To commute at this time of year, I am planning to fit a B&M dymotec 6 dynamo on my bike (mk2 Sherpa) but I need to choose between left and right dynamo. I guess, being on the right side but facing backwards, I need a left one.
One question: Do you agree with that?
Hi Blue!
I realize you didn't really get your dynamo lighting question answered, so I'll circle back and give it a shot. Before going the battery route, I'd suggest calling SJS Cycles and asking which "side" bottle dyno they recommend for sure, but Peter White has some advice (below) that should help. Don't forget, if you do go this route, you would also need a mounting bracket to fit the Sherpa Mk2's fork bosses. A variety are available from SJSC here:
http://www.sjscycles.co.uk/page/find/?name=thorn&page=1#filterkey=cat&cat=127&page=1While a bottle dynamo might not be ideal compared to a dynohub, it does get you into self-powered lighting, and that's not a bad thing. No batteries to deal with, more theft-resistant, and always there when needed. Year ago, I commuted nightly with a Union 9814 bottle generator, and the thing offered as much drag-induced braking as my rim brakes did in the wet. Still, it was the ideal solution at the time and I remember being remarkably happy with it. The B&M Dymotec 6 you're considering is in a different universe from the old Union 9814 and would be a much happier experience. No, it isn't a dyno
hub, but it is dyno
lighting and very useful.
You mentioned...
I am planning to fit a B&M dymotec 6 dynamo
Here is what Peter White says about it...
The Dymotec 6 is very reliable and a good choice for riders with a short commute or limited budget. Available for either right or left side mounting....The Dymotec 6 will power either a headlight with a 2.4 watt bulb and a taillight with a .6 watt bulb for a total of 3 watts, or it can power a single headlight with a 3 watt bulb. It can also power any 6 volt LED headlight I sell, with or without a taillight attached. Since the dynamo itself acts as the on/off "switch", you can use headlights without a switch, saving some money. Dymotec 6 comes with a rubber roller, 185cm dual strand wire and connectors.
He does recommend the wire roller for riding in the rain, but cautions alignment is even more critical than for the rubber roller (to avoid tire sidewall damage). As for left- or right-mounting, he offers this advice...
When ordering your dynamo, you'll need to specify right side or left side mounting. The dynamo itself, (not the mount you purchase separately), is built specifically for either right side or left side mounting. And since this assumes the dynamo will be positioned ahead of its mounting point, those who choose to mount the dynamo to the rear on the right side, should choose a left side mount, since of course, everything is in reverse. For instance, if you're mounting the dynamo on the right rear seat stay, ahead of the stay, within the rear triangle of a standard bicycle frame, you would use a right side mount. But if you choose to place it behind the right seat stay, you would use a left side mount. If this doesn't make sense, don't hesitate to ask about this when you place your order.
Placing the light behind the right-side for blade on your Mk2 Sherpa would be akin to placing it behind the right rear seatstay. So, yes, it sounds like you would need a left-side mount bottle dynamo.
You mentioned...
I plan to fit a Busch & Müller LYT Senso Plus LED
The Lyt is an inexpensive LED headlight with a cutoff. It is nowhere near as bright in luminance as the Cyos (25lux vs. 40/60 for the Cyos), but it does better than most of the halogen lights that were highly regarded just a few short years ago. The light beam on the pavement is not great (see:
http://www.bumm.de/produkte/dynamo-scheinwerfer/lumotec-lyt.html ), but it is among B&M's least expensive lights, costing between 1/2 and 1/3 what a Cyo might, depending on options.
In operation, a bottle generator typically has more drag than a hub dynamo (the old LightSpin was pretty close), so most people don't run them all the time; the bottle dynamo then becomes the on/off switch, so a separate switch isn't needed for the light. For that matter, a Senso option (that would turn the light on and off automatically according to ambient light levels) isn't needed with a bottle dynamo, either. Passing these options by saves a bit more money, as they really are no advantage with the sidewall dynamo. Depending on one's environment, a "Plus" option (built-in capacitor to keep the light on at a lower level for a few minutes after stopping) can be useful. Of course, everyone has differing needs, but I have found it comforting to remain visible to some degree while stopped at a traffic light, and that bit of light makes it very convenient to find and fit my garage door keys on returning home.
You also said...
I plan to fit...a B&M 4D-Toplight at the back. Feel free to comment on that too.
There are a variety of D-Toplights available, and I'm certain which one you have in mind. They range from battery-powered to dynamo-powered. The upper-range 4D Toplight is a clever battery-dynamo hybrid that allows manual or automatic switching between the two power sources. Looking at it from my perspective, I think I would go with the less expensive Toplight Line Plus with the 2 LEDs firing through a full-width prism to make a bright band of light. Then, as an adjunct, I'd fit a battery-powered LED blinky. The Toplight Line Plus works so wonderfully well, I can see it being all that is needed for most use, and it is cheaper than the 4D at most outlets. If you get the Plus version, you'll still have (reduced) rearward illumination from the light while stopped, so you'll be visible at traffic lights.
I hope this helps. Lighting choices are hard ones, and many options are pretty expensive. Expense is something most of us have to consider, especially after purchasing a new bike, when funds may be a bit low. It surely was a factor for me, and I transferred my lighting from one bike to another rather than buying new for that very reason. This is something to keep in mind if you go the battery-powered route and use disposables instead of rechargeables; the battery costs add up with regular use. It is nice to have lights always at the ready and not have the worries and hassle of battery changes. Along with reduced theft potential, a dynamo setup at any level can be pretty attractive, especially for the daily commuter or tourist.
I hope this helps.
All the best,
Dan.
