Weight: 16 grams/pair
Aside from making your rear derailleur look super-cool, SLF Motion’s R Version Hyper Pulley Wheels (the R stands for Road/Race) should save you a few watts at your next race. According to Friction Facts, using these pulleys will cost you .017 watts total — that’s nearly half the watts CeramicSpeed’s Gr3 Hybrid wheels (.033 watts) will set you back, and a pretty significant drop from stock Shimano Dura-Ace pulleys (.159 watts). *
We can see why. These pulleys seem to spin endlessly on full ceramic bearings with Silicon Nitride races and PTFE seals. The ball bearings are full-ceramic, as opposed to steel balls coated in ceramic. And it’s plain to see that they spin a lot more freely than stock SRAM eTap pulleys with ceramic bearings. Perhaps that’s simply a psychosomatic take on what makes your bike ride faster, but less friction should, in theory, equal less energy expended to turn the pulley wheels.
Of course, all those free watts can be undone if you don’t keep your drivetrain clean. This isn’t a set-it-and-forget-it upgrade for your everyday ride. Think of these pulleys as a race-day weapon and you’ll get the most out of them; get them gnarly with grit for days or weeks at a time and you’ve just dropped coin on some colorful wheels that won’t help you go faster.
Installation of these 16-gram pulleys took only a few minutes. Once they were on, we did have to do a bit of rear derailleur adjustment, though it wasn’t clear whether that was due to the pulleys themselves or just routine maintenance. Once that was done, shifting was as clean and crisp as it was with the stock pulleys.
The wheels themselves are CNC-machined from a “self-lubricating” plastic (that means oils within the plastic are a part of the material’s structure and are always present on the surface of the plastic, even though you may not feel it). This should help prevent premature wear. After a few hundred miles of riding, the pulleys do not appear to have worn noticeably, but we’ll have to put in some more miles to really get a sense of the long-term wear factor. We’ll keep you posted.
Are they worth the $225 price tag? That all depends on your goals and wallet heft. If you’re solidly in the Cat 1/Pro marginal-gains crowd, these pulleys, paired with a CeramicSpeed-treated chain, will likely have you expending fewer watts during the course of your race. But if your race day consists mostly of chasing KOMs with buddies, maybe pocket that $225 and save it for post-ride beer and pizzas.
(*The SLF Motion Friction Facts test was done as a one-off specifically for SLF Motion, while the CeramicSpeed pulleys were included in a broader test of several brands. The testing protocol is identical between the two tests, though Friction Facts buys the pulleys off the shelf for the independent test, while SLF Motion sent pulleys to Friction Facts for its test.)