A few notes about the 144#47 track chain rings by 44RN. These rings are designed to be extremely quiet, right out of the packaging but there are a few things you need to do:
-run a new chain
-run a new cog
Check out why below.
This shouldn’t be news but some people might overlook it. Any bike shop will tell you it’s the right thing to do, but it’s especially important to do it with these rings. Why? Because chains and rings wear in the same spots. And putting an old chain onto a new ring will wear it down faster.
“Prior to selecting a machine shop, I machined prototype blanks (chainrings with no aesthetic features) with the new tooth profile that I had been developing. I gave these hand-numbered blanks to friends and had them roadtest the fit, noise-level, and wear of the tooth profile. Noise-level might seem like a strange parameter on which to conduct performance tests, but I was trying to get the widest quiet-running tooth possible. Wide BMX-style teeth grind and grate until they are broken in and I wanted these chainrings to be smooth and quiet from day one. I also went through a dozen or so designs before settling on the the cut-out design and labeling scheme.”
“At no point in the process of making these chainrings did a file or manual deburring instrument touch the parts, every single edge on the chainring (front and back) has a precision machine-broken 45-degree 0.010-in deep chamfer. A custom 20-degree chamfer tool was used to precisely bevel each tooth during the machining process.”
The rings were fully CNC machined from certified 6061-T6 aircraft grade aluminum plate stock. Each ring was then lightly buffed and delivered to another local shop for black and clear hardcoat anodizing.
Basically, you’re getting a bicycle component that is designed and manufactured by someone who cares and actually knows what he’s talking about. I wouldn’t sell these rings if that wasn’t the case.
Follow 44RN on his site for more design-oriented geekery. Thanks again man!