Chainrings

 

PCD Explained

PCD = Pitch Circle Diameter. It's the diameter of the circle that the chainwheel bolts are on.

It's also commonly called the Pin Circle Diameter (as in chainwheel pin, as it fits the abbreviation).

Also known as BCD (Bolt Circle Diameter)

If you get a chainring with the wrong PCD, it won't fit.

As well as different PCDs, chanwheels can use 4 bolts (mountain bikes) or 5 bolts (most road bikes).

This table lists the common PCDs, with rough conversions to a bolt-to-bolt measurement to make it easy to work out what PCD you're dealing with.

PCD

 Bolt to Bolt

 Comments

 64mm (4-bolt)  45mm  Current standard MTB inner chainring
 74mm (5-bolt)  43mm  Old triple crankset inner ring
 80mm (4-bolt)    This is used by SRAM/Truvativ on some of their double MTB cranksets (inner chainring)

 94mm

(4-bolt)

   Used on some SRAM cranks/chainrings.
 94mm (5-bolt)  55mm  Short-lived triple middle & outer. 8-speed Deore LX (also in 110mm)
 104mm (4-bolt)  74mm

 Current standard MTB middle and outer ring. An important variable within this standard is the inner diameter of the chainring (the support-ramp diameter of the spider). This is either 88mm or 90mm and both diameters can appear on the same crankset (different for middle or outer ring). This applies to Shimano, SRAM/Truvativ and RaceFace cranksets. Very difficult to predict - you'll just have to measure, even though this is difficult for the middle chainring.

Some middle chainrings from Shimano are made of carbon fibre and steel and as the carbon gives them great rigidity they don't use a support ramp on the spider, so the inner diameter of these is not important (though it measures up at about 82mm).

 110mm (5-bolt)  65mm  Shimano compact road and Campagnolo compact road. Also was used on old MTB cranksets before the 104mm standard took over.
 120mm (4-bolt)    This is used by SRAM/Truvativ on some of their single and double MTB cranksets (outer chainring)
 130mm (5-bolt)  76mm  Shimano road but the 110mm standard is taking over. Minimum chainring size of 39T.
 135mm (5-bolt)  79mm  Campagnolo Road
 144mm (5-bolt)  84mm  Old Campagnolo Road and (if I'm not mistaken) current Campagnolo Track.

 

 

Chainring Inner Diameters

There is a variable in mountain chainrings apart from number of teeth, bolt circle diameter, number of gears and (sometimes relevant) brand. The inner edge of the chainring will be either 88mm or 90mm in diameter (matches the support ramp diameter of the crankset). This is easily measured when the chainring is off the crank, and is also easily measured for the outer chainring while the ring is still on the crank. But be aware that Shimano did at one stage make a crankset that had one ramp diameter for the outer chainring and another for the middle chainring. So, to ensure compatibility, measure carefully.

 Crank Model  Middle Chainring  Outer Chainring
 Raceface  90mm  88mm
 Shimano FC-M410  88mm  
 Shimano FC-M510  90mm  
 Shimano FC-M572  90mm  
 Shimano FC-M582  88mm  
 Shimano FC-M760  88mm  88mm
 SRAM X-5 Triple  90mm  
 SRAM X-O Triple  90mm  
     

 

 

Chainwheel Screws BMX (Set 5)

2664
!
Set of 5 chainwheel screws, suitable for BMX race bikes or for single chainring setups on other bikes.

Weight: 19g.

FSA Chainring 36T 5 Arm 110mm

1699
!
  • Teeth: 36
  • Position: Inner (double) or middle on some older triples
  • Speeds: 7/8/9/10
  • Bolt Count: 5
  • PCD: 110mm
  • Support Ramp Diameter: n/a
  • Material: Precision CNC machined AL7075/T6, anodized black.
  • Weight: 41g
  • Compatibility: Compact road inner (FSA / Shimano / Campagnolo ) and some old 5-arm triple MTB cranksets such as Shimano Deore
  • Notes: We stock this to suit older 5-arm triple cranksets as the original chainrings are no longer available.

