Showing posts with label bike computers. Show all posts
Showing posts with label bike computers. Show all posts

Wednesday 9 January 2019

Magnetic Attraction






So, with freshly rebuilt dynohub wheel safely returned to me, and Univega waxed, following some mucky January mile munching, it was time to switch to fixed. 
Following frankenpute euphoria, you’ll imagine my dismay at a flickering and sometimes unresponsive computer display. Big fat flashing zeros are not cool.  
Let us be clear (as the present UK administration is so fond of touting). I had inserted fresh CR2032 cells, adding a slither of Vaseline to the battery contacts, nipped the sensor ties and magnet tight…Most probable causes isolated.
A seasonal Lurgy curtailed further diagnostics, but all seemed to be behaving normally. Both on the work stand and a subsequent mile long loop.
Three days later, back in the saddle, out along the lanes. Dynamo on, blinkies pulsing, erratic readouts... So, I switched the Trelock LS 906 https://www.sevendaycyclist.com/trelock-ls906-dynamo-front-light  lamp off. Consistently accurate, precise readouts resumed. Fluctuations gone.  This remained the case, over two rides and 45 miles.
I’ve never experienced these symptoms with my Univega’s Ultegra, or elderly Nexus hub dynamos. However, Strong magnetic forces, such as those experienced around power plants, and pylons are notorious points of interference. 97.6mph along a long, straight road, anyone? 
 I am also advised Shutter Precision hubs have particularly strong magnets.
Carbon fibre can also prove conductive, which is why good quality greases/assembly pastes must be used on metal components, to avert risk of galvanic corrosion/seizure. Bottom bracket threads being prime candidates. Could it be that the wonder weave, is amplifying said magnetic field, and creating these irregular signals?  
This may dictate moving sensor and magnet to chain-stay and rear wheel. Doing will exhaust computer and sensor cells a little faster. But provided I don’t exceed the 1 metre rule, everything should play nicely.
A wired unit is my last resort. Aside from defeating my “make do and reinvent narrative”, I’ll need to be more mindful when performing headset strips, and similar maintenance.  Blackburn have advised they no longer keep spares for the Atom units and, surprisingly, have deleted computers from their range.
Another rummage through the bodge box unearthed this VDO M3 WL, which appears to have a sensor fault. I’ve tried all the above techniques, but they won’t play nicely. Nor any other brands, for that matter, so I’ve emailed their UK importer for help. 
Despite constant headlines threatening a second ice-age, the thermostat has hovered around a seasonally typical 5 degrees.
No call for spikes just yet, although the wind chill prompted donning of Northwave Balaclava, once or twice.  These Oxford bright 4.0 gloves https://www.sevendaycyclist.com/oxford-1
have also come into their own and Steve’s been impressed by Proviz Reflect 360 CRS Plus Jacket https://www.sevendaycyclist.com/proviz-reflect360-crs-plus-jacket  
Chainsaw oil is continuing to do the business and some 140 miles in, is probably the closest to a bike specific, wet lubricant. I’m bargaining 500 miles from a single application. On paper, it’s looking a costlier option, compared with the bargain basement 5w/40. However, the latter attracted more scuzz. Most apparent within the cassette.
There’s been some further perch swapping, courtesy of this Pro Turnix gel saddle, which now graces my fixed gear winter/trainer. Its Selle Italia Novous boost superflow has been ported over to my tubby tourer and I’ve earmarked the BBB Echelon, elsewhere. Possibly the Goldhawk Roadax, if I can’t live with its stock/OEM model.