Fox SLS and Steel Spring Rear Shock Fitment

Spring Measurements

Fox springs have two measurements, and for this example we will use 2.8" x 500 lbs.

  • - “2.8"” refers to the maximum free stroke of the spring. Free stroke is the maximum amount a spring can be compressed until the coils touch and create “coil bind” which is very bad. This example spring can be compressed 2.8" before coil bind occurs.
  • - “500 lbs” refers to the spring rate, which is how stiff or soft the spring is.
  • - Springs also have a "TLG" length which just means Total Length. This is physically how long the spring is when uncompressed.


The following must apply for proper spring fitment:
- Each shock has a minimum and maximum TLG that fits, which is shown in the first set of charts below.
- The goal is to find a spring with your desired spring rate and with a TLG that falls within the range of TLG for your shock’s model and size.
- The stroke length of the spring MUST be larger than the stroke length of your shock. If it is not, coil bind will occur and parts will explode.


HOW TO FIND WHICH FOX SPRING FITS YOUR SHOCK

STEP 1
- Find your shock’s model and size in the first group of charts.
- Write down the shortest and longest TLG lengths shown in the chart.
STEP 2
- Scroll down to the model of Fox spring you want.
- Refer to the right side “Commonly Used With” to quickly locate which length most likely applies. Still double check that this size fits your shock!
STEP 3
- Look for the spring rate you want in the chart. Some sizes have the same spring rate twice, so note that.
- Look at that spring’s TLG to see if it fits within the range of your shock that you wrote down.
- If your desired spring rate is listed twice, check each TLG to see which will fit.
STEP 4
- Make sure the spring’s stroke length is larger than your shock’s stroke length.
- For example: If you have a 65mm stroke, convert that to inches which is 2.6”. If a 2.8” spring’s TLG fits, then you are set since 2.8” is larger than 2.6”.
- If you find a TLG that fits, but the shock’s stroke is longer than the spring’s stroke, you may not be able to use a coil shock or need to find a different spring.
STEP 5
- If multiple springs show to fit, choose which one you'd like to use.
- A slightly shorter spring will sit farther down on the preload threads, while the longer option will sit higher on the threads.
- There is no performance advantage either way, and this is just personal preference. A shorter spring will be slightly lighter, but that is all.
STEP 6
- Order the spring that meets all criteria and ride!


Eye-to-eye Stroke Shortest TLG Spring That Fits Longest TLG Spring That Fits

165mm (T)

40-55mm

3.947" / 100.2mm

4.485" / 113.9mm

185mm (T)

47.5-55mm

4.341" / 110.3mm

5.273" / 133.9mm

190mm

40-55mm

3.947" / 100.2mm

4.485" / 113.9mm

205mm (T)

57.5-65mm

4.735" / 120.3mm

6.061" / 153.9mm

210mm

47.5-55mm

4.341" / 110.3mm

5.273" / 133.9mm

225mm (T)

67.5-75mm

5.128" / 130.3mm

6.848" / 173.9mm

230mm

57.5-65mm

4.735" / 120.3mm

6.061" / 153.9mm

250mm

67.5-75mm

5.128" / 130.3mm

6.848" / 173.9mm

Eye-to-eye Stroke Shortest TLG Spring That Fits Longest TLG Spring That Fits

7.5 in

2 in

4.32" / 109.7mm

4.83" / 122.7mm

7.875 in

2 in

4.32" / 109.7mm

5.21" / 132.3mm

8.5 in

2.5 in

4.82" / 122.4mm

5.83" / 148.1mm

9.5 in

3 in

5.32" / 135.1mm

6.84" / 173.7mm

10.5 in

3.5 in

5.82" / 147.8mm

7.83" / 198.9mm

185mm (T)

47.5-55mm

4.48" / 113.8mm

5.30" / 134.6mm

210mm

47.5-55mm

4.49" / 114.0mm

5.60" / 142.2mm

205mm (T)

57.5-65mm

4.88" / 123.9mm

6.09" / 154.7mm

230mm

57.5-65mm

4.88" / 123.9mm

6.39" / 162.3mm

225mm (T)

