Whenever you are coasting on your bike, does your “high-quality” rear wheel sound like a naughty little kid attached playing cards to the spokes with clothespins while you weren’t looking?
Anyone who rides a bicycle with Chris King or Campagnolo hubs probably knows what I’m talking about. While not quite as loud as bikes with the former, the new Yishun 27-mm alloy rear wheel I got for the Super Bike was too loud for my liking. But not anymore. Why? No, not because I had swapped it out for another wheel or tossed it into a dumpster while exclaiming “quiet you fool!”—even though there may have been times I was tempted to.
Instead, I silenced the rear wheel in about 20 minutes in my workshop. The noise, of course, was caused by pawls clanging on engagement teeth of the freehub. So it was just a matter of quieting these pawls.
Happily, the freehub body was extremely easy to remove. The procedure was as follows:
- Remove the rear wheel from the bike.
- Remove the cassette from the wheel.
- Remove the quick release axle from the wheel, and insert hex keys into the two opposing axle end caps.
- Unscrew and remove the axle end cap on the cassette side.
- Slide the freehub body off the hub.
The pawls on my Chosen hub were on the inside of the freehub body. There were three pawls.
To silence the freehub, I did the following three things:
- Removed one of the three pawls (and associated spring) altogether. (Caution: Depending on the design on the hub, this can be risky. For example, in the 2005 Giro d’Italia, the mechanic for admitted doper Tyler Hamilton removed three of the six pawls in his rear wheel to save one or two grams, and his wheel catastrophically failed and resulted in a crash. Use your own judgment or do your own experiments, but do not sue me if you remove some pawls and have a Tyler Hamilton moment as a result.)
- Adjusted the spring tension for the remaining two pawls so that they don’t clang against the engagement teeth so hard.
- Lubricated the pawl engagement points (i.e., teeth) on the hub with lithium grease. (Caution: if the grease you use is low quality and dries out, this could cause problems with the pawls engaging. The lithium grease I use doesn’t seem to dry out in hubs even after 10 years, but again, if you choose to do this, know that you do so at your own risk.)
Then I reassembled the rear hub in reverse order of the disassembly procedure described above.
In terms of reducing noise, I’d rank the above fixes in increasing order of effectiveness as follows: greasing the pawls (least effective), removing a pawl (slightly more effective), and altering the spring tension (most effective).
The cumulative result was dramatic, as you can see (hear) from this before video:
and after video:
While not as quiet as the Shimano Ultegra 6500 hubs currently on my Cannondale 3.0 which are totally inaudible at speed, the Yishun rear wheel is no longer any noisier than the wheels on the rest of my bikes while coasting. I’d describe the sounds emitted from the coasting Yishun (Chosen) freehub as a low-level hum like that emitted by some outdoor power lines.
In any case, I no longer feel the need to shout “you shut up!” at the wheels whenever I coast.
March 2013 Update
I have gotten a few questions this month about whether my wheel has suffered any ill effects since implementing these modifications since a couple years ago. I am happy to report that my wheel has remained just as quiet and has performed beautifully even through epic rides such as riding 750 miles from Boston to Montreal and back in 3.4 days with 30,000 feet of climbing. Thus I consider this “fix” a total success.