TK45 for my bike

Hey everyone! I made my rounds reading all of the things I could find on here about bike lights and Fenix lights, but wanted to run this decision by 'ya'll just to make sure I'm on the right track. I want to add a light to my mountain bike, but bike lights start at $100+. I figure if I'm going to spend that kind of money, I'd better get something to do double duty as a flashlight.

I like the Fenix TK45 for this purpose. It's ridiculously bright, is regulated and lasts for along time, has a wide beam, and uses AA batteries. All of these attributes are important to me. I am concerned, though, that the light won't last long if it's knocked around too much. Perhaps this tough duty is where SureFire lights are required? I'd hate to spend $150 on a light only to have it break my first time on the trail.

Are there any other lights that can serve this purpose well for less money? I don't own any high end flashlights like Fenix or SureFire (just some Petlz and Tektite LEDs that I've owned for a while), so besides what I've read on this and other forums, and I don't know what to expect from such a large investment.

Any help is appreciated. Thanks!

P.S. As a secondary science question, does the relatively thinner body of the TK45 block all of the EMR generated from such a powerful light?

the tk45 initially appealed to me as a bike light/flashlight but the fact it takes 8 AA batts means its only as good as the weakest cell and youll need something like the maha charger to check them, ive heard the batteries rattle in it, its probably going to be heavy with all the batts and its too wide to mount on the handlebar, i havent seen any bike mount that will take a 4cm diameter torch.

there are loads of thinner torches in the 700-900 rated range that will be in the same ball park and cheaper dx ones mentioned in the budget light form.

i use the olight m30 for a cycle light, its lightweight and has a very useful spill.

I agree that I don't think a TK40 or 45 would work too well as a mt. bike light. For a road bike it would probably be okay, but not for the bouncing and banging it's going to get off road.

I use a Quark XPG NW with an 18650 body on my handlebars pointed immediately in front of my bike, about 10 ft. ahead of my front wheel. It's got a very floody beam so does a great job of showing me the road right in front of my bike. I use a two-fish bike block to attach it to my handlebar.

Also, I use another two-fish block to attach my Raptor RRT-0 Q3 to the top of my helmet. It's very throwy, so it puts a good spot on anything I want to look at, even pretty far down range. The control ring UI is also great for this purpose, because all I have to do to change modes is reach up and flick the ring; it eliminates the hassle of trying to half click on a tail switch, and is easy to do even with full finger gloves on. This combination has worked excellently for me so far. I particularly like the fact it's a 2 min. job to pull the lights out of my messenger bag and attach them to my bike/helmet. In fact, I usually just leave the raptor on my helmet all the time.

If I didn't already have these lights, I'd probably get this:

http://www.geomangear.com/index.php?main_page=product_info&cPath=4_41&products_id=180

One of the other members in the astronomy club my wife and I are in has one and he raves about it. I will probably eventually get one too, but for now my Quark and my RRT-0 do the job pretty well.

Here my set up.

That's the TK40. I will try the TK45 in my holder once I get one. It's just a twofish C sized holder with a longer velcro strap and my own buckle made from a washer.

Since the TK40, I've got the magicshine too. The beam, the magicshine has a much better spill and wider hotspot. The other issue is the TK40 is a bit wobbly with my set up but it's not going to fall off. I do have to adjust it quite a bit on rough roads. I've had one stack and it stayed on but the rubber on the twofish had a bit of a tear but the TK40 still stayed on.

Obviously the magicshine is less wobbly but it's not that easy to use as a flashlight. I think the LD40 that's coming from fenix might be a good choice though.

i tried a similar arrangement with the twofish block and a long velcro strap with a 4.3 cm diameter light (~700g) but it was too wobbley and needed elastic wraps around it.
the 'upgraded' C-cell version of the two fish lock block that has the cordura nylon backing to the velcro that you can buy is still too short in the length of the velcro straps to fit a 4cm diameter torch.
if only someone made a simple longer version of the twofish block ,say about 10 cm long rubber block, with velcro straps at each end.

Mr Floppy said:

Here my set up.

That's the TK40. I will try the TK45 in my holder once I get one. It's just a twofish C sized holder with a longer velcro strap and my own buckle made from a washer.

Since the TK40, I've got the magicshine too. The beam, the magicshine has a much better spill and wider hotspot. The other issue is the TK40 is a bit wobbly with my set up but it's not going to fall off. I do have to adjust it quite a bit on rough roads. I've had one stack and it stayed on but the rubber on the twofish had a bit of a tear but the TK40 still stayed on.

Obviously the magicshine is less wobbly but it's not that easy to use as a flashlight. I think the LD40 that's coming from fenix might be a good choice though.

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What about a magicshine on your handlebars and something small, bright, and throwy on your helmet? That's what I do. A 1xAA size light would work very well in twofish block on a helmet; there are many now that are barely larger than a chapstick and put out 100+ lumens.