67.5-75mm

5.27" / 133.8mm

6.88" / 174.7mm

250mm

67.5-75mm

5.28" / 134.1mm

7.18" / 182.4mm

Eye-to-eye Stroke Shortest TLG Spring That Fits Longest TLG Spring That Fits

7.5 in

2 in

4.05" / 102.9mm

5.15" / 130.8mm

7.875 in

2 in

4.05" / 102.9mm

5.53" / 140.5mm

7.875 in

2.5 in

4.30" / 109.2mm

5.53" / 140.5mm

8.5 in

2.5 in

4.55" / 115.6mm

6.1" / 156.2mm

8.75 in

2.75 in

4.80" / 121.9mm

6.40" /162.6mm

9.5 in

3 in

5.05" / 128.3

7.15 in/181.6mm

10.5 in

3.5 in

5.55" / 141.0mm

8.15" / 207.0mm

185mm (T)

47.5-55mm

4.21" / 106.9mm

5.19" / 131.8mm

210mm

47.5-55mm

4.43" / 112.5mm

5.92" / 150.4mm

205mm (T)

57.5-65mm

5.00" / 127.00mm

5.97" / 151.6mm

230mm

57.5-65mm

5.22" / 132.6mm

6.71" / 170.4mm

225mm (T)

67.5-75mm

5.78" / 146.8mm

6.76" / 171.7mm

250mm

67.5-75mm

6.00" / 152.4mm

7.50" / 190.5mm


2.4"/61mm Travel (1.385in ID)

Part # Description (Old Part #)

803-04-177

2.4" x 300 lb - 4.28" TLG

033-22-000

803-04-178

2.4" x 325 lb - 4.41" TLG

033-22-001

803-04-179

2.4" x 350 lb - 4.38" TLG

033-22-002

803-04-186

2.4" x 375 lb - 4.52" TLG

033-22-003

803-04-187

2.4" x 400 lb - 4.6" TLG

033-22-004

803-04-188

2.4" x 425 lb - 4.54" TLG

033-22-005

803-04-189

2.4" x 450 lb - 4.74" TLG

033-22-006

803-04-190

2.4" x 475 lb - 4.68" TLG

033-22-007

803-04-191

2.4" x 500 lb - 4.67" TLG

033-22-008

803-04-192

2.4" x 550 lb - 4.91" TLG

033-22-009

803-04-193

2.4" x 600 lb - 4.97" TLG

033-22-010

803-04-184

2.4" x 650 lb - 4.97" TLG

033-22-011

803-04-185

2.4" x 700 lb - 4.97" TLG

033-22-012

Commonly used with:
- 7.875" x 2.25"

- 185mm(T) x 50mm
- 185mm(T) x 52.5mm
- 185mm(T) x 55mm
- 210mm x 50mm
- 210mm x 52.5mm
- 210mm x 55mm
- 230mm x 57.5mm

Still double check that the spring fits if your shock size is listed here!


2.65"/67mm Travel (1.385in ID)

Part # Description (Old Part #)

803-04-194

2.65" x 250 lb - 4.69" TLG

033-22-013

803-04-195

2.65" x 275 lb - 4.63" TLG

033-22-014

803-04-196

2.65" x 300 lb - 4.74" TLG

033-22-015

803-04-197

2.65" x 325 lb - 4.71" TLG

033-22-016

803-04-198

2.65" x 350 lb - 4.85" TLG

033-22-017

803-04-199

2.65" x 375 lb - 4.97" TLG

033-22-018

803-04-200

2.65" x 400 lb - 5.14" TLG

033-22-019

803-04-201

2.65" x 425 lb - 5.08" TLG

033-22-020

803-04-202

2.65" x 450 lb - 5.11" TLG

033-22-021

803-04-203

2.65" x 475 lb - 5.23" TLG

033-22-022

803-04-204

2.65" x 500 lb - 5.32" TLG

033-22-023

803-04-205

2.65" x 550 lb - 5.38" TLG

033-22-024

803-04-206

2.65" x 600 lb - 5.47" TLG

033-22-025

803-04-207

2.65" x 650 lb - 5.60" TLG

033-22-026

803-04-208

2.65" x 700 lb - 5.61" TLG

033-22-027

Commonly used with:
- 8.50" x 2.50"

- 205mm(T) x 60mm
- 205mm(T) x 62.5mm
- 205mm(T) x 65mm
- 230mm x 60mm
- 230mm x 62.5mm
- 230mm x 65mm

Still double check that the spring fits if your shock size is listed here!


