Save 35% or More on Select Mountain Bikes

Yeti Cycles SB4.5 Turq Mountain Bike Frame - 2018

Yeti Cycles SB4.5 Turq Mountain Bike Frame - 2018
Compiling options for this bike.
It'll be just a moment...

Item # YTI00BG

Find your size

Note: Actual inseam is not the same as pant inseam.How to measure

Recommended Size

We recommend a size in this bike.

EditMore details

Our size calculator is a starting point for finding the right size for you. To get personal advice talk to one of our fit experts at 1.888.276.7130 or chat now

Select options
  • Select options
  • Raw, S ($3,400.00)
  • Raw, M ($3,400.00)
  • Raw, L ($3,400.00)
  • Raw, XL ($3,400.00)
  • Storm, S ($3,400.00)
  • Storm, M ($3,400.00)
  • Storm, L ($3,400.00)
  • Storm, XL ($3,400.00)
Compiling options for this bike.
  • 100% Guaranteed Returns
Item # YTI00BG

Selected Option:

Add To Cartsave for later


A silver spoon in a world of soup.

When you're a well-rounded rider, you tend to find pleasure in tackling all sorts of trails, from flowy all-mountain riding with pockets of rock gardens and gnarly roots to steep and trying XC climbs that test just how hard you can push your lungs and quads. With riding so varied, having a bike with restrictive geometry and suspension that can't support the trails you point it up or down can make you angrier than a man with a fork in a world of soup. Yeti Cycles offers us a spoon in this soupy world with the 2018 SB4.5 Turq mountain bike frame. Effectively finding the balance between a capable trail bike that can handle some chunky rock gardens, and a smooth-trail-loving, pedal-mashing XC bike, the SB4.5 features lighter weight, and more nimble handling to earn its spot as a true all-mountain bike.

With geometry that rides the line between trail and XC, the SB4.5 runs a 64.7-degree head tube, which is significantly slacked out beyond the 70-degrees we find on most cross-country bikes. This makes for incredible stability when descending, but because the seat tube angle remains steep you'll still be centered in your cockpit for laying down the power on climbs. In the back, progressive Boost spacing stretches the hub spacing to a wider 148mm that not only enables your hub to be laced up into a stiffer and snappier wheel, but also allows space for the rear wheel to be tucked in closer to your frame for a shorter chain stay for faster power transfers when you need to mash down on the pedals.

The guts of the bike, the Switch Infinity suspension, lie just above the bottom bracket, which helps maintain a low center of gravity. Tucked inside the bottom of the seat tube and the rear triangle you'll find two silky-smooth Kashima-coated stanchions with a slider that moves in conjunction with the 144mm of Kashima-coated Fox Factory DPS shock to soak up blows while balancing out pedal bob with linear travel and anti-squat technology. While it'll be happy to soak up some rough and burly square-edge bumps, it's important to note that the travel isn't bottomless the way the SB5 or 5.5 is, instead it prefers riders who like to clean descents with precise line choices and maneuvering rather than those who take the point-it-and-send-it approach to their rides.

With the claim of a much stiffer pedaling platform than Yeti's other bikes, the SB4.5 will be appreciated by XC enthusiasts and those who love smooth and flowy trails alike. It's capable of finding the neutral position after taking a hit, and the "dead spot" previously seen by some riders on the older Switch Link is nearly completely eliminated, so you won't experience wallowing in the travel. The stiff pedaling platform allows for minimal pedal bob and maximum power transfer on your climbs. With this in mind, the bike craves flowy and smooth XC and trail riding, pockets of rock gardens, and even consistently rough and rocky rides. Sequential hits from rocks and roots at high speed aren't the favorite activity of this bike, and on big drops the 114mm of travel won't offer the same bottomless feel it generously offers through isolated rock gardens and roots. Combined with the stiff boost-spacing and 29-inch wheels it does feel quick, supportive, and stiff.

