Personally, I just really have owned a lot of bike lights. Starting with the Light & Motion NiMH Metal ARC that weighed in at over three pounds, but over the last 20 years, things have really stabilized around LED lights and they are small and lightweight, so here are some recommendations:
- Garmin Vario UT 800 Light and RTL 515 Radar. OK, if you are bicycling nut, then if you have bike computer, these are the ones to get. They turn on and off depending on motion and the rear system has a radar in it and it shows on your bike's computer. I haven't ridden outside very much, but while heavy, they are very bright. There is a new radar with a camera, but the RTL 715 is way bigger and bulkier. Also these days, you don't need the UT800 as there are lots of ANT+ compatible lights, but the mount is nicely integrated with the Garmin mount. Today, I actually run a Karoo 2 with the Garmin adapter and this works well. The Radar is expensive at $150, but the regret factor is high when someone runs you over.
- NiteRider Lumina 750. If you don't need a bike computer, then you don't need to spend as much. Outdoor Gear Labs is pretty reliable and likes the Lumina 750 as a front-mounted light and it is just $70 unlike the Garmin combination above but those reviews are four years old from 2018.
- Bontrager Ion 200 and Flare RT. Bicycling Magazine has a much newer 2020 review and for daytime, they like this front and rear light, they aren't smart, but they sure are small for $130. These are also ANT+ compatible so they will work with your computer.
- Ascher USB Rechargeable. Hey at $16 for a set, these are cheap and disposable, so good if it's really a bike you don't care that much about.
- NiteRider Lumina OLE 1200 Boost. Insanely expensive at $170, but it is a full 1,200 lumens at a maximum setting which is basically like the sun and two hours in normal use.
Helmet Lights and Smart Helmets
- Light & Motion Vis 360. One of my favorite lights is the dedicated helmet light because it has both a front and rear and you can run it on your helmet so you don't forget it.
- Smart Bicycle Helmet. OK, I have not tried this, but I really do want to, rather than a clumsy strap-on thingy, it integrates the lights directly into the helmet. It does mean that when the light fails, you need a new helmet, but the visibility is excellent.
- Lumos Ultra has front and rear lights and senses left and right turns so has turn signals is a Kickstarter project for $120 and can even have MIPS internal wrap (for an extra $10). There were on Kickstarter and seem to have delivered successfully with good reviews. What's amazing is that with COB (chip on board), the weight penalty is minimal, it is just 370 grams. My current helmet the Kask Protone is great and light at 260g and is 280g for a Large and the Vis 360 is definitely another 100g. And with MIPS it is 414 grams which is really not bad as this is more protection. And if you want to get a skateboarder urban combat look, then the Lumos Matrix is huge with a gigantic LED light on the back.