Forks
A 40 mm suspension fork for gravel that smooths out rough tracks and locks out for tarmac. Before travel, the frame decides: the tapered head tube and the axle-to-crown length must match.
The frame decides before travel
A suspension fork is taller than a rigid fork, to make room for its travel. The KS GTC needs a frame with a 1.5-inch tapered head tube, designed for 435 mm axle-to-crown. On a frame drawn around a shorter rigid fork, every extra centimetre raises the front and slackens the head angle by about half a degree: the steering gets slower, the position higher. The right reference is sagged axle-to-crown, with the fork compressed under your weight: between 425 and 429 mm for the GTC. Measure your current fork, from the wheel axle to the headset bearing. If in doubt, send us your frame geometry from the contact page.
Set the pressure by sag
The GTC is air-sprung. KS gives a starting point by rider weight: from 72 to 80 kg, 105 to 112 psi, or 7.2 to 7.7 bar. Fine-tune it with sag, how far the fork sinks under your weight, aiming for 15 to 25% of travel, or 6 to 10 mm. The workshop technique: a cable tie fastened on the stanchion, against the seal, then get on fully kitted, in riding position, hands on the bar, and get off without bouncing. The gap between the tie and the seal gives the sag. Rebound is adjusted at the bottom of the fork leg, and the dial on the crown locks the fork for the road.
What it changes, and its limits
On rough tracks, the front wheel follows the ground instead of bouncing: the line holds, and your hands no longer take every stone. The cost has to be weighed: 1,385 g, about a kilo more than a rigid carbon fork like those in our gravel framesets. At 6% and 15 km/h, that kilo costs about 2.5 W on a climb. KS limits it to ASTM 1 and 2 use: roads, tracks and mild cross-country. It needs a service every 125 hours or every year, and carries a 24-month warranty for the first owner: the warranty and after-sales page explains the process.
Frequently asked questions
How much travel for a suspension gravel fork?
Around 30 to 50 mm. The KS GTC offers 40, enough to smooth out roots and stones without turning the bike into an MTB.
Can I fit a suspension fork on any gravel bike?
No. You need a compatible tapered head tube and a frame designed for a fork of that height: 435 mm axle-to-crown for the KS GTC. On a frame designed for a shorter rigid fork, the geometry changes.
What pressure in a gravel fork?
The one in the manufacturer's chart for your weight, then set by sag: for the KS GTC, 6 to 10 mm of compression under your weight, kitted out, in the riding position.