Plus-sized tires might be the next big thing in the mountain bike world, but for its latest product Mantiou reached back to its roots and revived a classic nameplate.
While the original Magnum of 20 years ago used elastomers, the new model uses a version of the Dorado air spring in the left leg with self-balancing positive and negative chambers. Air is added at the bottom beneath a threaded cap to protect the valve, and volume adjustment spacers can be accessed by opening the top of the left leg. What’s nice is that you don’t have to worry about losing the spacers if you’re not using them—the seal is simply repositioned with the spacers in one of five positions.
Manitou has a handy tuning guide on its website that helps users understand how the air pressure and volume work together for the desired performance. The right leg houses the compression and rebound dampers and bottom out adjustment. At the top of the leg is a three-part control that lets you dictate high- and low-speed compression as well as Manitou’s hydraulic bottom out. The bottom out adjustment has four positions and only affects the final third of the fork’s travel. Rebound damping is controlled at the bottom of the right leg.
According to Manitou, the high-speed compression control works as an incremental platform adjustment. It allows riders to fine-tune not just how much platform they want with the low-speed compression dial, but how firm that platform is by adjusting the high-speed multi-control dial. To simplify it, you can leave the high-speed multi-control adjustment at max, then use the low-speed compression dial to select which platform setting that you need, from climb to descend, via the five position dial.
On the outside the Magnum has a strong family resemblance with a hollow, sculpted crown and a reverse arch design holding 34 mm stanchions. Tying the two legs together is Manitou’s own QR15 axle design, which has hexagonal ends to prevent twisting and a small barb that locks it into place with a 90 degree twist of the QR lever. It takes a bit of practice to get the motion just right, but once you do it goes in quickly and can be removed with just a twist and pull.
The amount of tuning possibilities can be a bit daunting at first, but even at the extremes of their range none of the controls result in a disastrous ride. I appreciated the firm low-speed compression platform and experienced no unwanted brake dive or wallowing around in the mid-stroke, even with the low-speed compression dialed back. With the hydraulic bottom out tuned all the way back the spring rate seems fairly progressive, and I’d recommend running the volume adjustment at full volume unless you’re really hitting things hard.
The motion is extremely fluid with no appreciable stiction and it’s buttery smooth off the top. I was also extremely impressed with the finish quality and solid feel to all the controls. This isn’t just a mediocre fork that was adapted to fit the bigger tires. The Magnum Pro is as nice as any trail fork I’ve ridden lately and even has a leg up on the big brands in the 27plus category. Throw in the fact that it is one of the few 29plus options out there and I predict fans of big tires will have big smiles with one of these installed.
Manitou Magnum Details
- Price: $899
- Wheel Sizes: 27.5 x 3.4” (tested) or 29 x 3.4”
- Travel: 27plus: 80/100 mm or 120/140 mm (tested); 29plus: 80/100/120 mm
- Hub spacing: 110 mm Spring: air with self-balancing negative spring
- Damping Adjustment: high- and low-speed compression, lowspeed rebound, hydraulic bottom out control
- Axle: 15 mm quick-release
- Offset: 48 mm (27plus), 51 mm (29plus)
- Weight: 2,081 grams