The best mountain bike coil spring for most riders in this roundup is the RockShox Metric Coil Spring, 134 mm, 400 lb, a focused replacement option for compatible Metric shocks that need a specific rate. Riders who want to tune spring rate without replacing the spring should look at the Sprindex Adjustable XC/Trail, while the Öhlins Lightweight Steel Coil Spring suits buyers seeking a named premium spring with a defined rate and stroke. The main tradeoffs are fit and spring rate versus adjustability, intended use, and how much confidence you can place in a listing’s specifications. Several options are complete shocks or fork springs rather than direct rear-shock replacements, so category labels alone are not enough to confirm compatibility. Read on for the full comparison and practical fit checks before choosing.
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Key Takeaways
- Fit matters more than the brand name: the RockShox Metric springs are replacement springs for compatible shocks, while the Buachois, Tongze, Glamorway, and BUCKLOS listings describe shock assemblies.
- Adjustability is the Sprindex family’s clearest distinction: its XC/trail, downhill, and 2.2-inch-stroke options target different spring-rate ranges and applications, so they are not interchangeable just because they share the brand.
- RockShox’s Metric options offer defined rates and dimensions: the 250, 300, 400, 450, and 500 lb listings help buyers match a known setup, but each rate and length must suit the shock and rider.
- The Öhlins spring stands apart by its stated 502 lb/in rate and 75 mm stroke: that specificity can help a buyer with a matching setup, but it does not make the spring a universal upgrade.
- Some listings are less directly comparable: the BoXXer spring is fork-specific, the 23.6 mm two-pack is described as a fork spring, and several generic coil-shock listings need careful verification of dimensions and fitment.
| RockShox Metric Coil Spring, 134 mm, 450 lb, Electric Red |  | Best for Mid-High Spring Rate Tuning | Brand: RockShox | Model number: 00.4118.200.106 | Spring rate: 450 lb | VIEW LATEST PRICE | See Our Full Breakdown |
| RockShox Metric Coil Spring, 300 lb, 151 mm, 65 mm Travel |  | Best for Lower-Rate, Longer-Travel Metric Setups | Brand: RockShox | Model number: 00.4118.200.007 | Spring rate: 300 lb | VIEW LATEST PRICE | See Our Full Breakdown |
| RockShox Metric Coil Spring, 134 mm, 47.5–55 mm Travel, 400 lb |  | Best Steel Replacement Spring | Brand: RockShox | Model: 00.4118.200.001 | Material: Steel | VIEW LATEST PRICE | See Our Full Breakdown |
| Buachois 150 mm Coil Spring Shock Strut for Bicycles |  | Best Complete Replacement Shock Option | Brand: Buachois | Material: Aluminum alloy and steel | Hole center-to-center distance: 150 mm (5.9 in) | VIEW LATEST PRICE | See Our Full Breakdown |
| RockShox BoXXer Firm Blue Coil Spring |  | Best for BoXXer and Domain Fork Tuning | Brand: RockShox | Model number: 11.4015.380.030 | Spring firmness: Firm | VIEW LATEST PRICE | See Our Full Breakdown |
| Tongze 180 mm Rear Shock Absorber with Adjustable Coil Spring |  | Best Complete Shock for Broad Compatibility | Eye-to-eye length: 180 mm (7.1 in) | Mounting-hole diameter: 8 mm (0.315 in) | Spring thickness: 8 mm (0.315 in) | VIEW LATEST PRICE | See Our Full Breakdown |
| Bicycle Front Fork Shock Absorber Coil Springs, Steel, 2-Pack, Black (23.6 mm) |  | Best Front-Fork Pair Replacement | Package quantity: 2 springs | Material: Steel | Length: 28.5 cm (11.2 in) | VIEW LATEST PRICE | See Our Full Breakdown |
| Sprindex Adjustable XC/Trail Rear Coil Spring, 55 × 126 mm, 610–690 lb |  | Best Adjustable XC/Trail Spring | Spring rate range: 610–690 lb | Spring length: 126 mm | Inner diameter: 38.3 mm | VIEW LATEST PRICE | See Our Full Breakdown |
| RockShox Metric Coil Spring, 134 mm, 47.5–55 mm Travel, 500 lb, Electric Red | | Best Fixed-Rate Metric Replacement | Spring length: 134 mm | Travel range: 47.5–55 mm | Spring rate: 500 lb | VIEW LATEST PRICE | See Our Full Breakdown |
| Öhlins Lightweight Steel Coil Spring, 502 lb/in, 75 mm Stroke |  | Best Premium Fixed-Rate Spring | Spring rate: 502 lb/in | Stroke: 75 mm (3.0 in) | Inner diameter: 36 mm | VIEW LATEST PRICE | See Our Full Breakdown |
| RockShox Metric Coil Shock Spring, 134 mm, 250 lb, Black |  | Best for Light Spring Rates | Brand: RockShox | Model number: 00.4118.200.072 | Spring length: 134 mm | VIEW LATEST PRICE | See Our Full Breakdown |
| Sprindex Adjustable Downhill Rear Coil Spring, 3-Inch Stroke, 340–370 lb |  | Best for Adjustable Downhill Setup | Brand: Sprindex | Model: Downhill | Stroke: 3 inches (75 mm) | VIEW LATEST PRICE | See Our Full Breakdown |
| Glamorway 150mm Rear Shock Absorber, 750 lb/in Spring for Mountain and Folding Bikes |  | Best Complete Shock for Lighter Riders | Brand: Glamorway | Model number: N02496 | Eye-to-eye length: 150 mm (6 in) | VIEW LATEST PRICE | See Our Full Breakdown |
| Sprindex Adjustable Rear Coil Spring, 2.2-Inch Stroke, 380–430 lb |  | Best for Adjustable XC and Trail Setups | Brand: Sprindex | Model: Trail | Stroke: 2.2 inches (55 mm) | VIEW LATEST PRICE | See Our Full Breakdown |
