Jags, Andre,
Thank you both for your input and views. Jags, I'm interested to know if you have some idea of the life you're getting from the Dura-Ace chain. Over here, they're terribly expensive compared to their lesser brethren, and I wasn't sure they would be worth the extra cost over their service life. If they are unusually long-wearing, then the cost would be amortized and they could well be worth the extra expense.
I was horrified at the reviews I read on a number of 'Merkin websites indicating my Shimano HG73 is so break-prone as to be worthless -- as is the KMC x9.93 and nearly every other 9-speed chain one could name! It seems there is little middle ground in the reviews. A few riders claim great durability from their chains and rarely if ever break them. By frequency, the majority feel 9-speed chains of any stripe are break-prone and it is not a matter of if but when they will part and likely sooner rather than later and at the most inconvenient time in the most remote locale. Worse yet, few of the customers writing reviews take the time to indicate which model chain they have, so the reviews for a given model may encompass the dredges of a given manufacturer's product line as well as the apogee.
I decided a little triangulation was in order, so I hied myself over to some UK-based review sites and found the opposite.
I am beginning to wonder if a) Radically different stock is sold with the same designation on two different countries, or b) There is something different about how riders ride in the US vs the UK, or c) There are different ways to join a cut chain and people over here are doing it wrong. Shimano has some pretty explicit instructions about where to cut a chain, and where to rejoin it using one of their elongated, snap-off pins. I have a feeling a number of people may be reusing a "spent" mushroomed pin or are using a competitor's connecting link and there may be a slight difference in length that leads to subsequent failure (the research methodologist in me wonders about a lot of other possibilities, including self-selection and sample stratification. Complainers seem more likely to write and whinge than if they were the satisfied and silent majority; maybe we are more apt to vocalize our complaints more over here). It is also possible the majority of American reviews are written by mountain-bikers while those in the UK are written by a greater cross-section of riders, including commuters and tourists/trekkers and road-bike cyclists. That could skew the reviews.
I'm used to chains intended for 5-6 speed friction drivetrains and my previous "new" bike, the 7-speed indexed 1989 Miyata 1000LT. The world of 9-speed indexed drivetrains as on my Sherpa is a new one for me, and I feel some wonder at what I read of failure rates. I've never, ever broken a chain, and I approach indexed shifting as I did friction, easing off the load during a shift and avoiding cross-chain combinations. I spin the pedals at a pretty constant 110-120rpm and shift early to keep torque loads low. I set up my previous bikes with half-step gearing arranged such that my most frequently used combinations had little if any chainline issues. I typically discarded my chains at around 3,000 miles (4,800km), and I am still running my large, thick alloy chainrings at 35,000 miles (56,000km) with no complaints. Things have changed, particularly with regard to chainring size, which has to accelerate wear as a function of surface area. Same with 11t cogs. My highest cog is the same size as my derailleur pulley! Makes me glad the two inner 'rings on my Deore chainset are steel.
Andre, your experience with the KMC is a great help and reassurance to me, and I feel much more comfortable laying-in three of the x9.93s. I was a little leery of the dot-dash silver-black pattern, but on reflection, realized I've never had a chain rust on me...not even the all-black models. I'd far rather replace a chain prematurely than to "go long", risking greater wear of the chainrings and cassette cogs.
Along those lines, my reading reveals a number of folks are running two or three chains and swapping them in and out periodically. I can see this would get one back on the road more quickly, perhaps, but beyond that, does the practice have any real benefit over running a single chain to its wear limits and then exchanging it for a new one on the same 'rings and cogs? (as I have always done). The only advantage I can see would be the difference in wear between a given chain and the chainrings/cogs would be less than if one put a new chain on worn cogs. Maybe the idea is to eke out a bit more life on the 'rings and cogs than would otherwise be the case. Perhaps this is more critical with 9-speed equipment, where there is considerably less surface-area than in older drivetrains with fewer cogs.
I welcome your thoughts and ideas on this.
Thanks!
Best,
Dan.
