Surefire UM2 Ultra

[teak]

Do you mean the UM2? Or the U2 Ultra that came out in 2004? Both are great lights in my opinion. :twothumbs

The UM2 with depleted batteries seems to ramp down the output gracefully so you should get plenty of notice before it goes dark.

As was the case with the U2, I do wish that the lowest level on the UM2 were a little lower. I took the light out for the country walk at midnight on a moonless light. It's easy to fire off the light full blast at the ground to announce my presence to a passing pickup truck. A neighbor in an SUV stopped to ask if I'd seen her chicken that flew the coop. I told her I'd be on the lookout and used the UM2 to check a couple of nearby fields. I heard a commotion in the woods and four deer bounded across the road ahead of me. Like the U2, the UM2 feels very good in the hand. I'm getting used to the UM2 selector ring but it just doesn't feel as robust as the U2 selector. I may get some magnets off the refrigerator and see if they make the UM2 change modes like they do on the U2.

The mode changes seem to occur right at the detents on the new light. Is the same technology used to change modes on the UM2 as on the U2 (thought to be Hall effect switches)? Is a three bit Gray code involved with multiple magnets? Or a single magnet on the ring passing six sensors in the body of the light? I'll let somebody else do the teardown this time.

Sorry. UM2. I love the u2 ultra. Sounds like your enjoying yours so far.

 

[Minimoog]

I have the original U2, but upgraded with an XPH-50 neutral LED. That is so good that I wonder why SF did not just do this themselves.

 

[tab665]

The selector ring feels a little cheesy but otherwise this is a great light.

what do you mean by the selector ring feeling "cheesy"?

 

[WDR65]

what do you mean by the selector ring feeling "cheesy"?

I think he means that it doesn't feel like it's on ball bearings which is how the original U2 feels. The level detents also feel rough and somehow less well crafted than earlier examples, including the U2 and even the UB3T.

 

[RobertMM]

Maybe with some use the rough spots on the ring will even out and the lube will thin out and spread, and it will improve smoothness.

 

[RobertMM]

Please delete, sorry.

 

[Vox Clamatis in Deserto]

Maybe with some use the rough spots on the ring will even out and the lube will thin out and spread, and it will improve smoothness.

And I'm not sure what lube, if any, should be used on this ring. It almost feels like the detents are somehow mechanically involved in the mode switching.

The roughness of the UM2 selector ring movement is a pretty minor quibble. Like the tint, I probably wouldn't notice it except by comparison to another light.

 

[StandardBattery]

I have the original U2, but upgraded with an XPH-50 neutral LED. That is so good that I wonder why SF did not just do this themselves.

That sounds very nice. Same driver?

 

[kssmith]

So I've been using mine for a bit now; and must say they I really like this light. May be my favorite used light. The selector ring on mine doesn't feel cheesy for sure. Nice and solid. Also, I think the length is perfect, it falls in between the P2X and P3X.

I did accidentally find out how to remove the selector ring tho. I was unscrewing the head, and unintentionally took the base of the head off. This caused the ring to come loose. Since I wasn't ready for this, and I don't want to break it, I did not further explore. I screwed the base back on and performed function tests.

I am probably going to try and remove the pocket clip and see how I like that set up. Looks like the retaining ring screws on. Has anybody else tried this?

 

[Vox Clamatis in Deserto]

I am probably going to try and remove the pocket clip and see how I like that set up. Looks like the retaining ring screws on. Has anybody else tried this?

I was thinking the same thing but haven't tried it yet. It looks like a plastic nut comes off and you can easily remove the clip.

I've had good luck with the RCR123A's in this light. An old worn set of AW RCR's cuts out after a couple of minutes on high but quickly recover when the power is cycled, similar to their performance in power hungry legacy incandescents. On lower levels the AW's run to exhaustion with plenty of warning as they lose power. As always, you probably don't want to run regular RCR's too low on voltage if you can avoid it.

A new set of Olight 16340 650 mAh RCR123A's work great in the UM2 and like the AW's seem to have no issues with voltage even hot off the charger. I've been using this battery in the PK-PR1 lately as well.

 

[LumensMaximus]

The U2 Ultra is no longer on the Surefire website, I could have sworn they were on in 2016

 

[teak]

The U2 Ultra is no longer on the Surefire website, I could have sworn they were on in 2016

I never noticed them to ever be, however, I don't look at the website much these days. Last time I looked on there was to see if they still had the LX2 listed. Well they didn't.

 

[Vox Clamatis in Deserto]

The U2 Ultra is no longer on the Surefire website, I could have sworn they were on in 2016

It appears that the the U2 was listed online at surefire.com as late as November 2015, it seemed to disappear shortly thereafter:

http://web.archive.org/web/20151121...ire.com/illumination/flashlights.html?clear=1

I never noticed them to ever be, however, I don't look at the website much these days. Last time I looked on there was to see if they still had the LX2 listed. Well they didn't.

