Dynamo Lights

Many thorn customers fit dynamo with front only; then just a AA battery rear... no idea why....

Lack of confidence in wiring, gives a choice between a light that can't be seen, and may not be working, or a cheap reliable battery light.
Back light uses very little power.
Non familiarity with stand lights.
You can buy rear lamps at Poundland.
Despite all these issues, I have just upgraded to modern dynamo lights, front and back and it is an improvement.
But I don't know what I'll be doing next year!

Many thorn customers fit dynamo with front only; then just a AA battery rear... no idea why....

The power consumption for a rear light is miniscule compared to a front light, partially because its only purpose is to be seen rather than illuminate the road, and partially because red LEDs are more efficient anyway, as they don't need the floursecent coating that allows white LEDs to be white. A good battery powered rear light will last months on a single set of batteries. A good front light won't. Having a dynamo powered front and battery rears makes sense to me.

I get this, but why not just fit a rear dynamo light and forget about it?!

Because the cost/benefit analysis is marginal when the faff of wiring in a rear dynamo light is taken into account, particularly if you're going to do it neatly and not have zip ties and electrical tape everywhere.

And moving a battery-powered light is far easier if it turns out your saddle-bag/top bag/panniers obscure the rear light as you don't have to worry about cables.

Basically, cos wiring.

And dynamo rear lights don't flash.

I wonder if you could add something inline to modify the pattern. Something like [3 sec on, 1 sec quick blink, repeat] would be cool.

Klite ones do!

But flashing is not so great, yes it draws attention, but it’s so much harder to see where the bike actually is.

Depth perception on a solid light is infinitely easier.

Still looking for way to fit a dyno light to my dads suspension fork crown.

Thinking about a very long cap screw to tension the headset, then screw a tapered bung into the bottom of the steerer with some sort of mounting feature on it.

Or maybe a steel p clip with rubber around the forks lower leg.

Not sure how we manage the cable over the suspension travel either.

All ideas welcome.

I just left some cable slack no issue with it. And I mount the light on the bars.

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Can't you just put a star nut in the bottom of the steerer?
Because good luck finding that long screw.
Or as Skinny says, handlebar mount.

Star nut in the bottom of the steerer might work, depending when the taper starts.

Problem with the bars is a rather large ortileb handbag bag in the way.

I’m sure you’ll agree it’s wise to run two rear lights. Drivers can have a go at judging distance and speed by triangulation as they close-in. If you’re running two lights it makes sense to have one that can flash. As you say - a flashing light draws attention and there are definitely times (riding solo in heavy traffic in dull winter daylight) when that’s useful. Battery rear lights are better for this job. Now you have a battery rear light ... and ... (as I said on the previous page) charging two small lights is not twice the issue of charging one.

tl:dr Dynamo rear lights are nice: a sensible 2nd, constant light. But I can take them or leave them.

I use a SON rear and Cateye rapid X on pulsing, depends where you ride I guess!

I use a Supernova rear. No issues. Love not thinking about batteries.

When I'm racing ultras I add one or two Lezyne blinkies for race rules, backup, etc.

Depending on the fork, what about a hole through the cross brace??

I will probably put my dynamo setup lights on sell later this week.
supernova e3 front & rear. (all black), I'll spam here in case happens as I am still reluctant but they are sleeping on a drawer since last year...
p.s. I do have front & rear b&m setup on my commuter, splendid!

As far as I'm aware there's precious little hard evidence as to whether rear lighting improves safety; my gut feeling* is that - by analogy with what research we have on hi-viz etc.- it probably makes not a huge amount of difference beyond a basic light or even just a rear red reflector. We know that the danger mostly comes from drivers not looking or not caring, and zapping out more photons doesn't make a difference to that.†

I like the fit and forget nature of dynamo lighting, which means I am never caught without lights; I'm not fast enough to care about swapping wheels etc, so the wiring is only a PITA once, on installation. I do carry backup blinkies in the saddlebag just in case, but my experience is that a battery light is no less likely to fail than a dynamo rear (and I've not yet had a dyno light rear failure that couldn't be fixed on the road - usually just a dicky contact). I prefer the bigger lights with a built-in reflector (I've got B+M toplines and a Spanninga Elips), partly as a fail-safe, and partly because the bigger illuminated surface possibly helps with distance perception. As a FBNPNA enthusiast mine are all mounted to a rack, but there are also mudguard and seatstay options for racier bikes.

*Highly scientific, I know...
†There's also the semi-related issue of target fixation; the fact that emergency vehicles still get hit whilst stationary on the hard shoulder with blue lights suggests this may be a factor in some RTCs.

little hard evidence as to whether rear lighting improves safety; my gut feeling* is that

And that's before we even get to those strobe lighting cunts who are actively reducing the safety of everyone else with their ridiculously bright flashing lights, front and back.

In b4 @Skülly

I can moan for myself thangyouvermuch.

Not sure how we manage the cable over the suspension travel either.

If you don’t figure out a way to avoid travelling across the suspension, you could perhaps try making the cable section there into a curly phone-style cable. Very easy to do, looks awesome and neat, I use this to traverse between fork crown and frame for rear light cabling. Can show you pics of my setups later. Basically you wind the cable tightly like a spring around a screwdriver stem, and gently heat the wire.

I consider this^ my ‘scoble’s third mudflap’ moment ...

Ooh, I'd done the 'twist round a screwdriver' thing, but the Edelux coax cable's quite bulky and likes to spring back. Will have to investigate tactical deployment of a hairdryer...

A good idea, hopefully it doesn't come to that.

Thinking maybe a rubber coated "P" clip around the cross piece.

the Edelux coax cable's quite bulky and likes to spring back.

Not when you’ve heated it fam!

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