I have the TK45, and I think it needs a very well engineered and stable holder to be used as a bike light, as it is very heavy and if not properly blocked tends to bounce a lot.
That said, the beam pattern, runtime and achievable brightness are just perfect for a bike light.

I use a Solarforce with UCL lense and Nailbender 1.4A XP-G NW drop-in on my bars, and a well secured T100C2 NW with OP reflector well secured on my helmet for long range lighting and extra long runtime. It works great both on and off-road! :thumbsup:

My experience with an led flashlight mounted on a bicycle:

In the past I had my small 5mm led's front and back. Where I live it's mostly adequate to be seen but not to see. But I got tired of buying new coincells so I used my NEX on a two-fish mount. it's very bright. As some of you have experienced yourselves, when you pass people on a bike with about 200 lumens, they sometimes say to you whilst passing: "Wow, I thought you were a car overtaking me slowly..."

Then I thought, let's try a brighter light in the woods. So I mounted my D-Mini EX in the two-fish and went to the forest at night. Safe to say when I turned it on (stationary) in total darkness I was a bit blinded. Sure, it lit up everything in front of me but there was too much light scattering back at me. The NEX with half it's lumens output was much better at being a forward bike light.

Why? I think because it is more of a thrower than a flooder. And since the Dutchielands have crowded roads I'd end up blinding everyone if I were to use the D-Mini EX...:huh:.

My point is, there is a reason for dedicated/specialised bike lights. They (usually) put out a much more usefull beam pattern which doesn't blind oncoming traffic... but does light up the road. Remember, getting blinded is not a nice thing to happen, when your riding/driving at night .

I am currently using an incan headlamp mounted on the front suspension powered by magnets on the front axle. Safe to say it's rather underpowered, yellow, full of artifacts but all in all a very convenient solution since I am the battery. At the rear there is a strip of AA powered 5mm lights. Not a very flashaholic way of lighting my bike, I know but sometimes I do mount the D-Mini EX as an "extra" light .

Big light = mounting difficulty.

For the price of a TK45, you could get 3 smaller lights that would combine for the same output. A car doesn't have only one bright headlight for a reason.

I'd suggest a couple of 2xAA lights in any of the myriad of mounts available. Redundancy, versatility, and convenience FTW.

fareast said:

My point is, there is a reason for dedicated/specialised bike lights. They (usually) put out a much more usefull beam pattern which doesn't blind oncoming traffic... but does light up the road.

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My experience with the simple (read, low cost), bike lights that I've used over the last 25 years of regular bike riding and bike commuting doesn't agree with this. Even some of the higher priced lights (>$100) from mass production companies such as CatEye have been disappointments. For example, a couple of years ago I bought a CatEye Single Shot Plus ($140 US retail, but got a better deal on it). At the time it was the best self contained bike light I'd ever had. (I've had external battery systems that were better, but also more expensive.) Even then, the beam pattern on the latest CateEye I bought was poor. Not floody enough to light up a significant portion of the road in front of me, nor powerful enough to give any kind of decent throw.

In contrast, the Quark AA2 I use on my handlebars gives a bright and floody beam, rivaling dedicated bike lights I've used in the past that cost $300 or more. I've met people with dedicated single beam NiteRider systems who are blown away because the Quark on max is brighter and about 1/3rd the cost. With the 18650 battery tube I use with it, it also runs just as long, and overall it is probably 1/4th the weight of those other high priced systems. Finally, it's a 1 min. job to attach or detach it from my handlebar and stick it in my pocket or messenger bag. Combined with the RRT-0 I have on top of my helmet, I've never wanted for light with this set up. I do take care not to flash oncoming cars, etc. with it when using it. Even without that it's powerful enough that 99% of car drivers give me extra room because of it, perhaps because they don't want to be blinded by it. Once in a while though, I do have to flash someone to make my presence known because even with all the light I'm putting out, they're just not paying attention and don't see me, so I have to blatantly flash them. :naughty:

Using my flashlights this way gives me a lot more versatility and bang for the buck than being limited to a dedicated bike mounted system. I feel kind of stupid that I didn't get into this whole LED flashlight thing sooner, or realize they could be used as very good bike lights as well. Having just a couple high quality, high output LED flashlights has been a game changer in so many things for me; biking, camping, hiking, etc. Sometimes I feel like I just woke up from being frozen in a glacier for 1000 years when I consider how incredible this kind of technology really is.

B0wz3r said:

What about a magicshine on your handlebars and something small, bright, and throwy on your helmet? That's what I do. A 1xAA size light would work very well in twofish block on a helmet; there are many now that are barely larger than a chapstick and put out 100+ lumens.

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Was that advice for me or the original poster?

The only time I wear a helmet is when I mount my 3 L2D's on it these days.