Been looking at the other thread where people strap much more cost effective hand torches to their helmets instead spending hundreds on dedicated bike lamps.

It gets ruddy cold during the winter 'ere in central Europe (-15 Deg C isn't unusual ) and it's better if the batteries are kept warm with body heat.  I also want the headlamp to use on longer evening walks / ski tours as well as for biking. http://en.wikipedia.org/wiki/Ski_touring

Have been looking at tings like the Petzl Ultra belt (350 lumens) but the price is putting me off 

http://www.hitchnhike.co.uk/acatalog/petzl_ultra_belt_headtorch.html

 Ideally looking for 5-6 hrs battery life and 300+ lumens with a boost mode for biking/skiing downhills.   

If anyone can come up alternatives in a non-techno speak that I might understand I'd appreciate it. 

http://www.backcountry.com/store/PTZ0216/Petzl-MYO-XP-Belt-Headlamp.html?CMP_ID=SH_FRO001&CMP_SKU=PTZ0216&mv_pc=r126

not as bright though.

i would look at getting one with the battery on the head strap then just rewire in a larger capacity battery in a bum bag

Trust me the P7 runs hot enough to keep the batterys inside even if its -20c out side plenty warm enough,  hold it in your hand and it's a great hand warmer to.

Thats a seriously expensive head torch there.

Just wear your MTB helmet yes you'll look strange but much safer then no helmet and it's dark so no one can see anyways   And strap torches too ofcourse!!

Thanks for the info, ordering a cheap torch from the USA is OK but an expensive head torch is probably too risky as there's the long postage times along with warranty issues should anything go wrong to consider.

I do wear a ski helmet while ski touring but normally not on the climb up, while out walking I could wear a climbing helmet which would look more the part than a bike helmet.  The P7 does look impressive concerned about battery life and if the cold weather will significantly affect battery life.  

Was wondering if it might be possible to rig up something with this, a remote battery pack, some sort of housing / casing and a switch.

http://www.dealextreme.com/details.dx/sku.14413

Wouldn't get that drop in,  it's trying to be a spot and P7's only suite a flood had 1 the same in my trustfire and it's huge 55mm diamater or something.

Personally I think you'll get a good return off snow so I'd go for something smaller,  lighter and easier to fit to your helmet.

One of these  it'll generate enough heat to keep the battery okay,  run time optimal 2 1/2 hours so even if it drops to 1/2 that it'll do maybe ??  maybe put something thermal around it to help it retain it's heat inner tube say which would help with mounting maybe ??

For the price you could run 2 of them,  better range to than a P7 for higher speed skiing.

Just keep the spares inside your clothing so there warm when you put them in.

Maybe the best solution would be something like this (as posted by serge before)

http://www.outdoorsmagic.com/news/article/mps/uan/5158

 http://www.facewest.co.uk/Petzl-Myo-XP-Belt.html

and a P7 or Cree Q5 mounted to the helmet(s) for the downhills. 

 Here's a recent test on the ultra ....

http://www.outdoorsmagic.com/news/article/mps/uan/5540

I could pick one up for around 340 Euro (275 GBP).

I think 2 of mine would be better,  save both on for descents,  remember you don't want just 1 light at speed if the thing goes off for any reason it's going to hurt,  fine for slow stuff ofcourse.

Haven't tried 1 of those yet,  but I'm eye balling 1 or 2 of them for my bar lights as there abit more floody than others cheap and 1 of the few torches that'll run on the high capacity 18650's.

Although the output and price of the hand torches you mentioned are very good from what I've read the run times look very short.  The petzl myo XP doesn't have anywhere near the output but looks to have a much longer battery life.  I'd switch on both during the descents just in case one stopped working and night time ski descents are taken with caution anyway.  The thought of having to fiddle about with batteries in sub zero temps while on snow is a disaster waiting to happen - drop the battery and it's gone.

What is the run time on high capacity 18650's?

The L1 is still a top bit of kit,  doesn't waste any light puts it all into a small circle,  a mates still using mine.

The LX is more of a conventional torch beam sadly

 In this german test of headlamps the "Petzl Myo XP" wins with the "silva LX" and "Blackdiamond icon" given as "buy tips".  The "Mammut Lucido TX-1" had the best spot but lost out on the flood lighting performance similar to the L1. 

=3957]http://www.outdoor-magazin.com/lampen.3960.3.htm?a[]=3957

How much light does a mountain biker really need ?  How should it be quantified - spot throw distance, lumens or something else? 

Saintly gets away with his Silva L1 and it looks like the newer Mammut Lucido TX1 has approx twice the throw.  Compared the TX1 and  Petzl Myo today in a shop, the TX1 spot was a lot stronger than the Petzl in boost mode (which I understand is 150 lumen) and the burn time is really long.

problem is that Leds use differing light figures, lux and lumens, lumens are the light whilst lux is the lumens per Mtr2. but you have no idea about the throw or the flood of the light, whilst most bulbs use watts as an indicator.

I personally find a light of around 700 lumens to be spot on, for skying would it not be worth changing the colour a bit to prevent glare.

this is a good company, i bought by lithium polymer battery from them and the delivery is not stupid.

http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=519