Coil Shocks Rule, Except…

Coil Shocks Rule, Except…

Most people ride the wrong spring rate. If too stiff, they don't get full travel, have poor small bump absorption, and diminished traction. If too soft, they bottom out on bigger hits and damage themselves or worse yet their bike.

Problem 1: The right spring rate depends on more than the rider's weight. It's also about the bike, the sort of trails the rider rides, the weight of the stuff the rider brings along, and riding style.

Problem 2: Springs only come in big intervals...typically every 25 or 50 lb/in. Let's say you know your current 450 lb/in coil is too stiff because you know you're not getting full travel during a ride. What spring rate should you buy next? If you buy a 400, you might find it's still too stiff. If you buy a 350, you might bottom out. So you end up having bought 2 springs and the best you can do is ride the 400, which is still too stiff.

Problem 3: The ideal spring rate for a rider is different depending on the trail. A trail with big drops would require a stiffer spring rate than one with smaller drops. If your spring rate is right for the first trail, it's wrong for the second. Some riders actually switch out their coils for certain rides or races to try to solve this, but this is a big hassle and the spring rate change is big.

Problem 4: Many shock springs have spring rates dramatically different from claims. The problem is so significant, that sometimes a "weaker" spring is stronger than a "stronger" spring. For example, we have measured (major brand) claimed "400" springs that are actually 375 lb/in and claimed "350" springs that are actually 380 lb/in.

Problem 5 Spring rate is NOT the same thing as preload. They are unrelated. Preloading a spring that is too soft might correct the sag amount, but would not compensate for shock travel or prevent bottom-out. Preloading causes the coil to partially compressed, which requires a higher initial force to start coil movement but very little affect on force at full stroke. Preload does not increase spring rate. Too much preload causes:

  1. poor small bump absorption resulting in a harsh ride and poor traction.
  2. poor solution to a coil bottoming out because preload will still be small compared to the load at full travel.
  3. increased stress reduces coil life.
  4. sometimes reduces full shock travel.

Solution: Sprindex. Our system allows you to easily adjust your spring rate by hand and without tools. Sprindex spring rates can be adjusted through a range of 30 to 60 lb/in, depending on the coil model. Spring rate can be adjusted to any rate between the min and max, and there's a gauge that shows you your adjusted spring rate. Also, it is important to us that our spring rates are accurate.

How does Sprindex adjust spring rate? Sprindex works by altering the number of active coils available for deflection. The spring's active coils are the coils that can flex as the spring is compressed. Fewer active coils makes for a stiffer spring and vice versa. Think of it like this: the less wire there is to bend, the stiffer the spring. The spring rate of a spring is the amount of force it takes to deflect the spring a certain distance (typically pounds per inch or Newtons per mm). Spring rate is a function of 4 characteristics: wire diameter, coil diameter, material, and number of active coils.




Sprindex is compatible with a wide variety of shocks.

There are three different Sprindex lengths and strokes available, and each Sprindex coil can be adjusted through a certain spring rate range. Be sure to use the correct included adapter as described. Make sure that the spring length fits on your shock and that your maximum shock travel is not more than the specified Sprindex coil travel.

IF YOUR SHOCK IS NOT LISTED IN THE BELOW COMPATIBILITY TABLE:

Determine what your shock's stroke is and then compare that to the available Sprindex coils. Sometimes, you can find the stroke specification on the website of your bike brand for your bike model. The stroke printed on your existing coil is a clue, but it might have more stroke than your shock actually needs. Or, just measure the stroke per the picture above. Ideally, choose the Sprindex coil that has at least the amount of stroke that your shock requires, and then measure whether that Sprindex coil overall length can fit between your shock's flanges. The Sprindex coil lengths are listed in the below compatibility table. Note that most shocks can only achieve about 5mm less than their listed stroke because the bottom-out bumper can only be compressed so far, so in most cases it is okay if the Sprindex coil has up to about 3mm less stroke than your shock's stroke rating.