| BUCKLOS MTB Coil Spring Rear Shock, 190 × 50 mm |  | Best for Damping Adjustability | Brand: BUCKLOS | Model: GRAVO | Shock size: 190 × 50 mm | VIEW LATEST PRICE | See Our Full Breakdown |
| mountain bike coil spring | Brand | Material |
|---|---|---|
| RockShox Metric Coil Spring | RockShox | — |
| RockShox Metric Coil Spring | RockShox | — |
| RockShox Metric Coil Spring | RockShox | Steel |
| Buachois 150 mm Coil Spring Sh | Buachois | Aluminum alloy and steel |
| RockShox BoXXer Firm Blue Coil | RockShox | — |
| Tongze 180 mm Rear Shock Absor | — | — |
| Bicycle Front Fork Shock Absor | — | Steel |
| Sprindex Adjustable XC/Trail R | — | High-tensile spring steel |
| RockShox Metric Coil Spring | — | — |
| Öhlins Lightweight Steel Coil | — | Steel |
| RockShox Metric Coil Shock Spr | RockShox | — |
| Sprindex Adjustable Downhill R | Sprindex | Steel |
| Glamorway 150mm Rear Shock Abs | Glamorway | Steel |
| Sprindex Adjustable Rear Coil | Sprindex | Steel |
| BUCKLOS MTB Coil Spring Rear S | BUCKLOS | — |
More Details on Our Top Picks
RockShox Metric Coil Spring, 134 mm, 450 lb, Electric Red
I’d shortlist this 450 lb RockShox spring for riders whose compatible metric rear shock calls for a firmer rate than the 400 lb version. Both use a 134 mm length and support 47.5–55 mm of spring travel, so the rate—not the fit dimensions—is the main distinction between them. Compared with the 300 lb, 151 mm RockShox spring, this one serves a different shock setup and a higher spring-rate requirement; those springs are not interchangeable just because they share a brand.
The Electric Red finish makes the part easy to identify, but the useful buying check is the shock manufacturer’s specified spring size and rate. It is sold on its own, so it won’t replace a shock or solve a mismatch in hardware. I’d choose it only when those specifications line up.
Pros:- 450 lb rate offers a firmer tuning option than the listed 400 lb spring in the same 134 mm size.
- Supports a stated spring travel range of 47.5–55 mm.
- Designed for compatible metric rear shocks.
- Electric Red finish helps distinguish it from the black 400 lb option.
Cons:- Sold separately; no shock is included.
- Fit depends on matching the shock’s required spring dimensions and rate.
- The stated size and rate do not establish compatibility with every metric shock.
Best for: Riders replacing a spring in a compatible metric rear shock that specifies 450 lb and a 134 mm spring for 47.5–55 mm travel.
Not ideal for: Riders who have not confirmed their shock’s required spring dimensions and rate, or who need a complete rear shock rather than a replacement spring.
- Brand:RockShox
- Model number:00.4118.200.106
- Spring rate:450 lb
- Spring length:134 mm
- Spring travel:47.5–55 mm
- Position:Rear
- Color:Electric Red
- Included component:Rear shock spring only
Our verdict“Choose this spring when your compatible metric shock calls for a 450 lb rate in the 134 mm, 47.5–55 mm travel size.”
RockShox Metric Coil Spring, 300 lb, 151 mm, 65 mm Travel
This 300 lb RockShox spring is the clearest fit in this group for a compatible metric shock that specifies a 151 mm spring and 65 mm of travel. Its lower rate sets it apart from the 400 lb and 450 lb RockShox options, but the different length and travel specification matter just as much: those shorter 134 mm springs are not substitutes for a shock designed around this size. A lower number alone is not a reason to pick it; the shock’s required rate and dimensions must match.
The product data identifies the bicycle rear-shock application but does not state the spring material, leaving less construction detail than the 400 lb RockShox entry, which is listed as steel. It is a practical replacement component, not a full suspension unit, and the listing gives no broader fit guarantee.
Pros:- Clearly specified 300 lb spring rate for suspension tuning.
- 151 mm length and 65 mm travel identify the intended size.
- Designed for compatible bicycle rear shocks.
Cons:- Compatibility depends on matching the shock’s spring dimensions and rate.
- Product data does not specify the spring material.
- Sold as one spring, not as a complete rear shock.
Best for: Riders with a compatible metric rear shock specified for a 151 mm spring, 65 mm travel, and a 300 lb rate.
Not ideal for: Riders whose shock requires a 134 mm spring, a different travel range, or a higher spring rate, and buyers seeking a complete shock.
- Brand:RockShox
- Model number:00.4118.200.007
- Spring rate:300 lb
- Length:151 mm
- Travel:65 mm
- Color:Black
- Compatible application:Bicycle rear shocks
- Quantity:1
Our verdict“Pick this only for a metric rear shock that specifically calls for the 151 mm, 65 mm travel, 300 lb spring specification.”
RockShox Metric Coil Spring, 134 mm, 47.5–55 mm Travel, 400 lb
For a compatible metric shock requiring a 400 lb rate, this RockShox spring offers a straightforward replacement in a stated 134 mm length and 47.5–55 mm travel range. The listed steel construction gives buyers a material detail missing from the 300 lb, 151 mm RockShox listing. Compared with the 450 lb spring in the same 134 mm size, this is the lower-rate choice; the right pick depends on the rate specified for the shock, not on a general preference for softer suspension.
