MTB suspension calculator

Setup cockpit

Pick the hardware and mass first. The result below shows PSI, SAG and exact dial settings.

Brand

Section

Rider + gear

50 kg176 lbs115 kg

Bike

How RideLab models mass

80 kg

fork spring mass

80 kg

rear spring mass

0 kg

typical bike

PSI uses part of bike mass, rebound follows rider mass, and LSC/HSC get a separate heavy-bike correction.

Names: fork, rear shock, damper

The fork is the front suspension. The rear shock sits between the frame and linkage. The damper is the oil cartridge controlling rebound and compression inside a fork or shock.

Model widelca

Skok

Damper

Ride profile

This tells the calculator what to protect: sag target, support, traction or bottom-out resistance.

80 kg

How do you actually ride?

Pick the real riding use, not the bike label. This sets the SAG target, rebound and the general support level. If you don't ride a bike park or race — pick Trail.

What dominates the trail?

Pick the problem the suspension must solve. This only moves compression (LSC/HSC) away from the manufacturer baseline. Rebound stays from the riding-style choice above — change the style to change rebound.

How this changes the result

Trail (regular forest) sets the SAG target. Mixed singletrack sets the LSC/HSC priority. typical rider mass: manufacturer base is a useful center.

Fox 10/5, SRAM center and similar values are only starting baselines. RideLab still calculates the final clicks from rider mass, bike mass, terrain, skill, SAG/PSI, tokens and damper dyno behavior.

Riding level

Fox 36 FLOAT (2025/2026) · 150mm · GRIP X2 · Trail (regular forest)

Rider: 80 kg (176lbs) · Range: 77-82 kg

Pressure

86 PSI

limit 120 PSI — check SAG

SAG Trail (regular forest)

27.0-33.0 mm

18-22% — Default style: forest singletrack, roots, rocks, short descents. Pick this if you do NOT ride a bike park or race.

Volume Spacers

2 pcs

fabryka 2 · max 7 · Trail: fabryka OK

Step 1 · set SAG before clicks

Fork SAG measurement

Set the real sag in the green target zone first. Rebound and LSC/HSC only make sense after this measurement.

1. Open compression fully — Turn LSC/HSC counter-clockwise to the stop and set the lever to OPEN.

2. Set 86 PSI (table for 80 kg)

3. Wear full riding gear — Helmet, shoes, pack, protection and everything you actually ride with.

4. Slide the o-ring on the stanchion down to the dust seal.

5. Cycle the fork 2-3 times, get into attack position and bounce lightly twice.

6. Dismount carefully without pulling the bike or grabbing the brake.

7. Measure from the seal to the o-ring. That distance is fork SAG in millimeters.

20.0%

30 mm z 150 mm skoku

0 mm27-33 mm (18-22%)44 mm

✓ PERFECT — 20.0% in target 18-22% (Trail (regular forest))

💨 Pump removal pressure loss: fork ~1-2 PSI (large air chamber), rear shock ~3-5 PSI (smaller volume, larger relative loss). If your SAG comes out too firm or too soft after removing the pump, compensate by +2-5 PSI on the next inflation. Quick-release pumps (RockShox Digital, Topeak D2) lose less air.

STEP 2 · MOST IMPORTANT

Note your actual PSI after setting SAG

Table 86 PSI is the table value for 80 kg. Your real PSI after proper SAG may differ by ±10-20 PSI due to frame kinematics, negative-chamber compression, riding style, pump accuracy. This is YOUR number — not the table's.

At 18-22% SAG the pump showed:

PSI

Rebound — GRIP X2 (turn fully clockwise → back out counter-clockwise)

openclosed

Low-Speed Rebound

middle

Open 9 clicks from closed

1Turn clockwise until closed

2Back out counter-clockwise: 9 / 16

openclosed

High-Speed Rebound

middle

Open 5 clicks from closed

1Turn clockwise until closed

2Back out counter-clockwise: 5 / 8

Engine: Fox table per weight + style/terrain/skill/PSI (source of truth, see RationalePanel below).

Compression — GRIP X2

The Fox baseline is a neutral manufacturer start, not an 80 kg table. The result below adjusts for style, terrain, skill, PSI and bike mass.

openclosed

Low-Speed Compression

middle

Open 11 clicks from closed

1Turn clockwise until closed

2Back out counter-clockwise: 11 / 18

openclosed

High-Speed Compression

middle

Open 5 clicks from closed

1Turn clockwise until closed

2Back out counter-clockwise: 5 / 8

After the ride — expand a symptom in the diagnostics below to fix the specific thing. The LSC/HSC cheatsheet and symptom diagnostics are below — no theory duplication.

