Which is not to say that I would never by a hub geared bicycle at some future time, just that I think derailleurs still have a lot going for them.
I agree, Peter; I still have a fleet of bicycles happily using derailleurs -- and freewheels -- that are friction-shifted and date from the late 1970s through the 1980s. Their thick unramped, unpinned alu chainrings seemingly last forever, and I wouldn't think of converting them to greater modernity if they can be made to go on as they are.
Carrying it further, I believe modern-day indexed shifting has simplified derailleur
use (shifting) to a point where it is about equal to a Rohloff for sheer ease...so long as we're talking rear shifting. The front shift still proves problematic for some (especially if friction-shifted), but on the whole, rear shifts are the same as on an IGH -- pause or ease momentarily (or don't, with modern mechs), yank the lever a click or two, and there you are; a nice, clean shift to the next gear. What a derailleur drivetrain cannot do is allow one to shift the entire range sequentially with a single control, or allow one direct access to the next higher or lower gear in the entire range without at least one double-shift. You have to watch out for the "naughty combinations" that result in cross-chaining and greatly increased friction and wear.
One area where derailleur drivetrains have slipped over time is in component lifespan. In current versions, the cheaper (steel) stuff can actually outlast the more expensive (alu) 'ringed versons. In the quest to make shifting ever easier and more convenient, to make chain pickup even faster when shifting under load, the teeth have been contoured to the point (sorry) where there is much less surface area. In an effort to increase gear range with crossover shifting layouts, more cogs have been added to the cassette, meaning the chains have also become narrower -- all while maintaining about the same number of usable gears, thanks to chainline issues.
What this has amounted to is faster drivetrain wear due to decreased contact surface area between meshing components. I'm a 1960 model rider, who thinks the apogee of derailleur drivetrains came with my half-step triple/7-speed cassettes and sort of trailed off from there -- at least, where component life is concerned. An interesting take on this issue of diminishing returns wrt more/narrower cogs/chains/'rings on derailleur drivetrains can be found in an article by Dan Towle at R&E Cycles in Seattle:
http://www.rodbikes.com/articles/web_articles/retrogrouch.html Look especially at the subheads labeled "Durability" and "Increased Cost". It is on this point where high-end modern derailleur systems that see heavy use are nearing the economic breakover point to being as costly over time as high-end IGH drivetrains like the Rohloff. Taking Dan T's argument to its logical extension, a high-mileage rider could expect to buy a dozen chains and cogsets each year with a drivetrain running a 10-speed cassette; 9- or even 8-speeds are more economical to operate, but harder to find repacement parts for. The thrust of Dan T's argument is here:
Durability:
10-speed chains are very thin, as are the 10-speed cogs. This means that they don't last near as long as a thicker chain and cogs. In cases of heavy commuting or touring we've seen many customers who get about 700 to 800 miles out of their chain and cogs. For some of those customers, that's about 1 month of commuting. That's 12 chains and 12 cog sets per year. For a customer riding across the United States, that's 4 chains and 4 cog sets. When used on a tandem, the mileage decreases by about 30%. By contrast, these same customers would be getting 1,200 to 1,500 miles on a 9-speed chain and cog set. Does this mean that an 8-speed chain and cog set would be even more durable? Yes, but 8-speed shifters are not available anymore, so 9-speed shifters are the new durability choice.
Increased Cost:
A 9-speed chain sells for $30. A 9-speed cog set sells from $45 to $60. By contrast a 10-speed chain costs $70, and 10-speed cog sets are $100 and up. When you multiply the frequency of replacement by the cost of equipment, your maintenance costs are increased by 200%. A 200% increase in maintenance costs are not the direction that most of our commuting and loaded touring customers want to go. Some people have no problem with the increased costs or service. Rest assured we still build touring bikes with 10-speed shifting quite a bit. We just want to share why 9-speed shifters are standard on our touring bikes.
Interesting stuff, and a factor in my choosing a Rohloff for long-distance
touring (and the fact that the expedition-grade Nomad Mk2 is only available
mit Rohloff) going forward. It is simply going to have lower operating costs and longer component life in future, and these are huge features for me in a bicycle I expect to last for the next 20+ years of high-mileage use. It is...freeing to simply twist the dial shifter and go "up" or "down" to adjust effort or ease as desired. The Nomad is the first of my bikes never to have a gear chart, and I still catch myself looking back inside my right leg to check which gear I'm in, chuckling when reminded I don't have to! On the other hand, I still enjoy the fun and challenge of manual/friction shifting my now-vintage 5- and 6-cog derailleur bikes, just as I enjoy driving a car with a manual transmission -- there's a certain joy in accomplishment in employing the skills I've acquired and that adds to my riding pleasure rather than detracting from it. I'll keep my older derailleur bikes and drivetrains for as long as they last, but when they die?...Dunno what I'll do. At that point, the Rohloff-hubbed Nomad may become my
only bike.
All the best,
Dan. (who loves
bicycles, no matter the drivetrain...)
