Trail pedigree, XC ambitions.
The enduro scene has been getting a lot of love lately, with ever deeper travel and ever slacker geometries defining industry trends. Yeti's decision to discontinue its SB95 without a replacement seemed to confirm this trend; however, the SB4.5 Carbon XT/SLX Complete Mountain Bike proves that there's still a space in the tribe for trail riding. It's a moderately slack 29er with 4.5in of travel that's designed for stability and speed on descents with plenty of snappy climbing for those who prefer to be the engine on climbs.
Though it was created to fill the trail niche in Yeti's line, the SB4.5 has a noticeable focus on losing weight, which combines with the wagon wheels to keep it versatile enough for straight-up XC riding. The carbon fiber frame is stiff and light, with a relaxed 67.5-degree head tube angle and stability-enhancing 17.2in chainstays that don't get in the way on climbs. The FOX Performance 34 fork also provides confidence on descents with 140mm of plush, forgiving travel that gives you the option to pick a line when you feel like it and just point the bike downhill when you don't. Yeti uses its relatively new Switch Infinity suspension in the SB4.5, which keeps the pedal stroke consistent and reduces squat by using a pivot system that switches direction as you move through the bike's travel.
Yeti's inclusion of Boost axles also contributes to the SB4.5's stiff, efficient pedaling platform, and the departure from the 142mm rear standard allows for more space between the hubs for better tire clearance and shorter chainstays—dimensions that are especially relevant for 29ers. With a greater hub distance, you also get a better spoke bracing angle, which creates a stiffer wheel and chassis platform. Finally, the hub's bearings themselves will experience less damaging torsional forces with the wider footprint, prolonging their lifespan and leading to a more efficient rear triangle as a whole. This stiffness and Switch Infinity's pedal-ability are what make the SB4.5 more adept at climbing than you'd expect, aptly demonstrating Yeti's reluctance to allow its bikes to fall too neatly into one category alone.
The bike is built here with a curated blend of Shimano's XT and newly redesigned SLX components, with the former managing chain tension at the rear derailleur and the latter keeping price down throughout the rest of the drivetrain. The Race Face Aeffect crank is the exception to Yeti's all-Japanese party, but it's one that we're happy to see—especially when its battle-tested 30t chainring is combined with Shimano's 11-46t gearing spread across the cassette. Whether you're indulging in some granny gear spinning on a steep climb or dropping into that 11t speed ring while dropping into a flow trail, the finishing touch of a FOX Transfer dropper post ensures that you'll never be more than a switch throw away from keeping your saddle at the right height.
- A wagon-wheel super bike with bad intentions on the trail
- 4.5in of Yeti's premier Switch Infinity devours big hits
- Trail bike geometry remains stable across the funky stuff
- Stubby stays keep 29er handling sharp
- Stiff, light carbon frame brooks no nonsense on climbs
- Massive BB shell and Boost spacing maintain stiff pedaling
- Dropper post keeps your perch at the right height
- Drivetrain handles trail abuse on race day and every other day