GravelKing X1: was 32.99 now 25.99Gravel tyres suited even to three and four-season UK conditions that roll well on the road too. Snap them up while this deal still exists it ends in nine-and-a-half hours at the time of writing.View DealAs a gravel convert of a few years now, I've ridden a number of tyre brands, widths and treads. I've found success with a few of these, depending on the time of year and the terrain, but among the best I've used of late has to be the Panaracer GravelKing X1. They are sporting some solid discounts this Amazon Prime Day as, in fact, are the whole GravelKing line in Panaracer's UK Amazon shop, with discounts up to 51% depending on what you're buying.Going on tread alone, the X1s are the gnarliest in this venerable line, which began with the original SK version and has become something of a benchmark in the discipline. However, the on-bike experience tells a different story. They have a decent amount of bite off-road, of course, but they're also fast-rolling on hardpack and tarmac, so I've used them for all manner of rides in all manner of seasons, including 50-mile-plus rides that are mostly tarmac.In all that time, I've experienced no issues, and no flats. In terms of getting them mounted, it depends which wheels you're using. I've used them on a couple, and they were super easy on one set, super hard on the other (in that case I used the Tyre Glider - not discounted this Prime Day, but so affordable you probably don't need it to be. Job done).The X1s are sold on Amazon in either all-black or black with brown sidewalls, and 35, 40 and 45mm sizes. There's also a 48mm version in all-black only. They feature Panaracer's ZSG compound for grip, and Beadlock for easy mounting and seating. With the 45mm versions available from 25.99, this is a great opportunity to buy.