RaceFace Narrow/Wide Chainring 32T Blue

2061
!
  • Teeth: 32
  • Position: Single chainring
  • Speeds: 9/10/11
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter: 90mm
  • Material: Machined from 7075-T6 aluminium, aerospace grade strength
  • Weight:  37g
  • Compatibility: Single chainring drivetrains only
  • Notes:
    • The narrow/wide tooth profile helps the chain stay on without the need for a chain-retention device.
    • Burly enough for DH racers and dirt jumpers, but light enough for XC / single-speed riders.
    • Stiff 4mm plate thickness and I-Beam construction transfers loads without flexing.

Shimano FC-3403 9-Speed Chainring 39T

1076
!
  • Teeth: 39
  • Position: Middle (triple)
  • Speeds: 7/8/9
  • Bolt Count: 5
  • PCD: 110mm
  • Support Ramp Diameter:
  • Quality Level: Sora
  • Material: Steel
  • Weight:  104g
  • Compatibility: Road triple (Shimano / Campagnolo)
  • Shimano Part Number: Y1H998010

Shimano FC-6700 10-Speed Chainring 39T

1005
!
  • Teeth: 39
  • Position: Inner (road double)
  • Speeds: 8/9/10
  • Bolt Count: 5
  • PCD: 130mm
  • Support Ramp Diameter:
  • Quality Level: Ultegra
  • Material: Aluminium
  • Weight: 35g
  • Compatibility: Road Inner (non-compact)
  • Shimano Part Number: Y1LJ39000

Shimano FC-M361 8-Speed Chainring 32T

90589
!
  • Teeth: 32
  • Position: Middle (triple)
  • Speeds: 8
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter: 88mm
  • Quality Level: Acera
  • Material: Steel
  • Weight: 90g
  • Compatibility: Shimano triple 8sp
  • Notes: black
  • Shimano Part Number: Y1KN98030

Shimano FC-M411 8-Speed Chainring 28T

1402
!
  • Teeth: 32
  • Position: Inner (triple)
  • Speeds: 8
  • Bolt Count: 4
  • PCD: 64
  • Quality Level: Alivio
  • Material: Steel (with plastic guard)
  • Weight: 82g
  • Compatibility: Shimano triple 8sp
  • Notes: plastic chain guard included to prevent chain from jamming between chainring and frame
  • Shimano Part Number: Y1GL98090

Shimano FC-M430 9-Speed Chainring 32T

90588
!
  • Teeth: 32
  • Position: Middle (triple)
  • Speeds: 7/8/9
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter: 88mm
  • Quality Level: Alivio
  • Material: Steel, silver
  • Weight: 87g
  • Compatibility: Shimano / RaceFace
  • Shimano Part Number: Y1M098060

Shimano FC-M540 9-Speed Chainring 32T

2840
!
  • Teeth: 32
  • Position: Middle (triple)
  • Speeds: 7/8/9
  • Bolt Count: 4
  • PCD: 104
  • Support Ramp Diameter: 90mm
  • Quality Level: Deore
  • Material: Steel (titanium colour)
  • Weight:  88g
  • Compatibility: Shimano / RaceFace
  • Shimano Part Number: Y1FM9804

Shimano FC-M590 9-Speed Chainring 22T Black

1619
!
  • Teeth: 22
  • Position: Inner (triple)
  • Speeds: 7/8/9
  • Bolt Count: 4
  • PCD: 64mm
  • Support Ramp Diameter: not applicable
  • Quality Level: Deore
  • Material: Steel, black
  • Weight: 38g
  • Compatibility: Shimano / RaceFace
  • Shimano Part Number: Y1LD22000

