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Serfas Thunderbolt USB Front Bike Light


    Serfas Thunderbolt USB Front Bike Light

    With convenient mounting and a bright output up to 90 lumens, the Serfas Thunderbolt USB rechargeable front bike light gets you noticed when you're riding. See details

    • $45.00

    Item # 852328

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    With convenient mounting and a bright output up to 90 lumens, the Serfas Thunderbolt USB rechargeable front bike light gets you noticed when you're riding.

    Product size and color

    With convenient mounting and a bright output up to 90 lumens, the Serfas Thunderbolt USB rechargeable front bike light gets you noticed when you're riding.

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    With convenient mounting and a bright output up to 90 lumens, the Serfas Thunderbolt USB rechargeable front bike light gets you noticed when you're riding.

    • The strip of 15 white, double-strength micro-LED bulbs puts out up to 90 lumens of light; strip design puts out a non-directional flood of light for wide coverage
    • Water-resistant, flexible and finish-friendly silicone body and adjustable straps stretch around your bike's frame or handlebar for easy, tool-free mounting and removal
    • 4 modes (with run times): high beam/constant (1.75 hrs.), low beam/constant (6.5 hrs.), high flash (3.5 hrs.), low flash (9 hrs.)
    • The Serfas Thunderbolt USB rechargeable front bike light lets you recharge the light via a USB port; recharges in 2 hours


    Item 852328

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    Serfas Thunderbolt USB Front Bike Light Specs
    Best use
    15 micro
    90 lumens
    2 hours
    Lithium ion
    1.5 hours
    6.5 hours
    9 hours
    50 grams
    Bulb type
    Number of bulbs
    Max light output (lumens)
    Headlight mounting
    Charge time
    Integrated battery
    Battery life on high
    Battery life on low
    Battery life flashing

    Serfas Thunderbolt USB Front Bike Light

    Loading Ratings & Reviews...

    Serfas Thunderbolt USB Front Bike Light is rated 3.0 out of 5 by 6.
    Rated 3 out of 5 by from Its Bright but not focused I used the product for about one or two weeks before i gave up on it being useless for me. If all you want is to be visible to other people (be they in a car, on a bike, or pedestrians) then this is a good light. It hardly gives you any usefulness to see where you are going because you have to point the light downward so it doesn't blind you.
    Date published: 2014-04-14
    Rated 3 out of 5 by from This light is small and cute. The light is small and cute. Puts out a lot of light in a small package. The battery life is short, less than an hour at full brightness, only a few hours on the dimmer setting. Not enough light as the sole source of light to ride totally dark trails or roads safely. It works well as a strobe. I got it for my 2 hour commute to work and the battery life falls short. I should have realized that it is just too small to have any real capacity. Great light for short trips, fits in the seat bag, and will attach almost anywhere. Not good if it is your only light source on a dark road. Charges in a few hours. The charge port is not easy to access when the light is attached to the bike, so it's not easy to plug it into a dynamo or external source. I would recommend it, but know it has limitation for being in such a small package.
    Date published: 2014-03-21
    Rated 3 out of 5 by from Bright, but dies quickly. I timed it and 1 hour and 20 minutes is about how long this thing lasts on its highest setting. I have a 30 minute commute to the office, and 30 minutes back. I need to charge it every day or else it will die in the middle of my commute. It does have an orange blinking light to warn you that it's about to die, but that only gives you a few minutes of notice. It is a good light otherwise, but inconveniently, I still have to carry a backup light for the various times this thing has died on me in the middle of traffic.
    Date published: 2014-03-26
    Rated 3 out of 5 by from Great mounting options, low battery life After reading the full description on REI's website I'm less annoyed with the battery life--the package only says "up to 9 hours" but REI's breakdown of the different mode options seems to be pretty accurate. I've been using this on the brightest flashing mode and it doesn't make it past 2 hours. My evening commute is just under an hour so as long as I remember to charge it regularly this works for me. The light is bright and I mount it on the left front fork which lights the road in front of me nicely but keeps it out of other cyclists' eyes (I think) and is still visible to cars. I find it to be plenty of light for an urban commute. And I do like the mounting system, it's very flexible and allows me to mount it just about anywhere on the bike or my helmet. Detail about the USB charging: the light has a mini USB port (NOT micro, which many phones and tablets have now) and comes with a short cable that can plug into any USB port or power adapter (but does not come with the adapter itself).
    Date published: 2014-03-26
    Rated 2 out of 5 by from Not so great... I was impressed by the intensity of the beam and the design. The box said up to 9 hours of battery life per charge so I thought if I used it on low intensity in the blinking mode I should get that from a charge. Fully charged in low, blinking mode provided about 3 hours of light. My intended use was for daytime visibility while riding on highways. My rides are usually much longer so this would not work for me. I am not a big fan of the attachment straps either. These would likely deteriorate over time with repeated attachments and detachments in order to charge the light for each use (I attached to the frame head and on my bike that stretched the straps to their near limit). Overall, this is a cool light but did not meet my expectation or needs.
    Date published: 2014-03-26
    Rated 4 out of 5 by from Excellent LED with pathetic straps This is an excellent product in its primary function of visibility. Rechargeability makes it more practical. The only downside is cumbersome mounting straps and difficult to use power/mode button. It is a shame such a wonderful product does not come with a handle-bar/seat-post mounting backets (esy to clip on), which is standard in most LEDs now. Even if you have a mounting bracket the design permits you to mount it only with the two straps provided. The four modes of operation are built into the power button in a sequential manner. It is not soft touch and id difficult to operate while you are on the go. Hope serfas pays attention to resolve these issues of an otherwise wonderful product.
    Date published: 2014-04-04

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