Sea Otter 2015 | The Manitou Magnum Pro for plus-size tyres
Given the influx of 27.5+ bikes, Manitou have presented their newly developed forks, especially created for this plus-size tyre. Fitted with the new Boost 110 axle standard and a high-tech cartridge damper, they offer between travel of between 80mm and 120mm (29+) or 140mm (27.5+).
The purpose-built Magnum Pro forks have been in development for over a year to create specific forks for 27.5+ and 29+ wheel sizes. To accommodate the wider rims and tyres, the new Boost 110 standard (measuring 110x15mm) has been employed. The rigidity of the wheels is increased too, thanks to the favourable angles of the spokes, placed symmetrically on the wide rims to the wider hub. Moreover, there’s ample clearance around the fork arch to accommodate tyres with a width of up to 3.4″. The axle offsets have been tuned for the plus-size generation too: 27.5+ comes with 48mm offset, 29+ with 51mm. More on the new Boost 148 standard can be read in this article.
The forks come with Manitou’s striking reverse arch bridge, which reduces weight. For the suspension, it’s the distinguished Dorado Air System with TPC+ damping. With the IVA (Interval Volume Adjust), the size of the air chamber can easily be adjusted by moving the seal head up and down, while the MC² (Multi Control Compression System) enables separate fine-tuning of the high-speed and low-speed compression damping as well as a platform threshold that you can set. If you were to risk bottoming-out, the Hydraulic Bottom Out (HBO) unit does it utmost to prevent this by drastically slowing compression at the end of the travel.
Admittedly, while the forks are making use of already prevalent suspension and damping systems, these have undergone vital alternations to render them suitable for plus-sizes. As plus-sizes mean more unsprung weight and bigger tyres that absorb more impacts, the bumps are already soaked up to a certain extent by the time they reach the forks. According to Manitou, they’ve accounted for this behavioural spring change so that the forks work optimally with 3.0″-width tyres.
These Pro model forks are exclusively available on the aftermarket, but manufacturers can spec their bikes with a simpler COMP version. The COMP model employs slightly more basic travel and damping, which makes these forks a great and more affordable choice. The Manitou Magnum Pro have a RRP of 905 €.
Words: Martin Stöckl | Photos: Robin Schmitt