reelight city: magnic competitor

[SA_SA_SA]

I had hoped it might be worth them making a separate approved generator/lamp city-light variant to suit the Brompton....
but if the Brompton's rim is 349mm and the tyre is 37mm tall, they could mount the LEDs at the top of the lamp (surely that would be better for all bikes?).

NB I thought none of their other magnetic lamps was approved other than those than are covered by the UK flashing clause.

I wonder if the unrelated RL7xx generator part outputs raw ac or if it does the power conversion and if so what voltage: it would be nice if it could power a standard dynamo rear lamp.......

NB for the Brompton I was only interested in the rear one: as a backup against battery failure or dynamo hub loom failure or, if good enough, to avoid the need for the rear dynamo loom, leaving the hub dynamo for front lamps only.

[mjr]

I had hoped it might be worth them making a separate approved generator/lamp city-light variant to suit the Brompton....
but if the Brompton's rim is 349mm and the tyre is 37mm tall, they could mount the LEDs at the top of the lamp (surely that would be better for all bikes?).

NB I thought none of their other magnetic lamps was approved other than those than are covered by the UK flashing clause.

http://reelight.com/faq/ explains their view of legal situation but I suspect it's less clear whether Danish standards are Equivalent under RVLR than whether German ones are. Reading that, I'm now less sure whether they are indeed German approved. The page for the City http://shop.reelight.com/bicycle-lights ... ight-city/ says "this product have yet to be approved by the authorities in Denmark and Germany, and is not for sale in these countries" which makes me think they do usually go for German approval.

I think the reason for "downward" mounting is to get closer to the rim without fouling the tyre. Otherwise, it would need to be some sort of L shape which would probably be a bit more of a nuisance.

[Bicycler]

EDIT: Sorry, Rob got there first. I think the 2 models I mentioned in the 500 and 600 series are the only ones which fit the peculiarities of the Road Vehicle Lighting Regulations to be legal in the UK.

I've not checked every page but I'm pretty sure that all except the City (which is described as "pending") have German approvals (K markings), so should be OK under RVLR, thanks to the Equivalent Standards clause added in the 1994 amendment... but I'd expect that could be invalidated by mounting too low.

I don't think the ones which flash every time the wheel goes round (models 100, 500, 600) can be legal in the UK even if they are an approved design of another country (do the Germans even permit, never mind approve, flashing lights?) because the UK regulations specifically permit flashing lights only where they flash at a constant rate. Because the 120, 220, 520 and 620 charge a capacitor instead (in order to provide a standby function), which then flashes the lights at a constant rate these should be fine.

Their website does seem to suggest that some of their other models of light (presumably the constant rather than flashing ones) have German approval:

[Please see our other products which are already approved in these countries.]

If so, I'll bear that in mind for the future.

[SA_SA_SA]

...I think the reason for "downward" mounting is to get closer to the rim without fouling the tyre. Otherwise, it would need to be some sort of L shape which would probably be a bit more of a nuisance.

But they could have the LEDs a bit nearer the Top. But a separate generator and lamp would be best for the Brompton (and others).

[mjr]

But they could have the LEDs a bit nearer the Top. But a separate generator and lamp would be best for the Brompton (and others).

Maybe I'm being unimaginative but I don't see how. If it's much higher but not above the tyre, the wheel would hide the light more from vehicles on the other side to the light.

[SA_SA_SA]

But they could have the LEDs a bit nearer the Top. But a separate generator and lamp would be best for the Brompton (and others).

Maybe I'm being unimaginative but I don't see how. If it's much higher but not above the tyre, the wheel would hide the light more from vehicles on the other side to the light.

I mean move the leds upwards within the current casing, not redesign the casing shape.

[mjr]

Sorry if I'm not being clear: the top of the current casing is beside the rim so a light there wouldn't be visible from the other side. The internals shown in the video http://www.youtube.com/watch?v=qNzXCuSIOD0 makes me think there isn't much space up there anyway, with the eddy current dynamo occupying pretty much the whole case. Finally, would running wires next to the dynamo detract from the eddies at all?

