Friday, 20 October 2017

Dynamism








 John finished my Halo white rim, Shutter precision PD8 wheel build on Sunday. Beautifully true and expertly tensioned, I returned to my southern base, eager to see how it would perform. Schwalbe rim tape in place, I whipped on their excellent Marathon GT https://www.sevendaycyclist.com/schwalbe-marathon-gt-tyres  and went for a quick twenty mile, backroad “bonding session”.
Initial impressions are silky smooth, with minimal resistance. With lights off, they reckon resistance is 1watt at 30km/h. Tipping the scales at1239g (403g for the hub), it’s comparable with a 32hole Mavic Open Pro, laced to Schmidt SON deluxe. Shimano’s venerable Ultegra unit is my benchmark comparator for high power and relatively low resistance.
I barely notice it, which is a far cry from the old but nonetheless, worthy Nexus units. Now, according to Shutter Precision, the 8 is their workhorse model and purportedly the most efficient available. Lights on and at 17km/h, apparently its 73% efficient, dropping to 50% at 30km/h. Not overly enticing on paper perhaps and I’d be inclined to switch off when lighting/charging gizmos is not required. At least, on longer runs.  
Trelock and several other big brands like what we’re doing at Seven Day Cyclist www.sevendaycyclist.com Trelock have sent me their 80 lux LS906 bike-I pro dynamo lamp, complete with handlebar bracket. Looks perfect for the backroads. 100metres is reckoned the navigational field and visible to 1500metres.
Standlight technology is pretty much a given, when talking modern, good quality dynamo lighting. It also features an on/off switch and auto function. Build is, dare I say, typically Teutonic. However, the wiring instructions were a little vague. Diagrams imply feeding the exposed wires into the tiny white interfaces...
What you need to do is press these in, feed the exposed wires into the black holes either side. Now press the white parts again-this will lock the wires in situ.
The switch bracket is a hinged clamp affair. Unfortunately, this is very narrow. I had to unwind some bar wrap and place the switch on the narrowest section of bar. Even then, it called for a longer screw, which luckily I had in my tool chest. Minor misgivings aside, everything is behaving impeccably.    
Will be very interesting to see how it compares with Busch & Muller’ Lumotec LQ2 Luxus and of course, my Univega’s MK1 exposure revo. Since I’m here, a word about Lux and Lumens.
Obviously, factors such as diode, reflector and lens quality will have a big influence on real world performance. There is also an argument that lux is truth, lumens sales-speak, in the sense that horsepower sells cars, torque wins races. That said; by definition, any sweeping generalisation, is by definition, prone to glaring inaccuracy.
Lux is a measure of light, probably best thought of as light intensity within a specific area. Lumens is the total output of visible light, bigger numbers, brighter light. One Lux is equal to one lumen per square metre.
As light travels from its source, it gets dispersed, rates of dispersion depend upon factors, including the angle. Therefore, a light with 800 lumens but top notch lens, diode and reflector is going to be a whole heap better than a cheap 1500 lumen retina tickler.
Perhaps unsurprisingly, this explains why 650lumen torch type lights (the sort designed for sub/urban training/commuting and giving change from £60) don’t deliver the same navigational prowess, as a 600lumen trail type commanding twice the cash.  https://www.sevendaycyclist.com/blank-ypcqd   
Numbers are also pretty significant when it comes to rider apparel. Ratings of 10,000 are pretty standard for “waterproofing and breathability” for commuter jackets, especially those of the sub £100 price point.
Less will leave you feeling decidedly feted and clammy. Contrary to popular misconception, you don’t actually want something 100% waterproof, otherwise, your own moisture cannot escape and aside from feeling “boiled in the bag”, there’s an increased chance of catching a chill.  
In scientific terms, these figures mean the garment will resist and expel moisture reasonably efficiently-90minutes persistent downpour, which is adequate for commuting at a moderate pace. However, for more spirited and/or longer distance riding, 15,000-20,000 makes life a whole lot more comfortable. 
I like pockets. Hip, nelson and a poacher at the rear cover most bases and are really useful for commuting and touring, although a Nelson and poacher are more typical of training models. Long tails protect the back from spray and chill, elasticated/wrap over Velcro cuffs prevent it blowing in, especially when hunkered low on the drops. Might be a lot of that in the coming days, if our weather forecast is anything to go by... 

No comments: