Thursday, September 18, 2014

Public service announcement: 1991 Diamond Back Master TG seatpost size

Yep, it reads 27.0 mm on that Avenir 4130 steel seatpost.
 Per request from a reader, here are some images of the seat tube cluster on my 1991 Diamond Back Master TG. As these bikes age, there are likely still many usable frames out there in the wild. A critical element of putting one back together is to source the correct size of seatpost. As this type of info can be difficult to find elsewhere, I'm posting it here. For the record, the frame requires a 27.0 mm seatpost.

If you're here for the purpose of rebuilding an old Diamond Back road bike, you may be interested in learning more about my pepto-pink '91 Master TG, which I discovered nearly unused a few years ago. Good luck with your project!
Seat cluster from the back...

...the left side...

...and the right.

Saturday, August 23, 2014

Littleton Criterium

I don't do much with racing or competition on this blog, or in real life for that matter. However, I felt obliged to report that we watched at least part of the Littleton Criterium a couple of weekends back.

We had a good time, and especially enjoyed watching the women's intermediate race. Both girls were duly impressed with the speed of the riders, and enthusiastically rang our cow bell to cheer them each lap.

Dark clouds and nap time approached in the afternoon. We nearly won our race against the downpour, but were caught a few blocks from home. No breakaway for us. Drenched, but still a fine day out.






Saturday, August 16, 2014

Happy birthday Uncle Jake!

To Jake in Palau from all of us, enjoying ice cream in your honor at Western Welcome Week.

Friday, August 15, 2014

First day of school


As incomprehensible and summer-stealingly ridiculous as it sounds, today, mathematically not quite halfway through August, is the first day of school. We made the most of it, and had a nice family ride to get there. Little sis was a bit confused, especially when we towed her big sister's bike home, due to after school activities that will preclude the possibility of riding home.






Thursday, July 31, 2014

Dumpster + Stumpjumper = Dumpjumper

1988 Specialized Stumpjumper in size 21.5 inches, as found in a dumpster.
Please note that the following post will likely only appeal to and/or be comprehensible by the most bike nerdish among visitors here. You are hereby warned and/or welcomed.

I've fished many a bike out of dumpsters over the years. I don't generally go looking for them, but they often have a way of finding me. Some have been complete basket cases and others have only needed air in the tires. Yet, what never fails to amaze me is finding a decent quality bike tossed in the trash. Old bikes aren't like old computers, in that they never become completely obsolete or unusable. Old bikes aren't like old cars, in that they don't degenerate into egregious polluting money pits, but instead are cheap and easy to recondition. Old bikes aren't like old furniture or mattresses, in that they don't absorb unappealing substances from previous owners.

I can understand rationalizing the discarding of a less than functional department store bike that was never engineered to work well in the first place. That which is nearly useless readily becomes useless. However, bikes that were at least initially high in quality of materials and construction, unless mangled, are almost always repairable into good running condition. This goes doubly so for steel mountain bikes from the off road boom era of the 1980s; with sturdy tubing, user serviceable components, and lack of suspension, they're almost indestructible.

Don't get me wrong. I don't pine for the old days and I'm no longer the Luddite I once was concerning the evolution of bike design. I appreciate lugs and fancy steel, but I also know that great advances have been made in materials and technology, and that, venerable as they are, these sturdy old steel bikes are no match off road for something more modern, like my Salsa Horsethief for example.

On the other hand, I'm certain that with proper care the long-term viability of an old steel monolith will far outpace many modern bikes in the utility department, most likely to the tune of decades. There are far fewer things to go wrong with these old bikes as compared to newer bikes, and equivalent parts are still readily available. With components in good order, a set of lights, a pair of fenders, and some method to carry cargo, an old steel mountain bike can't be outmatched for usefulness.