Its limitations are simple but important: the spring is sold individually, and the shock is not included. The dimensions and rate also do not make it a universal fit. I’d treat this as a focused replacement part for riders who have already confirmed their shock’s requirements, rather than a way to change spring rate without checking compatibility.
Pros:- Steel material is specified.
- 400 lb rate provides a lower-rate alternative to the 450 lb spring in the same listed size.
- 134 mm length and 47.5–55 mm travel are stated.
- Designed for compatible Metric shock setups.
Cons:- Spring only; the shock is not included.
- Requires exact matching to the shock’s spring and rate requirements.
- Sold individually.
Best for: Mountain bikers replacing a spring in a compatible metric rear shock specified for a 400 lb rate, 134 mm length, and 47.5–55 mm travel.
Not ideal for: Riders whose shock calls for the 450 lb rate, the longer 151 mm spring, or a complete shock assembly.
- Brand:RockShox
- Model:00.4118.200.001
- Material:Steel
- Spring rate:400 lb
- Length:134 mm
- Travel:47.5–55 mm
- Weight:13.76 oz
- Included components:Coil spring only
Our verdict“Choose this steel spring when your metric shock specifies the 400 lb rate and 134 mm size, rather than the firmer 450 lb alternative.”
Buachois 150 mm Coil Spring Shock Strut for Bicycles
Unlike the RockShox entries, which are replacement springs for compatible shocks, this Buachois item is described as a coil spring shock strut. Its 150 mm hole-to-hole distance and adjustable tension make it a possible replacement route for riders matching a complete unit, including some mountain and electric bicycles. That broader application may appeal to buyers who need more than a spring, but it also makes careful fit checking more important than with the specifically dimensioned RockShox metric springs.
The listing identifies aluminum alloy and steel construction, yet its compatibility language spans bicycles and motorcycles, and the stated maximum working pressure is not clearly explained for bicycle suspension use. It also supplies no spring-rate figure to compare with the 300–450 lb RockShox options. I’d treat it as a fit-dependent replacement assembly, not a precise spring-tuning choice.
Pros:- Described as a shock strut rather than a spring-only replacement.
- 150 mm hole-to-hole distance is provided for fit checking.
- Adjustable tension spring is listed.
- Construction is described as aluminum alloy and steel.
Cons:- Compatibility description is broad, covering bicycles and motorcycles.
- No spring-rate figure is provided for comparison with the RockShox options.
- The listed maximum working pressure is unclear for bicycle suspension use.
Best for: Owners of a mountain or electric bike seeking a complete replacement shock strut whose mounting distance and application match the listed 150 mm fit.
Not ideal for: Riders fine-tuning a known metric shock by spring rate, or anyone unable to verify mounting dimensions and bicycle-specific compatibility.
- Brand:Buachois
- Material:Aluminum alloy and steel
- Hole center-to-center distance:150 mm (5.9 in)
- Extended length:15 cm
- Maximum working pressure:2000 kg (as listed)
- Weight:0.35 kg
- Quantity:1
- Compatible vehicles:Motorcycles and bicycles
Our verdict“Consider this assembly only if you need a complete replacement and have confirmed its 150 mm mounting fit and bicycle suitability.”
RockShox BoXXer Firm Blue Coil Spring
This is the lineup’s dedicated front-fork spring, not a rear-shock coil like the metric RockShox springs. It is a genuine RockShox firm replacement for specified BoXXer Race, RC, Team, and R2C2 forks from 2010 onward, plus Domain dual-crown forks from 2011 onward. That narrow model-and-year fit makes it more useful to an owner of one of those forks than a general-purpose spring, while ruling it out for riders shopping for a rear suspension coil.
The firm spring option supports fork tuning within the listed compatibility range, but it is not a universal upgrade: buyers need to check both fork model and year. The description also contains conflicting color information, listing firm blue alongside Xsoft silver, so I would verify the part identity before ordering. Unlike the 134 mm RockShox rear springs, its stated 35 mm size refers to this fork-part listing.
Pros:- Genuine RockShox replacement part.
- Firm spring option for tuning compatible forks.
- Compatibility is listed for several BoXXer models and Domain dual-crown forks.
- Light listed weight of 4 ounces.
Cons:- Fit is limited to specified fork models and model years.
- The listing has conflicting color details.
- Not suitable as a rear-shock spring replacement.
Best for: BoXXer Race, RC, Team, or R2C2 owners from 2010 onward, and Domain dual-crown owners from 2011 onward, seeking a firm replacement spring.
Not ideal for: Riders seeking a rear-shock coil spring or owners of forks outside the listed models and years.
- Brand:RockShox
- Model number:11.4015.380.030
- Spring firmness:Firm
- Listed size:35 mm
- Listed color:Blue
- Weight:4 ounces
- Compatibility:BoXXer Race, RC, Team, and R2C2 (2010 onward); Domain dual-crown (2011 onward)
- Quantity:1
Our verdict“Choose this firm coil only if you own a listed BoXXer or Domain dual-crown fork and have confirmed the model-year fit.”
Tongze 180 mm Rear Shock Absorber with Adjustable Coil Spring
The Tongze 180 mm is the only option in this group that arrives as a complete rear shock absorber rather than a replacement spring. That makes it a different kind of choice from the RockShox Metric 500 lb spring or Öhlins spring, which require a compatible shock assembly already in place. Its steel-and-aluminum body and coil are intended to reduce vibration, while the stated 180 mm eye-to-eye length and 8 mm mounting holes give buyers concrete dimensions to compare with an existing unit.
