Chris King has long been the most coveted ‘Merican hub builder, particularly for mountain bikes. Their RingDrive cassette body is fairly unique in design as well as being in no small small measure sonically irritating. Frankly, I hated King hubs on road bikes, where long coasting descents on King hubs are like being serenaded by squalling infant cyborgs genetically crossed with deep sea fishing reels. But on mtb, the RingDrive’s instant hook up is deeply satisfying while offroad riding’s rhythm is too busy to give the hubs a chance to be audibly annoying. Too bad King was slow to get on the band wagon for SRAM’s breakout 1x11 drivetrain. Their innovative 10-42T 11sp cassette requires a special, “XD” cassette body, and the RingDrive design apparently wasn’t easily adapted to XD configuration.
Well, King fixed that. Their popular “ISO” disc hubs will be available with the option of an XD-compatible RingDrive drive shell (ie cassette body). And if you’ve already invested in some premium King hubs, you’ll be extra excited to find out that King will be offering the XD drive shell as an aftermarket kit to retro fit your existing ISO rear hub. The kit includes all the necessary bearings to fit. It’s a little confusing, but make sure you order the full “conversion kit” if you are retrofitting, since apparently there are 2-3 different XD drive shell SKU’s that are available for servicing the hubs. You will need the King RingDrive tool to do the conversion, so probably count on having an experienced LBS do the work unless you already own the rather expensive King tool.
If you’re used to the bike industry’s press releases, then you’d probably assume that any product availability date is going to be “soft”, but as the bike shop’s hard goods buyer for over ten years, I have faith in whatever date Chris King gives. So I was quite surprised that King said May 1 for availability. You can pre-order ISO XD hubs or XD RingDrive conversion kits right now through your local bike shop. In fact, I just ordered a conversion kit for my own hub. If you are buying a new hub, the XD-compatible hubs are available in all the ISO’s current axle options: 135-QR, 10x135 thru, 12x135 thru, 12x142 thru, 12x150 thru, 12x157 thru. A complete ISO XD rear hub (12x142 thru-axle) weighs 331gr, and hubs are offered in all nine anodized colours.
You gotta give King credit for looking to give existing hub owners the option of upgrading their hubs. It’s indicative of their company philosophy in making hubs and headsets that represent an enduring investment in quality. On one hand, that approach does make King a bit slow to respond to industry trends, but you know when they do roll out new product that it will be great.