Since I cutting back from racing, I've been doing a lot of commuting and gravel/dirt riding on my road bike--sometimes late at night, sometimes in the snow--thus, being seen by cars is probably something I should do. I usually use a Giro Sutton helmet which has a clip for a rear light, but the rear lights I have are designed for seatposts and feel heavy when placed on the back of my head despite being relatively lightweight. Any suggestions for a good small rear light that might work well with the Giro Sutton or just a helmet in general? My helmet has a little clip for a rear light which is nice. I've considered the Blackburn Flea, but I'm looking for others and haven't come across much yet.

I would suggest the new Cygolite Hotshot Pro 80 as it's very small and light, USB rechargeable, and as I understand it also puts out a wider beam than the older Hotshot so aiming it just right wouldn't be as important.

The BlackBurn Flea is garbage. Hotshot is a much better choice for being seen.

I just ordered Light in Motion 360 Vis at half price at Backcountry online. It has a small headlight with tail light that is very light. I know you didn't mention headlight, but it's a nice, light setup to compliment a regular headlight.

That's good to know! Don't want to waste my money. Maybe I'm wrong, but it seems like the market for this kind of thing is really tiny unfortunately. I have multiple rear lights already, some of which are quite nice, but they are all just too bulky for a helmet (despite not actually being bulky in general). Thanks for all the suggestions guys!

Any taillight with a clip will work. Just run a velcro strap through the back of your helmet and it should securely hold your light. I use an L&M Vis 180 Micro USB on my helmet and a Cygo Hotshot USB on the rack for a bit of redundancy and extra visibility.

There are some helmets with LED's built in. Marketed for either city or kid use.

Rather than try and pick one for you just search for LED in the text here:
Bicycle Helmets for the 2015 Season

I have one of these on my seatpost, but it would be easy to pull the strap off and glue or velcro it onto your helmet:

Hot Waterproof USB Rechargeable Bicycle Bike Rear Light Helmet Warning Tail Lamp | eBay

Bright, very lightweight, inexpensive, and USB rechargeable...

+ 1. This is a fine light.

I was experimenting with this for a while. Has a helmet specific mount, which is always level.
Is lightweight but not very bright. I returned it:

https://www.youtube.com/watch?v=Oi8B...IoDLA&index=11

I tried one of these but didn't like their idea of strobe mode.

It sorts of pulsates but it's too subtle; I ride mostly in the daytime so I wanted more of a blinkie...

Hot Shot



PBSF

Blackburn 2'Fer. Lightweight, very bright as a warning light, and easily visible from the sides. Not particularly good as a headlight, however - it's bright enough, but too diffused. I'm using it on the front of my Bell Solar, mostly in flashing white mode. I like it well enough that I may add another to the back of the helmet in flashing red. The stretchy rubber band doodad fits through the air vents, and the 2'Fer clips onto the rubber band.

For now I'm using something I already had, an Energizer single red flashing LED. It's bright enough, just not quite as bright as the Blackburn. I used a zip tie to fasten it to the back of my helmet.

That's a great second light and the light in front helps to balance the weight of the battery pack/rear light, but it may be too heavy if the OP thinks a seatpost sized light is heavy.

Cygolite Hotshot would be my choice (is my choice, actually)

Check out the planet bike spok lights. I have a white and red, mounted with velcro to my helmet. Quite light weight. I do not rely on these as the sole means of "being seen" lights. I do like having something mounted on my helmet as I think it is more noticeable in certain situations.

https://www.amazon.com/Planet-Bike-30...keywords=spock

Wow guys, thanks for all the responses so far. Lots of options I had not seen/heard of. To clarify my situation, I live in NYC. Counter-intuitively to my locale, I ride on a lot of dirt/concrete paths in the Bronx that look straight out of Northern California--heavily tree lined, winding, beach access, deer occasionally try to join me, etc. Except sometimes when coming in and out of these trails I enter into big city traffic on my bike. It's an interesting juxtaposition. On a side note, the Bronx is highly undervalued for trail riding and you should try it if you get an opportunity.

Anyway, I already have a bright tailight on my seatpost. But cars can be crazy, so I want more visibility--thus, this helmet light idea. I just really do not like feeling like the weight of my helmet is unbalanced with too much weight back there. I tried a Portland Design Works light first, and even at a measly 60 grams it made my head feel lopsided. Maybe I'm just too sensitive as to the weight.

