Hi Zoslen!
Dan Towle at R&E Cycles in Seattle, WA wrote a nice article on this very topic:
http://www.rodbikes.com/articles/web_articles/retrogrouch.html...and another article detailing some of the reasons why these things occur:
http://www.rodbikes.com/articles/proprietary-parts.htmlI appreciate Thorn's commitment to proven, lasting components and tour-tested design; we're the lucky beneficiaries of designer Andy Blance's real-world use and testing in his own tours.
However, Shimano are a major OEM and aftermarket supplier (as are SRAM and Campagnolo and a number of smaller firms). Each year these companies make changes in their lines. Sometimes they are minor, other times, those changes are so large as to render previous generations obsolete through incompatibility. These major component suppliers also retire older lines from time to time, meaning no direct replacement parts are available. When derailleurs were friction-shifted, this wasn't much of a problem. With the introduction of indexed shifting, components became systems with less interchangeability. Yes, sometimes old and new parts can mix together fine, but increasingly, when old parts wear out, the fix requires major components of a new
system to get things working again.
I noticed at Thorn's latest brochures that Sherpa and Audax have moved on from 9sp to 10sp.
I am really wondering WHY?
My guess is Shimano is no longer making 9-sp components available in OEM volumes, so Thorn have
had to make the switch to 10-sp. Knowing their commitment to long-lived components and bicycles, I have no doubt they have vetted the available selection to spec the best of what's available.
Will it "last as long" as 9-sp? All indications would be no, but I was pleasantly surprised to learn 10-sp chains came out well in a real-world chain test:
http://www.bikerumor.com/2013/02/19/bikerumor-shimano-chainwear-challenge-the-results/ The reported test results?:
Simply put, the 10 speed chains lasted longer. Quite a bit longer, in fact. Even the difference between the worst performing 10 speed chain and best performing 9 speed chain was still 225 miles. The difference between Bob and Chris (both endurance racers of similar skill and size) was a whopping 470 miles.
While the performance of the 9 speed group was fairly constant, the 10 speed chains seemed to gain a second wind in the last half of their total mileage. They just wouldn’t die – I would tell riders to expect only about 50 more miles, only to have them return 100 miles later and still not be finished.
As to why, the article concludes:
We’ve spoken with Shimano many times about the durability of their chains, and what thinner chains mean for durability, and the answer is always the same – the new chains are stronger, because they are engineered to be. In fact, Shimano claims the new Dura Ace 11 speed chain is the strongest chain they’ve ever made which means it replaces the XTR Dynasys chain for that honor. In order to make this a reality the new chains are built with tighter manufacturing tolerances, improved plating, and improved design, all of which add up to better shifting, and better durability.
...with this surprising statement:
Shimano is quick to point out that there is actually very little correlation between chain width and durability, if any. Rather, ultimate durability comes down to the construction of the chain and the layout of the gearing like the wide range of the cassette and narrower range of the crankset on the Dynasys drivetrains.
If this is true, then there is hope better manufacturing (i.e. manufacturing to tighter tolerances) will result in 10-sp drivetrains as long-lived as 9-sp.
As for me, I still very much like my CA 1989 Shimano Deore 7-sp drivetrain..which has yet to "wear out". For that matter, I'm still running friction shifters and 5-sp and 6-sp freewheel drivetrains that work as nicely as I might hope for even after tens of thousands of miles.
At the other end of the spectrum, there's the Rohloff...proven, reliable, backward-compatible and about as trend-resistant as you can get, with the inbuilt advantage of very long life thanks to the design and shielded oil-bath lubrication. Pretty much the ultimate in reliable, robust drivetrains if wear-resistance is the key factor.
Best,
Dan.
