MTB CRANK & CHAINRING FAQ
Canfield Cranks FAQ
🔧 Fit & Sizing
What crank length should I choose for MTB?
Crank length plays a key role in comfort, efficiency, and pedal clearance. Canfield offers some of the shortest cranks in the industry—available in 5mm increments from 150mm to 170mm—giving riders of all sizes the ability to dial in their fit.
Shorter cranks can improve ground clearance, reduce joint strain, and help smaller riders or those on low-slung frames achieve better biomechanics. Use the chart below to find a recommended length based on your inseam and bike type.
Are my MTB cranks too long? Are shorter cranks better?
If you're hitting your pedals or feeling discomfort, your cranks might be too long for your frame or body. With modern mountain bikes trending toward lower bottom brackets, shorter cranks can help avoid pedal strikes and provide better clearance in technical terrain.
But the benefits go beyond clearance. Shorter cranks often reduce dead spots in the pedal stroke, improve power delivery, and lessen joint strain—especially for smaller riders or anyone with limited mobility. They also allow for a more upright, compact pedaling position that many riders find more efficient.
Should I use a smaller chainring with shorter cranks?
Shorter cranks reduce your mechanical leverage, so dropping crank length can feel like gearing up. For example, switching from 170mm to 160mm cranks is roughly equivalent to going up two teeth on your chainring.
That said, shorter cranks also spin smaller circles, which can feel smoother and easier to pedal—so many riders stick with their current chainring size and adjust only if needed.
If you want to maintain your original gear ratio, consider downsizing your front ring slightly when moving to shorter cranks.
Example: Final Gear Ratios (29” Wheel / 51T Cassette)
170mm cranks: 30T = 1.3:1 • 32T = 1.4:1
160mm cranks: 30T = 1.4:1 • 32T = 1.5:1
150mm cranks: 30T = 1.5:1 • 32T = 1.6:1
🔩 Compatibility
What width crank fits my mountain bike?
Canfield cranksets come in two spindle widths to match common MTB bottom bracket standards:
- 68/73mm / PF92 — Ideal for most trail, all-mountain, and enduro bikes
- 83mm — Designed for downhill bikes and frames with wider BB shells
Not sure what you need? Check your bike manufacturer’s bottom bracket specification. If you're running a 73mm shell (the most common), the 68/73mm crank is the way to go.
Will Canfield cranks work with a press-fit bottom bracket?
Yes—our cranks are designed around the SRAM GXP (24/22mm stepped) spindle standard and are fully compatible with PF92 press-fit bottom brackets when paired with the correct GXP-style bottom bracket.
We offer PF92 bottom brackets specifically designed for Canfield cranks.
What chainrings fit Canfield cranks?
Canfield AM/DH cranks use the SRAM 3-bolt direct-mount interface, making them compatible with a wide range of chainrings from major manufacturers.
We offer rings specifically matched to our cranks, but any SRAM 3-bolt direct-mount chainring will fit. Just make sure to select the correct offset based on your frame's rear spacing and desired chainline.
Chainline Recommendations for Canfield Cranks (2023+)
- Non-Boost (142mm rear) → 49mm chainline → -6mm offset ring (with spacer)
- Boost (148mm rear) → 52mm chainline → -3mm offset ring (with spacer)
- Super Boost (157mm rear) → 55mm chainline → 0mm offset ring (with spacer)
- Super Boost+ (157mm / wide chainstay) → 56.5mm chainline → 0mm offset ring (without spacer, use included washers)
2025+ models feature adjustable chainline capability using a removable 1.5mm spacer and included chainring bolt washers.
Note: Older (pre-2023) Canfield cranks use different offsets. See the “Crank Generations & Identification” section below for guidance.
Are Canfield cranks compatible with DUB, 30mm, or Shimano bottom brackets?
Canfield cranks use a 24/22mm stepped spindle based on the SRAM GXP standard. They are not directly compatible with bottom brackets made for:
- SRAM DUB (28.99mm)
- 30mm spindles
- Shimano Hollowtech II (24mm straight)
However, this doesn’t mean they won’t fit your frame. Canfield cranks are compatible with a wide range of modern bikes—you just need the correct bottom bracket. We offer Canfield bottom brackets that adapt our cranks to fit most common frame standards, including threaded and press-fit shells.
If you’re unsure what BB you need, reach out and we’ll help match your frame with the right setup.
🛠 Installation
Do I need to use the included spacers when installing my Bottom Bracket?
It depends on your bottom bracket shell width:
- 73mm shell: No spacers required.
- 68mm shell: Use one 2.5mm spacer on each side of the spindle.
Most modern bikes use a 73mm bottom bracket shell, but if your frame uses a 68mm shell, you’ll need spacers—we’ve got them. Just mention it in the “notes” section during checkout, and we’ll include them with your order.
My crank bolt seems tight during installation—how do I know when to stop tightening the crank bolt?
Tighten the non-drive side crank bolt until it bottoms out. The bolt will physically stop turning when fully seated. Do not stop early—an under-tightened crank can work loose while riding.
What is the torque spec for Canfield cranks?
- Standard torque: 65–70 Nm
- Initial install (new crank): May require up to 75 Nm
Always tighten until the crank bolt bottoms out for a secure, safe install.
Do I need to use the included chainring spacer on my cranks?
Yes—the included 1.5mm chainring spacer is used on all setups except Super Boost+ (56.5mm chainline). For standard chainlines (49mm, 52mm, and 55mm), install the spacer between the crank and chainring to achieve the correct chainline.
For Super Boost+ setups, do not use the spacer. Instead, install the chainring directly to the crank using the three included washers—one under each chainring bolt. This ensures the chainring seats properly and the bolts fully tighten without bottoming out.
Mechanic’s Tip:
When installing the crank, the spindle should slide cleanly through the bottom bracket and bottom out against the non-drive side (NDS) bearing. Avoid using force to install the spindle —this can dislodge the NDS bearing inside the cup.
A dislodged bearing can cause:
- A crankset that spins slowly or feels tight
- The chainring to sit too close to the frame—or even contact it
To ensure proper bearing alignment and chainring spacing, once the NDS crank arm is fully installed, use a rubber mallet or dead blow hammer to give the NDS arm a firm strike toward the drive side. This re-seats the bearing in the cup, aligns the entire system, and helps the crank spin freely.
Finally, re-check the crank bolt on the NDS arm to ensure it’s fully tightened. That last step can sometimes shift things just enough to require a quick torque check.
🧬 Crank Generations & Identification
How do I identify which generation of Canfield cranks I have?
-
🔹 Pre-2023 Cranks
Markings: Forged “C2” logo, no laser etching
Chainring Offset: Non-Boost: -3mm, Boost: 0mm, Super Boost: Not compatible -
🔹 2023 Cranks
Markings: C2 logo with laser-etched “3” on backside of drive-side arm
Offset: -3mm (Boost spacing) -
🔹 2024 Cranks
Markings: "Skully" logo on crank face
Offset: Standard Boost using -3mm chainrings -
🔹 2025 Cranks (Current)
Markings: Updated Skully graphic with redesigned arm profile
Features:- Chainline adjustability up to 56.5mm
- Includes a 1.5mm chainring spacer for fine tuning
- Spacer is used on all setups except Super Boost+
- For Super Boost+, use included washers under chainring bolts
- 49mm → -6mm offset ring (with spacer)
- 52mm → -3mm offset ring (with spacer)
- 55mm → 0mm offset ring (with spacer)
- 56.5mm → 0mm offset ring (no spacer, use washers)
Still have questions?
Reach out—we’re happy to help you get dialed in.
info@canfieldbikes.com
801-548-2556