[mjr]

I've ordered some because I like dynamo lights but there's a bike where I don't want to replace a wheel or hang a tyre dynamo for some reason. I hope they get their Danish and German approvals but until then, what would people like to know about them once I fit them?

Top of my list is to take them somewhere unlit and see what they look like, unlike in the promo video (most of that looks almost like it was filmed day-for-night) - I expect to need a "to see" lamp out there, but that's OK in this case.

[mjr]

They've arrived. First impressions were very good: they are pretty well presented, the instructions seem clear and there's everything needed in the box except the allen key. Clockwise from the top in this picture from the reelight shop, there's a foam pad and fork/stay-mounting (there are two of each), two lamp-holding rails, the lamps, the brake mounting brackets and two bolts that attach the rails to the mounting. Those were all in the box but not shown are four cable-ties for fixing the fork/stay mountings to the bike and the instruction leaflet.


Second impressions are sadly not as good: the brake mounting bracket doesn't seem to fit on my V-braked candidate bike because it conflicts with the brake arm. It doesn't fit another bike with Shimano Acera V-brakes either. On the caliper-braked bike, if the light is as close as recommended to the wheel then it strikes the tyre when the brake is used - wouldn't that also be a problem with V-brakes or do they move a lot less? The bracket seems a bit bendy anyway, with the pull of the magnet in the lamp being enough to bend it a bit.

The fork/stay-mounting can't get to the specified point (top-ish of lamp in line with the top of the rim, not as pictured) because the brakes are in the way. Mounting lower down still seems to light the lamp. It may help that my wheels are 36 spoke (I think) so there's plenty of moving steel there, but then I discovered another problem.

The frame-mounting kit (see http://rs.130928.mrsite.com/images/thum ... 51727.jpeg from http://practicalcycles.com/products/254 ... t-set.aspx ) can easily leave the light too close to the fork or stay and then that metalwork seems to act as a brake on the dynamo magnet. When that happened, the dynamo refused to work at some speeds and the lamp went out. If I moved it so it worked at low wheel speed, it went out at high speeds, and vice-versa. I think I've got it working by having the lamp mid-stay, the rails part-way out and the whole thing slightly turned. I think ideally it needs something inflexible and non-magnetic that won't rotate around the fork/stay, yet puts the lamp-holding rails further away from the fork. I really don't want a screw that bites the fork/stay - that's why I'm not using a bottle dynamo. Any ideas?

I think I've got it good enough to work, but the cable-tie-and-foam mounting is a bit wobbly, especially at low speeds as the magnet pulls the lamp towards each spoke. I'm unlikely to test it this evening because it's blowing a gale, I've got a cold and in these conditions, I'm not risking a mount failing and me needing to grub around in the verge to find a lamp knocked flying.

So this looks like a slick product potentially being reduced to only OK by a poor set of fixings but it's not yet tested in anger.

[mjr]

Mounting lower down still seems to light the lamp. It may help that my wheels are 36 spoke (I think) so there's plenty of moving steel there

Update: I'm still having problems with these, but I think I've worked out how they are supposed to work.

I think that if they were mounted at the recommended location (with the outer circumference of the rim level with what seems to be the axis of some sort of dynamo wheel - that axis is horizontal, parallel to the wheel axle), then magnetic attraction to each spoke nipple in turn would sort of whip the bottom of the dynamo wheel backwards and keep it spinning, thereby keeping the light on. I don't know if this is how magnic works, is it?

So inspired by the freelights instructions, I tried temporarily sticking extra bits of thin steel rod on the outside of some spokes on the lamp side that pass the light roughly at the height the spoke nipples would. That works a bit better but once the wheel starts spinning fast enough then the lamp still goes out. I think there's a speed where the little bits of extra steel go past too fast to move the wheel compared to the interference/braking effect from the rest of the spokes. I don't want to put thicker steel on the spokes because I worry about the weight (harder to stick on, if nothing else) and potential for striking the fork.

