OFTEN it’s considered dark magic, but suspension is based on fundamental scientific principles, and Mupo is using simple engineering to gain a big advantage.
The Italian aftermarket company is making waves in a few different capacities, but arguably their most high-profile innovation is the way in which users can alter the fork spring rate without changing the spring.
We’ve probably all seen progressive rate springs when we change our road bike forks for race or track kits… notice the coils are generally closer together at the top and bottom of the spring and further apart in the middle – this structure makes a spring softer when it first compresses, and harder the further down it’s pushed.
The construction of the spring coil itself is generally what determines a spring rate – whether it’s thicker metal to increase stiffness, or thinner to decrease stiffness, even the distance between each wind and the number of active coils determines the rate.
Mupo’s patent-pending K911 fork cartridges simply control the number of active coils by disengaging anywhere from zero to a handful at the top of the spring. The higher the number of coils the cartridge disengages, the higher the spring rate… and conversely, the less coils the cartridge disengages, the lower the spring rate.
This innovation might not seem like a massive improvement on the surface, but imagine you’ve had to make last-minute setup decisions, as most of us have had to at some point.
What’s the first thing most racers do when the weather changes from dry to wet? They alter their suspension to increase their feeling of the tyres, their sensitivity if you will.
The weather in this country changes all the time- and if you’re a man in a van like most club racers, you probably don’t have time to make a quick swap of springs before your next race, test session, or endurance stint.
And that’s just the front of the bike…
At the back, Mupo’s AB1 Evo Factory shock is all business as well, utilising a bladder over a traditional piston in the oil reservoir.
Instead of the metal that traditionally comprises a reservoir piston, Mupo’s bladder piston reduces friction and decreases operating temperatures by dispersing heat more slowly than a standard aluminium piece.
How successful is it so far? Ducati TriOptions Cup racer Phil Atkinson, who rides a different bike with a different suspension almost every weekend, reckons Mupo have a package worth looking at…
“It was my first time trying the Mupo suspension at round one [of the Ducati Cup at Donington Park], so no testing at all prior – not ideal.”
“But we managed a 3rd and a 4th so I’m pretty happy with that. The tyre wear looked very good after all the sessions I completed.”
It’s no wonder a good chunk of the Ducati Cup field and an increasing number of club racers are switching to the Italian marque – after all, time is money, and the more time you save in the pits, the more you spend on the track.
*Main image: Colin Port
*Side images: Mupo Suspension