Like many trends in the bicycle world, oval chainrings go through periods of dormancy and popularity. And while elliptical rings haven’t gained much traction in the on-road sector, there’s definitely no shortage of companies offering oval rings for dirt and gravel riding. On the surface, elliptical chainrings may look similar, but Wolf Tooth Components takes a slightly different approach with their US-made PowerTrac Elliptical™ rings.
Where round chainrings are measured strictly by tooth count (and BCD), elliptical chainrings are also classified by ovality and timing (sometimes referred to as clocking). The former measures the increase in effective diameter, whereas the latter indicates where on the chainring the ovality takes place. In other words: more ovality makes the chainring feel bigger, and timing affects where that increase occurs in the pedal stroke. So if a little ovality is good, shouldn’t more be even better? According to the folks at Wolf Tooth, not necessarily.
Like other elliptical chainrings, Wolf Tooth’s PowerTrac rings are designed to improve power output and increase traction. Unlike most of their competition, though, PowerTrac rings utilize reduced ovality (10%) that’s paired with more aggressive timing (112 degrees from top dead center). Why? According to Wolf Tooth, the PowerTrac design yields additional power and traction, but without the uneven pedal stroke commonly associated with more aggressively shaped chainings. Visually, the PowerTrac ring is radically different than a round chainring of the same tooth count. When you overlay the oval and round chainrings, however, the differences are much more subtle.
Wolf Tooth PowerTrac chainrings are compatible with most modern (1x-compatible) cranksets. Both conventional and direct-mount models are available, as well as a version designed specifically for the company’s unique CAMO chainring/spider system. Prices range from $44.95 to $99.95 USD, depending on size and material. I tested an alloy 28t ring on the SRAM-equipped Jeff Jones 29er that I reviewed in March of 2017, and a stainless steel 30t chainring on Otso’s Voytek 27.5+ bike (Shimano/RaceFace drivetrain). Most of my riding during this test period took place on the gravel roads and dirt trails along Colorado’s Front Range.
I have to admit that I was more than a little intrigued by Wolf Tooth’s claims of smoother cadence and increased power. My previous experience with more aggressively shaped oval rings was that they required lower cadence and higher gearing to maintain a consistent pedal stroke. While that combination seemed to produce more power, my legs would tire faster (and take longer to recover). Having ridden round chainrings exclusively for most of 2017, I found the switch to PowerTrac rings largely uneventful. Gear ratios felt similar to their round-chainring counterparts, and my pedal stroke remained relatively smooth. In short, the opposite of my experience with more radically shaped rings.
Switching back to round chainrings (with the same tooth count) felt downright odd by comparison. I found myself pedaling with a herky-jerky motion, regardless of terrain or grade. And despite not making any saddle height changes on either of the test bikes, I detected a distinct pause/stall at the top of my pedal stroke with the round chainrings. As far as added traction, the PosiTrac-equipped bikes didn’t exhibit noticeably improved traction on loose terrain or steep, technical climbs. To be fair, however, I didn’t do any riding in heavy mud or snow (it is August, after all). Both Wolf Tooth chainrings were retrofitted to well-used drivetrains, but I never experienced any chain suck, dropped chains, or excessive noise with either bike.
Is Wolf Tooth’s PowerTrac chainring for you? That’s a tough call to make over the Internet. The best recommendation I can make is that you should try one yourself. It’s unlikely that Wolf Tooth’s chainring will help snag the Strava KOM that’s been eluding you, but you may just find the oval ring helps smooth out a less-than-perfect pedal stroke while keeping your legs fresh. After several weeks of alternating between traditional round and Wolf Tooth’s elliptical chainrings, I found that the latter actually felt rounder, and produced a more fluid pedal stroke.
Disclosure: Wolf Tooth Components provided review samples for this article, but offered no other form of compensation in exchange for editorial coverage.