Find starting LSC (Low Speed Compression) and HSC (High Speed Compression) clicks for your MTB fork and rear shock. Compression damping is the most misunderstood part of MTB suspension, LSC controls slow inputs like braking dive and pedalling, while HSC controls fast impacts like drops and square-edged hits. This guide gives brand-specific starting clicks for Fox 36/38 and RockShox Pike/Lyrik/Zeb, plus a clear method for when to adjust each circuit.
LSC
7
clicks from closed
range: 5 to 9
Low Speed Compression
HSC
4
clicks from closed
range: 2 to 6
High Speed Compression
Turn OUT (counterclockwise) to open compression (more supple) · Turn IN (clockwise) to add damping (firmer)
⚠ For reference only. Compression tuning is the most complex part of suspension setup. These are baseline starting points. Many riders find factory (mid-range) settings work well until they develop a feel for their suspension's behaviour.
Sources for what the makers publish: Fox Owner’s Manuals and RockShox, Suspension Welcome Guide. Neither publishes a compression click table by fork model and riding style, so every number this calculator returns is this site’s own starting point.
Low Speed Compression (LSC) vs High Speed Compression (HSC)
The "speed" in LSC and HSC refers to shaft speed inside the damper, not how fast you are riding. LSC controls slow shaft movement, braking dive, pedalling bob, rolling compressions through berms and G-outs. HSC controls fast shaft movement, square-edged rock hits, landing from drops, harsh impacts that catch the wheel.
They are independent circuits on mid- and high-end suspension (Fox Factory/Performance Elite, RockShox Ultimate). Most confusion comes from riders thinking "high speed" means descending fast, it does not. A slow descent over a sharp rock still triggers HSC. A fast pedal stroke on smooth ground still triggers LSC.
Where these numbers come from
The click counts are ours. RockShox publishes no compression click table by fork model and riding style, and Fox publishes one baseline, not a table by riding style. Fox also states that high speed compression settings beyond 16 clicks out from fully closed do not change damping. So there is no published table to reproduce here, and the numbers this calculator returns are a starting point placed where there is room to move in both directions.
A click is not a fixed amount of damping. Dampers offer anywhere from about ten clicks to more than twenty, and Fox states that only the 16 positions closest to fully closed do anything on high speed compression. The same count is therefore a different setting on different suspension, in the way that the same flex number is a different stiffness at different boot makers. Count from your own adjuster’s end stop, not from someone else’s.
Order matters more than the number. Set sag first, then rebound, then compression. Compression is the last thing to touch, because a fork that is diving on a wrong spring pressure will not be fixed by adding low speed damping, it will just get harsh everywhere else.
What Fox and RockShox Actually Publish
Neither maker publishes a compression table by fork model and riding style. This is what each one does print, and it is a much shorter list than the internet suggests.
Fox, for the 36 and 38, model years 2021 to 2025: a single baseline of 10 clicks out on low speed compression and 5 clicks out on high speed, counted from fully closed. one baseline, not a table by riding style. Fox also states that high speed compression settings beyond 16 clicks out from fully closed do not change damping. Earlier model years used different baselines, so check the manual for your own year.
RockShox: set the compression knobs to the middle position on MY23 and later Ultimate and Select+ forks, or fully open on everything else, then use the TrailHead app for a personalised starting point. It publishes no compression click table by fork model and riding style.
Note that Fox’s own baseline has more clicks out on low speed than on high speed, which is the same order this calculator uses. Tables circulating with high speed above low speed do not match what Fox prints.
Our Starting Points, by Riding Style
These are the numbers the calculator above returns for a 75 kg rider, printed here so you can see the whole shape at once. They are this site's own convention for how compression varies with riding style; no maker publishes one, not manufacturer data. Set sag and rebound first.
Fork
Riding style
LSC clicks out
LSC range
HSC clicks out
HSC range
XC (Cross-country)
10
8 to 12
5
3 to 7
Trail
7
5 to 9
4
2 to 6
Enduro
5
3 to 7
3
1 to 5
Downhill
3
1 to 5
2
0 to 4
Rear shock
Riding style
LSC clicks out
LSC range
HSC clicks out
HSC range
XC (Cross-country)
8
6 to 10
4
2 to 6
Trail
6
4 to 8
3
1 to 5
Enduro
4
2 to 6
2
0 to 4
Downhill
3
1 to 5
1
-1 to 3
zero clicks is fully closed and the most damping; every click out opens the circuit and removes damping. a heavier rider gets FEWER clicks out, because more damping is needed, which is why the calculator moves a 90 kg rider down from the numbers above rather than up. Fox states that 16 positions from fully closed are the usable range on high speed compression, so a recommendation of two or three clicks out is near the firm end of a real adjuster, not off the end of it.
When to Adjust Compression vs Rebound vs Air Pressure
Compression damping is the LAST thing to touch in suspension setup, not the first. The correct order is: 1) Air pressure (sag), 2) Rebound, 3) LSC, 4) HSC. If your fork dives under braking but sag is wrong, adding LSC will not fix the problem, it will mask it and create harshness elsewhere. Always start with our MTB sag calculator, then dial in rebound damping on a curb, then use this page for compression starting points. Tyre pressure also affects how the suspension feels, see our MTB tyre pressure calculator.
