Choosing a rear shock is one of the most confusing purchases in mountain biking. Unlike a new tire or a set of brake pads, the wrong shock does not just underperform: it can make your bike feel entirely wrong or not fit at all.
The good news is that once you understand a few key concepts, the decision gets much simpler. This guide walks you through everything you need to know: how to size a shock for your frame, how to choose between air and coil, what damper features actually matter, and which brands are worth your money in Canada.
If you are ready to browse now, check out our full range of MTB rear shocks from Fox, RockShox, Ohlins, and more.
Step 1: Get the Sizing Right First
Before you think about brands or damper technology, you need to get your shock dimensions right. This is the step most riders skip, and it leads to buying a shock that does not fit.
Every rear shock has two critical measurements:
Eye-to-eye length: The distance between the centres of the two mounting bolts. This distance is measured in millimetres (for example, 210 mm).
Stroke length: How far the shock shaft travels when the suspension compresses fully. It is also measured in millimetres (e.g., 55 mm).
Your frame has a specific eye-to-eye and stroke combination it was designed for. Installing the wrong size will either prevent the shock from fitting, limit your travel, or put your suspension linkage in the wrong position entirely.
How to find your frame's shock size:
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Check your frame's owner's manual or the manufacturer's website
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Look for a sticker on the frame near the shock mount
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Measure your existing shock before removing it
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Bring your bike into Dunbar Cycles and we will measure it for you
Common shock sizes you will encounter include 210x55mm, 230x60mm, and 185x55mm, but there are many others. Always confirm before ordering.
Step 2: Choose Your Spring Type: Air or Coil
Once you have your sizing confirmed, the next decision is whether you want an air shock or a coil shock. This is the choice that has the biggest impact on how your bike rides.
We covered this topic in depth in our Air Shocks vs Coil Shocks: Which Is Right for BC Riding? guide, but here is the short version for rear shocks specifically.
Air Shocks
Air shocks use a sealed air chamber as the spring. You inflate them with a shock pump to your target pressure and adjust as needed.
Air shocks are the right choice if you:
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Ride a mix of climbs and descents
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Want to fine-tune your shock pressure easily
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Are on a trail or all-mountain bike
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Prefer a lighter overall setup
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Ride in mostly moderate temperatures
Popular air shock options at Dunbar:
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RockShox Super Deluxe Ultimate
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Fox Float X2 Factory
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Fox Float DPS Factory
Coil Shocks
Coil shocks use a steel or titanium spring. The spring rate is fixed and cannot be changed without swapping the spring itself.
Coil shocks are the right choice if you:
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Spend most of your time descending
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Ride chunky, technical terrain like the North Shore or Squamish
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Want the most planted and supple feel possible
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Ride year-round in cold BC conditions
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Are on an enduro or bike park-focused machine
Popular coil shock options at Dunbar:
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RockShox Super Deluxe Coil Ultimate
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Fox DHX2 Factory
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Ohlins TTX22M
If you go with a coil shock, you will also need to purchase the correct shock spring for your body weight and frame. We will cover how to choose the right spring rate in the next section.
Step 3: Choose the Right Spring Rate (Coil Shocks Only)
If you choose a coil shock, getting the spring rate right is critical. This stage is where many riders go wrong.
Spring rate is measured in pounds per inch (lb/in) or Newtons per millimetre (N/mm). A higher number means a stiffer spring. A lower number means a softer spring.
The right spring rate depends on three things:
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Your body weight with riding gear on
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Your frame's leverage ratio
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Your personal preference for how firm or plush you want the ride
A simple starting point based on rider weight:
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Under 65kg: 400–450 lb/in
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65kg to 80kg: 450–500 lb/in
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80kg to 95kg: 500–550 lb/in
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Over 95kg: 550–600 lb/in
These are starting points only. Your frame's leverage ratio can shift the ideal spring rate significantly in either direction. If you are unsure, come into the shop and we will help you work it out properly.
Step 4: Understand the Damper
The damper controls how fast your shock compresses and rebounds. Getting the damper right is what separates a shock that feels great from one that just feels average.
Every rear shock has at least these two adjustments:
Rebound: Controls how fast the shock returns after being compressed. Too fast and the shock kicks back and unsettles the bike. Too slow and it packs down over repeated hits and feels harsh.
Compression: Controls how much resistance the shock has as it compresses. More compression means the shock moves less easily. Less compression means it moves more freely.
