I've been looking over some images of fully loaded bikes.
Handlebar bags seem to be a big player in touring, but I have yet to find a bike with a headlight.

How do you mount a headlight with a bag on your bars?

I'm wrestling w/ this as well. I see three alternatives:
1) fork mount (need long cable, might be illegal (too low) in some states)
2) head tube mount (doesn't turn w/ front wheel
3) helmet mount.

I don't like the idea of putting one on the helmet, though the guys in the lighting forum all seem to love it. I'm getting a fenix L2D flashlight in the mail today, and will try out a couple options.

I'm wrestling w/ this as well. I see three alternatives:
1) fork mount (need long cable, might be illegal (too low) in some states)
2) head tube mount (doesn't turn w/ front wheel)
3) helmet mount.

I don't like the idea of putting one on the helmet, though the guys in the lighting forum all seem to love it. I'm getting a fenix L2D flashlight in the mail today, and will try out a couple options.

On my commutes I've been riding with a helmet light (L&M Solo Logic MV with a chunky NiMH battery) for this very reason.

I actually like using a helmet light, but since I don't carry a backpack on the commute, dealing with the battery is a pain. I'd like a better option, myself.

do it like this

I have my lamp mounted on the fork brake bolt. There is plkenty of room to fit a medium (Carradice) bar bag and the light is high enough for visibility.
The best mount I have found is an old chromed steel one for a front reflector. For my other bike I had to make a mount. I used a file and dremel on some old scrap al (cranks and rings) and it works quite well.

This would work since it stands up over the bar



Here it is under the bar but it could easily be mounted above the bar



Of course there's aways a helmet mount



I've seen someone mount their lights like edzo. I like that method too.

Tried this out the other night with my MiNewt Dual (one on each side) and liked it pretty well, though not quite as much as having them on top of the bars. I will definitely be doing it that way when I have a handlebar bag on though. It's doesn't get in the way of using the drops but it's a bit harder to get aimed right, though fine once you manage that.

One downside with the dual, I can see the wires being too short to do it if you have a wider bars than mine (stock bars on a 52cm Bianchi Volpe, 40cm c-c), the wire is long enough with mine, but there is not a lot of slack.

There are distinct advantages to the helmet mount. If you been over in the lighting forums, you've seen the photon blasters I use. Even with those powerful lights, they don't let me see into the corner when they are mounted on the bar. Last night, I did my first ride home with the new ones and, because of a design problem, I couldn't use my helmet lamp. As I dropped into corners...especially left hand turns...I couldn't 'see' the stuff there. With a helmet light, you illuminate those corners and actually see where you are going.

Another advantage is that you can sweep your light across a very wide arc. If necessary you can sweep it across some bonehead who isn't paying attention (with mine there's a hole out the back of their head). Additionally, the moving light...your head always moves a little...is far more attention getting than a front blinky. If not...look 'em in the eyes!

At least give it a try.

I'm experimenting w/ 2 lights of different heights. Well, not much of an experiment, I know my regular light is too low (it clamps to the front of the bar rather than the top like my wife's). I am mostly attempting to determine whether this tower of bar extender and then light to peek up over the bar bag is just too freaking much, then I will look into mounting something down around the fork crown (or ditching the bar bag).

My regular light, I can point it up enough so it peeks Kilroy style over the bar bag and even gives not bad vis beyond the shadow in front of my wheel, but it still reflects back off the top of the bag and does more damage to my night vision than I want. My wife's minewt, I'm just trying it solo today, may try it w/ the bar bag tomorrow if she's still not biking, see if I get less glare off the bag top.

The minewt down the drops is cool, but that is where my hands tend to be most of the time (bars raised, hands dropped, suppose I could lower the bars and use the tops more...)

All of this light raising is still after tipping the bar bag as far forward as possible so it doesn't dent the brake cable. Bar bag may just not be where it's at for my day-to-day use, at least in the lighting time of year.