▸Why this result? 5 channels

Manufacturer rangePhysical base (weight/coil)Algorithm (in range)Algorithm (out of range)

Rebound

9/18 clicks

018

Manufacturer: 8–10in range

Base from Fox 2025 manual (rider weight) — 9/18 clicks

LSR

9/16 clicks

016

Manufacturer: 8–10in range

Base from Fox 2025 manual (rider weight) — 9/16 clicks

HSR

5/8 clicks

Manufacturer: 4–6in range

Base from Fox 2025 manual (rider weight) — 5/8 clicks

LSC

11/18 clicks

018

Manufacturer: 9–13in range

Manufacturer starting point: 11/18 clicks from fully closed (source: Fox 2025 manual)

HSC

5/8 clicks

Manufacturer: 3–7in range

Manufacturer starting point: 5/8 clicks from fully closed (source: Fox 2025 manual)

Pressure table — Fox 36 FLOAT (2025/2026)

PSI table for Fox 36 FLOAT (2025/2026) by rider weight
Waga (kg)	Waga (lbs)	PSI
54-59	120-130	66
59-64	130-140	70
64-68	140-150	74
68-73	150-160	78
73-77	160-170	82
77-82	170-180	86
82-86	180-190	89
86-91	190-200	94
91-95	200-210	99
95-100	210-220	105
100-104	220-230	109
104-109	230-240	113
109-113	240-250	117

Sources and accuracy

PSI baselines and hookless limits are from official setup guides; per-click recommendations, terrain/skill modifiers and engine output are RideLab heuristics labeled at each result. Fox 2025 Tech Help Center · RockShox 2025 Front Suspension Specifications and TrailHead · Öhlins owner manuals and product sheets. Where a brand does not publish a universal click table for every bike, RideLab labels the result as a starting heuristic and asks you to confirm sag and the trail symptom.

Post-ride tuning

Shorter decision path

Start with the calculator, then validate on trail. Do not change five things at once: one change, one ride, one conclusion.

SAG

Set PSI and measure real sag in the kit you actually ride in.

Rebound

Tune after SAG. It controls whether suspension recovers between repeated hits.

Compression

Adjust LSC/HSC for a specific symptom, not rider weight alone.

Tokens

Final step: SAG is correct, but the end of travel still feels wrong.

Post-ride diagnosis

Pick the trail symptom. The order of fixes matters.

LSC

Low-Speed Compression

Support for slow shaft movement: braking, berms, pumping and pedaling. If the bike dives or sinks in corners, start here.

HSC

High-Speed Compression

Response to fast impacts: roots, rocks, chatter and landings. Square edges often need more open HSC; landings usually need more support.

Do not do this›

Do not fix rebound with compression

Packing after repeated hits is usually rebound too slow, not too little LSC.

Do not copy random clicks

Setup depends on trail, tires, spacers, service state, riding style and frame kinematics.

Do not hide bad SAG

If SAG is wrong, go back to PSI. Clickers tune behavior; they do not fix the wrong spring.

Fox Factory, SRAM Trailhead, Öhlins setup material, Vorsprung and practical suspension-tuning references.

RideLab setup reference

Pre-ride reference

Quick reference: setup order, SAG ranges by discipline, and answers to common service questions.

PSI and SAG

Set pressure first and measure real SAG. For rear shocks, the table is only a starting point because frame kinematics matter.

Rebound

Tune after PSI. Too slow packs down in repeated hits; too fast feels bouncy and loses traction.

Compression

LSC supports braking, pumping and corners. HSC handles square edges, chatter and landings.

Tokens

Adjust only after SAG is correct and the bike still bottoms out or refuses to use full travel.

Typical SAG ranges

Discipline	Fork	Rear	Who it's for
XC	15-18%	20-25%	XC races, marathons, long rides
Trail	18-22%	25-30%	Regular forest: singletrack, roots, short descents
All-Mountain	20-22%	28-30%	Harder trails, drops up to ~60 cm, you climb up
Enduro	20-25%	28-32%	Enduro racing, lift-assisted, 1 m+ drops
DH / Bike park	20-25%	30-35%	DH racing, gravity park: full terrain mix — big jumps, rock gardens, braking bumps, roots

Setup FAQ

Should I copy settings from the internet?›

Not as a final setup. Weight, tires, trail, temperature, spacers, service condition and frame kinematics all change the result.

When should I adjust LSC?›

When the bike dives under braking, sinks in berms, bobs while pumping or lacks mid-stroke support.

When should I adjust HSC?›

When suspension feels harsh on square edges, loses grip in chatter or bottoms on landings despite correct SAG.

SAG is correct but the bike bottoms out. What next?›

Check HSC and landing technique first. If it repeats on the same hits, add a spacer/token instead of masking everything with very firm compression.

Why is shock PSI less reliable than fork PSI?›

The rear shock works through the frame linkage. Leverage ratio, progression and manufacturer tune can move real pressure by tens of PSI.

Related tools

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