The tradeoff is fit certainty: “universal” does not replace checking the original shock’s length and mounting hardware, and the listing’s broad vehicle claims do not establish compatibility with every mountain bike. Its 1500 lb maximum load is specified per pair, and it is not intended for heavy vehicles. I’d choose it for a dimension-matched replacement, not for fine spring-rate tuning.
Pros:- Supplied as a complete rear shock, unlike the RockShox and Öhlins spring-only options.
- Lists eye-to-eye length, mounting-hole diameter, and spring thickness for fit checks.
- Steel and aluminum alloy construction is intended to cushion impacts and reduce vibration.
- Designed for a range of compatible bikes and small vehicles.
Cons:- Compatibility depends on matching the original shock dimensions and vehicle requirements.
- The 1500 lb maximum load is stated per pair, and the unit is not suited to heavy vehicles.
- The broad fit claims do not specify mountain-bike frame or suspension-linkage compatibility.
Best for: Riders replacing a complete rear shock on a compatible mountain or downhill bike who can match the 180 mm eye-to-eye length and 8 mm mounting holes.
Not ideal for: Riders seeking a spring-only upgrade, precise spring-rate adjustment, or a fit guaranteed for a particular frame without checking dimensions.
- Eye-to-eye length:180 mm (7.1 in)
- Mounting-hole diameter:8 mm (0.315 in)
- Spring thickness:8 mm (0.315 in)
- Maximum load:1500 lbs per pair
- Position:Rear
- Materials:Steel, aluminum alloy, and silicone
- Included:1 shock absorber
- Warranty:30 days
Our verdict“Choose the Tongze if you need a complete replacement shock and have confirmed its mounting dimensions match your bike.”
Bicycle Front Fork Shock Absorber Coil Springs, Steel, 2-Pack, Black (23.6 mm)
This two-spring set fills a different need from the rear-shock coils elsewhere in the roundup: it is intended for compatible mountain-bike front forks, allowing both sides to be replaced together. The listed 23.6 mm diameter, 3.8 mm wire, and 28.5 cm length offer useful measurements for checking against the springs already in the fork. Compared with the Sprindex rear spring, it does not offer adjustable rate or a stated progressive response; its appeal is a straightforward matched pair for a dimension-compatible fork.
That simplicity comes with a fit-sensitive purchase. The listing also describes Type B and Type C dimensions, so the selected variant must match the existing spring rather than relying on the title alone. Weight information is ambiguous, which makes it harder to compare replacement mass. I’d shortlist it for a standard paired replacement, but skip it if your fork’s spring size or required rate is unknown.
Pros:- Two springs allow both sides of a compatible fork to be replaced together.
- Steel construction is specified for the replacement springs.
- The 23.6 mm diameter, 3.8 mm wire, and 28.5 cm length support dimension checks.
- Other listed size variants provide alternatives for forks requiring different dimensions.
Cons:- Fit depends on matching the selected spring dimensions to the original fork springs.
- Weight data is ambiguous and does not identify which variant it describes.
- No spring-rate figure is provided, limiting rate-based comparisons.
Best for: Mountain-bike owners replacing both front-fork springs who can identify the correct diameter, wire thickness, and length from their current fork.
Not ideal for: Riders seeking a rear-shock spring, adjustable spring rate, or a replacement whose compatibility can be confirmed without measuring the fork.
- Package quantity:2 springs
- Material:Steel
- Length:28.5 cm (11.2 in)
- Diameter:23.6 mm (Type A)
- Wire diameter:3.8 mm (Type A)
- Other available sizes:Type B: 25.2 mm diameter, 4.0 mm wire; Type C: 27.0 mm diameter, 4.3 mm wire
- Weight:About 224 g or 277 g; variant not specified
- Compatibility:Mountain bike front forks; verify dimensions before purchase
Our verdict“Pick this pair when your front fork calls for the listed spring dimensions and you want to replace both sides at once.”
Sprindex Adjustable XC/Trail Rear Coil Spring, 55 × 126 mm, 610–690 lb
The Sprindex adjustable spring earns its place for riders who want to tune rate without swapping to a different coil. Its 610–690 lb range gives more flexibility than the fixed-rate RockShox 500 lb and Öhlins 502 lb springs, provided the rider’s shock and bike fall within this model’s intended setup. The stated progressive support in the final 20% of stroke is aimed at helping resist harsh bottom-outs on bigger hits while retaining a linear-linkage XC or trail setup.
Adapters are included for different shock sizes and setups, but they do not make this a universal fit: the 126 mm spring length, 38.3 mm inner diameter, and 2.2-inch stroke still need to match the shock. Its rate range is also much higher than those two fixed-rate alternatives, so it is not a sensible substitute when a bike calls for a lighter coil. I’d prioritize it for compatible riders who value adjustment over a simple fixed-rate replacement.
Pros:- Adjustable spring rate spans 610–690 lb.
- Progressive support is designed to resist big hits near the end of shock stroke.
- Adapters are included for different shock sizes and setups.
- High-tensile spring steel is specified for the coil.
Cons:- Compatibility is limited to matching shock dimensions and the intended XC/trail setup.
- The 610–690 lb range is substantially stiffer than the listed RockShox 500 lb and Öhlins 502 lb springs.
- The progressive design may not suit riders seeking a conventional linear-rate replacement.
Best for: XC and trail riders with a linear-linkage bike and compatible shock who want to adjust spring rate within the 610–690 lb range.