Shimano FC-M590 9-Speed Chainring 44T Grey

1621
!
  • Teeth: 44
  • Position: Outer (triple)
  • Speeds: 7/8/9
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter: 88mm
  • Quality Level: Deore
  • Material: Alloy
  • Weight:  81g
  • Compatibility: Shimano / RaceFace
  • Shimano Part Number: Y1LD98100

Shimano FC-M660 9-Speed Chainring 32T

90937
!
  • Teeth: 32
  • Position: Middle (triple)
  • Speeds: 9
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter: not applicable (no support ramp on the carbon/steel middle rings)
  • Quality Level: SLX
  • Material: Carbon & steel
  • Weight: 60g
  • Compatibility: Shimano SLX / XT
  • Notes: These chainrings fit cranks that don't provide a support ramp for the middle ring.
  • Shimano Part Number: Y1KF98040

Shimano FC-M660 9-Speed Chainring 44T

90035
!
  • Teeth: 44
  • Position: Outer (triple)
  • Speeds: 9
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter: 88mm
  • Quality Level: SLX / LX
  • Material: Alloy, black anodized
  • Weight: 85g
  • Compatibility: Shimano / RaceFace
  • Notes: The pin on the chainring lines up with the right side crank
  • Shimano Part Number: Y1KF98060

Shimano FC-M770 10-Speed Chainring 24T

90544
!
  • Teeth: 24
  • Position: Inner (triple)
  • Speeds: 7/8/9/10
  • Bolt Count: 4
  • PCD: 64mm
  • Support Ramp Diameter: n/a
  • Quality Level: Deore XT
  • Material: Aluminium
  • Weight: 24g
  • Compatibility: Shimano / RaceFace
  • Notes: AE type chainring (for 42-32-24 10-speed)
  • Shimano Part Number: Y1LW24000

Shimano FC-M770 10-Speed Chainring 42T

90543
!
  • Teeth: 42
  • Position: Outer (triple)
  • Speeds: 7/8/9/10
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter:
  • Quality Level: Deore XT
  • Material: Aluminium
  • Weight: 82g
  • Compatibility: Shimano / RaceFace
  • Notes: AE series chainring. The pin aligns with the right crank.
  • Shimano Part Number: Y1LW98030

Shimano FC-M770 9-Speed Chainring 22T

2562
!
FC-M770 22T
  • Teeth: 22
  • Position: Inner (triple)
  • Speeds: 7/8/9
  • Bolt Count: 4
  • PCD: 64mm
  • Support Ramp Diameter: n/a
  • Quality Level: Deore XT
  • Material: Alloy, black
  • Weight: 20g
  • Compatibility:
  • Notes: Hollowtech II inner chainring. These have a larger inner diameter to give clearance over external bottom bracket bearings.
  • Shimano Part Number: Y1J122000

Shimano FC-M780 10-Speed Chainring 32T

1088
!
  • Teeth: 32
  • Position: Middle (triple)
  • Speeds: 10
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter: Not applicable on carbon/steel middle chainrings
  • Quality Level: Deore XT
  • Material: Carbon & alloy
  • Weight
  • Compatibility: Shimano SLX / XT 10sp
  • Notes: Fits cranks without a support ramp for the middle chainring on the spider. The bump (inside) aligns with the right crank.
  • Shimano Part Number: Y1MM98130

Shimano FC-M785 Chainring 38T AK

2576
!
  • Teeth: 38
  • Position: Outer (double)
  • Speeds: 10
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter:
  • Quality Level: Deore XT
  • Material: Alloy
  • Weight: (shipping weight 108g)
  • Compatibility: Shimano
  • Notes: This (AK) version of the 38T outer ring is designed for use with a 24T inner chainring.
  • Shimano Part Number: Y1ML98020

Shimano FC-M8000 Single Chainring 32T

90322
!
  • Teeth: 32
  • Position: Single
  • Speeds: 11
  • Bolt Count: 4
  • PCD: Asymmetric
  • Support Ramp Diameter: n/a
  • Quality Level: Deore XT
  • Material:
  • Weight
  • Compatibility: Shimano Deore XT asymmetric - not interchangeable with other cranksets
  • Notes:
  • Shimano Part Number: ISMCRM80A2