Find your shock on the below table and note which Sprindex family you need.

Shock Brand/Model

Regular or Trunnion

Shock eye to eye

Stroke

Metric / English

Sprindex spring family (stroke x length)

Fox DHX2

230 mm

60 mm

metric

65 x142

Fox DHX2

230 mm

65 mm

metric

65 x 142

Fox DHX2

Trunnion

205mm

60mm

metric

65 x 142

Fox DHX2

Trunnion

205mm

65mm

metric

65 x 142

Fox DHX2

8.5 inch

2.5 inch

English

65 x 142

Fox DHX2

8.75 inch

2.75 inch

English

65 x 142

Fox DHX2

7.875 inch

2.0 inch

English

55 x 126

Fox DHX2

7.875 inch

2.25 inch

English

55 x 126

Fox DHX2

210 mm

50mm

metric

55 x 126

Fox DHX2

210 mm

52mm

metric

55 x 126

Fox DHX2

210 mm

55mm

metric

55 x 126

Fox DHX2

Trunnion

185mm

55mm

metric

55 x 126

Fox DHX2

9.5 inch

3 inch

English

75 x 162

Fox DHX2

Fox DHX2

Trunnion

250mm

225mm

75mm

75mm

metric

metric

75 x 162

75 x 162

Shock Brand/Model

Regular or Trunnion

Shock eye to eye

Stroke

Metric / English

Sprindex spring family (stroke x length)

MRP Hazzard

230 mm

65 mm

metric

65 x 142

MRP Hazzard

230 mm

60 mm

metric

65 x 142

MRP Hazzard

230 mm

57.5 mm

metric

65 x 142

MRP Hazzard

Trunnion

205 mm

65 mm

metric

65 x 142

MRP Hazzard

Trunnion

205 mm

60 mm

metric

65 x 142

MRP Hazzard

Trunnion

205 mm

57.5 mm

metric

65 x 142

MRP Hazzard

200mm

51mm

metric

55 x 126

MRP Hazzard

200mm

57mm

metric

55 x 126

MRP Hazzard

210mm

50mm

metric

55 x 126

MRP Hazzard

210mm

55mm

metric

55 x 126

MRP Hazzard

9.5 inch

3 inch

English

55 x 126

Shock Brand/Model

Regular or Trunnion

Shock eye to eye

Stroke

Metric / English

Sprindex spring family (stroke x length)

Marzocchi 2019 Bomber CR

230 mm

60 mm

metric

65 x 142

Marzocchi 2019 Bomber CR

230 mm

65 mm

metric

65 x 142

Marzocchi 2019 Bomber CR

Trunnion

205 mm

60 mm

metric

65 x 142

Marzocchi 2019 Bomber CR

Trunnion

205 mm

65 mm

metric

65 x 142

Marzocchi 2019 Bomber CR

7.875 inch

2.0 inch

English

55 x 126

Marzocchi 2019 Bomber CR

7.875 inch

2.25 inch

English

55 x 126

Marzocchi 2019 Bomber CR

210mm

50mm

metric

55 x 126

Marzocchi 2019 Bomber CR

210mm

55mm

metric

55 x 126

Marzocchi 2019 Bomber CR

Trunnion

185mm

52.5mm

metric

55 x 126

Marzocchi 2019 Bomber CR

Trunnion

185mm

55

metric

55 x 126

Marzocchi 2019 Bomber CR

250mm

75mm

metric

75 x 162

Shock Brand/Model

Regular or Trunnion

Shock eye to eye

Stroke

Metric / English

Sprindex spring family (stroke x length)

