Bike Tail Light USB Rechargeable by Apace - Super Bright 100 Lumens LED Bicycle Rear Light Easily Clips on as a Red Taillight for Optimum Cycling Safety

I've been using this light for almost 2 years, and it has never failed me. It's very bright-I use it on flash, and it makes me feel safer and much more visible. The mounting system and rubber on the back make it versatile and easy to fit it on a number of different surfaces, i.e., seat post, rack, etc. The battery lasts multiple, multi-hour rides, and charges easily and quickly. If I needed another tail light I would buy this one again in a second, with no hesitation. Highly recommend.

I bike often. Unfortunately, even with wearing bright clothes and having fancy brand name blinky lights front and rear, I am still invisible at times on the road. To up the "can you see me" factor, I have added lights front and rear. The company that makes this exceptionally bright red light, also makes an obnoxious white light for the front of the bike (obnoxious meaning in strobe mode it hurts the eyes if looked at for too long). After using that one in addition to the other brand name light on the front and have had much success with it, I decided I need another obnoxious red light in the back of the bike. Ta da - exactly what my bike was missing. This red light is easy to use, mount, and charge. Mine is mounted on the seat post below the reflector, within reach of turning on and changing the setting. Well worth the cost. Long lasting too. Although, I charge all my lights after 3 rides (most rides are 2.5hrs), so I have yet to witness this light or the front light run low on battery. Highly recommend and yes, I would definitely buy again.

This is one of my all-time favorite tail lights. Clever, reliable, durable bands and fittings make it fit pretty much any rear rack or seat post. There are many modes to click through -- flashing modes of varying speeds and brightness, a pulsing mode, and some steady modes, including blazingly bright. I turn on this light whenever I have to ride at dusk or near traffic. Even in broad daylight it gets attention. Charges quickly via USB cable, indicator turns from red to green when fully charged. Great customer service, they reply quickly to queries.

This is an outstanding light--bright, seen very well from the sides, long-lasting, and easy to mount securely. The best taillight I have used in 40 years of cycling! And best of all their customer service is unparalleled.

See Five year review update at bottom...Form and function:First if you have an aero seatpost, the included mount pads might not be ideal. You can probably find a way to make it mount. It's also a bit too large for most seat stays and it doesn't easily mount on saddle rails or saddle bags either. Anything is possible with some creativity, but it's really best for round seat posts. It does include plenty of mounting pads and bands, and a nice little pouch. To me the slightly large size is good. It allows high total ouput without high pinpoint intensity when viewed up close. That's less blinding and easier to focus on and locate, while still just as visible at a distance.It weighs about 52 grams including the pad and band. It seems pretty rain proof. It generally looks and feels like a good quality gadget.It charges fully in about two hours (I didn't monitor it closely) consistent with 0.5A charging claims.The daybright mode is very nice, very visible in the daytime. My riding buddies commented on seeing it far up the road in the daytime. I think it's using the full 100 lumens, or a good fraction of it, in short pulses to get attention and last long. I wouldn't use that at night. The pulse mode is interesting for night. I am not a fan of blinky modes at night, but pulse dims and brightens smoothly without going off, improving ability to focus on the light while still getting some improved peak brightness without all of the runtime reduction of a steady bright mode.Mode claims:It comes with a manual with these modes listed:Low 12 hoursMedium 6.5 hoursHigh 2 hoursSlow flash 45 hours (a standard on-off flash, low power)Smart flash(TM) 7 hours (Similar to Slow flash but brighter)DayBright Flash(TM) 15 hours (Short high intensity pulses)BritePulse(TM) 4.5 hours (Pulsing wave pattern in time, never off)Performance testing:The good:I've actually done some fairly quantitative testing on this light. I have no absolute reference, but on high I measure it about twice the total output (scattered light from all directions) of a 50-lumen claimed moon MK-II, and has a similar beam pattern. That's a smaller and lighter-weight light that fits on seat-stays and has lower claimed runtime and obviously brightness. Both lights drop off in brightness some as voltage depletes, dropping to about 70% eventually. It's pretty common for lights not to have true voltage regulation, which requires a little more electronics. The medium steady mode is about 1/4 the output of the high mode initially, and the low mode is about 1/8. This all seems fine and in line with claims relative to at least one competitor.Also I tried to test the daybright mode but not using suitable equipment for pulsed output. By eye, close up, it appears not as bright as the high mode, but perception of fast pulses is complicated. I was able to get readings that weren't far off of full brightness in spite of not have fast triggered sensors, and as mentioned it's very visible from a distance.The ugly:After 20 minutes on the high steady mode, aside from the initial voltage-related drop to about 75% brightness, it also steps down again to about 75% of that from a hard-coded timed step-down, and it steps down by a little over twice again after 1 hour and 20 mintues, reaching about 20% of its initial brightness at that point. I get a total of almost 3 hours of runtime before switching to the battery saving blink mode. That lasts about 1.25 hours (they claim 30 minutes, and I'm happy that it's longer).The two steps are not thermal or voltage related. They are just hard-coded timing steps and it would seem they exist to extend runtime while still getting the initial high lumen output. The step downs are even done in multiple steps a few seconds apart, making it less likely that you'll realize this. If I reset the light after each programmed step down, it follows a similar output curve as the Moon light, and gets a runtime of 1.5 hours, not the claimed 2 hours. As it stands the high mode is like a "turbo boost". You set it when you need to get through a few miles of dense city traffic but it will drop back down after that. To me, that seems a bit like cheating on runtime claims, or at best not explained up front, and I also just find it as not an ideal configuration personally. If I want to use high for a short time I'll do that and if I need low for a longer time, I'll change to low.To their credit the customer support manager has been very responsive and sympathetic. He did discuss with their manufacturers and verify the issue, and I think he's sincere in saying he wants to fix this. I don't think they can fix it and still get a claimed 2hr runtime on high. I think at 1.5 hours, it's still a great light, especially at this price, but they should remove the step downs. In their defense, their most direct competitor (over three times the promotional Apace price) has the same battery capacity and their claimed runtimes don't add up. It seems they may be doing similar tricks, and I understand the need to compete to sell lights.Overall:A long running light with great day and night capabilities, especially for the price, but some limitations in mounting options and some unecessarily dubious performance claims that might not hold to up to what you'd expect from the description. Customer service seems sincere in addressing it, and the light can still be a great buy, especially at the promotional price of about 3x less than the competitor.Five year review update:I have used this light probably six days a week for five years. Although I never re-measured it, it still had good run times. After about 4 years the usb c plug broke off of the circuit board it attaches to. After cracking the glue to open the light I was able to fix that and re-seal it. This can be avoided by avoiding stress on the plug when charging. I often charged it on the bike with the light twisted to expose the plug, but creating a little pressure. It's not super strong though, and thicker solder connection to the plug housing (which I added) could have improved this.But now after 5 years, it won't charge anymore. This appears to be a different issue as the usb connection is still solid. The light operates after first bypassing the board to charge the battery manually, but the usb charging circuit seems dead. Anyway, 4 or 5 years isn't bad, so I bought a new one.