Shimano FC-MC20 8-Speed Chainring 22T Silver

 
76222
!
  • Teeth: 22
  • Position: Inner (triple)
  • Speeds: 7/8
  • Bolt Count: 4
  • PCD: 64mm
  • Support Ramp Diameter: n/a
  • Quality Level: Alivio
  • Material: Steel. Silver colour
  • Weight:  46g
  • Compatibility: Shimano / RaceFace
  • Notes:
  • Shimano Part Number: Y1CY22000

SRAM Chainring 22T 10sp Triple X0

90288
!
  • Teeth: 22
  • Position: Inner (triple)
  • Speeds: 7/8/9/10
  • Bolt Count: 4
  • PCD: 64mm
  • Support Ramp Diameter: not applicable
  • Quality Level: X0
  • Material: Alloy
  • Weight: 15g
  • Compatibility: Chainrings are fully interchangeable between X7, X9 and X0 triple cranksets.
  • Notes:

SRAM Chainring 33T 10sp Triple X0

90287
!
  • Teeth: 33
  • Position: Triple middle
  • Speeds: 10
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter:
  • Quality Level: X0
  • Material: Aluminium
  • Weight: 42g
  • Compatibility: SRAM X7, X9 and X0 triple.Chainrings are fully interchangeable between X7, X9 and X0 triple cranksets.
  • Notes: We have had a cheaper SRAM 33T 10speed chainring for cheaper cranksets but there was a problem with the ramp diameter and so this is, for now, the only 10 speed 33T chainring we offer.
  • SRAM Part Number: 116215188290

SRAM Chainring 38T 10x2 104

1590
!
  • Teeth: 38t
  • Position: Double outer
  • Speeds: 10
  • Bolt Count: 4
  • PCD: 104
  • Support Ramp Diameter:
  • Quality Level:
  • Material:
  • Weight: 70g
  • Compatibility: SRAM / Truvativ
  • Notes:
  • SRAM Part Number: 116215188420

SRAM Chainring 39T 10sp Double GXP X0

90284
!
  • Teeth: 39
  • Position: Double outer
  • Speeds: 10
  • Bolt Count: 4
  • PCD: 120mm
  • Quality Level: X0
  • Material: Alloy
  • Weight: 70g
  • Compatibility: SRAM/Truvativ X9 and X0 10sp MTB double with GXP BB. Not interchangeable with triple cranksets. Chainrings are interchangeable between SRAM X9 and X0 double cranksets (not X7)
  • Notes:
  • SRAM Part Number: 116215188260

SRAM Chainring 44T Triple GXP X9/X7

76442
!
  • Teeth: 44
  • Position: Triple outer
  • Speeds: 7/8/9/10
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter:
  • Quality Level: X9/X7
  • Material:
  • Weight: 74g
  • Compatibility: SRAM/Truvativ with GXP bottom bracket. Chainrings are fully interchangeable between X7, X9 and X0 triple cranksets.
  • Notes:
  • SRAM Part Number: 116215087000

Steel Chainring BMX 36T Chrome

2293
!
  • Teeth: 36
  • Position: Single
  • Speeds: Single
  • Bolt Count: 0
  • Material: Steel, chrome plated
  • Weight: 193g
  • Compatibility: One-Piece cranks
  • Notes: For 1/8" chain only (not 3/32")

Steel Chainring BMX 44T Steel Black

90227
!
  • Teeth: 44
  • Position: Single
  • Speeds: Single
  • Bolt Count: 0
  • Material: Steel, black
  • Weight: 273g
  • Compatibility: One-piece cranks
  • Notes: Suits 3/32" or 1/8" chain.

Step Collar 19mm to 22.2mm

 
76704
!

Steel one-piece chainwheel spacer.