DVO Jade Coil

230 mm

65 mm

metric

65 x 142

DVO Jade Coil

230 mm

62.5 mm

metric

65 x 142

DVO Jade Coil

230 mm

60 mm

metric

65 x 142

DVO Jade Coil

230 mm

57.5 mm

metric

65 x 142

DVO Jade Coil

Trunnion

205 mm

65 mm

metric

65 x 142

DVO Jade Coil

Trunnion

205 mm

62.5 mm

metric

65 x 142

DVO Jade Coil

Trunnion

205 mm

60 mm

metric

65 x 142

DVO Jade Coil

Trunnion

205 mm

57.5 mm

metric

65 x 142

DVO Jade Coil

210mm

50mm

metric

55 x 126

DVO Jade Coil

210mm

52.5mm

metric

55 x 126

DVO Jade Coil

210mm

55mm

metric

55 x 126

DVO Jade Coil

Trunnion

185

50

metric

55 x 126

DVO Jade Coil

Trunnion

185

52.5

metric

55 x 126

DVO Jade Coil

Trunnion

185

55

metric

55 x 126

DVO Jade Coil

250 mm

70 mm

metric

75 x 160

DVO Jade Coil

250 mm

75 mm

metric

75 x 162

DVO Jade Coil

Trunnion

225mm

70mm

metric

75 x 162

DVO Jade Coil

Trunnion

225mm

75mm

metric

75 x 162

Shock Brand/Model

Regular or Trunnion

Shock eye to eye

Stroke

Metric / English

Sprindex spring family (stroke x length)

X-Fusion Vector Coil HLR

222 mm /8.75 in

69 mm

Metric/English

65 x 142

X-Fusion Vector Coil HLR

200mm

57mm

metric

55 x 126

X-Fusion Vector Coil HLR

240mm

76mm

metric

75 x 160

Shock Brand/Model

Regular or Trunnion

Shock eye to eye

Stroke

Metric / English

Sprindex spring family (length x stroke)

Cane Creek DB coil CS

222 mm

63 mm

Metric

65 x 142

Cane Creek DB coil CS

222 mm

66 mm

Metric

65 x 142

Cane Creek DB coil CS

Trunnion

205mm

57.5mm

Metric

65 x 142

Cane Creek DB coil CS

Trunnion

205mm

60mm

Metric

65 x 142

Cane Creek DB coil CS

Trunnion

205mm

65mm

Metric

65 x 142

Cane Creek DB coil CS

230mm

57.5mm

Metric

65 x 142

Cane Creek DB coil CS

230mm

60mm

Metric

65 x 142

Cane Creek DB coil CS

230mm

65mm

Metric

65 x 142

Cane Creek DB coil CS

210mm

50mm

metric

55 x 126

Cane Creek DB coil CS

210mm

52.5mm

metric

55 x 126

Cane Creek DB coil CS

210mm

55mm

metric

55 x 126

Cane Creek DB coil CS

200mm

50mm

metric

55 x 126

Cane Creek DB coil CS

200mm

57mm

metric

55 x 126

Cane Creek DB coil CS

Trunnion

185mm

50mm

metric

55 x 126

Cane Creek DB coil CS

Trunnion

185mm

52.5mm

metric

55 x 126

Cane Creek DB coil CS

Trunnion

185mm

55mm

metric

55 x 126

Cane Creek DB coil CS

250mm

70mm

metric

75 x 162

Cane Creek DB coil CS

250mm

75mm

metric

75 x 162

Cane Creek DB coil CS

Trunnion

225mm

70mm

metric

75 x 162

Cane Creek DB coil CS

Trunnion

225mm

75mm

metric

75 x 162

Cane Creek DB coil IL

210mm

50mm

metric

55 x 126

Cane Creek DB coil IL

210mm

52.5mm

metric

55 x 126

Cane Creek DB coil IL

210mm

55mm

metric

55 x 126

Cane Creek DB coil IL

200mm

50mm

metric

55 x 126

Cane Creek DB coil IL

200mm

57mm

metric

55 x 126

Marzocchi before 2018, some models

65 x 142

Shock Brand/Model

Regular or Trunnion

Shock eye to eye

Stroke

Metric / English

Sprindex spring family (length x stroke)