Deore index/friction thumbshifters and Deore 4-finger brake levers.
Now for a little velo-pathology to explore how this bike may have traversed the past quarter century. This particular Stumpjumper seems to have spent much of its life dormant, stored somewhat haphazardly, and perhaps used intermittently. It has plenty of telltale signs of neglect, in the form of nicks and scratches in random places, probably from being leaned against things or falling against other items in a shed or garage, and a veneer of dried on grease and oil from infrequent maintenance. The underside of the downtube is mostly free of rock strikes and the drive-side chainstay shows little sign of chain slap, so I'd wager that the bike traveled most of its miles on smooth surfaces in town as opposed to rough trails.

Non drivetrain side. Notice the pronounced bend in the rear rack's shelf and support struts.
The remains of a decal that once proclaimed the bike's chromo tubing and Taiwanese manufacture.

That's a solid forged aluminum stem. They don't make 'em like that any more. The stem alone probably weighs more than a modern carbon frame.
Though this bike likely hasn't seen a lot of miles, it had no easy life. It spent enough time outside for the graphics to fade, and there is a bit of surface rust where the steel has been exposed due to paint chips. The components that are still present are without exception original and stock, even down to the grips.

The drivetrain and brakes are Shimano Deore, from back in the days when Deore was on the penultimate tier of Shimano's off road lineup. The cranks are in good shape, and the teeth of the very '80s Biopace chainrings look healthy. Bearings haven't fared as well, as the bottom bracket is indexed, and the headset is in poor adjustment. However, the open seat tube is not rusted, and the chain is oily and moves freely. The derailleurs look fine and move well, but the cables and housing are sluggish and gummy. The shifters are intact, though the mount for the left shifter is bent. The good thing is that all the components on this bike are rebuildable, and the bearings are easily replaceable if needed.

There are a few additions to the bike that have occurred over the years. Though now badly bent, a period concurrent, white Blackburn Mountain Rack was a common addition to many bikes of the era. There is evidence of bar ends once installed but now gone, a sign of an update in the early to mid '90s when bar ends enjoyed popularity. A cycle computer mount at the rear wheel, indicates this bike was probably used on a stationary trainer at some point. Bright red paint under the upper and lower Zefal plastic pump mounts along the back of the seat tube signal that they were probably installed at or near the time of purchase.

Drive side top tube.
Drive side down tube.
Non drive side top tube.
Non drive side down tube.
As its year of manufacture is the same as that when I finished high school, bikes much like this one dotted the college campus of my undergraduate career. Distinctive two-tone paint schemes, unique to 1988 and 1989 Specialized bikes, seemed omnipresent for many years.

This Stumpjumper is readily identifiable as being an '88, due to its under the chainstay u-brake, a feature adopted by most manufacturers for a brief period spanning from about 1986 to 1988. Builders and riders went crazy for u-brakes because of the clean looking cable lines and the u-brake's powerful stopping ability. The popularity abruptly ended once the same builders and riders realized that under the chainstay was a less than convenient location for brake maintenance and made for a tremendous mud and debris catchment area. I've owned a few such u-brake equipped bikes, and though the reason the design was quickly dropped remains potentially problematic, the brakes are dependable and powerful if properly adjusted.

I've yet to get my hands dirty with this Stumpjumper, but that I will rebuild it is not in doubt. I'm happy to have saved the bike from an ignominious end, and I know it has at least a couple more decades of service within its capacity. Whether it will be with me or with someone else is yet to be determined.

Bikes like this Stumpjumper are the antecedent to a growing renaissance of steel, multipurpose, high utility bikes, such as the Surly Long Haul Trucker and the Surly Troll, among others. While at present it seems absurd that a desirable Surly frame will ever make its way to a dumpster, 25 years ago it seemed equally improbable to one day discover a Stumpjumper in the trash. I can only hope that in another quarter century, I'll be the lucky one to find a crusty old Troll next to yesterday's coffee grounds.

I threw on a pair of wheels to get a visual. My parts bin came up short in the quest for a 26.6 mm seatpost.