Try either the Minoura Space Bar (2 sizes) or the Minoura Swing Bar.
The Space bar doesn't move up or down but the swing bar does
These can be mounted on the stem under a bar bag

I don't wear a helmet on tour [GASP!..] so I just wear my Princeton Tec EOS headlamp when I need light at night. I also don't ride at night on tour as a general rule. It is the same headlamp I'd take just to use around camp so there isn't anything extra to carry. I also carry a Planet Bike Superflash taillight which I clip onto the back part of the headlamp strap when riding at night. The normal place I'd put it [on the seatpost] is often obscured my stuff on my rear rack.

You obviously haven't had a look at my bicycle then.
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The swing bar is poorly designed and will fail from fatigue if you mount lights on it. The space grip may be better.

Best yet is to mount your lights on the forks. But many touring cyclists rarely, if ever, ride in darkness. for emergency use, consider an LED head lamp that you can attach to your helmet. Serves double duty as a camp light and bike light.

If you plan to regularly ride at night, consider a generator light so you don't need to deal with batteries.

I seldom ride at night. My light is intended to help others see me (like cars making a right turn into me from a side street, or cars making a left turn in front of me from the oncoming lane.) It doesn't really allow me to see every pothole on the road, or glass shards.

I mounted my front light on the top of my front rack. It's a Tubus Tara. There's that tube that wraps over the top of the front wheel. It's not being used to carry anything - it's just there to keep the rack stable. I mounted my light there (with lots of spacing material, since it's intended to attach to a handlebar.) I know it would probably increase my chances of being seen if it were mounted higher, but it's very convenient, and frees up one more space for junk on my handlebars. On a positive note, when I turn my front wheel, the light turns with it.

I think if I were going to start riding at night regularly, I'd opt for a helmet mounted light with a big, honking battery - like those crazy nighttime mountain bikers use.

Thanks for the replies. I have yet to do any touring, but most of my commute is in the dark. Also, a big portion of my utility cycling is at night, (mostly trips to the grocery store).

I've decided to get a trekking handlebar for my bike. I think I'll end up with enough real estate to mount the light and bar bag.

I have scads of bike parts in my garage. I think I can build a bracket similar to Machka's if I need to. And BKT's post reminded me that I have a Minoura Swing Grip in one of my parts bins.

I should be getting my trekking bar within the next week so I'll post some picks when I get it all set up.
Thanks again.

I mount mine at the fork crown, just like in Machka's picture. This works best with Busch & Mueller or Schmidt generator powered headlights, which come with two different mounting brackets for caliper or cantilever brakes. I also favor small handlebar bags, which don't get in the way of a fork mounted light and don't mess up the steering as much.

I use a (hub powered) light mounted on top of the front rack. It's a bit tight with a sleeping bag but has worked very well since I got it three years ago. The mount was originally made for a cheap rear light designed to be mounted on a rear rack.

While touring I also bring a Petzl Myobelt 5. Perfect also around camp and as a tent lamp.

This is pretty much my situation as well. I'm setting up an LHT for a big tour next summer, but I'm using it now to commute. Unfortunately, I am totally hooked on my ortlieb handlebar bag, and it pretty much takes up the whole handlebar (the 2" offset does give me room for cross brake levers).

I've been playing w/ a Fenix (L2D, 180 lumens) on my helmet. It does work, and is quite bright. cyclecommute's points about being able to point it wheverever you want, including a motorists eyes if necessary, are well taken. During the day I've been leaving the flashlight off, but the TwoFish bikelock on the helmet. Looks kind of goofy, but convenient.

Edit: The bag makes me very happy. In addition to carrying wallet, phone, etc up front where I can just take the whole thing off the bike, I leave the garage door opener in one of the outside mesh pockets and open the garage door by smacking the side of the bag as I approach the house. For years it's been bugging me that I have to stop, twist, and find the opener in one of the back panniers. I can't give this up!

i mounted the light on the drop. worked great. i tend not to ride in the drops when its dark anyway, and took off the mounting bracked and light when i wasn't using it.

also a LED light on a headstrap used for camping works well. I carry one anyway and when it was really dark, used both lights.

check topeak hb bag. they have an attachment you can clip your headlight to underneath the bag itself. same concept goes on top so you can mount a wireless computor. pretty handy!
i use helmet mounted lights as well.
see and be seen!