Not ideal for: Riders whose shock dimensions or required spring rate fall outside the listed range, or those with a setup not specified for this spring.
- Spring rate range:610–690 lb
- Spring length:126 mm
- Inner diameter:38.3 mm
- Stroke length:2.2 in
- Material:High-tensile spring steel
- Position:Rear
- Item weight:10.08 oz
- Included components:Rear shock spring and adapters
Our verdict“Choose this Sprindex when your compatible XC or trail setup needs a high-rate coil with on-spring adjustment.”
RockShox Metric Coil Spring, 134 mm, 47.5–55 mm Travel, 500 lb, Electric Red
For a rider whose shock calls for a 500 lb metric coil, this RockShox spring is the most direct fixed-rate option in this group. Its 134 mm length and 47.5–55 mm travel range make it more specific than the Tongze complete shock, while the spring-only format suits a rider keeping a compatible rear shock. Compared with the near-identical-in-rate Öhlins 502 lb/in spring, this pick is defined by its stated travel range and 134 mm length; those dimensions, not the red finish, should drive the fit decision.
The main limitation is that the shock is not included, and compatibility is restricted to the required shock dimensions. A fixed 500 lb rate also offers less tuning flexibility than the Sprindex adjustable coil. I’d choose this when the frame and shock setup call for the listed rate and travel, not as a general-purpose upgrade or a way to change spring rate by feel.
Pros:- Specified 500 lb spring rate suits setups calling for that rate.
- 47.5–55 mm travel range helps narrow compatibility checks.
- 134 mm spring length is stated for comparison with the existing coil.
- Spring-only format lets riders retain a compatible shock assembly.
Cons:- Sold as a spring only; the shock is not included.
- Fixed rate gives less adjustment flexibility than the Sprindex spring.
- Fits only compatible shock dimensions and travel requirements.
Best for: Riders replacing a rear coil on a compatible RockShox Metric setup that specifies a 500 lb spring and the listed travel range.
Not ideal for: Buyers needing a complete shock, an adjustable spring rate, or a coil for a shock with different dimensions or travel requirements.
- Spring length:134 mm
- Travel range:47.5–55 mm
- Spring rate:500 lb
- Color:Electric Red
- Component type:Rear shock spring
- Weight:1.2 lb
- Width:4.5 in
- Included:1 rear shock spring
Our verdict“Buy this RockShox coil when your compatible Metric shock requires a 500 lb spring in the stated travel range.”
Öhlins Lightweight Steel Coil Spring, 502 lb/in, 75 mm Stroke
The Öhlins 502 lb/in spring is the premium fixed-rate pick for riders who already have a compatible rear shock and want a spring specified around a 75 mm stroke. Its heat-treated steel construction is intended to balance strength with reduced weight, while the stated 36 mm inner diameter gives a key measurement for checking fit. Compared with the RockShox Metric 500 lb, this coil specifies a 75 mm stroke and 36 mm inner diameter rather than a 47.5–55 mm travel range, so the two should not be treated as interchangeable based on their similar rates.
This is a focused replacement, not a complete suspension solution: the shock is absent, and the assembly must match the inner diameter and stroke requirements. The listing also advises a stiffer spring when more than two turns of preload are needed, which can limit how far riders should try to compensate for an incorrect rate. I’d select it for a verified fit and spring-rate requirement, not simply for the brand name or weight claim.
Pros:- Heat-treated steel construction is specified.
- 502 lb/in rate and 75 mm stroke provide clear selection criteria.
- 36 mm inner diameter helps buyers verify shock compatibility.
- Designed to balance strength and reduced weight.
Cons:- Requires a compatible shock assembly with a 36 mm inner diameter.
- Spring is supplied without a shock.
- More than two turns of preload calls for a stiffer spring, limiting preload as a substitute for rate selection.
Best for: Riders with a compatible 36 mm inner-diameter shock that calls for a 502 lb/in spring and 75 mm stroke.
Not ideal for: Riders who need a complete shock, have a different spring diameter or stroke requirement, or need to correct excessive preload with a softer coil.
- Spring rate:502 lb/in
- Stroke:75 mm (3.0 in)
- Inner diameter:36 mm
- Material:Steel
- Weight:1 lb
- Width:4.5 in
- Model number:18073-12
- Included component:Rear shock spring
Our verdict“Choose the Öhlins spring when your shock matches its 36 mm diameter and 75 mm stroke and requires a 502 lb/in coil.”
RockShox Metric Coil Shock Spring, 134 mm, 250 lb, Black
I’d choose this RockShox when a compatible Metric shock calls for a 250 lb spring rate and a precise 134 mm spring length. Its stated fit range of 47.5–55 mm of travel makes the intended application clearer than the Glamorway 150 mm shock, which requires checking eye-to-eye fit and is recommended for a particular rider-weight range. Unlike the adjustable Sprindex Trail spring, this RockShox has one fixed rate, so it cannot be tuned across a range if your setup needs change. That simplicity is useful when you already know the correct rate and want a spring specified for your shock. I’d skip it if your shock dimensions or required rate don’t match; a spring’s brand name cannot make an incompatible fit work.
Pros:- Specified for 134 mm shocks with 47.5–55 mm travel
- Clearly identified 250 lb spring rate
- Designed for mountain bike suspension
Cons:- Fixed spring rate offers no on-spring adjustment
- Compatibility is limited to shocks matching the listed specifications
Best for: Riders with a compatible 134 mm RockShox Metric shock who need a fixed 250 lb spring rate for 47.5–55 mm travel.
