Finally understanding suspension terms (instead of just turning dials)
Many riders turn clicks without really knowing what they are changing. The result: coincidence instead of a system.
In this article, you will learn the most important suspension terms in a way that allows you to understand setups, compare them, and improve with purpose – regardless of whether you wrench on your own bike or work with a tuner.
Part 2 of the series MTB-Raceshop Pro Suspension. Part 1: What your suspension really does.
1) The basics: Travel, Sag & working range
Travel describes the maximum compression distance of your fork or shock (e.g., 170 mm). It is important, but rarely the factor that truly changes your ride feel. The decisive element is how you use that travel.
Sag is the static compression of your suspension while standing still – fully geared up. It is the starting point for every setup.
- Too little sag → harsh, little grip, nervous
- Too much sag → deep in the travel, unstable, restless while pedalling
Negative travel / top-out is the range the suspension needs to absorb small bumps sensitively and maintain constant ground contact. Without sufficient negative travel: less grip, less control.
2) Spring curve: linear vs. progressive
The spring curve describes how much the resistance increases over the course of the travel.
- Linear → constant resistance (typical for coil)
- Progressive → gets significantly harder toward the end (typical for air springs)
Why this is important:
- Progression protects against bottom-outs
- It determines how much support is provided in the mid and end stroke
Key terms:
- Bottom-out → hitting the end of the travel
- Midstroke support → hold in the middle of the travel to prevent wallowing
3) Damping: Compression & Rebound – the two directions
Damping does not control hardness, but the speed of the movement.
Compression
Regulates how much the suspension movement is slowed down during compression.
- More compression → more support, less bobbing
- Too much → less comfort, less grip
- Too little → bike wallows, feels undefined
Rebound
Regulates how quickly the suspension extends again after compression.
- Too fast → nervous, kicks, loses lines
- Too slow → suspension "packs down," becomes harsh, uses travel poorly
4) Low-speed vs. high-speed – the most common misconception
Low- and high-speed have nothing to do with your riding speed. They refer to the speed of the damper movement.
Low-speed compression (LSC)
Acts during slow movements:
- Braking
- Cornering
- Pumping
- Weight shifts
Effects:
- More LSC → more support, higher in the travel
- Too much → less grip on small bumps, harsh feel
High-speed compression (HSC)
Acts during fast, harsh impacts:
- Roots
- Rocks
- Drops
- Hard edges
Effects:
- More HSC → more protection, more control on impacts
- Too much → stubborn, harsh, deflects, loses traction
Rebound Low / High (if available)
Same principle for extension:
- LSR → base speed of extension
- HSR → recovery after hard impacts
5) Tokens / Volume spacers & air pressure
Air pressure
- determines sag
- determines your base height in the travel
Tokens / Volume spacers
- make the air spring more progressive
- primarily influence the end of the stroke
Rule of thumb:
- Air pressure = where you sit in the travel
- Tokens = how much the resistance increases at the end
- Too many tokens → travel is not used effectively
- Too few → frequent bottom-outs
6) Platform, lockout & pedal mode (properly categorised)
These modes usually increase low-speed damping to reduce bobbing. For gravity descents, the rule is almost always: run it open – anything else is a compromise.
7) Typical symptoms → what is really behind them
So that these terms don't remain abstract:
- Arm pump / lack of comfort → too little sag, too much LSC/HSC, rebound outside the window
- Bike not balanced → fork and shock aren't working together: sag or rebound don't match front to rear, bike dives at the front or hangs low at the back
- Bike nervous, kicks → rebound too fast, often combined with too little HSC
- Bike wallows, feels mushy → too much sag, too little LSC, too little midstroke support
- Suspension gets progressively harder during a run → rebound too slow (packing) or temperature/fading issues
Outlook
In the next part of the series, you will set your sag step by step: on the fork, on the shock and with guide values for enduro and downhill.
If you don't want to guess your setup, but want to understand it: