The Cane Creek VALT Progressive Spring offers the effect of requiring more force to compress the spring as you get deeper into the travel
MRP and others have offered similar products for years now, but the Cane Creek VALT Progressive Spring is around £40 cheaper. The idea is that the steel spring is wound more tightly at one end, so coil intervals reduce towards the end of the stroke and as such isn’t linear as regular coils. It ramps up.
Whether your bike has a linear suspension design that wouldn’t otherwise work well with a coil shock, or crave more ramp-up on a coil-friendly bike, I can’t really see any drawbacks to this progressive design as it makes even the best mountain bikes feel more sensitive off-the-top without losing any of the grip and tracking of a coil shock.
VALT’s progression starts from halfway through the travel and is designed to replicate a DB Air shock with one volume spacer inside. The design’s useful for bikes where the leverage rate doesn’t fall away towards the end of the travel, as they rely on the shock to provide the ramp-up. Fine with an air shock but less optimal when running a coil shock and charging hard on demanding terrain. My Evil Wreckoning actually has a leverage curve that works with a coil shock, but that didn’t stop me trying the progressive spring. I ran a 450-550lb rate for my 82kg weight, in place of the standard 500lb spring that came with the bike. The spring’s effect translates to a more supple feel off-the-top. And at the opposite end of the travel the progressive spring resisted bottom-out on a couple of big drops to harsh landings at Dyfi Bike Park.
There’s a slight sense of a two-stage feel to the Cane Creek VALT Progressive Spring when you’re bouncing in the car park, but I couldn’t sense any rate change while riding. The progressive coil does weigh slightly more than a standard linear coil spring, but that’s about the only minor drawback.