Not ideal for: Riders who need a different spring rate, an adjustable rate, or have not confirmed that their shock matches the listed dimensions.
- Brand:RockShox
- Model number:00.4118.200.072
- Spring length:134 mm
- Travel range:47.5–55 mm
- Spring rate:250 lb
- Color:Black
- Compatible vehicle type:Bicycle
- Warranty:Limited warranty
Our verdict“Choose this RockShox if your compatible Metric shock needs a 250 lb spring; skip it if you need adjustability or a different fit.”
Sprindex Adjustable Downhill Rear Coil Spring, 3-Inch Stroke, 340–370 lb
The Sprindex Downhill earns its place for riders who want to fine-tune a 340–370 lb rate without swapping to another fixed spring. Its stated progressive support in the final 20% of travel is aimed at adding resistance near bottom-out, while the included adapters help accommodate different shock setups. That makes it a more specialized alternative to the RockShox Metric 250 lb spring, which has a fixed rate and a narrower stated shock fit. The tradeoff is that this Sprindex is not a general-purpose choice: it is specified for a 3-inch stroke and bikes with linear linkage. I’d pick it for a matching downhill system, but not for a trail bike or a shock whose dimensions and linkage requirements have not been confirmed.
Pros:- Spring rate adjusts from 340 to 370 lb
- Progressive support is designed for the final 20% of travel
- Adapters are included for different shock sizes and setups
- High-tensile steel construction
Cons:- Designed specifically for 3-inch-stroke shocks
- Intended for bikes with linear linkage
- Narrower rate range than a spring selected for a substantially different rider or setup
Best for: Downhill riders with a linear-linkage bike and a compatible 3-inch-stroke shock who want to adjust spring rate between 340 and 370 lb.
Not ideal for: Riders with trail bikes, non-linear linkage, or shocks that do not match the 3-inch stroke and spring dimensions.
- Brand:Sprindex
- Model:Downhill
- Stroke:3 inches (75 mm)
- Spring length:160 mm
- Adjustable spring rate:340–370 lb
- Inner diameter:38.3 mm
- Material:Steel
- Compatibility:Linear-linkage bikes; adapters included
- Part number:60350
Our verdict“Pick this Sprindex for a compatible linear-linkage downhill bike when on-spring rate adjustment matters more than broad compatibility.”
Glamorway 150mm Rear Shock Absorber, 750 lb/in Spring for Mountain and Folding Bikes
Unlike the other picks here, the Glamorway is a complete rear shock, not a replacement spring, so it may suit a buyer replacing an entire compatible unit. Its 150 mm eye-to-eye measurement and 750 lb/in spring rate give useful starting points for checking fit, and the listed recommended rider range is 50–60 kg. That makes it a more targeted option than the BUCKLOS GRAVO, which offers adjustable damping and a 550 lb spring but is listed in a 190 × 50 mm size. The Glamorway’s limitation is its narrow rider-weight recommendation and the need to measure the existing shock and check the spring nut before riding. I wouldn’t select it by bike category alone: frame fit and the intended rate must match.
Pros:- Complete rear shock for compatible mountain and folding bikes
- Lists both 150 mm eye-to-eye length and 750 lb/in spring rate
- Recommended rider-weight range is clearly stated
- Spring nut is secured against the spring
Cons:- Recommended for a limited rider-weight range of 50–60 kg
- Fit must be confirmed by measuring the original shock
- Product is a shock assembly rather than a standalone replacement coil spring
Best for: Lighter riders weighing 50–60 kg who need a complete rear shock and have confirmed their bike accepts a 150 mm eye-to-eye unit.
Not ideal for: Riders outside the stated 50–60 kg range, or anyone seeking a spring-only replacement or adjustable damping features.
- Brand:Glamorway
- Model number:N02496
- Eye-to-eye length:150 mm (6 in)
- Spring rate:750 lb/in
- Recommended rider weight:50–60 kg (110–132 lbs)
- Material:Steel
- Finish:Silver
- Compatibility:Compatible mountain and folding bikes
- Included:1 rear shock
Our verdict“Consider the Glamorway as a complete replacement shock for a 50–60 kg rider only after confirming the 150 mm fit and spring suitability.”
Sprindex Adjustable Rear Coil Spring, 2.2-Inch Stroke, 380–430 lb
For a compatible linear-linkage XC or trail bike, this Sprindex gives a broader 380–430 lb adjustment range than its Downhill counterpart’s 340–370 lb range. Both models add progressive support in the final 20% of travel and include adapters, but this one is sized for a shorter 2.2-inch (55 mm) stroke. That distinction matters more than the shared adjustability: the Downhill spring’s 3-inch stroke is not a substitute if your shock requires this shorter format. I’d favor this model when the listed dimensions and rate range suit the setup, especially if you want to tune spring feel without buying several fixed-rate coils. Its limitation is equally clear: the stated linear-linkage application and shock dimensions must match, so it is not a universal trail spring.
Pros:- Adjustable spring rate from 380 to 430 lb
- Progressive support is designed for the final 20% of travel
- Adapters are included for different shock setups
- High-tensile steel construction
Cons:- Intended for bikes with linear linkage
- Compatibility depends on matching shock dimensions and setup
- Shorter 2.2-inch stroke rules it out for shocks requiring the Downhill model’s 3-inch stroke
Best for: XC and trail riders with a compatible linear-linkage shock requiring a 2.2-inch stroke and a spring rate within 380–430 lb.
Not ideal for: Riders with downhill-length shocks, non-linear linkage, or a required spring rate outside the adjustment range.
