Why We Like The Mojo HD5 Mountain Bike Frame
When it comes to bikes that do it all well, the Ibis Mojo HD reigns supreme. Everything from challenging black diamond singletrack that can only be reached via long, arduous climbs, to high-speed flow trails at the bike park, this bike handles it all in stride. Though it has seen a number of revisions over the past decade, the bike's core traits of exceptional all-around performance and intuitive handling remain the same. The newest iteration is the Mojo HD5, serving as Ibis' flagship enduro steed for the challenging trails of high-level enduro racing. Though the bike has more travel and gets the requisite longer and slacker treatment, it's actually faster both up and down the mountain thanks to modernized geometry and refined suspension. Of course, the HD5 retains the lively handling that the Mojo series is known for, making it a great choice for riders of all skill levels searching for a bike that won't hold them back on any terrain.
Taking a closer look at the HD5's geometry, you'll find that the reach and wheelbase figures are both lengthened, and the head tube angle is slackened to 64.2-degrees compared to the 64.9 found on the HD4. This lends more stable handling, particularly at higher speeds, but also improves the bike's overall balance, which pays off at lower speeds, too. Ibis also shortened the seat tube length to allow room for longer dropper posts (175mm on a medium, 150mm on a small), allowing riders to get the saddle down lower and further out of the way on tricky descents. The stack height is also increased for better composure on steep terrainâ€”a change Ibis made after taking into account a lot of different racer's preferences.
These changes all sound good for the gravity side of things, but Ibis was keen on making the HD5 a more efficient climber too, which is why they gave the bike a steeper 76-degree seat tube angle (2-degrees steeper than the HD4). This puts the rider in a more comfortable pedaling position and also makes it easier to control the front end on the climbs. Along with this comes the move to a 37mm offset fork, with the shorter offset helping to calm the steering, thus improving the bike's handling both uphill and down.
On the suspension side of things, travel remains at 153mm out back. Ibis took cues from the Ripmo's travel paring, however, and went with a longer travel 170mm fork up front. This helps to soften the bike's leading edge, but Ibis also discovered that over-forking the bike gives the suspension a more balanced feel. Since fork travel moves on the axis of the head tube angle, a 170mm fork only moves about 153mm vertically when using all of its travelâ€”a number that matches the rear end perfectly resulting in a balanced, confident ride. Keen eyes will also notice the switch to IGUS bushings for the lower link, like the Ripmo. These links don't rotate all that much as the suspension cycles, so Ibis found bushings to be more durable than bearings in this location, and even backs them up with a lifetime warranty.
Naturally, the bike still uses their esteemed DW-Link suspension platform. Very few suspension designs pedal this efficiently, attributable to the ideal anti-squat characteristics inherent to DW-Link. Throughout its travel, the feel is linear and very active when you need it to smooth rough stretches of trail, with enough ramp-up near the end of its travel to preserve that bottomless feel on bigger hits. These traits make the HD5 an absolute pleasure to ride, and allow it to cater to both point-and-shoot as well as playful riding styles.
Because DW-Link doesn't rely on the rear shock's compression settings to pedal efficiently and free of energy-wasting pedal bob, Ibis starting experimenting with ways to improve the suspension performance through tuning. To find the perfect tune, Ibis used an innovative data acquisition system developed by Motion Instruments, which allowed them to quantify what the critical wheel speeds should actually be in both directions (compression and rebound). After two years of research along with countless suspension tests, Ibis came up with a new system called Traction Tune. Traction Tune uses extra light damping in the high-speed compression and rebound circuits, which allows the wheels to react more quickly to changes in terrain, resulting in smoother bump absorption and glued-to-the-ground traction. By balancing this effect front and rear, the bike chassis stays flat relative to the ground as the suspension moves, keeping the geometry consistent and providing more predictable handling in rough terrain. It's a feature that Ibis's team riders were pushing for, but it provides benefits to riders of all skill levels.
Ibis continues its expert carbon frame construction with the Mojo HD5. A new carbon lay-up yields a frame that's stiffer than the HD4, all while keeping the frame weight about the same. The one-piece carbon lay-up results in a lightweight and strong frame with phenomenal stiffness, contributing to a responsive ride that tracks really well through corners and rough terrain. We also appreciate that Ibis made the switch to clean-looking internal cable routing with molded tunnels, simplifying maintenance because you can feed the housing into one hole and it pops out the other side right where it needs to be, thus eliminating the hassle of fishing inside the frame for brake or shifter housing.
Other frame details include the addition of upper and lower pivot guards, protecting areas that were historically subjected to rocks being flipped up by the rear tire. A tough polycarbonate downtube protector shields the frame from other rock impacts, while molded rubber guards on the swingarm protect the frame from chain slap and keep things running quiet. Thankfully, the HD5 still has a trusty and creak-free threaded bottom bracket shell, as well as plenty of room for a water bottle in the main triangle. As for tires, there's enough room for up to 2.6in rubber, if desired.
- Ibis' 27.5 enduro brawler loves steep trails and high speeds
- New carbon frame boosts stiffness without increasing weight
- DW-Link suspension platform is efficient, active, and smooth
- Traction Tune rear shock improves traction and handling
- Longer travel 170mm fork lets you charge harder than before
- Longer and slacker geometry improves stability on descents
- Steeper seat tube is more comfortable and efficient on climbs
- Internal cable tunnels and lower-link bushings ease the maintenance burden