  • Width: 6.8..
  • Inner Diameter: 19.1mm
  • Outer Diameter: 21.8mm
  • Material: steel
  • Weight: 8g
  • Compatibility: 19mm axle and 22.2mm chainring mount hole
  • Notes: External diameter of 21.8mm might mean a slightly loose fit as the chainwheel is likely to have a 22.2mm hole

Step Collar 22.2mm to 23.8mm

 
76702
!
cw spacer
  • Width: 10mm
  • Inner Diameter: 22.2mm
  • Outer Diameter: 23.8mm
  • Material: alloy
  • Weight: 2g
  • Compatibility: 22.2mm axle and 23.8mm chainring mount hole
  • Notes:

Truvativ Chainring 22T Alloy

76224
!
  • Teeth: 22
  • Position: Triple inner
  • Speeds: 7/8/9/10
  • Bolt Count: 4
  • PCD: 64mm
  • Quality Level: X9/X7
  • Material: Alloy, black
  • Weight: 16g
  • Compatibility: SRAM/Truvativ
  • Notes: V3 chainring
  • SRAM Part Number: 116215089000

Truvativ Chainring 24T Alloy

2593
!
  • Teeth: 24
  • Position: Triple inner
  • Speeds: 7/8/9/10
  • Bolt Count: 4
  • PCD: 64mm
  • Quality Level:
  • Material: Alloy
  • Weight: 20g
  • Compatibility: SRAM/Truvativ
  • Notes:
  • SRAM Part Number: 11.6215.093.000

Truvativ Chainring 32T Alloy Ramped

76321
!
  • Teeth: 32
  • Position: Triple middle
  • Speeds: 7/8/9/10
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter:
  • Quality Level:
  • Material: Alloy, black anodized
  • Weight: 35g
  • Compatibility: SRAM/Truvativ.
  • Notes:
  • SRAM Part Number: 11.6215.086.000

Truvativ Chainring 32T DH

 
76320
!

Truvativ alloy chainring for single chainring setups. 32 teeth.

PCD: 110mm. Weight: 38g.

  • Teeth: 32
  • Position: Single
  • Speeds: 8/9/10
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter:
  • Quality Level:
  • Material: Alloy
  • Weight: 38g
  • Compatibility: Single ring drivetrains with 104 x 4 bolts
  • Notes:
  • SRAM Part Number: 116215077000

Truvativ Chainring 36T Alloy Ramped

2592
!
  • Teeth: 36
  • Position: Double inner or Triple mid
  • Speeds: 7/8/9/10
  • Bolt Count: 4
  • PCD: 104mm
  • Support Ramp Diameter: 90mm
  • Quality Level:
  • Material: Alloy
  • Weight
  • Compatibility: SRAM/Truvativ
  • Notes: Ramped and pinned - for use on double and triple cranksets
  • SRAM Part Number: 116215091000

Salt Pro Drive Sprocket 25T Black

2003
!
  • Teeth: 25
  • Position: Single
  • Speeds: Single
  • Bolt Count: 0
  • Material: 6061-T6 aluminium, stamped. Anodized black.
  • Weight: 58g
  • Compatibility: 19mm and 22mm crank spindles.
  • Notes: Suits 1/8" chain. Supplied with 19mm and 22mm spindle adaptors. Strengthened crank arm fix point.

Salt Pro Drive Sprocket 25T Blue

2009
!
  • Teeth: 25
  • Position: Single
  • Speeds: Single
  • Bolt Count: 0
  • Material: 6061-T6 aluminium, stamped. Anodized black.
  • Weight: 58g
  • Compatibility: 19mm and 22mm crank spindles.
  • Notes: Suits 1/8" chain. Supplied with 19mm and 22mm spindle adaptors. Strengthened crank arm fix point.

OneUp narrow wide 104BCD chainrings

!
Eliminate chain drop in 1x systems with these well designed chainrings. Avaiable in black from 30T to 36T.
Compatible with Shimano and SRAM 9, 10 and 11 speed systems.