2.90"/74mm Travel (1.385in ID)

Part # Description (Old Part #)

803-04-210

2.9" x 300 lb - 5.36" TLG

033-22-028

803-04-211

2.9" x 325 lb - 5.24" TLG

033-22-029

803-04-212

2.9" x 350 lb - 5.33" TLG

033-22-030

803-04-213

2.9" x 350 lb - 5.54" TLG

033-22-031

803-04-214

2.9" x 400 lb - 5.54" TLG

033-22-032

803-04-215

2.9" x 425 lb - 5.64" TLG

033-22-033

803-04-216

2.9" x 450 lb - 5.80" TLG

033-22-034

803-04-217

2.9" x 475 lb - 5.85" TLG

033-22-035

803-04-218

2.9" x 500 lb - 5.83" TLG

033-22-036

803-04-219

2.9" x 550 lb - 5.85" TLG

033-22-037

803-04-220

2.9" x 600 lb - 5.85" TLG

033-22-038

Commonly used with:
- 8.75" x 2.75"

- 225mm(T) x 70mm
- 250mm x 70mm

Still double check that the spring fits if your shock size is listed here!


3.15"/80mm Travel (1.385in ID)

Part # Description (Old Part #)

803-04-221

3.15" x 225 lb - 5.39" TLG

033-22-040

803-04-222

3.15" x 250 lb - 5.54" TLG

033-22-041

803-04-223

3.15" x 275 lb - 5.46" TLG

033-22-042

803-04-224

3.15" x 300 lb - 5.61" TLG

033-22-043

803-04-225

3.15" x 325 lb - 5.7" TLG

033-22-044

803-04-226

3.15" x 350 lb - 5.94" TLG

033-22-045

803-04-227

3.15" x 375 lb - 5.92" TLG

033-22-046

803-04-228

3.15" x 400 lb - 6.04" TLG

033-22-047

803-04-229

3.15" x 425 lb - 6.16" TLG

033-22-048

803-04-230

3.15" x 450 lb - 6.28" TLG

033-22-049

803-04-231

3.15" x 475 lb - 6.41" TLG

033-22-050

803-04-232

3.15" x 500 lb - 6.33" TLG

033-22-051

803-04-233

3.15" x 525 lb - 6.60" TLG

033-22-063

803-04-234

3.15" x 550 lb - 6.52" TLG

033-22-052

803-04-235

3.15" x 575 lb - 6.60" TLG

033-22-064

Commonly used with:
- 9.5" x 3.00"
- 225mm(T) x 72.5mm
- 225mm(T) x 75mm
- 250mm x 72.5mm
- 250mm x 75mm

Still double check that the spring fits if your shock size is listed here!


3.65"/93mm Travel (1.385in ID)

Part # Description (Old Part #)

803-04-236

3.65" x 225 lb - 6.26" TLG

033-22-053

803-04-237

3.65" x 250 lb - 6.42" TLG

033-22-054

803-04-238

3.65" x 275 lb - 6.49" TLG

033-22-055

803-04-239

3.65" x 300 lb - 6.75" TLG

033-22-056

803-04-240

3.65" x 325 lb - 6.72" TLG

033-22-057

803-04-241

3.65" x 350 lb - 6.83" TLG

033-22-058

803-04-242

3.65" x 375 lb - 6.93" TLG

033-22-059

803-04-243

3.65" x 400 lb - 7.08" TLG

033-22-060

803-04-244

3.65" x 425 lb - 7.22" TLG

033-22-061

803-04-245

3.65" x 450 lb - 7.51" TLG

033-22-062

Commonly used with:
- 10.5" x 3.5"

Still double check that the spring fits if your shock size is listed here!

2.3"/58mm - 2.5"/65mm Travel (1.385in ID)

Part # Description (Old Part #)

803-04-130

2.5" x 250 lb - 4.285" TLG

039-03-011

803-04-131

2.5" x 300 lb - 4.344" TLG

039-03-012

803--04-132

2.45" x 350 lb - 4.990" TLG

039-12-011

803-04-133

2.45" x 400 lb - 4.675" TLG

039-03-014

803-04-134

2.37" x 450 lb - 4.723" TLG

039-03-015

803-04-135

2.35" x 500 lb - 4.733" TLG

039-03-016

803-04-136

2.35" x 550 lb - 4.776" TLG

039-03-017

803-04-137

2.35" x 600 lb - 4.830" TLG

039-03-018

803-04-138

2.30" x 650 lb - 4.954" TLG

039-03-019

803-04-139

2.30" x 700 lb - 5.200" TLG

039-03-100

803-04-140

2.55" x 700 lb - 5.701" TLG

039-03-009

803-04-141

2.30" x 800 lb - 5.280" TLG

039-03-101

Commonly used with:
- 7.875" x 2.25"
- 185mm(T) x 50mm
- 185mm(T) x 52.5mm
- 185mm(T) x 55mm
- 210mm x 50mm
- 210mm x 52.5mm
- 210mm x 55mm

Still double check that the spring fits if your shock size is listed here!


