Hub-based pressure controller spotted on Edoardo Affini's Cervélo S5
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By Jack Evans
Published: March 29, 2023 at 3:37 pm
Team Jumbo-Visma appears to be trialling the KAPS adjustable tyre pressure system at Dwars Door Vlaanderen.
Edoardo Affini’s Cervélo S5 was photographed with the technology installed into a Reserve wheelset at the start of the cobbled classic.
As spotted by Twitter user @JVerlaeckt, a cable runs from the KAPS hub to the valve of the as-yet unreleased Vittoria Corsa tubeless tyre.
The Kinetic Air Pressure System enables the rider to inflate and deflate their tyres on the go via a wireless handlebar remote, according to the brand. The pump is powered by the wheel’s motion.
Affini seems to be using the KAPS system in Team Jumbo-Visma’s usual wheels, though for consumers the technology appears only to be available in a Gravaa wheelset. The R-40|44 road version costs €4,299.
While it’s certainly an emerging technology, an adjustable tyre pressure system seems best-suited to cobbled Classics such as Dwars Door Vlaanderen, if it is going to take off at all.
The early-season races of Belgium and northern France alternate between smooth tarmac and bone-jarring cobbles, where lower tyre pressures are commonly acknowledged to be faster and provide better traction and comfort.
Could Team Jumbo-Visma be giving KAPS a whirl before the two cobbled Monuments, the Tour of Flanders on Sunday and Paris-Roubaix the following weekend?
Professional riders have been progressively lowering their tyre pressures for the Hell of the North in recent years, thanks in part to the adoption of wider tyres and tubeless technology.
Lizzie Deignan won the Queen of the Classics with reportedly just 33psi in her tubeless tyres.
KAPS could, in theory, enable a rider to drop their pressure even lower ahead of key cobbled sectors, such as the Forest of Arenberg.
This could be especially valuable in the wet. In the same year as Deignan’s victory, Gianni Moscon was leading the men’s race solo before crashing following a bike change. Eurosport commentators speculated that excessive tyre pressure on his spare bike reduced his grip on the wet pavé.
Prior to last year’s Paris-Roubaix, Team DSM hinted its riders would use another wireless tyre pressure adjuster, but didn’t on the day.
The brand says the rotation of the bike’s wheels powers the cylinders of the pump, which is held within the wheel hub.
To save the pump’s battery, the rider can switch it off when not in use with a pneumatic clutch on the handlebar, according to KAPS.
The narrow valve connecting the hub to the valve of the bike tyre is said to compress the air flow to enable rapid inflation or deflation.
The hub pairs to the handlebar remote via Bluetooth or ANT+. Pressing the button up or down raises or lowers pressure. Current pressure can be displayed on a bike computer, according to KAPS.
If you simply wish to maintain the same tyre pressure, KAPS says the system can hold a set tyre pressure, even apparently adding air when it detects a puncture.
Digital Writer
Jack Evans is a digital writer for BikeRadar.com Jack learnt to ride on rough Cotswold trails before switching to tarmac in his teens. Gravel riding and cyclocross racing (badly) has since taken him back to his roots. Most at home scaling south Wales climbs, Jack more commonly escapes his home in Birmingham via the lanes and bridleways of Worcestershire, riding either his Canyon Ultimate road bike or Canyon Grail gravel bike. He wishes he was as good at riding as he is drinking espresso. But he has completed the 296km Dragon Devil sportive in under 10 hours and finished in the top 100 at the 2022 UK National Hill Climb Championships. Jack is an NCTJ-trained journalist and a former press agency hack with bylines in The Times, Daily Telegraph and Daily Mirror. He was once electrocuted for a Sun frontpage exclusive and taste-tested camel milk for The Times.
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