Carrying through with lightweight stiffness, Yeti offers the SB4.5 in its top-tier Turq level carbon fiber as the building-block for a durable and responsive frame. Meticulously laid, the carbon fiber wraps around a mold to reinforce joints and high-stress points without adding excessive and bulky materials, landing you with a strong and exceptionally lightweight frame, claiming to come in at 5.28lbs—nearly 300 grams lighter than their regular Carbon series. With such stiffness and light weight it's no wonder the SB4.5 climbs with such ease while keeping its composure on descents.

  • A roll-ready 29er for miles of pedal mashing and flow trails
  • Hungry for rock gardens, 4.5in of Switch Infinity eats up hits
  • Slacked out head tube offers stability where pure XC bikes suffer
  • Snappy and nimble handling courtesy of stubby stays
  • Intensely lightweight stiffness afforded by Turq level carbon
  • Buttery-smooth Kashima coated shock smooths out blows
  • Internal cable routing offers a clean finish

Tech Specs

Frame Material:
high-modulus Turq carbon fiber
Switch Infinity
Wheel Size:
Rear Shock:
Fox Factory DPS
Rear Travel:
Head Tube Diameter:
1-1/8 - 1-1/2in
Headset Included:
Bottom Bracket Type:
Cable Routing:
Front Derailleur Mount:
not front derailleur compatible
Brake Type:
Seatpost Diameter:
Rear Axle:
Boost 12 x 148mm
Claimed Weight:
Recommended Use:
cross-country, trail
Manufacturer Warranty:
5 years limited

Geometry Chart

Yeti Cycles

Geometry Chart


SB4.5 Carbon
140mm Travel Fork

Seat Tube


Effective Top Tube






Stand Over

Head Tube


Head Tube Angle


Seat Tube Angle


Bottom Bracket Height




S 16.5in 22.8in 23.9in 15.6in 29.6in 3.5in 67.4o 73.3o 13.1in 17.2in 44.4in
M 17.5in 23.8in 24.1in 16.6in 29.6in 3.7in 67.4o 73.3o 13.1in 17.2in 45.4in
L 19in 24.8in 24.5in 17.5in 29.6in 4.1in 67.4o 73.3o 13.1in 17.2in 46.4in
XL 20.5in 25.8in 25in 18.3in 29.6in 4.7in 67.4o 73.3o 13.1in 17.2in 47.5in

Reviews & Community


Write a review

    Add a:
  • Photos
  • Videos

No file chosen

Rather attach a photo from your computer?


Only jpg, jpeg, png, gif or bmp files please.

Submit ReviewCancel

I cant quit this bike

    Ripley's, 429's, Tallboy's, 5010's, Mojo's, Following, etc... I've owned a lot of 27.5 and 29er trail bikes. I usual ride a bike for a season or 2 and move on to something different and have never been brand loyal until now. I bought and sold the 2016 green sb4.5; but couldn't find anything even remotely close to it, so I had to come back to it. First time I've ever sold a bike and went back to it. The price is ridiculous and I feel like an idiot for spending this much on a frame but the Switch Infinity Suspension is that good. I'm a 200 lb rider and for me its the only suspension design that works well for larger riders. There is absolutely zero pedal bob and the suspension works flawlessly when its supposed to. traction and efficiency on climbs is simply amazing. I've compared the switch infinity back to back with VPP and DW; the ride characteristics and quality feels like your going from a Toyota to a Porsche. Like I said the price is extremely off putting but i understand why its more expensive than the other brands, because its better. theres simply no debate, the Switch infinity is hands down the best suspension platform on the market. Other than the suspension, the geometry and travel are exactly what I like in a bike. Relatively short chainstays for a 29er, the 67.5 head angle is perfect for those that climb and descend, and the 140 mm upfront is enough for the types of trails I ride. The 4.5 in the rear can feel undergunned at times but its a trade off I'm willing to make to get the geometry I like. For me the Trail bike category has the best geo for tight technical trail handling and still excellent climbers/descenders.

    I cant quit this bike