Monday, December 05, 2016

Sometimes the old days really were good

A couple of bike tourists have left me their Sevens to reconfigure with 9-speed cassettes, triple cranks and barcon shifters. This is after a few years riding with the carbon compact cranks, 10-speed cassettes, and SRAM Double Tap shifters originally installed.

They came in originally because one of the shifter paddles had snapped off on one of those SRAM Double Tap shifters, they way they are prone to do. SRAM offers the shifter paddle as a replacement part, but only below the point at which they always snap off.

Any of my regular readers will know how I scoff at the brifter concept for anyone but a dedicated racer. The fact that spell check produces the word "grifter" when it flags brifter as a misspelling seems highly appropriate. Oh boy! More expensive crap to break! And don't even think about fixing it yourself.

Accustomed to vehicles that can't be repaired and that use mysterious assemblies that function perfectly until they suddenly don't function at all, modern riders have been well trained to avoid doing much of their own maintenance and repair. You can still change a tire, dial in your index shifting, and lube a chain, but don't mess with anything else.

As part of the design process, I pored over gear charts to come up with cassettes that would offer helpful gear intervals int he ranges these riders will actually use. I came up with a good range on a 9-speed 13-36, with 26-36-48 chainrings, that had no duplicates (one, actually, but not in a combination one should use) and gave closer spacing in the low range than the high range. Unfortunately, we would have to buy at least four cassettes, plus eight or ten Miche cogs, to get two cassettes with the desired cog sizes.

Here's where the olden days were better than nowadays: When cassettes were introduced by Shimano around 1980, they offered a rider complete flexibility to spec and assemble gear ranges suited to individual need or desire. This could still be true, but some bean counter figured out that it was cheaper for the company to offer specific cassettes with unchangeable ranges. The free-range cog has nearly vanished.

Miche offers complete custom capability, but only from 11 to 29 teeth.

My customers could use some sort of dinky crank with a tiny BCD, but 64-104 or 110-74 are widely available in case of a breakdown in the boonier parts of the world. So topping out at 29 is not the best option.

Having discovered that the cogs for my ideal cassettes will be expensive to collect, I'll dig back into the gear charts and figure out how to make the best of what the industry forces on us. With the War on Front Derailleurs, some crazy wide-range cassettes are showing up. I sketched out a few ideas for an 18-speed cassette, just to try to get ahead of the trend by a year or two. Maybe out of all the horseshit and chaos I'll find something off the shelf that does most of what I had put together in my original design.

Crankwise, the workhorse Deore triple seems like the best choice. I like the old reliable Sugino XD 600, but I wonder when the square tapered bottom bracket axle will finally disappear. I should start stockpiling.

It's the time of year when the weather can change radically from one day to the next. It snowed all day today, only netting a couple of inches. The National Weather Service outlook for December sets up parameters that could bring snow, but their three-month outlook inclines toward more drought or possibly rain. Attempts to park and ride or park and ski fail because no one plows out places to park. The trip to work becomes all or nothing.

For the past several years I have put studded tires on my path commuter, and then either had bare ground or deep snow to deal with. Installing them is still the signal that winter is really here.


Grego said...

Howdy. I've had really good luck and overall low cost in replacing my 10sp Shimano triple with a double crankset (11sp 36-52, but still a 10sp drivetrain), wide-range cassette (11-34) and a Wolf Tooth RoadLink derailer extender. I now have the exact same top gear and bottom gear ratio as before, but the double shifts a whole lot better than the triple crank ever did. I strongly recommend this setup.

Steve A said...

Perhaps I'm confused. Don't nine speed rear cassettes use narrower chains than cassettes with eight or fewer speeds? Seems that giving up chain wear in exchange for 3 extra speeds is less than ideal. Myself, I'd go for a compact crank, combined with a well-chosen set of eight gears in the rear. Actually, if cycling around flat lands like Ocean Shores, a single in the front with seven rear gears is more than what I use. I DO like barcons, however.

cafiend said...

Steve A: I got my 9-speed-spaced 8-speed on a 7-speed cassette to work fine with an 8-speed chain on my road bike. That was what encouraged me to go with 9 on these two touring bikes. They ride in hilly and mountainous country, so they can use lots of gear options.

Gego: I avoid 12s and 11s because I cling to the idea that more teeth engaged means somewhat slower wear. Not that tourists will spend a lot of time in top gear, but that also favors a 13, to move the steps closer together across the range. Going with a more robust chain is another durability issue, based on a bit more metal carrying the load.

I'm not sure how we ended up with the triple, except that they already have a 34-36 for low gear, and a 26 lets them pull that down further. They don't need the snappiest shifts. My debate is whether to go square taper on the BB so they have the option of converting their triples back to compact doubles if they decide they prefer it. With friction shifting they can play these sorts of games. Shove the chain line in and out by changing a relatively inexpensive cartridge BB.

Steve A said...

Hope you had a GREAT Christmas!