2.8"/71mm Travel (1.385in ID)

Part # Description (Old Part #)

803-04-142

2.8" x 250 lb - 4.924" TLG

039-03-022

803-04-143

2.8" x 350 lb - 5.799" TLG

039-03-001

803-04-144

2.8" x 400 lb - 5.459" TLG

039-03-002

803-04-145

2.8" x 450 lb - 5.409" TLG

039-03-003

803-04-146

2.8" x 500 lb - 5.728" TLG

039-03-004

803-04-147

2.8" x 550 lb - 5.949" TLG

039-03-005

803-04-148

2.8" x 550 lb - 5.750" TLG

039-00-600

803-04-149

2.8" x 600 lb - 6.382" TLG

039-03-007

803-04-150

2.8" x 600 lb - 5.750" TLG

039-00-601

803-04-151

2.8" x 650 lb - 6.150" TLG

039-03-008

803-04-152

2.8" x 700 lb - 6.402" TLG

039-03-010

Commonly used with:
- 8.5" x 2.5"
- 205mm(T) x 60mm
- 205mm(T) x 62.5mm
- 205mm(T) x 65mm
- 230mm x 57.5mm
- 230mm x 60mm
- 230mm x 62.5mm
- 230mm x 65mm

Still double check that the spring fits if your shock size is listed here!


3.19"/81mm - 3.25"/83mm Travel (1.385in ID)

Part # Description (Old Part #)

803-04-153

3.25" x 250 lb - 6.468" TLG

039-09-010

803-04-154

3.24" x 300 lb - 6.126" TLG

039-03-000

803-04-155

3.25" x 300 lb - 6.476" TLG

039-09-000

803-04-156

3.25" x 350 lb - 6.689" TLG

039-09-001

803-04-157

3.25" x 400 lb - 6.634" TLG

039-09-002

803-04-158

3.25" x 450 lb - 6.760" TLG

03909-003

803-04-159

3.15" x 500 lb - 6.600" TLG

039-00-603

803-04-160

3.25" x 500 lb - 6.909" TLG

039-09-004

803-04-161

3.15" x 550 lb - 6.400" TLG

039-00-604

803-04-162

3.25" x 550 lb - 6.929" TLG

039-09-005

803-04-163

3.25" x 600 lb - 7.114" TLG

039-09-006

803-04-164

3.19" x 650 lb - 6.815" TLG

039-09-007

803-04-165

3.19" x 700 lb - 7.130" TLG

039-09-008

Commonly used with:
- 8.75" x 2.75"
- 9.5" x 3.0"
- 225mm(T) x 70mm
- 225mm(T) x 72.5mm
- 225mm(T) x 75mm
- 250mm x 70mm
- 250mm x 72.5mm
- 250mm x 75mm

Still double check that the spring fits if your shock size is listed here!


3.64"/92mm - 3.85"/98mm Travel (1.385in ID)

Part # Description (Old Part #)

803-04-166

3.85" x 150 lb - 6.800" TLG

039-12-000

803-04-167

3.80" x 200 lb - 7.000" TLG

039-12-001

803-04-168

3.80" x 225 lb - 7.000" TLG

039-12-008

803-04-169

3.75" x 250 lb - 7.200" TLG

039-12-002

803-04-170

3.75" x 275 lb - 7.500" TLG

039-12-009

803-04-171

3.70" x 300 lb - 7.750" TLG

039-12-003

803-04-172

3.70" x 325 lb - 7.755" TLG

039-12-010

803-04-173

3.70" x 350 lb - 7.750" TLG

039-12-004

803-04-174

3.65" x 400 lb - 7.750" TLG

039-12-005

803-04-175

3.65" x 450 lb - 8.100" TLG

039-12-006

803-04-176

3.64" x 500 lb - 8.250" TLG

039-12-007

Commonly used with:
- 10.5" x 3.5"

Still double check that the spring fits if your shock size is listed here!


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