What goes around comes around, right? Those who've been riding for a decade or two will remember when the thing to do to your long-travel bike was to put massive tires on your equally massive rims, and while the technology at the time was rudimentary, the benefits were still pretty obvious: more traction from a larger contact patch and lower air pressure, and hopefully better reliability. The downsides were that these gigantic tires and rims weighed as much as a golden retriever, and reliability actually wasn't that great due to everyone being more concerned with finding the thickest possible downhill tubes to stuff in there rather then thinking about getting rid of the tubes altogether.
How things have changed. Tire and rim manufacturers are back to offering mega-wide rubber and rim options, but now the weights are extremely competitive, and, in a lot of cases, a proper wide tire and rim combo can be made to be more reliable than a Unimog. The best part, though, is the improved traction that comes from running the right tire on a wide rim and at low pressure. With their new $99 USD ARC rims, Easton is the latest company to jump on the 'wider is better' wagon train, and they're offering the aluminum rim in three different widths to match the differently sized tire options out there. ''Rim width should match tire volume. If you are running a large volume tire, a 30mm internal rim width provides an optimal tire profile,
'' Easton says. Not looking to run the big meat? ''For lower volume cross-country and trail tires, 24 and 27mm internal rim widths provide the ideal balance between tire shape and wheel weight.
Mounting up a massive tire on a skinny rim is going to mean that you're going to suffer from a lot of casing roll, and using a skinnier tire on a wide rim is going to change the shape of the tire so much that it won't work as designed, so Easton offering the ARC in three different widths does make sense. The weights are competitive as well: 425g for the 24mm wide rim in 27.5", 475g for the 27mm wide rim, and 490g for the 30mm wide model. The same three width options are also available in 29" sizes, with them weighing marginally more. The 32 hole, tubeless-ready rims accept standard spokes, and complete tubeless kits with rim strips and valves are sold separately.
We'll have more information from Sea Otter later this week, as well as a full test at a later date. www.eastoncycling.com