Ohlins TTX22 coil

230mm

57.5mm

Metric

65 x 142

Ohlins TTX22 coil

230mm

60mm

Metric

65 x 142

Ohlins TTX22 coil

230mm

65mm

Metric

65 x 142

Ohlins TTX22 coil

Trunnion

205mm

65mm

Metric

65 x 142

Ohlins TTX22 coil

210mm

50mm

metric

55 x 126

Ohlins TTX22 coil

Trunnion

185mm

55mm

metric

55 x 126

Ohlins TTX22 coil

7.87 inch

2.0 inch

English

55 x 126

Ohlins TTX22 coil

7.87 inch

2.25 inch

English

55 x 126

Ohlins TTX22 coil

9.5 inch

3.0 inch

English

75 x 162

Ohlins TTX22 coil

Trunnion

225mm

70mm

metric

75 x 162

Ohlins TTX22 coil

Trunnion

225mm

75mm

metric

75 x 162

Shock Brand/Model

Regular or Trunnion

Shock eye to eye

Stroke

Metric / English

Sprindex spring family (stroke x length)

Rockshox Super Deluxe Coil RCT

230mm

60mm

metric

65 x 142

Rockshox Super Deluxe Coil RCT

230mm

65mm

metric

65 x 142

Rockshox Super Deluxe Coil RC World Cup

230mm

60mm

metric

65 x 142

Rockshox Super Deluxe Coil RT Remote

230mm

60mm

metric

65 x 142

Rockshox Super Deluxe Coil RT Remote

230mm

65mm

metric

65 x 142

Rockshox Super Deluxe Coil R

230mm

60mm

metric

65 x 142

Rockshox Super Deluxe Coil R

230mm

65mm

metric

65 x 142

Rockshox Super Deluxe Coil RCT

Trunnion

205mm

57.5mm

metric

65 x 142

Rockshox Super Deluxe Coil RCT

Trunnion

205mm

60mm

metric

65 x 142

Rockshox Super Deluxe Coil RCT

Trunnion

205mm

65mm

metric

65 x 142

Rockshox Super Deluxe Coil RCT

210mm

55mm

metric

55 x 126

Rockshox Super Deluxe Coil RT Remote

200mm

57mm

metric

55 x 126

Rockshox Super Deluxe Coil RC World Cup

250mm

75mm

metric

75 x 162

Rockshox Super Deluxe RC

Trunnion

225mm

70mm

metric

75 x 162

Rockshox Super Deluxe RC

Trunnion

225mm

75mm

metric

75 x 162

Shock Brand/Model

Regular or Trunnion

Shock eye to eye

Stroke

Metric / English

Sprindex spring family (stroke x length)

