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LANDING CALCULATOR

To calculators

Calculates where the handlebars and saddle are actually located relative to the bottom bracket and transfers the riding position from one bike to another. You enter the stack, reach, and angles from the manufacturer's table plus your cockpit — you get the coordinates, the drop from saddle to handlebars, the offset, and the selection of the stem with spacers for the new frame.

How to reschedule a landing: step-by-step guide

What we consider
Steering wheel coordinates Saddle coordinates Saddle-steering wheel difference Saddle-handlebar departure STR Selection of take-out and spacers

All coordinates are from the center of the carriage: X forward, Y up, millimeters. The link to the page saves both configurations, it can be thrown to the chat or bike twitter.

A — the standard of landing

Bike A (current)

Frame
Cockpit
Saddle
Steering wheel X (forward)
475 mm
Steering wheel Y (up)
655 mm
Saddle X
-207 mm
Saddle Y
700 mm
Saddle-steering wheel difference
45 mm
Saddle-handlebar departure
682 mm
STR (stack / reach)
1.53 · gravel / comfort

Gravel and comfort: high steering wheel, quiet landing for the whole day.

B — where are we moving to

Bike B (new)

Frame
Cockpit
Saddle
Steering wheel X (forward)
487 mm
Steering wheel Y (up)
623 mm
Saddle X
-207 mm
Saddle Y
700 mm
Saddle-steering wheel difference
77 mm
Saddle-handlebar departure
695 mm
STR (stack / reach)
1.43 · endurance

Endurance: a long-distance highway, the steering wheel is slightly higher than the racing one.

Deltas B − A
Δ steering wheel X
+13 mm
Δ steering wheel Y
-31 mm
Δ difference
+31 mm
Δ saddle-handlebar departure
+13 mm

On the B handlebar на 13 mm дальше и на 31 mm ниже — это как вынос +10 mm и на 4 проставки меньше.

Rough translation heuristics in detail: 10 mm in X is approximately a one—step extension of the length, 7 mm in Y is one spacer.

Pick up the cockpit for B for landing A
Take-out length
100 mm
Spacers + topcap
45 mm
Residual miss X/Y
+4 mm / -3 mm

It doesn't exactly add up: the nearest of the available combinations misses by4 mm по X и 3 mm по Y.

Flip the stem (angle 6°): с ним попадание точнее — 100 mm выноса и 30 mm проставок, промах 4.7 мм.

We sort out only what is really on the shelf: take-out60–140 mm increments of 10, spacers0–45 mm increments of 5. We take the take-out angle from the fields of bike B — change the sign to see the inverted version.

The scheme
Bike A Bike B Carriage — the origin of coordinates

Triangle carriage — saddle — handlebar in scale. The more the orange and blue contours diverge, the more noticeable the difference in landing will be on the first trip.

How to measure

Stack and reach — they are taken from the manufacturer's geometric table, not from the tape measure: this is the vertical and horizontal from the center of the carriage to the center of the top of the steering tube. Steering (HTA) and seatpost (STA) angles are from the same table, in degrees from the horizon.

Spacers — count together with the topcap: add up the height of all the rings under the outrigger and the height of the lid. Enter the height of the take-out clamp separately, the calculator itself will take half of it to get into the center of the clamp.

Saddle height — from the center of the carriage to the top of the saddle along the axis of the seat tube, tape measure along the tube, not vertically. Saddle shift forward — how much the landing point is shifted from the seatpost axis: forward plus, backward minus.

Length and angle of removal — the length of the marking (the distance between the centers of the clamps), the angle is also marked. Taking out "-6°" down is -6, it's inverted up is +6.

What's next: first combine the saddle (height and shift), then achieve the coincidence of the steering point with the extension and spacers. The saddle-steering wheel difference and the saddle-steering wheel departure are the two main figures by which the landing feels the same on different frames.

The calculator counts geometry, not physiology. It does not replace the bike fit: if the landing hurts, it's to a live specialist.