Applies to: SB120 29" frames, model years 2023 and newer.
The SB120 is a 29" bike with 120mm of rear travel. This article covers SB120 frame specs, part compatibility, suspension setup, and warranty.
SB120 frame specs
- Rear travel: 120mm
- Wheel size: 29"
- Frame sizes: XS, SM, MD, LG, XL, XXL
- Recommended fork travel: 130mm or 140mm for model year 2026 and newer; 130mm for model years 2023 to 2025 (tested up to 150mm; max axle-to-crown 564mm)
- Rear shock size: 190 x 45mm (air shocks only; no coil)
- Shock hardware: front M8 x 36mm; rear Yeti shock eyelet spacer
- Bottom bracket: threaded BSA 73mm
- Rear hub spacing: 148 x 12mm Boost
- Rear thru axle: 172mm long, M12 x 1.0 thread pitch
- Derailleur hanger: SRAM Universal Derailleur Hanger (UDH)
- Chainline: 55mm Boost. For SRAM cranks, use SRAM DUB Wide (CL55).
- Chainring size: 28T to 34T round, or 30T to 32T oval
- Chain guide mount: 2-bolt ISCG '05
- Headset: integrated 41mm/52mm tapered
- Seat post diameter: 31.6mm
- Seat collar: 36.4mm
- Rear brake mount: post mount, 180mm (no adaptor needed for a 180mm rotor)
- Rear rotor size: 180mm minimum, 203mm maximum
- Maximum tire width: 2.6"
SB120 frame and part compatibility
What size seat post and seat collar does the SB120 use?
The SB120 uses a 31.6mm seat post and a 36.4mm seat collar. Seat collar torque depends on the seat post manufacturer's recommendation.
Can I run an internally routed (stealth) dropper post on the SB120?
Yes. The SB120 has routing for stealth (internally routed) dropper posts only.
What is the longest travel dropper post I can run on the SB120?
The longest SB120 dropper post depends mostly on your inseam. The SB120 frame has no dropper length limit, so you can run any travel as long as the post is above its minimum insertion mark and your tire does not rub your saddle. Your local Yeti dealer can help you choose. Yeti runs a 150mm drop on XS and SM frames, 175mm on MD frames, and 200mm on LG to XXL frames.
What travel fork is the SB120 designed to use?
Model year 2026 and newer SB120s are designed for a 130mm or 140mm travel fork. Model years 2023 to 2025 are designed for a 130mm fork. Yeti tested the SB120 frame up to 150mm of fork travel, so you can run up to a 150mm fork. The maximum axle-to-crown measurement is 564mm.
- A longer fork slackens the head tube and seat tube angles and raises the bottom bracket.
- A shorter fork steepens the head tube and seat tube angles and lowers the bottom bracket.
Can I use an angleset on the SB120?
No. The SB120 has an integrated headset with the headset cups molded into the frame. Some aftermarket anglesets fit this headset style, but the SB120 frame was not tested with them and they should not be used. Installing an angleset voids the Yeti warranty, and the customer assumes all liability.
What rear wheel axle fits on my SB120?
The SB120 works only with SRAM's Universal Derailleur Hanger (UDH) axle at 12 x 148mm spacing. The axle is 172mm long with a 12 x 1.0 thread pitch. This axle only fits frames designed for the Universal Derailleur Hanger. The stock SB120 axle threads in and out with a 6mm hex wrench from the non-drive side. Some aftermarket companies offer a compatible axle with a quick-release lever.
What cranks and bottom bracket can I use on the SB120?
The SB120 uses a BSA 73mm threaded bottom bracket and is compatible only with wide q-factor cranks. Shimano, SRAM, and RaceFace cranks fit; other brands need a fit check.
What chainline was the SB120 designed around?
The SB120 was designed around a 55mm Boost chainline. Other chainlines may work depending on the crank and chainring, but check clearance first. The minimum clearance from the chainring teeth to the chainstay is 3.5mm.
What is the largest chainring that fits on the SB120?
With Shimano or SRAM 55mm chainline Boost cranks, the SB120 fits up to a 34T round or 32T oval chainring. The minimum is 28T round or 30T oval. The limit depends on crank chainline and chainring shape. Not sure? Ask your local Yeti dealer or contact Yeti Cycles support.
