Measuring Chain Wear

A bicycle chain elongates as it is used. This elongation – commonly referred to as “stretch” – is caused by the wearing down of the pins that hold the chain links together and the enlargement of the bore hole in the inner plates that the pins are inserted through. If left unchecked, wear on the chain causes the teeth on the cassette cogs and crank chainrings to become reshaped to the point that they will no longer mesh with a new chain. To extend the service live of these more expensive components, it behooves one to replace the chain before it becomes excessively worn. For drivetrains below 10-speed, the common advice is to replace the chain when it measures 0.75% elongation. For drivetrains above 10-speed, the common advice is to replace the chain when it measures 0.50% elongation. For 10-speed drivetrains, opinion varies between the two measurements, so take your pick.

Chain elongation may be measured with a ruler – 12 complete links on a chain should measure exactly 12 inches – but performing this measurement with accuracy and precision, and identifying when the measurement is off by 0.50% or 0.75% can be difficult. Hence the market for chain measurement tools.

In the past I have used a Park Tool CC-3.2 and a Park Tool CC-2. The CC-3.2 was a simple go-or-no-go measurement tool which attempts to identify when the chain has reached the 0.50% or 0.75% limits. The gauge of the CC-2 provides a more detailed look, attempting to show you not just if the chain has reached the replacement point but also how closely you are approaching it. Both of these tools share the same weakness: they measure from opposing roller faces, meaning that when the tool is inserted into the chain it is applying pressure in opposite directions. This behaviour incorporates inconsistencies of the roller diameter into the measurement, rather than just measuring the pin-to-pin distance, which can result in the tool providing a premature indication of the chain’s wear.

Pedro's Chain Checker Plus II

Recently I purchased the Pedro’s Chain Checker Plus II. This is one of a newer generation of tools which attempts to eliminate the previous inaccuracy by measuring from the same side of the roller. The tool applies the load to the chain in the same direction during measurement, rather than pulling in opposite directions. This simulates how the cog experiences the chain when the bike is pedaled and allows the tool to more accurately gauge the pin-to-pin distance. Compared to an older style tool like the Park CC-3.2 or CC-2, it should tell you to replace the chain later. Getting more life out of the chain (without potentially damaging the other components of the drivetrain) is useful not only for your wallet, but also to reduce waste. A Duke University study claims that the manufacturing of a chain is one of the more wasteful parts of bicycle production.

The Park Tool CC-4 should provide the same measurement as the Pedro’s Chain Checker Plus II. I went with Pedro’s option because it also provides a chainring nut wrench (useful when tightening or replacing chainrings) and a chain hook tool (theoretically useful when installing or removing chains with master links, though I’ve never found a tool necessary for this).

I learned about these newer tools thanks to Dave Rome’s excellent article on CyclingTips, which includes many more details on chain wear and measurement.

This post was published on . It was tagged with gear, bicycle.

Better Bondage with ROK Straps

ROK Straps are superior bungie cords. They are designed to be safe and long lasting during prolonged outdoor use. Each end of the strap consists of a sewn loop, allowing it to be securely fastened to a wide variety of frameworks without concern for scratching or marring the surface, or for a hook coming released under tension and finding its way into an eyeball. Cargo secured by the ROK Strap is easily accessed via the side-release buckle. Most of the ROK Strap is simple webbing, adjustable thanks to the buckle. One side of the ROK Strap has a short segment of a durable natural rubber, giving the strap some elasticity, but not enough that unintended recoil will likely result in the strap finding its way into an eyeball. The rubber is contained in a polyester braid for UV protection and additional durability.

ROK Strap: Models

For securing cargo to a bike rack, my preferred model is the Pack Strap. These expand from 12” to 42” inches. They are 5/8” wide and are rated to carry up to 55 lbs. I find this is the right size for most cargo and have used it to transport: sleeping pads, folding chairs, toilet paper restocks, a year’s supply of paper towels, pizza, and takeout yakisoba.

  • ROK Straps: Toilet Paper Transport
  • ROK Straps: Yakisoba Transport

The smallest model is the Commuter Strap. These expand from 12” up to 28”. They are 1/2” wide and are rated to carry up to 40 lbs. If you just want to lash down a jacket or sleeping bag, these may be appropriate. They are long enough to secure common small cargo on a bike, but I would always rather have the extra range of the Pack Strap for handling awkward loads.

ROK Straps are also available in the ATV Strap model. These expand from 18” to 60”. They are 1” wide and are rated to carry up to 100 lbs. Apparently these are popular among people who ride motor-scooters. The 18” minimum length is too large for some of what I want to attach to a bike, and I’m not keen to carry cargo that would require the 60” maximum length. I saw a photo once of somebody who used these to attach a 45 gallon trash can to the back of his scooter. If that’s what you need to do, I guess consider these, but for what I find myself carrying I don’t need the extra length or weight rating of these over the 42” Pack Strap. This model stays at home in my bag of miscellaneous bondage.

The above measurements are of the ROK Straps when the rubber is at rest. When under load, all three models can stretch about an additional 4”.

The loose ends of the ROK Straps can be secured using either VELCRO One-Wrap or ITW Web Dominators.

