Off-road · 2026

Yamaha YZ125 ergonomics: seat height, rider triangle & fit

The Yamaha YZ125 has a 38.6 in seat. Here’s how riders of different sizes fit, and what you can change.

Seat height: 38.6 in
Wet weight: 212 lb
Wheelbase: 56.9 in
Power: 26.7 kW

Specs: ManufacturerBars & pegs: ManufacturerSeat width: Estimated

Try it with your measurements

Units

Your measurements

Height (in)

Inseam (in)

Arm length

Seated shoulder height

Boot sole

Preferred posture

Motorcycle

Modifications

Try common parts and see how they change your fit. The picture shows your setup over the stock bike.

Seat

Seat height0

Thicker or thinner seat. Lower makes it easier to reach the ground.

Lowering kit0

Lowers the whole bike. Easier to reach the ground, a little less legroom.

Handlebar

Bar risers0

Raises the bars. You sit more upright with less weight on your wrists.

Bar pullback0

Brings the bars closer to you. Shorter reach, good for shorter arms.

Footpegs

Lower pegs0

Lowers the footpegs. More knee room, less cramped legs.

Move pegs back0

Moves the pegs back (or forward). Further back feels sportier.

Windscreen

Windscreen height0

Taller or shorter screen. Changes how much wind hits your chest and helmet.

62Compromised

Specs: ManufacturerBars & pegs: Manufacturer

Single · 125 cc · Hold W or Space to accelerate, ↑ / ↓ to change gear · Synthesised from the engine layout and firing order. Not a recording.

Original illustration, motorcycleergonomics.com

Fit score

62/100

Compromised

Knee 79°

Within range

Comfort 58–100°

Hip 119°

More open than comfortable

Comfort 82–118°

Elbow 134°

Within range

Comfort 110–165°

Back lean 6°

Within range

Comfort 0–25°

Ground reach

4.1 in short of flat feet

Tiptoes on one foot

Seat height with sag: 35.6 in
Leg length needed: 36.9 in
Your inseam + boots: 32.8 in

Wind

Full wind on chest and helmet

Suggested fixes

Lowering links -1.8 in

Fit score 62 → 73

Find parts ↗
Low seat or reshaped foam -1.4 in

Fit score 62 → 71

Find parts ↗
Boots with a thicker sole +0.8 in

Fit score 62 → 69

Find parts ↗

Lowering changes handling and side-stand lean; check with a specialist.

Compare

Estimate. Handlebar and peg positions for this bike are manufacturer. Always sit on a bike before you buy it.

Fit by rider size

Shorter riders: at 5′4″ with a 29.5 in inseam, expect feet don’t reach the ground.
Taller riders: at 6′4″, knee angle is about 71°; fit score 83/100.

Rider	Inseam	Fit	Ground reach	Knee	Lean
5′1″	28.1 in	44	Feet don’t reach the ground	92°	11°
5′4″	29.5 in	47	Feet don’t reach the ground	87°	9°
5′7″	30.8 in	52	Feet don’t reach the ground	82°	8°
5′10″	32.2 in	64	Tiptoes on one foot	78°	6°
6′1″	33.5 in	73	One foot flat, hips shifted	75°	5°
6′4″	35 in	83	Balls of both feet	71°	4°

Reference riders with average proportions and 20 mm boot soles. Your proportions may differ.

Spec sheet

Drawn to scale from this bike's geometry.

Geometry & specifications

Geometry & specifications	Value	Source
Seat height	38.6 in	Manufacturer
Seat width at the front	—	Estimated
Handlebar grip	17.3 in ahead of the seat, 7.5 in above it	Manufacturer
Footpeg	2.4 in ahead of the seat, 16.9 in off the ground	Manufacturer
Wheelbase	56.9 in	Manufacturer
Wet weight	212 lb	Manufacturer
Rake	26°	Manufacturer
Trail	4.3 in	Manufacturer
Engine	Single · 125 cc	Manufacturer
Power	26.7 kW	Manufacturer
Tyres	80/100-21 / 100/90-19	Manufacturer
Category	Off-road	Manufacturer