Premium shocks split compression into two separate adjustments:
Low-speed compression (LSC): Controls resistance to slow, rider-generated forces like pedalling, braking, and cornering. Increasing LSC makes the bike feel more supported and less likely to wallow.
High-speed compression (HSC): Controls resistance to fast impacts like square-edged hits, roots, and rock gardens. Increasing HSC makes the shock feel firmer through big hits.
For most trail riders, a shock with a single compression adjustment is more than enough. The dual compression adjustment is a genuine advantage for enduro riders who want precise control over how the bike behaves in different terrain.
Step 5: Match the Shock to Your Frame's Design
Not every shock works in every frame. Before you buy, confirm these three things:
Leverage ratio compatibility: Some frames are designed specifically for air shocks and do not perform well with coil. High leverage ratio frames (common in long-travel enduro bikes) can develop spring curve issues with certain coil setups. Check with your frame manufacturer if you are unsure.
Mounting hardware: Rear shocks use different hardware sizes at each mounting point. The most common sizes are 8mm and 6mm hardware, but the size varies by frame. Make sure your new shock comes with the right hardware or that you can source it separately.
Bushing type: Shocks use either trunnion mounts or standard eyelet mounts. These are not interchangeable. Your frame dictates which type you need.
Step 6: Set Up Your New Shock Correctly
Once your new shock is installed, take 15 minutes to set it up properly before your first ride. A shock that is not set up correctly will never feel right, regardless of how effective it is.
Set your sag first. Sag is how much your sock compresses under your body weight alone. The target range for most rear shocks is 25% to 30% of total travel. For a shock with 65mm of travel, that is roughly 16mm to 20mm of sag.
To measure sag:
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Put on your full riding kit
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Sit on your bike in your normal riding position
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Have someone check where the rubber O-ring sits on the shock shaft
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Adjust air pressure (or spring preload on coil) until you hit your target range
Set your rebound next. Start with a rebound fully slow, then speed it up gradually until the shock returns quickly without bouncing. A useful test is to push down on your seat and watch how the shock returns. It should come back smoothly and settle without any bounce.
Leave compression for last. Start at the manufacturer's recommended setting. Once your sag and rebound feel right, experiment with compression in small increments.
For a more profound look at shock setup, check out our MTB Suspension Buyer's Guide 2026, which covers sag, rebound, and compression in detail.
What to Spend: Rear Shock Pricing in Canada
Here is a realistic guide to what you can expect at each price point:
Entry level ($250 to $400 CAD): Good damping performance with basic rebound and compression adjustment. Suitable for trail riders who are not pushing the limits. Brands: RockShox Deluxe, Fox Float DPS Performance.
Mid-range ($400 to $650 CAD): Noticeably better small bump sensitivity and more tuning options. This is where most serious trail and enduro riders land. Brands: RockShox Super Deluxe Select+, Fox Float X Factory.
Flagship ($650 to $900+ CAD): The best damping technology available. The design includes independent high- and low-speed compression adjustments, premium seals, and measurably better performance. The brands are RockShox Super Deluxe Ultimate, Fox Float X2 Factory, and Ohlins TTX22M.
Coil shocks follow similar price tiers but remember to budget an additional $60 to $200 for the spring.
Our Top Rear Shock Picks for BC Riding
Best air shock for trail riding: RockShox Super Deluxe Select+ A well-rounded shock with excellent small bump sensitivity, easy setup, and reliable performance across all trail conditions. Great value for the price.
Best air shock for enduro: The Fox Float X2 Factory Independent HSC and LSC adjustments give you precise control on BC's varied and demanding terrain. A favourite among enduro racers and aggressive trail riders.
Best coil shock for all-around riding: RockShox Super Deluxe Coil Ultimate The coil version of RockShox's benchmark shock. It's supple, reliable, and works well on a wide range of frames. A strong choice for riders making the switch from air.
Best coil shock for maximum performance: Ohlins TTX22M The gold standard for coil shock feel and performance. Not the cheapest option, but riders who make the switch rarely go back.
Shop MTB Rear Shocks at Dunbar Cycles & Corsa Cycles
We stock a full range of MTB rear shocks and suspension components from Fox, RockShox, Ohlins, EXT, and more. Free shipping across Canada on orders over $150.
Not sure which shock is right for your frame? Visit us at our Vancouver location at Dunbar Cycles or at Corsa Cycles in Squamish — our team rides the same BC trails you do and has been setting up suspension since 1928. Come into either shop or reach out online: we'll help you get the right setup the first time.
