Originally Posted by
Broctoon
I like to buy stuff in the middle of the spectrum. My road bike has a combination of 105 and Ultegra components, and Mavic Open Pro wheels. I have a WTB seat, a Fabric, a Fizik, and a few Brooks. My best, most expensive fixed gear bike rolls on Reynolds carbon rims and Phil hubs (that I bought used), and it has a Zipp seat post, Profile stem, Cinelli handlebar, Tektro brake lever, and DuraAce caliper. My bike that I ride more than all others is a Surly with All City crank, Fabric seat, and Velocity wheels. I don't pay full retail for anything, but look for clearance sales and lightly used parts from private sellers. I would not be opposed to spending for a DuraAce cog. Most of my cogs run in the 20-30 dollar range, from All City, Surly, and Soma, plus a few cheapo stamped ones that I don't use but keep as spares...
My point in the message above was not to degrade the quality of nice, somewhat expensive parts, but to point out that as you go up in price point, you gain lesser and lesser practical improvements. Along the spectrum from the absolute cheapest to most expensive parts, I believe the stuff of best value* usually falls somewhere around the 20 to 40% range. As an example, I just checked Retrogression's range of cog offerings. They go from the 2-Dolla cog at one extreme to the Sugino Gigas (with invaluable NJS stamp!) at the other: a range of $2 to $110. Whaddya know! The DuraAce sits right at 28% in that range.
You can do this with tires, frames, even complete bikes, and it almost always works. Sometimes you have to exclude the high outliers, like primo boutique parts. Otherwise, it seems the 30-ish percent price point almost always offers the most value for ordinary guys like me.
I doubt most people will notice any difference between a DA cog, at $30, and a $20 Soma while installing it or riding it. Most probably will notice subtle benefits from a DA vs. a stamped Chinese 2-Dolla cog. But I'm almost certain nobody here will be able to differentiate the DA from the $110 Gigas without looking to see which is installed. If you've got lots of money, go ahead and spend it on bling parts. If you're a Keirin racer, you have to spend extra for the NJS stamp. For all the rest of us, the best bang for our buck comes from the low to mid-range stuff... not the cheapest available, but not stuff at even the 60% point on the price spectrum.
* value = quality per dollar
I notice a little difference between Gigas and DA it is maybe not huge but I need to do a side by side because it has been a while since I have used the Gigas cog (WI freewheel took over on the cross bike) It is certainly a very quiet drivetrain with the same chainrings but slightly different chains (though both pretty high quality decent dollar ones). No I didn't buy it for the NJS stamp and could care less for it but mainly for a top notch drivetrain which is way cheaper than going full Dura Ace road or XTR mountain.
I will say mid range stuff is just fine for most folks and I would say Dura Ace is a good mid-range cog. The lower end stuff not so much but spending for a DA cog is not that much compared to your Soma cog and I think would be of better quality or at least more of a known quality. Soma makes fine stuff don't get me wrong but everyone knows Duraaces the finest of all the Italian components ; )
105 and Ultegra is great stuff. My road bike is all Ultegra (well eeBrakes are the exception and those aren't cheap) and I probably wouldn't go Dura Ace unless I got a better deal on it because I think Ultegra through most of their iterations except maybe the 9 speed era has always looked better. My vintage road bike is 7400 Dura Ace but honestly the 600 tricolor looks way way better. Especially over the Dura Ace rear derailleur, but maybe back then it looked better but alas I was a bit young to be working in a shop then.