Review Part I: Fitting
Yesterday I bought a set of Reelight SL500 lights, which retail at £24.99 for front and £24.99 for rear.
For those of you not familiar with the lights, they operate on a magnetic dynamo system, whereby a pair of magnets are fastened to the spokes, and a small generator unit to the fork leg and seat-stay. It's a similar principle to a cycle computer or cadence sensor, except the magnets are used generate power rather than data! That's right, free light, no batteries required, and no need for a wheel to be rebuilt around a generator hub. Each time the magnet passes the generator, the light flashes, thus with two magnets, the light flashes twice per every revolution of the wheel and flashes faster as you ride faster.
The generators are not very heavy, no worse than a good quality Cat-Eye unit such as a HL-530. And although the generator unit weighs a little, the lamps themselves are very light, containing only a reflector and bulb.
I fitted them myself, and the only tools I needed were a phillips/cross-head screwdriver and a pair of cable-cutters.
Fitting was relatively straight-forward, you mount the bulb unit on the handlebars of seatpost like any modern battery-light, with rubber shims inside the collars to accomodate narrow/wide handlebars and posts. The only problem I encountered, was that no matter where on the handlebars I placed the headlamp, my brake cables obscured the lower third of the lamp. This was just unlucky, a different handle-bar with less rise would have avoided this issue.
After you're happy with the position, you mount the generator unit on the fork leg and/or seat-stay (the instructions suggest the right fork leg/stay). This is slightly trickier, first you have to trim the rubber shim inside the generator clamps to suit the width of your fork and stay. I had to trim quite a bit off the rear, because my steel stays are very narrow.
You then fasten the generator to the fork or stay by way of two screws that when tightened, drag a peforated metal band tight around the leg or stay, (very similarly to plumbing clips). For the rear, I had to trim the excess band that remained, because my stays are very narrow.
You then fasten the magnets onto the wheel, familiar if you've fitted a cycle computer before, only these magnets are longer and fasten with three small screws. You place them on opposite sides of the wheel (up and down, not left/right), so both are on the righthand-side of the wheel, at 12 oclock and 6 oclock positions. Where exactly you place them depends on the generator position and the way your spokes are laced.
You can then move the generator unit closer or further from the spokes on little rails, by way of a button and ratchet system. You need to have the magnets pass within 1-3mm of the generator, or the lights won't operate.
Here I encountered my first problem, the instructions show the generators mounted high on the fork leg and stay. However, my Surly 1x1 has heaps of mud-clearance, and even when adjusted right in, the Generator did not come within 1-3mm of the magnets, more like 10mm! I therefore had to move my generators much closer to the centre of the wheel, where the spokes were closer to the fork-leg and seat-stay; as they met the hub flange.
I then routed the cables, making sure they could not snag against the brakes, tyres or spokes. You can rotate the generator to suck in excess cable, but I didn't have to since I mounted them so low. The lights included some tiny zip-ties to help with this.
The quality of all components seems fairly high, and although the wires are quite thin, they are no more delicate than the cable for a computer, or traditional hub dynamo unit.
All things considered, these lights were more difficult to fit than a battery-powered set, and took me roughly 45 minutes, including re-positioning them lower.
Ease of Fitting 3.5/5
I'll report back after my first ride and try to give a little review on how well they operate in practise!
Edit: Pictures of the lights on my bike!
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