Does the SB120 have ISCG mounts?
Yes. The SB120 has an integrated 2-bolt ISCG '05 mount. The SB120 works best with low-profile modern chain guides; some older guides with larger upper guides may not fit. Always fit-check a specific chain guide before riding. The SB120 is not compatible with 3-bolt ISCG '05 chain guide and bash guard combinations, and using one voids the frame warranty.
How big a rear rotor fits on the SB120?
The SB120 runs a 180mm rear rotor without a brake adaptor. With a brake adaptor, the SB120 fits up to a 203mm rear rotor.
How big a tire can I fit on the SB120?
The SB120 fits tires up to 2.6" wide. Actual tire sizes vary by manufacturer, so clearance can differ between brands.
Can I fit a water bottle inside the SB120 front triangle?
Yes. SB120 sizes MD to XXL fit a standard water bottle inside the front triangle. Size SM fits a standard 21oz bottle, and size XS fits Yeti's 15oz Hot Lap bottle. Piggyback shocks, like the one on Lunch Ride builds, reduce bottle clearance on sizes SM to LG. A side-entry cage gives the easiest access.
Can I convert the SB120 to a mullet (27.5" rear wheel)?
It is possible, but Yeti does not recommend it. A 27.5" rear wheel on the SB120 lowers the bottom bracket too much and slackens the head tube and seat tube angles. If those changes suit your riding style, it is your call.
What is the difference between the TURQ and Carbon series SB120?
TURQ series SB120 frames use Yeti's highest-grade carbon fiber for the best balance of stiffness, durability, and compliance. Carbon series SB120 frames use a modified layup with different materials to lower the price while keeping the strength and stiffness of the TURQ frame. A Carbon series SB120 frame weighs about 200g more.
SB120 suspension setup
What shock does the SB120 use?
The SB120 uses a 190 x 45mm rear shock. The shock can be locked out, but Yeti recommends running the SB120 shock fully open for the best compliance and traction.
What shock hardware does the SB120 use?
The SB120 uses M8 x 36mm hardware on the air can side and a custom Yeti reducer on the shaft side. If you swap shocks, you can buy the Yeti shock eyelet spacer on yeticycles.com.
How do I install a RockShox Super Deluxe shock on an XS SB120?
On XS SB120 frames, a RockShox Super Deluxe shock must be deflated to install or remove it. Attach a shock pump and slowly let air out until the shock shortens enough to fit.
Can I put a coil shock on the SB120?
No. A coil shock does not fit the SB120 because of size constraints and limited clearance at the link.
What sag should I run on the SB120?
Start the SB120 at 30% sag, which is 13.5mm of shock stroke, for the best pedaling efficiency and terrain compliance. Set sag at your normal riding weight with your gear on. You can go slightly above or below 30% to suit your preference. The Yeti shock setup calculator gives starting settings for your shock.
How often should I service the SB120 Switch Infinity link?
Grease the SB120 Switch Infinity link every 40 hours of riding through its external grease ports. Do not over-grease it, and wipe off dust and dirt regularly. Grease and service parts are available from the Yeti webstore or your local Yeti dealer.
SB120 parts, upgrades, and warranty
Can I upgrade the components on my SB120?
Yes. Many aftermarket parts fit the SB120, and parts from major brands like Fox, Shimano, and SRAM are largely standardized. Have a professional mechanic confirm each part matches the SB120's standards and mounts securely without interference or play. Check the fit before riding.
Can I replace or modify Yeti frame parts on my SB120?
Use only genuine Yeti replacement frame parts on the SB120. You can get them from your local Yeti dealer or the Yeti webstore. Yeti cannot verify that aftermarket frame parts are safe on its frames. If any SB120 frame part is modified or replaced with a non-Yeti part, all warranties are void and the customer assumes all liability.
What is the warranty on the SB120?
The SB120 frame and Switch Infinity link have a lifetime manufacturer's warranty against defects for the original purchaser from an authorized Yeti Cycles dealer. Paint and finish are covered for 1 year. Yeti will repair or replace, at its discretion, any frame it finds defective. To use the warranty, register your bike online at yeticycles.com and take it to an authorized Yeti Cycles dealer for processing. The warranty does not cover ordinary wear and tear, neglect, or intentional damage. See the Yeti Cycles Warranty for full terms.