Saturday, 20 August 2011

A km too far

How much can we or should we expect out of a carbon frame? Well, the answer to that question, at least in the case of my el cheapo ~ 3 1/2 year-old Cellnago, is approx 40 000 km, although this finality was realised by Iain (aka E), the metaphorical straw that broke the camel’s back. The bike i loved to hate, is finally kaput, but perhaps not for reasons one might have expected.

Due to a concoction of Chinese beaurocracy, painting issues, and life just being plain busy, the rolling out of the Wombat took 6 months more than expected, the result being that the Cellnago had done over 41 000 km before i had finished with it. Technically, this was only true for the front fork (original), whilst the current frame had done 25 000. Frame #1 developed fractures in the lacquer in the bottom bracket area after 15 000, although in light of my recent experience with the idiosyncrasies of clearcoating, i wonder whether the fracture pattern was really a hint of imminent failure, or merely a skin-deep cosmetic issue.

In any case, E had expressed an interest in using bike #2 once i’d moved on. My main concern was the fork and what condition it might now be in. The carbon blades were basically unscratched and good as new to the eye, despite its first and only bingle experienced just months earlier. My research on the subject revealed that the properties of carbon are such that barring extreme or catastrophic impact (ie. often resulting in breakage), carbon actually has an extremely good fatigue life – like steel but unlike aluminium, which has no fatigue limit. What this means is that an aluminium structure will accumulate fatigue regardless of the magnitude of the stresses involved (eventually accruing to failure), whilst steel and carbon will only accrue fatigue if a particular threshold stress is achieved.

I had pre-emptively acquired a replacement fork with aluminium steerer from ebay (approx $100), should another park-bench style incident befall one of us, and offered to install it for E before handing it over. However, E was either unfazed or sufficiently accepting of my qualification that the fork was probably OK, at least for the time being whilst he got his new bike sorted (another cleanskin in the works), that this new fork was never installed.

And so a few weeks rolled by until the unimaginable happened one morning this week on his commute to work. Actually, this was the second unimaginable occurrence to have occurred last week.

Incident and get-out-of-jail award #1 goes to Lawrence, who upon clearing the dip (60 km/hr) of the Kirribili Exit off the freeway (heading to the SHB), and having just lost most of his momentum, hit a normally innocuous ripple in the surface only to have a catastrophic front hub failure. Three consecutive spokes parted from the hub taking the hub flange with them, with the warped-rim locking the front wheel. Not mentioning any names (campag, radially laced, aluminium hub body, probably at least 5 years old). Bloody lucky that boy had no speed when it happened.

Now to the second get-out-of-jail card. E was out of the saddle and heaving up a steep bike-path incline (ironically en route to meet Lawrence, who was now waiting on his MBT) when the handlebars sheered clean off the fork! It wasn’t the carbon fork blades, but the aluminium steerer tube of the fork that had sheared at the stem collar. Again, lucky he had no speed to speak of. Inspection of the fissure revealed that 1/3 had probably started to open some time ago – a straight line corresponding to wear instigated most likely by the edge of the stem, with the newly peeled surface constituting the other 2/3. In hindsight, the headset had mysteriously loosened up about a month before the handover, so perhaps the initial crack had started to open then. The fact that these things happened just days apart is slightly creepy. Hopefully these things don’t happen in threes.

In answer to the question posed at the top – I reckon 3-4 years or 30 000 km is probably a reasonable life to expect out of a frame – at least that is the rule of thumb i think i’ll ride by (@ ~ 70 kg). A lighter rider will get away with more. Frequent inspection of the steerer tube is probably a good idea also, especially if carbon (look for cracks). Similar lifespan probably a good idea for wheels as well (maybe 5 years max), especially if you are running less than 32 spokes and have radial lacing patters (= higher spoke tension). If you must true the wheel yourself, try to do so by releasing tension, rather than increasing it, although a gentle uniform increase can be done if the overall tension is getting sloppy, which also tends to occur with age.

Good news story of the week; Jonesy – who is the most prolific of any rider i have had the pleasure of knowing, and who is himself a chronic flog-it-till-it-dies advocate (or at least used to be) – just became a world record holder . 491 km in 12 hrs at nearly a 41 km/hr average. Amazing ride Jeff!