Rockshox Vivid

200

57

55 x 126

Rockshox Vivid

216

63

65 x 142

Rockshox Vivid

222

70

65 x 142

Rockshox Vivid

240

76

75 x 162

Push

2.25 inch

English

55 x 126

Push

2.5 inch

English

65 x 142

Extreme Racing

EXT STORIA LOK V3

200

57

English

55 x 126

EXT STORIA LOK V3

217

63.5

English

65 x 142

EXT STORIA LOK V3

222

67

English

65 x 142

EXT STORIA LOK V3

210

50

Metric

55 x 126

EXT STORIA LOK V3

210

52.5

Metric

55 x 126

EXT STORIA LOK V3

210

55

Metric

55 x 126

EXT STORIA LOK V3

230

57.5

Metric

65 x 142

EXT STORIA LOK V3

230

60

Metric

65 x 142

EXT STORIA LOK V3

230

62.5

Metric

65 x 142

EXT STORIA LOK V3

230

65

Metric

65 x 142

EXT STORIA LOK V3

250

67.5

Metric

75 x 162

EXT STORIA LOK V3

250

70

Metric

75 x 162

EXT STORIA LOK V3

250

72.5

Metric

75 x 162

EXT STORIA LOK V3

250

75

Metric

75 x 162

EXT STORIA LOK V3

Trunnion

185

50

Metric

55 x 126

EXT STORIA LOK V3

Trunnion

185

52.5

Metric

55 x 126

EXT STORIA LOK V3

Trunnion

185

55

Metric

55 x 126

EXT STORIA LOK V3

Trunnion

205

57.5

Metric

65 x 142

EXT STORIA LOK V3

Trunnion

205

60

Metric

65 x 142

EXT STORIA LOK V3

Trunnion

205

62.5

Metric

65 x 142

EXT STORIA LOK V3

Trunnion

205

65

Metric

65 x 142

EXT STORIA LOK V3

Trunnion

225

67.5

Metric

75 x 162

EXT STORIA LOK V3

Trunnion

225

70

Metric

75 x 162

EXT STORIA LOK V3

Trunnion

225

72.5

Metric

75 x 162

EXT STORIA LOK V3

Trunnion

225

75

Metric

75 x 162

EXT STORIA LOK

200

57

English

55 x 126

EXT STORIA LOK

217

63.5

English

65 x 142

EXT STORIA LOK

210

50

Metric

55 x 126

EXT STORIA LOK

210

55

Metric

55 x 126

EXT STORIA LOK

230

60

Metric

65 x 142

EXT STORIA LOK

230

65

Metric

65 x 142

DH Racing:

EXT ARMA HBC V3

222

67

Metric

65 x 142

EXT ARMA HBC V3

241

74

Metric

75 x 162

EXT ARMA HBC V3

230

57.5

Metric

65 x 142

EXT ARMA HBC V3

230

60

Metric

65 x 142

EXT ARMA HBC V3

230

62.5

Metric

65 x 142

EXT ARMA HBC V3

230

65

Metric

65 x 142

EXT ARMA HBC V3

250

70

Metric

75 x 162

EXT ARMA HBC V3

250

72.5

Metric

75 x 162

EXT ARMA HBC V3

250

75

Metric

75 x 162

EXT ARMA HBC V3

Trunnion

205

57.5

Metric

65 x 142

EXT ARMA HBC V3

Trunnion

205

60

Metric

65 x 142

EXT ARMA HBC V3

Trunnion

205

62.5

Metric

65 x 142

EXT ARMA HBC V3

Trunnion

205

65

Metric

65 x 142

EXT ARMA HBC V3

Trunnion

225

70

Metric

75 x 162

EXT ARMA HBC V3

Trunnion

225

72.5

Metric

75 x 162

EXT ARMA HBC V3

Trunnion

225

75

Metric

75 x 162

EXT ARMA HBC

222

70

Metric

75 x 162

EXT ARMA HBC

241

76

Metric

75 x 162


PERFORMANCE ADAPTERS

Performance Adapters are included. Sprindex coils fit a wide variety of shocks, but you must use the Performance Adapter for most of them. Our Performance Adapters both improve the fit between the coil and your shock and are made of low friction Delrin to improve shock performance by allowing the spring to twist during high deflection. See bottom of Performance Adapter for direction of which adapter you should use. For Rockshox, no adapter is necessary but we recommend you use the Performance Washer Adapter for shock performance.

COIL DIRECTION

The Sprindex coil can be installed in either direction and should be installed in the direction that provides the best adjusting access. If your entire shock has good access, then install the Sprindex with the Dial away from the piggyback for easiest hand access.

ADJUSTING SPRING RATE

To adjust the spring rate, hold the coil with one hand and twist the Dial with your other hand or vice versa. The spring rate value is identified by the printed number on the coil displayed through the Dial opening. Preload is not a substitute for a spring that is too weak.

Metric Spring Rate Conversion

Spring rate is shown in pounds per inch (lb/in) on Sprindex coils. Below is a conversion from lb/in to N/mm.

Lb/in

350

360

370

380

390

400

410

420

430

440

450

N/mm

61

63

65

67

68

70

72

74

75

77

79

Lb/in

460

470

480

490

500

510

520

530

540

550

560

N/mm

81

82

84

86

88

89

91

93

95

96

98