- Brand:Sprindex
- Model:Trail
- Stroke:2.2 inches (55 mm)
- Spring length:124 mm
- Adjustable spring weight:380–430 lb
- Inner diameter:38.3 mm
- Material:Steel
- Part number:24400
- Included components:Rear shock spring and adapters
Our verdict“Choose this Sprindex for a dimension-matched linear-linkage XC or trail bike that benefits from adjustable 380–430 lb springing.”
BUCKLOS MTB Coil Spring Rear Shock, 190 × 50 mm
The BUCKLOS GRAVO is another complete rear shock, but its strongest distinction is damping control: compression is adjustable and rebound has nine settings. For steep, rough downhill riding, that gives the buyer more ways to shape shock response than the Glamorway, which lists a fixed spring rate and no damping adjustments. The BUCKLOS also uses a 550 lb coil spring and an aluminum-alloy body, though the supplied details do not establish a rider-weight range or frame-specific fit. Its 190 × 50 mm size is only one listed option among several available lengths and travels, so matching the exact frame requirement is essential. There is no lockout, making it less suited to riders who want a firm pedaling mode on smoother climbs.
Pros:- Adjustable compression damping
- Nine-speed rebound adjustment
- 550 lb coil spring
- Aluminum alloy and carbon steel construction
Cons:- No lockout feature
- Frame compatibility depends on selecting the correct size
- Listed details do not specify a recommended rider-weight range
Best for: Downhill riders seeking a complete 190 × 50 mm rear shock with adjustable compression and multiple rebound settings, provided their frame accepts that size.
Not ideal for: Riders who need a lockout, a spring-only replacement, or a shock size other than one confirmed for their frame.
- Brand:BUCKLOS
- Model:GRAVO
- Shock size:190 × 50 mm
- Rebound adjustment:9-speed
- Compression damping:Adjustable
- Lockout:None
- Available lengths:190–265 mm
- Available travel:50–80 mm
- Materials:Aluminum alloy, carbon steel
Our verdict“Choose the BUCKLOS if your downhill frame accepts 190 × 50 mm and you value adjustable compression and rebound over a lockout.”
How We Picked
I ranked these options by how clearly their listed dimensions, spring rates, and intended applications support a mountain-bike suspension purchase. Compatibility came first: a replacement spring with a defined length, rate, and shock family is easier to evaluate than a generic listing that leaves fitment unclear. I also weighed whether the product is a spring alone or a complete shock, whether it offers a useful choice such as adjustable rate, and how clearly it identifies its intended use.
That logic puts the more specifically identified replacement springs and adjustable Sprindex options ahead of broadly described assemblies, not because every rider needs a premium or adjustable spring, but because the buyer can make a more informed fit decision. RockShox Metric springs rank by the usefulness of their stated specifications, with no single rate treated as universally superior. The BoXXer and fork-spring listings rank lower for rear-shock buyers because they serve different suspension positions; generic shock assemblies also sit lower when the listing provides fewer fit details. I did not infer compatibility or performance beyond the supplied product information.
| mountain bike coil spring | Brand | Material |
|---|---|---|
| RockShox Metric Coil Spring | RockShox | — |
| RockShox Metric Coil Spring | RockShox | — |
| RockShox Metric Coil Spring | RockShox | Steel |
| Buachois 150 mm Coil Spring Sh | Buachois | Aluminum alloy and steel |
| RockShox BoXXer Firm Blue Coil | RockShox | — |
| Tongze 180 mm Rear Shock Absor | — | — |
| Bicycle Front Fork Shock Absor | — | Steel |
| Sprindex Adjustable XC/Trail R | — | High-tensile spring steel |
| RockShox Metric Coil Spring | — | — |
| Öhlins Lightweight Steel Coil | — | Steel |
| RockShox Metric Coil Shock Spr | RockShox | — |
| Sprindex Adjustable Downhill R | Sprindex | Steel |
| Glamorway 150mm Rear Shock Abs | Glamorway | Steel |
| Sprindex Adjustable Rear Coil | Sprindex | Steel |
| BUCKLOS MTB Coil Spring Rear S | BUCKLOS | — |
Factors to Consider When Choosing Best Mountain Bike Coil Springs
Before choosing by rate or brand, I would match the spring to the suspension system already on the bike. A coil spring is a fit-specific component, and a mismatch can make a promising listing unusable. These checks help distinguish a spring replacement from a complete shock purchase and prevent rate, stroke, or mounting details from being overlooked.
Match the Spring to the Exact Shock
Start with the shock manufacturer, model, and spring dimensions, then compare them with the replacement listing. A stated length such as 134 mm does not by itself confirm fit; the spring’s internal diameter, seat shape, and the shock’s spring-retention hardware may also matter. Do not treat Metric, BoXXer, and generic rear-shock listings as equivalent categories. A fork spring belongs to a fork, while a rear-shock spring must fit the rear shock’s body and hardware. If the listing omits a dimension, check the shock maker’s documentation or ask the seller before ordering. This extra check is more useful than choosing a spring based only on color or brand.
Choose Spring Rate From a Setup, Not a Guess
Spring rate describes how much force is needed to compress a spring, but the number alone does not tell you whether it suits your bike. Rider mass, riding gear, leverage ratio, suspension design, desired sag, and riding style all affect the rate that works. A 400 lb/in spring in one frame can feel different from the same rate in another because the frame’s leverage curve changes how the spring is loaded. Use the bike or shock manufacturer’s rate guidance as a starting point, then fine-tune around the sag target. A common mistake is copying another rider’s rate without matching their frame and setup. If you are between rates, check whether the shock has enough preload adjustment to support either option without exceeding its guidance.