ROK Straps: One-Wrap

ROK Straps: Web Dominators

Ritual Masks

The use of respirator masks in popular culture is often more about social signaling than medical efficacy, similar perhaps to decorating your door frame with lamb’s blood. Yet huge global demand has caused a shortage in hospitals, where the use of respirators does actually serve a functional purpose. A Vietnamese company – possibly realizing that much of the current demand stems from symbolic usage – decided to make masks out of toilet paper. These would have sold well in Hong Kong during the SARS epidemic, where mask usage emerged as an important social ritual:

In a masked city it was difficult to recognize the identity even of one’s friends and colleagues as they passed. Yet mask-wearing became the quickly improvised, if obligatory, social ritual; failing to don one was met with righteous indignation, a clear sign of ritual violation. The mask symbolized a rule of conduct -– namely, an obligation to protect the wider community – and an expectation regarding how one was to be treated by others (Goffman 1967b [1956], p. 49). More simply, the mask was the emblematic means by which people communicated their responsibilities to the social group of which they were members. Through mimicry and synchronization… mask-wearing amounted to a joint action, normatively embodied, the entrainment and attunement of the society as a whole. By disguising an individual’s face, it gave greater salience to collective identity. By blurring social distinctions, it produced social resemblance. Mask-wearing activated and reactivated a sense of a common fate; it was a mode of reciprocity under conditions that supremely tested it. Accordingly, mask demeanor was much more than a prophylactic against disease. It showed deference to public emotions and the decision to respect them.

Today mask usage interferes with facial recognition. That AI researchers and corporations are scrambling to work around this limitation is expected, but in a sane timeline individuals would identify this limitation as an unexpected bonus of the ritual. Instead the response is printing faces.

A Sign of Dystopia

This post was published on . It was tagged with air, quote.

Consecutive nights of reduced sleep may lead to the same deficit in cognitive behaviour as complete sleep deprivation.

A 2003 study concludes:

Since chronic restriction of sleep to 6 h or less per night produced cognitive performance deficits equivalent to up to 2 nights of total sleep deprivation, it appears that even relatively moderate sleep restriction can seriously impair waking neurobehavioral functions in healthy adults. Sleepiness ratings suggest that subjects were largely unaware of these increasing cognitive deficits, which may explain why the impact of chronic sleep restriction on waking cognitive functions is often assumed to be benign. Physiological sleep responses to chronic restriction did not mirror waking neurobehavioral responses, but cumulative wakefulness in excess of a 15.84 h predicted performance lapses across all four experimental conditions. This suggests that sleep debt is perhaps best understood as resulting in additional wakefulness that has a neurobiological “cost” which accumulates over time.

via Sean Bonner

This post was published on . It was tagged with micro, sleep, quote.

Shoulder Mounted OC

In 2014 I identified the ASP Defender series as the best pepper spray for my needs. I stand by this today, except that originally my preference was for the 4.5” Palm Defender. Over the years my preference has migrated to the 5.75” Key Defender. The Key Defender is in my pocket every day.

While I prefer pocket-carry for everyday, I’ve often thought about something that would allow for quicker access – especially on the bike. I’ve looked at a number of solutions for mounting a capsicum delivery mechanism to a bike, but never found one I liked. Instead, I ended up purchasing a second ASP Key Defender and mounting it to the shoulder strap of my backpack, which I wear frequently when in the saddle.

Shoulder Mounted OC

A small split ring connects the Defender to a magnetic clasp. This in turn is attached to a Lucky Line Flex-o-loc (the same thing I’ve been using on my keychain for seven years), which connects the whole setup to the webbing on my shoulder strap. To prevent the Defender from swinging around, I attach an IWB Soft Loop around the shoulder strap and shove the Defender through that.

The Soft Loop holds the Defender tight enough against the strap that it doesn’t spin around during daily carry. When mounting the Defender, I orientate it so that safety clasp (which I still cover with grip tape) is against the shoulder strap. This eliminates any chance of the safety somehow accidentally becoming released and the trigger actuating. It also keeps the safety in a known, consistent position when the Defender is drawn.

Shoulder Mounted OC

Enough of the shaft of the Defender is left below the Soft Loop that it can be easily gripped. It is deployed by simply ripping downward. The magnetic clasp breaks away and the top of the device slides through the Soft Loop. This is very quick and very easy to do, with either hand, even when wearing gloves.

Another neat benefit to the magnetic clasp is that it allows you to easily reattach the Defender, if you decide you quickly want both hands free. The magnet is strong enough that it will connect if you simply wave the top of the Defender within a couple inches of the half of the clasp still attached to the shoulder strap. This can be done without looking. Of course, the Defender will swing around as you move until you shove it back underneath the Soft Loop – a procedure which does take two hands and at least one eye.

Shoulder Mounted OC

I’m happy with this setup as a supplement to the OC carried in my pocket. It can move easily to different backpacks. It could probably be made to work with any pepper spray intended to be attached to a keychain, though it works especially well with the ASP Defender series thanks to the hammer grip used to deploy them.

Whenever I buy a new piece of equipment, I store its manual as a PDF.

If an internet search doesn’t come up with a copy of the manual, I’ll scan the dead tree version and OCR it. The document is then stored in an annex at ~/documents/manuals/. I rarely reference the product manual after initial setup, but when I need it, it’s extremely valuable to have it available – immediately and offline – as a PDF with a searchable text layer.

Some products don’t have manuals, but do have specification sheets. I store these in the same location. Sometimes I’ll just save the product page from the manufacturer’s website as a PDF. This allows me to easily lookup the dimensions of a thing I bought 14 years ago, despite the product being long discontinued by the manufacturer, or the manufacturer no longer existing.

This post was published on . It was tagged with micro, annex.

Of the many defunct blogs in my feed reader, one of those I miss the most is As the Crow Flies.

Crow is a woman who spent the summers hiking (mostly all or part of the PCT) and the winters as a cabin hermit (mostly in north-central Washington). Her interests in long-distance travel and off-grid living share many commonalities and resulted in much valuable information and insight. Long time readers here will remember her from The Vagabond’s Spatula.

This post was published on . It was tagged with micro, blogroll.