S : with the 140-cranks we will have a min. inseam length of (49,5 + 6,5 + 14) = 70 cm

  • MAD4ONE - M : with the 140-cranks we will have a min. inseam length of (53 + 6,5 + 14) = 73,50 cm

  • MAD4ONE - L : with the 140-cranks we will have a min. inseam length of (55 + 6,5 + 14) = 75,5 cm

NOTE: if we shorten our cranks we reduce the minimum inseam length however, if we mount longer cranks, the inseam length will increase.

The MAD4ONE Muni frames have been designed for hubs with 42mm bearings, with 100 mm pitch (distance between the bearings).

The LONG-NECK

This frame is the ideal choice for taller riders.
It offers greater stiffness and a more stable placement of your saddle.
Combined with our MAD XXL seat-post this frame ensures the right position of your legs even if you are more than 2 mt tall.
The min. leg inseam of the Long Neck frames is 11 cm longer than the min. leg inseam of all the standard frames.

  • MAD4ONE- LONG-NECK - M : with the 140-cranks we will have a max. inseam length of (63 + 6,5 + 14 + 28,5) (9cm of our MAD XXL seatpost) = 112 cm

  • MAD4ONE- LONG-NECK - L : with the 140-cranks we will have a max. inseam length of (65 + 6,5 + 14 + 28,5) (9cm of our MAD XXL seatpost) = 114 cm

A leg-length of 115cm corresponds to a height of approx. 2,30 mt.

Frame URC - Steel CrMo-4130


Frame size XS   

Wheel size 20" mounts tires up to 20" x 4.00

Frame size S

Wheel size 24" mounts tires up to 24" x 4.00
Wheel size 26" mounts tires up to 26" x 2.40

Frame size M

Wheel size 26" mounts tires up to 26" x 4.00
Wheel size 27.5" mounts tires up to 27.5" x 3.50
Wheel size 28" mounts tires up to 29" x 2.50 *

Frame size L

Wheel size 27.5" mounts tires up to 27.5" x 3.50
Wheel size 28" mounts tires up to 29" x 3.25 *

* The 28" and 29" wheels mount the same rim with a ETRTO diameter of 622mm.

The URC frames are designed for standard hubs with 100 mm pitch (distance between the bearings).

The height of the frame, together with the length of the cranks, build the measure to consider when you define the size of our mountain unicycle based on the min. inseam length (Inseam is the length of the inner leg).

Below the frame height:

  • URC-Extra-Small = 45 cm

  • URC-Small = 49,5 cm

  • URC-Medium = 53,5 cm

  • URC-Large = 55 cm

Thickness of the saddle: approx. 6,5 cm.

  • URC-Extra-Small: with the 125-cranks we will have a min. inseam length of (45 + 6,5 + 12,5) = 64 cm

  • URC-Small: with the 140-cranks we will have a min. inseam length of (49,5 + 6,5 + 14) = 70 cm

  • URC-Medium : with the 140-cranks we will have a min.inseam length of (53,5 + 6,5 + 14) = 74 cm

  • URC-Large : with the 140-cranks we will have a min.inseam length of (55 + 6,5 + 14) = 75,5 cm

NOTE: if we shorten our cranks we reduce the min. inseam length, if we mount longer cranks, the inseam length will increase.

On the other hand, if we speak of the tire, the choice here is really wide. The URC frame has therefore a second PLUS, I can buy a frame and different wheels, each one for a specific need / terrain / riding.

In the Mountain Unicycle framework we have also a valid option for the youngest or smallest riders, this is the MINI-MUNI with disc brake mounting taps. The perfect choice to learn since the beginning how to control your unicycle with the brake. The MINI-MUNI mounts the XS URC frame.