Cycling UK Forum

I want to fit a dynamo light to the rear of my bike - I already have a dynamo light (incandescent) on the front.

I'm wondering whether it makes any difference whether they're LEDs or incandescents. Presumably incandescents draw more power - but does that mean more drag at the dynamo? And is this enough to make it worth getting LEDs?

Fwiw, I'm hoping to find a mudguard-mounted one, in case anyone has some recommendations (otherwise I'll speak to the good people at SJS).

Thanks for any help!

The big plus for LEDs is their reliability. A front incandescent blowing you will notice but how long might you pedal with a dead rear light before noticing it? My LED rear light also has built in capacitors so when I stop at a junction it continues to glow.

LED every time. You get about four times as much light for the same amount of electricity.

The dynamo drag goes with current (more or less) so a more efficient light that draws a smaller amount of current (normally at higher voltage) also gives less drag.

With LEDs you also get more useful light at lower speeds. My LED rear light is perfectly visible at a walking pace; I've never had an incandescent lamp that was like that .

cheers

LEDs every time. Some battery-powered LED rearlights are so bright and last so long that it's hardly worth the bother of stringing a cable. I have one on a seat stay as backup for the rack-mounted dynamo light (2008-vintage B&M Toplight??), and I've had occasion to be glad of it when the wire came out of the lamp's internal connectors. Never much liked that Toplight's clinching system - I ended up soldering the cable in place. Newer ones might be better.

http://www.bike24.com/1.php?content=8;n ... ;orderby=2

This is the cheapest I know of , 9.90 Euros.

LEDs - absolutely every time.

You get:
- More light
- Better reliability
- More optional extras (like a standlight that will work for 5+ minutes)