The next test idea is to buy some craft magnets and attach them to the spokes and move the light a bit further away from the spokes to reduce the braking effect. I think the reelight is far easier to spin than it sounds like the freelights are, which I guess is what a decade or so of development does, so I'm hoping I don't have to mount things within 0.5mm.

On the plus side, the fork mounts seem much less wobbly than I feared.

Any tips, suggestions or questions gratefully received.

[Brucey]

IIRC these lights work on eddy currents and the best eddy currents will be in an aluminium rim.

The ideas that the spoke nipples are magnetic is unlikely (they are usually brass) also attaching magnets to the wheel might well be counterproductive; that isn't how these lights work!

So far as the mounting is concerned the light should not move with the brake!

Perhaps the instructions are not clear but AFAICT Reelight intend you to mount the lamp on the canti brake boss bolt, not the brake arm itself. If you do this correctly the light will not move with the brake. You may have to reshape the bracket to gain enough clearance with some brakes.

cheers

[mjr]

IIRC these lights work on eddy currents and the best eddy currents will be in an aluminium rim.

I thought that's how magnic lights work, but the reelight city seem to be different.

The ideas that the spoke nipples are magnetic is unlikely (they are usually brass) also attaching magnets to the wheel might well be counterproductive; that isn't how these lights work!

Useful to know. Thanks. My new theory is that it's the spoke end then. I'm not sure whether it matters because presumably craft magnets whizzing past will produce some eddy currents?

So far as the mounting is concerned the light should not move with the brake!

Perhaps the instructions are not clear but AFAICT Reelight intend you to mount the lamp on the canti brake boss bolt, not the brake arm itself. If you do this correctly the light will not move with the brake. You may have to reshape the bracket to gain enough clearance with some brakes.

That's what I expected and I think it would work better but it's definitely not what's in the instructions (excerpt attached - sorry I think I screwed up to get it under the max allowed size but hopefully picture 3 is still clear enough to show it's mounting on the back of the block) or the pictures on the practical cycles site. The bike I really want to use it on has side-pull calipers anyway. I could bend the bracket to try to get them to work on the folding bike, but I'd really like to get them working somewhere before I deliberately modify them and make them even less returnable

[Brucey]

Spokes vary as well; some are ferritic and some are austenitic. I do not think they have anything to do with the operation of these lights, else they would be placed close to the spokes not the rim.

If as I suspect the lights work on eddy currents there will be a strong permanent magnet in the lamp unit; you can easily determine if this is the case or not. Both the magnet and the rotor within the unit need to be close to an aluminium rim in order for the light to work, I think; the closer the better within reason.

Looking at the Reelight site they appear to show these lights mounted to the pivot boss, not the brake block, on a V brake bike. I would be amazed if they work reliably when attached as per the instructions you have posted, since the clearance to allow movement must compromise the normal operation of the lamp.

If you want to use these lights with side-pulls I suspect you will need to fabricate your own brackets.

My suggestion would be to use p-clips + a simple steel bracket (if the forces are low) or a dynamo mounting bracket (or similar) if the forces are somewhat higher.

cheers

[mjr]

If you mean this:

then I think it may show mounting as instructed, because the bracket arm to the brake block would be hidden behind the lamp-holding rails that are bolted perpendicular across the front of the bracket.

If there's another image, please let me know where.

If they only work with aluminium rims, then that'll be disappointing because one of the bikes I wanted to use this on has steel rims. http://practicalcycles.com/products/254 ... t-set.aspx only says "metal rims" and warns against carbon.

[Brucey]

It isn't that clear but in that image you can see (I think) a second part of the bracket mounted onto the pivot bolt. If not that, those brakes are very odd-looking; you can see something projecting downwards.

You will get the best eddy currents with aluminium rims if that is what the lamp is designed for. They definitely worn't work with an all-carbon rim, but the transient magnetic fields generated in steel rims will have high hysteresis; the likely outcome of this is that at a certain (not very high) speed the light will simply stop working.

cheers