Monday, 1 August 2011

Escaping the Bogan's Nest

Despite having recovered from the rigors of Tour dependency, and gone easy at Ham and Lisa’s do on Sat night (thanks guys), I joined the collective and skipped the Sunday Morning spin and instead indulged in some Twittering and Tweeting, in a non social-media kind of way – although perhaps the fact you are reading this betrays my smug hypocrisy. 

Sunday morning; the mudge and I approach the coffee shop via the off-road alternative, walking the ~2 km of bush track below Buzerko Rd, and collected ~35 species en route.  Not a bad offering from a slither of weed-riddled bush. 

After coffee we jumped in the car and made what would constitute our second effort to bag a couple of species which have thus far eluted our birdlists – Regent Honeyeaters and Swift Parrots.  In fact we made a concerted effort to nab these guys a month or so back, but made the journey to the central coast only to come back tickless. 

Regent Honeyeaters are probably the rarest bird in this part of Oz – officially endangered, with generally only sporadic sightings recorded each year.  Their range supposedly covers the Sydney and Hunter River basins to the western side of the blueies.  This year, however, there have been numerous winter sightings in Morriset, just south of Newcastle, in a particular stand of Swamp Mahonganys, which are flowering profusely at the moment.  Swift Parrots, on the other hand, are more numerous, but seasonal visitors, which winter in coastal NSW, before returning to breed in NZ.  Fortuitously, healthy recordings have also been made in the Wyong region, just south of Morriset – hence the chance to nab 2 species with one drive.

First of all the Regents.  Last time we made the trip we failed to find the particular hotspot reported on the web, but found loads of Swamp Mahoganys full of other honeyeaters and lorikeets one might expect to see.  The site is in bushland surrounding an old Psychiatric Hospital.  Unfortunately, not everyone who should perhaps be confined within the said institute were inside the gates.  Especially on this particular Sunday, the 4WD bogans with their booze, fags and pig-dogs, and the accompanying stink bike vermin, where everywhere – ripping up the place, knocking down trees, bulldozing scrub, and no doubt leaving litter wherever it suited – evidenced by the trash that was found, well pretty much everywhere.  How’s the serenity?  

We somehow managed to navigate the myriad of 4WD tracks, dodge the bikes and locate what we thought to be the electricity substation that is mentioned on the web.  About 30 min of searching later, and actually only 150 m from the substation across a little creek, we were rewarded with great sightings of not one, but 4 Regent HEs, skirting the flowering gums which were raucously patrolled by loads of Noisy Friarbirds and Rainbow Lorikeets.  We couldn’t quite believe we had Regents in our sights – which remained glued through our binoculars even as trails bikes screamed past in a haze of dust only meters away (can’t imagine what they must have thought).  A few hugs and high fives later (yes, it was emotional), we made a be-line for the car and got the hell out of there before a lynch mob could be assembled to get the weirdo greenie interlopers out of their playpen (please mazda, don’t fail us now – a few scrapes, wheelspins and bottoming outs and we were gone).

With Regents in the bag we gained the highway and headed south to the oddly named “Spotted Gum Park” in the heart of suburban Wyong (technically Wotanobbi).  Not a spotted gum could be found, just a thin stand of mature ironbarks on a ridge.  The place seemed deathly silent as the sun was starting to wane.  I had joked that we’d either see dozens of Swifties or nothing.  Nothing it appeared to be, until my ears picked up the faintest squeak.  Peering through the bins, high in the canopy my eyes gazed upon a parrot of type I’d never seen before.  Having both breathed it in, minutes later we found another dozen in another tree, then were treated to no less that three more flocks of approx. 10 each, coming in to roost for the night.  Smaller than I imagined – not that much bigger than a budgie, and far less raucous, I still can’t quite get my head around the fact that in one leap they make the journey across the Tasman, twice a year!  No pissed hoons in 4WDs to worry about this time.  We were able to enjoy the moment before setting course for Sydney on a doubly successful birding foray, which brings my Australian tally to approx. 310 species.  Only another 300 to go!