The specs on American Classic's Wide Lightning 27.5 Tubeless mountain bike wheels blow typical expectations out of the water. Despite the tubeless-compatible rims boasting an unusually generous 29.3mm inner width, their actual weight is XC-light at just 1,487g (687g front, 800g rear) – 25g below claims. As is often the case, however, you don't get something for nothing.
Until you've experienced them for yourself, there's no way to adequately describe the boost in performance you gain with significantly wider rims. An extra few millimetres over the norm may not seem like much and, indeed, a 2.25in-wide Michelin Wild Grip'R tyre mounted on a Wide Lightning rim measures out at 61mm across – just 4mm more than the same tyre on a more typical 23mm-wide rim.
Whereas many companies' trail and enduro rims are still just 23-26mm wide, the American Classic Wide Lightning is a healthy 29.3mm between the bead hooks
Those few millimetres in width add up to roughly 15 percent more air volume, though, and the difference on the trail is huge. Whereas we could typically run 21-23psi on more conventionally sized rims, we were able to consistently drop down 3-5psi on the Wide Lightnings with little fear of folding the tyres or burping them in hard cornering thanks to the extra sidewall support that broad foundation provides.
This improves ride quality and comfort, of course, but it also makes for tremendous gains in cornering, drive, and braking traction compared with similar tyre setups on narrower rims – all without any noticeable increase in rolling resistance or the additional weight of switching to a bigger tyre size.
Carbon rims may be grabbing attention these days but American Classic deserves credit for sticking with aluminium. Ultra-thinwalled extrusions help keep the claimed weight down to a feathery-light 380g or so each, yet they've shrugged off countless rock strikes over nearly a full year of testing in Colorado's notoriously abusive Front Range – and whatever small dents we did suffer were easily pulled out with a Morningstar Rim 'Rench instead of exploding on impact. One might rightfully expect such a paper-thin aluminium rim to be unnervingly flexy but these actually feel reasonably solid.
Go ahead and beat up on these. Thanks to the ductile aluminium construction, dents can be easily pulled out if and when necessary
American Classic's Taiwanese factory seems to be doing a bang-up job of building these things, too, as we've barely had to touch our test set. Save for one or two very minor adjustments, our samples have stayed true and properly tensioned – a fact that's perhaps further aided by each wheel's comparatively generous 32-spoke drilling.
As with anything in life, however, you don't get something for nothing and there are definitely some compromises made here to keep things so impressively light. In this case, the biggest one is in the freehub design.
The Wide Lightnings feature the same basic driver mechanism that company founder Bill Shook has used seemingly since the dawn of time. The (now reliable) system is ingenious in that the ratchet teeth are integrated directly into the one-piece aluminium freehub body while a steel cam plate simultaneously engages and disengages six aluminium (!) pawls depending on whether there's pedalling load being applied.
The hubs are light but also somewhat compromised for hardcore use
Since there's so little steel used, the hub is incredibly light – an astounding 225g, according to American Classic – and it's practically silent when coasting. However, building the key load-bearing elements out of aluminium also means that the ratchet teeth have to be bigger than usual to withstand the applied forces. There are just 24 of them, in fact, which yields a languid 15-degree engagement speed. That engagement point also feels distinctly spongier than more most competing designs.
Shook says that while the Wide Lightnings are strong enough for enduro, their low weight makes them more appealing to cross-country riders and racers, who in his opinion spend most of their time 'on the gas' and don't care as much about engagement speed. That may be for anyone whose local trails don't have much in the way of technical features but if you regularly need to throw in a quick shutter-step or half-pedal to make it up a pitch, these feel glacially slow and can legitimately mean the difference between riding and walking.
Twenty-four teeth, lots of waiting
Shook also stands firmly behind the front and rear hubs' basic bearing and axle design, which uses conventional radial cartridges and a simple two-nut preload system. It works well if adjusted correctly (which, in fairness, it was from the factory) but the bearings themselves are rather small and only minimally sealed. At the very least, we'd like to see more durable angular contact bearing cartridges used instead.
Finally, wider rims can also significantly change your tyre's cross-section and handling characteristics. Rounder tyres become more squared off, for example, while square tyres become even more so. For the former, this will usually mean a more pronounced 'bite' when turning but for the latter, this can yield a distinctly digital, on/off feel when cornering.
That all said, if you're interested in more traction on the trail – and realistically, who isn't? – you're conscious about weight, and you can live with the rear hub's lazy pick-up and somewhat delicate bearings, the Wide Lightnings are still a solid choice.
For more information, head to www.amclassic.com.