Frame Features and Geometry

The 29" model features a slack 64-degree headtube angle, a 470 mm reach, 645 mm stack, and a steep, low seat tube with a 77-degree angle and 410 mm length. The bike's 430 mm chainstays, 5 mm longer than the 27.5" version, with a 50 mm BB drop. Despite the extended rear end, it doesn't hinder the bike's ability to perform tricks like manuals and bunny hops. The combination of a short reach and a steep seat tube provides a compact feel while seated. The effective top tube length for a size large is 619 mm.

Marin's approach to stretching the bike's dimensions caters to riders who want a bike suitable for skateparks and enduro trails. The San Quentin's geometry, with its slack head tube angle and large wheels, is a versatile choice for riders looking to do it all.

The frame is rigid, even for an aluminum hardtail, offering an efficient transfer of trail feedback. The bike has internal cable routing, ISCG tabs, and a stylish paint job. However, the paint on the down tube may wear down over time. The size large bike weighs 32.8 lbs with pedals, which is relatively heavy for a hardtail but can be reduced with lighter tires and wheels.

Part Spec

The San Quentin 3, priced at $1,799, offers excellent value. It comes equipped with a 140 mm Marzocchi Bomber Z2 fork, which, while good, may feel underpowered for larger riders. The aggressive 2.5" Maxxis Assegai tires, although grippy, can dampen the bike's zippy feel. Swapping them for more moderate trail-oriented tires is a recommended modification. The dropper post could be longer to match the bike's low-slung frame. The San Quentin features a reliable Deore drivetrain, and although Marin's website mentions a Sunrace cassette, some bikes come with a Deore cassette. It also comes with TRP Slate brakes, offering consistent and strong braking performance, with high-quality levers. Swapping the included resin pads for metallic ones can enhance braking power.

Climbing

Compared to the 27.5" version, the 29" San Quentin offers fewer pedal strikes, making it suitable for tight, technical climbs despite its slack head tube angle and longer wheelbase. The steep seat tube angle places the rider's weight between the wheels, improving grip and pedaling efficiency. The Assegai tires are the primary factor holding back the San Quentin on climbs due to their weight and deep knobs. While it can ascend, it's not designed for speed.

Descending

The San Quentin excels in descending. With a 64-degree head tube angle and 29" wheels, it instills confidence on steep, technical terrain without sacrificing the fun factor on flowier trails. The bike is intuitive for getting off the ground, and its low-slung frame allows for better cornering with balanced weight. The Assegai tires provide exceptional grip, even on off-camber sections, although they can feel sluggish on well-groomed flow trails. The Bomber Z2 fork may flex slightly on bigger hits for larger riders, but smaller riders may not experience this issue.

Jumping

Despite having 29" wheels, the San Quentin remains agile on dirt jumps and at the pump track. It's easy to maneuver and offers an excellent platform for tricks like whips and tables. However, it's not a dedicated dirt jump bike, mainly due to its slack headtube angle, and the Assegai tires aren't ideal for this style of riding. Still, it's a capable jump bike with the same attributes that make it enjoyable on aggressive trail rides.

Final Thoughts

Overall, I was very impressed by the 29” San Quentin 3. I think the addition of bigger wheels will make it a better option for most riders, upping its trail bike prowess without detracting from its playful side. At just $1,799 the San Quentin 29” 3 is a killer value, but riders looking to spend a bit less can also opt for the San Quentin 29” 2 which list for $1,399. The bike’s versatility makes it a great option for riders looking to get an affordable, aggressive hardtail that can handle everything from enduro racing to skateparks.