Check Stroke and Spring Length Separately
Stroke refers to how far the shock shaft travels, while spring length describes the spring itself; neither number can substitute for the other. A spring needs enough usable travel to avoid coil bind before the shock reaches full stroke. It also needs to sit securely on the shock with the correct preload and retainers. Listings that specify a 2.2-inch or 3-inch stroke may be describing an intended shock application, not every dimension needed to confirm compatibility. Compare the shock’s required spring length and stroke with the product documentation rather than relying on a rough conversion. This is especially relevant when comparing adjustable Sprindex options with conventional springs.
Decide Whether Adjustability Is Worth the Tradeoff
An adjustable-rate spring can make small setup changes easier without swapping to a different fixed-rate spring. That flexibility is most useful for riders who regularly change equipment load, terrain, or setup preferences and can identify what adjustment they need. A fixed-rate spring is often simpler when the correct rate is already known, and it avoids paying for a feature that may go unused. Adjustable does not mean universal: the spring still has to match the shock dimensions, stroke, and intended application. Check the range carefully, since an XC/trail model and a downhill model can cover different needs. I would choose adjustability for tuning flexibility, not as a substitute for confirming fit.
Know Whether You Need a Spring or a Complete Shock
Several products in this roundup are described as shock absorbers rather than standalone replacement springs. A complete shock purchase involves mounting dimensions, eye-to-eye length, stroke, hardware, and frame compatibility, along with the spring rate. Replacing only a spring is a narrower job and usually makes sense when the existing shock is compatible and in serviceable condition. Do not compare a low-detail complete-shock listing directly with a named spring as if they solve the same problem. Confirm that a complete unit suits the frame and that its spring rate can support the rider and bike. If your goal is simply to change the feel of an existing shock, first verify whether its spring can be replaced independently.
Weigh Build Details Against Documentation
Material and finish can matter, but they should follow fit and rate in the decision order. A steel spring may offer a familiar, serviceable replacement, while a lighter spring can appeal to riders managing bike weight; the listing still needs to match the shock. Clear specifications make future maintenance easier because you can identify the installed rate and dimensions. Look for information on spring compatibility, included hardware, and whether the product is sold as one spring or a pair. Generic listings with limited documentation call for more verification, not automatic rejection. I would pay more for a clearly specified option when uncertainty about fit could lead to buying the wrong part.
Frequently Asked Questions
Can I replace a RockShox Metric spring with any spring that has the same rate?
No. The rate is only one part of compatibility. You also need the correct spring length, internal diameter, seat and retainer fit, and enough clearance for the shock’s full stroke. Confirm that the replacement is intended for your exact shock family and check the manufacturer’s fit guidance before ordering. A matching rate with the wrong dimensions can be unusable or unsafe to install.
How do I choose between a fixed-rate RockShox spring and an adjustable Sprindex spring?
A fixed-rate RockShox spring is a straightforward choice when you know the rate your compatible shock needs and want a defined replacement. A Sprindex model makes more sense if you want to tune within its stated range without swapping springs, provided its dimensions and application match your shock. Compare the exact range and stroke designation rather than choosing by brand alone. If your current setup already reaches the desired sag and feel, adjustability may add little practical value.
Are the complete coil shock listings interchangeable with replacement springs?
No. A complete shock includes the shock body and mounting interfaces, while a replacement spring is intended to fit a compatible shock you already own. For a complete unit, confirm eye-to-eye length, stroke, mounting hardware, frame clearance, and frame approval. For a spring alone, confirm the shock model, spring dimensions, and rate. Treating these product types as interchangeable can lead to an incorrect purchase even when both listings mention a coil spring.
Can I use the RockShox BoXXer spring or the 23.6 mm two-pack on a rear shock?
These listings are identified as fork-related options, not general rear-shock springs. A BoXXer spring is associated with a specific suspension fork family, and the two-pack is described as bicycle front-fork springs. Rear shocks use different dimensions and spring seats, so a similar material or coil shape does not establish compatibility. Check your fork model and manufacturer specifications before buying either option, and do not install one on a rear shock unless its maker explicitly lists that fit.
What should I do if I do not know the spring rate currently fitted to my bike?
Look for a rate marking on the installed spring and record the shock model and spring dimensions before removing anything. If there is no readable marking, consult the bike or shock documentation, or ask a suspension shop to identify the spring and recommend a rate based on your setup. Rider weight alone is not enough because frame leverage and desired sag also affect the result. Avoid choosing a rate just because it appears in the middle of this roundup’s range. Confirm the recommendation against your shock’s setup guidance before ordering.
Conclusion
My best overall pick for a defined replacement is the RockShox Metric Coil Spring, 134 mm, 400 lb, for riders whose compatible shock calls for those specifications. For best value in setup flexibility, I would shortlist the appropriate Sprindex model when its adjustment range and dimensions match the bike; its value is the tuning option, not universal fit. The best premium-style choice is the Öhlins Lightweight Steel Coil Spring for buyers with a compatible setup that calls for its stated 502 lb/in rate and 75 mm stroke. For beginners, I recommend starting with the exact spring rate and dimensions specified for the existing shock rather than guessing at a generic complete-shock listing. For specific needs, choose the BoXXer spring or fork-spring pair only for the matching fork, and consider the Buachois, Tongze, Glamorway, or BUCKLOS assemblies only after verifying frame fit and full shock specifications. The safest final choice is the one that matches your suspension hardware and setup requirements—not simply the highest rate or most adjustable label.
