Bike measurements

Our 3D Motion system collects a detailed set of bike measurements that combine both traditional relationships and modern XY metrics.

Bike measurements as shown in 3D Motion
Bike measurements as shown in 3D Motion

The definitions for these measurements are listed below.

Saddle height

Measured from the centre of the Bottom Bracket to the top of the saddle. If the velogicfit Saddle Jig is used the saddle measurement point is where it is 80mm wide. Without the Jig the standard measurement point is 140mm back from the saddle nose for a road saddle or 100mm for a ISM Adamo style noseless saddle.

Saddle height measurement
Saddle height measurement

Saddle Setback

The horizontal distance between the centre of the Bottom Bracket and the tip of the saddle. Can be measured using a Plumb Bob, Level or by finding any vertical straight edge such as the corner of a wall. Alternately you can place the rear wheel against a wall, measure from the wall to the centre of the Bottom Bracket then from the wall to the nose of the Saddle.

Saddle setback measurement
Saddle setback measurement

Handlebar X

The horizontal distance from the centre of the Bottom Bracket to the centre of the Handlebar clamp. This can be measured using an XY tool, or a vertical straight edge or you can place the rear wheel against a wall, measure from the wall to the centre of the Bottom Bracket then from the wall to the centre of the Handlebar clamp.

Handlebar X measurement
Handlebar X measurement

Handlebar Y

The vertical distance from the centre of the Bottom Bracket to the centre of the Handlebar clamp. This can be measured using an XY tool, after ensuring the bike is truly vertical measure from the floor to the centre of the Bottom Bracket then from the floor to the centre of the Handlebar clamp.

Handlebar Y measurement
Handlebar Y measurement

Handlebar Width - Road

The centre to centre distance of the Drops. Easily measured with a tape from the inside of one side of the bar to the outside of the other. Note that some bars flare from the Hoods to the Drops so you may need to note both Hoods and Drops width.

Handlebar width (on road frame)
Handlebar width (on road frame)

Handlebar Width - MTB

End to end of the bar, easily measured with a tape.

Handlebar width (on mountainbike frame)
Handlebar width (on mountainbike frame)

Handlebar Width - Tri/TT

Centre to centre of the basebar grips. Easily measured with a tape from the inside of one side of the bar to the outside of the other.

Hood X

The horizontal distance from the centre of the Bottom Bracket to the upturn of the Brake Hoods. This can be measured using an XY tool, or a vertical straight edge or you can place the rear wheel against a wall, measure from the wall to the centre of the Bottom Bracket then from the wall to the upturn of the Brake Hoods.

Hood X measurement
Hood X measurement

Hood Y

The vertical distance from the centre of the Bottom Bracket to the upturn of the Brake Hoods. This can be measured using an XY tool, after ensuring the bike is truly vertical measure from the floor to the centre of the Bottom Bracket then from the floor to the upturn of the Brake Hoods.

Hood Y measurement
Hood Y measurement

Bar Drop

The vertical distance between the top of the Saddle and the top of the Bars (beside the Stem). Can be measured using a level or by measuring from the ground to the top of the Saddle and ground to top of the Bars. Note that if your Bar Drop is a negative number it indicates that the Bars are higher than the Saddle

Bar Drop measurement
Bar Drop measurement

Saddle to bars

The direct distance from the nose of the Saddle to the top of the Bars at the centre of the Stem clamp

Saddle to bars measurement
Saddle to bars measurement

Saddle to drops

The direct distance from the nose of the Saddle to the end of the Bar drops.

Saddle to drops measurement
Saddle to drops measurement

Frame X

Also known as Reach (this is the number you will see in most geometry charts). The horizontal distance from the centre of the Bottom Bracket to the centre of the top of the Headtube. This can be measured using an XY tool or a vertical straight edge or you can place the rear wheel against a wall, measure from the wall to the centre of the Bottom Bracket then from the wall to the centre of the top of the Headtube.

Frame X measurement
Frame X measurement

Frame Y

Also known as Stack (this is the number you will see in most geometry charts). The vertical distance from the centre of the Bottom Bracket to the centre of the top of the Headtube. This can be measured using an XY tool or, after ensuring the bike is truly vertical, measure from the floor to the centre of the Bottom Bracket then from the floor to the centre of the top of the Headtube.

Frame Y measurement
Frame Y measurement

Seatpost X

The horizontal distance from the centre of the Bottom Bracket to the front of the Saddle Rail clamp. This can be measured using a vertical straight edge or you can place the rear wheel against a wall, measure from the wall to the centre of the Bottom Bracket then from the wall to the front of the Saddle Rail clamp.

Seatpost X measurement
Seatpost X measurement

Seatpost Y

The vertical distance from the centre of the Bottom Bracket to the front of the Saddle Rail clamp. This can be measured using an XY tool or, after ensuring the bike is truly vertical, measure from the floor to the centre of the Bottom Bracket then from the floor to the front of the Saddle Rail clamp.

Seatpost Y measurement
Seatpost Y measurement