Climb Mode / Lockout vs Compression Damping
Most trail and enduro forks have a 3-position climb switch (Open / Medium / Firm on Fox; Open / Pedal / Lock on RockShox). This switch adds a large amount of low speed compression. Neither maker publishes how much, as a click equivalent or otherwise, and this site has no figure to give, so treat the switch as a separate mode rather than as a number of clicks off your normal setting. It is a quick way to reduce pedalling bob on smooth climbs without re-tuning your normal setting. Use the climb switch for pedalling efficiency, use the LSC dial for ride quality. Never use the lockout position on technical climbs, the suspension cannot track the trail and you will lose traction. For descents, always return the switch to fully Open before adjusting the LSC dial.
How it works
Compression Damping: Resisting Compression
Compression damping resists the suspension compressing. LSC (Low Speed Compression) affects small, slow inputs: pedalling forces, braking dive, rolling compressions. HSC (High Speed Compression) affects fast, large inputs: drops, square-edged hits, high-speed compressions. They are adjusted separately on mid-range and high-end suspension.
Clicks are counted from fully closed (maximum compression damping). Turning OUT (counterclockwise) opens the compression circuit for a more supple feel.
When to Adjust Each
Adjust LSC if: the fork dives too much under braking (add LSC, turn clockwise) or feels harsh over small bumps (reduce LSC, counterclockwise). Always adjust one dial at a time, one click at a time.
Adjust HSC if: the fork bottoms out on large hits (add HSC) or feels harsh on square-edged impacts (reduce HSC).
Always set up in order: sag first → rebound → LSC → HSC. Tuning compression before sag is set correctly wastes time.
Single Compression Adjuster
Many trail forks (Fox Rhythm, RockShox Select) have a single compression adjuster that controls both LSC and HSC together. Use the LSC value from this calculator as your starting point for single-adjuster forks.
Dedicated LSC and HSC adjusters appear on Fox Performance Elite/Factory and RockShox Pike/Lyrik/ZEB Ultimate level components and above. Budget shocks (RockShox Select, Fox Float Performance) also typically have a single compression adjuster.
Frequently asked questions
What is the difference between LSC and HSC?
LSC (Low Speed Compression) controls damping for slow suspension movements: braking, pedalling forces, and gradual compressions. HSC (High Speed Compression) controls fast impacts: square-edged rocks, drops, and high-speed hits. They affect different shaft speeds in the damper, not riding speed.
Do Fox and RockShox count compression clicks the same way?
Yes for compression. Both Fox and the modern RockShox Charger 3 damper count compression clicks from fully CLOSED (firmest). However, RockShox counts REBOUND clicks from fully OPEN (fastest), while Fox counts rebound from fully closed (slowest). The confusion is real: compression is the same direction across brands, but rebound is opposite. Always check your specific damper manual.
Should I use the same compression settings front and rear?
No. The rear shock typically needs slightly more LSC than the fork because the leverage ratio amplifies low-speed inputs (pedalling, G-outs) through the linkage. HSC can be matched or slightly less than the fork. A good test: ride the same section twice and feel if front or rear bottoms out first, add HSC to whichever bottoms first.
My fork has a 3-position switch, not clicks: what should I use?
Budget forks (Fox Rhythm, RockShox Select) use a 3-position climb switch instead of click-adjustable LSC. Use Open position for descents, Medium/Pedal for rolling trails or rough climbs, Firm/Lock for smooth seated climbs only. Never use Lock on technical climbs, you lose traction. The 3-position switch is essentially a preset LSC at three fixed levels.
Should I start with more or less compression?
Start with the manufacturer's mid-range setting and adjust from there. Most Fox and RockShox forks leave the factory close to mid-range compression. Adding too much compression makes the ride harsh; too little causes excessive dive and poor small-bump sensitivity.
My fork dives a lot under braking: which adjuster?
Braking dive is a low-speed movement, so increase LSC (turn clockwise, add damping) by 2 clicks. If dive is still excessive after 4 clicks, also check that sag is set correctly, as too much sag increases braking dive.
My fork feels harsh over small roots and pebbles: fix?
Reduce LSC by 2 clicks (counterclockwise). Small-bump sensitivity is primarily controlled by LSC and negative spring volume. If reducing LSC makes the fork dive too much under braking, you may need a volume spacer removed or a different damper tune.
What is platform/pedalling mode?
Many trail and enduro forks and shocks offer a platform mode (ProPedal on RockShox, Trail mode on Fox) which adds LSC specifically to reduce bobbing while pedalling. This is separate from the main LSC adjuster. Use platform mode while climbing, open it for descents.
Does compression affect sag?
No. Compression damping does not affect the static sag. Sag is determined by air spring pressure alone. You can change compression damping without affecting sag or rebound settings.
What is the correct setup order?
Always set up in this order: 1) Sag (air pressure first). 2) Rebound. 3) LSC. 4) HSC. Setting sag first ensures the spring rate is correct before tuning damping. Tuning compression before sag is set correctly wastes time as you will need to readjust.
My shock has only one compression adjuster: which is it?
Budget and mid-range shocks (RockShox Select, Fox Float Performance) typically have a single compression adjuster that blends LSC and HSC. Use the LSC value from this calculator as your starting point. Dedicated LSC and HSC adjusters appear on Shimano, Fox Factory, and RockShox Ultimate level components.