several years ago, i was privileged to have the opportunity to review an srm power meter, more as a means of investigating the technology rather than it being a means to some sort of sporting end. i was mechanically adept enough to fit the crankset to the bicycle, though the accompanying documentation did raise one or two doubts everytime the word calibration was mentioned. however, all seemed to be well during the myriad number of outings i undertook with the little srm box strapped to the bars, demonstrating not only the pathetic number of watts i was able to expend, but also the rather alarming heart rate at which those were achieved.
in practice, that's pretty much all that the liquid crystal display was able to offer; the real analysis arrived at home time, when all the acquired data could be uploaded to a piece of software (they'd call it an app nowadays) suitably configured to allow interpretation of those numbers. of course, not only would it normally be necessary to have some sort of a game plan prior to ride time, but it would help greatly to have someone on hand with an ability to understand just what all those numbers meant.
while riding the bike, it was fairly simple to watch the power output rise when the effort increased and vice versa, but at first i thought the calibration admonishments in the manual perhaps bore closer attention. for there, on the graph on my computer screen was an incontestable period of no reading whatsoever. how could that be? i had pedalled all the way round my route du jour; or had i? it transpired that the vacant lot, so to speak, had occurred during a short descent and during which there was no relevant power output to speak of.
in my particular case, all of the above was of mere academic interest, pursuant of a subsequent review outlining the capabilities of the device and whether it was something we all ought to be considering in our daily ministrations (it isn't). but from a professional rider's outlook or even that of the very interested amateur, those numbers could prove invaluable. i believe it is mathematically possible to calculate the number of watts necessary to climb any given ascent at a rate that would prevent the competition from breaking free. and knowing implicitly that if they did manage to break free, human physiology would prevent them from continuing apace for any significant, race-winning period.
assuming all matter to be equitable and that sort of wattage becomes doable, it would not be altogether iniquitous to assume that the same level of power could be managed by one's competitors. at that point, dave brailsford's marginal gains take on a greater importance. and that's sort of what i'm hoping is possible on a wheelsmith lightweight ascent wheelset, shod with schwalbe's (£67 per pair) one-pro tubeless tyres.
as i have iterated elsewhere, the first outing was, of necessity, a tad trepidatious, for there is something almost magical about a pair of tyres that are content to remain fastened to their wheel rims by nothing other than air pressure. what if i took a corner too fast and they rolled off? is there an upper inflation limit above which they might blow off the rim (110psi is the advised maximum), or perhaps a lower limit that would let them roll off all of their own accord (less than 70psi)? and suppose the wheels weren't as airtight as their description would have me believe. after all, the only way of checking would be to fit a tubeless tyre and go ride over the crappest road surfaces i could find in a single day.
which, now that you ask, is precisely what i did.
as i have mentioned, probably to the point of exhaustion, islay is peppered with a network of single track farm roads, many of which have fared rather badly over the winter months. aside from the tarmac patching which rarely enhances their verisimilitude to that of a billiard table, there are clumps of mud left in the wake of some alarmingly large tractors as well as the mess made by itinerant cattle and an entirely new set of potholes that i swear were not there at the tail end of last year.
riding with gusto across all that for several hours is as good a test of the mettle of tyres and wheels as you're likely to come across this side of the arenberg forest.
it would be unfair to separate out each component, if such were indeed possible, so my review is geared towards considering tyres and wheels as a single entity. i have previously mentioned that wheelsmith's ascent wheelset weighs a scant 1450 grams, while each tyre tips the scales at a nominal 255g. there are indeed lighter tyres on the market, but those inevitably have to share the limelight with an inner tube. either way, when time came to kick a** uphill, the minimised weight was of great assistance, especially to the physically challenged such as yours truly.
a corollary to that uphill kick revolves around my predilection for having the rear brake shoes ever-so-close to the rim. while this achieves a desired snappy excellence to rear-mounted braking, it has, in the past, brought a concomitant tendency for rim/shoe interface when those watts are flowing freely. it ought, therefore, to be noted that during said periods of ascension, the rear wheelsmith demonstrated no tendencies in this direction whatsoever. quite impressive, actually.
nor, indeed, was there any demonstrable yet anticipated squishiness from the tyres. my lack of experience in the tubeless department had given ride to having collywobbles about tyres rolling from the rims with the least amount of effort on my part. both you and i are doubtless pleased that this not only didn't happen, but displayed no signs of ever threatening so to do. however, this purported rigidity from the rubber, aided and abetted by the wheels had a slight downside that i hadn't quite considered up till now.
i should mention, at this point, an aspect of versatility demonstrated by derek mclay's £440 ascent wheels. the original set sent for review bore a shimano pattern freehub, when, in fact i had earmarked them for the campagnolo potenza equipped colnago master. the problem was very easily solved by derek sending a replacement campagnolo pattern freehub. swapping one for t'other was the proverbial piece of cake involving only a couple of differing sizes of allen key/wrench and no oily marks on either hand. should the future bring a need to swap back, you can rest assured you need not be a professionally trained mechanic to effect the change.
if i might refer you to my previous treatise on the lack of unformity of surface on many of islay's single track roads, regular tyres, now that i come to think of it, tend to breeze across the bumps and dips via a flexibility that we have all come to know and love. the tubeless schwalbes, however, tended to drop off each minor crevasse; not in an alarming manner, you understand, but noticeable enough to be noticeable. logic dictates that a tubeless tyre would have need of such rigidity, if only to prevent the disappearing act that had infiltrated my fears only just a few paragraphs above. the wheels, on the other hand, offered a solidity of feel allied to their propensity for speed. this must be how the professionals experience life.
my continued naivety with the subject matter at hand had led me to believe that the pro ones would offer a similar ride to that of tubular tyres. nothing, however, could be further from the truth. in fact, i'm not altogether sure that they have many ride characteristics in common with normal clinchers, though that should definitely not taken as a negative. in fact, aside from the excellent noise they make on the road, they have a number of other qualities to commend them, not least of which is a rather endearing alacrity when push comes to shove. in other words, acceleration. combined with the scant weight of the wheels, it takes less effort to bring them up to a speed that leaves others in your wake (a guy can dream, can't he?)
there will, almost inevitably, be a part three to this series, for i can't help feeling that i still treat the tyre/wheel combination with a temerity that is unbecoming, one that i expect will disappear the more comfortable i become riding on tyres with nothing but air pressure inside. at the moment, however, i'm rapidly becoming more amenable to a setup such as this, and i'm happy to note that schwalbe also saw fit to release a 28mm version of the pro-one.
to be continued...
monday 3 april 2017..........................................................................................................................................................................................................