I recently came across the Knog Blinder1 Rear Bike Light
Knog Blinder 1 Rechargeable LED Rear Bike Light | Rear Bike Lights | Merlin Cycles

Only weighs 15g! Is it a piece of **** though? Perhaps. I just care about added visibility though, so maybe not.

^^I do already run 1200 lumens on the front, so maybe I just need to amp it up on the back and achieve that UFO aesthetic when flying out of the trails.

You might like the Viz 360. It's heavier than anything you mentioned, but it's balanced and the weight doesn't bother me after riding a motorcycle for almost 20 years. The helmet light will allow you to make yourself more visible to the drivers who look like they're going to pull out in front of you too, I'd think that would be useful when you're riding in traffic.

This thread got me rethinking my own light setup. Originally I hadn't planned on riding at night unless absolutely necessary, but as it turns out I've ridden home at night several times the past few weeks and enjoyed it - less traffic, for one thing. And up until last week it was still pretty hot in Texas during the afternoons.

So I decided to move my lightweight lights to my helmet, and get brighter but heavier lights for the bike itself.

My helmet is a Bell Solar, very lightweight itself - the liner claims just under 300 grams and considering it's built like a styrofoam beer chest with a hard plastic outer coating, that's probably accurate.

I figured any significant additional weight would be noticeable but I can't feel any difference with the Blackburn 2'Fer on the rear and Vivo-Bike Illuminati on the front of the helmet. Blackburn says the 2'Fer weighs 18 grams. I haven't found weight specs for the Illuminati but I'd guess 24-30 gr - it's only a little heavier than the 2'Fer.

Both are very visible from the sides. Specs say these USB rechargeable lights last 1.5 to 5 hours, depending on brightness and steady/flashing options, and my experience over the past month confirms those estimates. Good enough for helmet use for errands and my short rides, usually 20 mile round trips.

And I can tell that drivers really notice the flashers. Several times in heavy traffic I've seen drivers at intersections and parking lots looking to jump into the street, then hesitate when they see my lights and wait for me. Years ago I commuted without lights and lost count of the number of close calls I had from distracted drivers. I'm a firm believer in flashing LEDs now.

Here are some photos of the lights strapped to the helmet. I'll probably redo the rear connector, with a sturdier Velcro strap for the 2'Fer. The Illuminati strap works fine through the helmet's air vents. I can't feel any additional pressure or bumps from the straps inside the helmet.

The third red LED dangling from zip ties is an Energizer blinker. Since I'm moving the Blackburn 2'Fer to the rear of the helmet I'm dispensing with that Energizer blinker. It isn't heavy, but the dangling thing is a bit distracting.

Mr. Headknocker Skeleton is for the weekend Halloween shenanigans. It's affixed with Blu-Tack gum and comes off in a day or two. It's heavier than the three lights combined and still barely noticeable.

I've also done some nighttime video demos of these lights, but haven't uploaded 'em to YouTube yet. I'll try to get that done this weekend. My demo videos show the 2'Fer and Illuminati are clearly visible at dusk up to a block away, the farthest I rode for the demo video.

The Illuminati is an adequate headlight for my nighttime speed, usually well under 15 mph (probably closer to 10 mph). Not sure yet whether there will be any advantage to being able to turn the beam along with my head. I'll try it this weekend if the rain lets up.

The photo from the front with the red glow and the skeleton needs to be your new avatar at some point.

I clipped a Metroflash Nocturna to the strap at the base of my helmet, instead of using the included seat post mount:

https://www.amazon.com/MetroFlash-Noc.../dp/B00GU0HIP4

Not sure how it might fit onto helmets that lack a strategically positioned strap, but I suppose you could string velcro across two rear vents....

Cygolite Hotshot Pro 80 is the tail light to buy.

I decided to go with the Knog Blinder1 Rear Bike Light mostly because of it's almost non-existent weight and a sale on it for only 14 dollars. Ordered online so should be here this week. I'll let you guys know how it performs it's duty or how it fails miserably. Cheers!

This weekend I was driving and saw a cyclist with a very visible rear light from about a half mile away. I caught up to him and asked him about it; he said it was a "Fire" and warned me that they are not cheap.

I did a search and all I could find was those silly x-Fires with those useless laser lane markers.

Anyone know of any other tail lights with that name..?