Looks like the LX2 still had a SF product webpage as recently as March 2016:

http://web.archive.org/web/20160327...com/illumination/flashlights/lx2-lumamax.html

 

[Up All Night]

I earlier said that I thought the U2 and UM2 tailcaps were identical. Upon closer inspection it looks like there is a collar around the spring inside that is metal on the U2 tailcap and plastic on the UM2 tailcap. They are indeed interchangeable on the two lights in my testing.

Those 3.0 volt Tenergy LiFePO4 batteries I was using are only rated at 400 mAh and have a high failure rate from my experience. I went for broke and put a set of AW RCR123's fresh off the charger into the UM2 for a 'smoke test'. They seem to work fine, unlike in some other recent SF lights such as the EB2. :twothumbs

The selector ring feels a little cheesy but otherwise this is a great light.

I tip my hat to your intrepid nature regarding the 2 x 3.7 volt AW batts. Price & geography will be keeping me out of this one. I'll enjoy vicariously!

Not to derail, could you expand on your EB2 experience on two 3.7v batteries. I have proceeded as far as two in the tube but I can't bring myself to engage the tac switch!
Thanks!

 

[Vox Clamatis in Deserto]

Not to derail, could you expand on your EB2 experience on two 3.7v batteries. I have proceeded as far as two in the tube but I can't bring myself to engage the tac switch!
Thanks!

Well, I was thinking that AW RCR123A's in my EB2 would make the light slowly blink due to overvoltage. However after searching my previous posts here, it appears that it is my early 200 lumen SF EB1 that I had tried with that result. And, it also appears that the latest 300 lumen version of the EB1 takes 3.7 volt RCR's just fine.


So, I took a set of AW RCR123A's hot off the charger at around 4.2 volts and put them in my late model EB2 for the 'smoke test' . To my surprise, they work fine. The head gets warm after a few minutes but it seems to be thermally stable sitting on a desk without a hand as a heat sink. I repeated the test with a new set of Olight RCR's with the same result.


Of the SF lights that I have, the EB2 is probably the closest competitor to the UM2 in terms of size and beam. Having six levels on the UM2 is a nice luxury but as zoom camera lens makers have long observed, most folks use the extreme settings a lot more than the intermediate ones. The high and low settings of the EB2 are close to the highest and lowest levels of the UM2 and the EB2 is significantly smaller and less expensive.


Maybe the EB2 was too close to the UM2 in the product line and the legacy military spec that sold U2's for so many years was never updated to include the new generation of lights that were four times as bright.


I love the classic knurling and finish of the UM2 and it is great having six well spaced levels of output. However, in the real world, the EB2 probably could do the same the same job in most cases.


If the UM2 is like some other SureFire closeouts and limited runs, the lights will sell at list price for a while until the niche market demand is satisfied. Then they will be discounted to clear out the remaining stock. Still later, the lights will appear on the auction site for a premium price since they are now out of production collectibles. The 9-11 edition red 6PX and the 30th anniversary pen and EB1 sets are in the premium price stage of this cycle on eBay for example.

 

[Up All Night]

^^
Thanks for going the extra mile with that reply! Much appreciated! :thumbsup:

 

[WarriorOfLight]

My UM2 arrived today :thumbsup: So far I like the Flashlight. The Selector Ring is more like the Dominator Selector Ring with defined "clicks" for each of the 6 stages. The U2 does not have this click stages on the selector ring, but the Kroma...

The beam looks good so far (currently I habe daylight - need to wait a few hours till dawn to say more). The beam color of the light is cold but not too blue.

At all for me I am pretty sure it was a good buy. I was waiting for this light really long.

Btw, I got the light at ebay and I also got the cap and the arms united stickers. Even if the shop was stated in Miami the tracking told me it was sent from Las Vegas.

 

[AR_Shorty]

I have some bad news. My light has started acting up. The two brightest settings on the selector ring don't increase brightness, but actually step down the brightness. It also will also switch brightness levels on its own (almost a ramping up effect) after selecting one of the last two levels on the ring. I'm very disappointed as I was really liking this light. Anyone have any idea what may be the problem? I wonder how Surefire would handle it if contacted about warranty work on one of these lights, since they were a limited run?

 

[Vox Clamatis in Deserto]

Anyone have any idea what may be the problem? I wonder how Surefire would handle it if contacted about warranty work on one of these lights, since they were a limited run?

Batteries are the first thing I would check, for example, the lower voltage on a single cell RCR seems to give the cycling on the two highest levels:

I tried a Keeppower 16650 and it cycled continuously between the two highest power levels so it seems that the single cell option will not work well with this light. Two Tenergy LiFePO4 RCR123A's work fine with all power levels.

And this is a high drain light on the last two levels, does your light work normally on the lower levels? I've seen the level seeking behavior on this light as various types of cells get weak. Some more of my UM2 battery experience:

I've had good luck with the RCR123A's in this light. An old worn set of AW RCR's cuts out after a couple of minutes on high but quickly recover when the power is cycled, similar to their performance in power hungry legacy incandescents. On lower levels the AW's run to exhaustion with plenty of warning as they lose power. As always, you probably don't want to run regular RCR's too low on voltage if you can avoid it.

Do you have another fresh set of primary CR123A's to try?

The longtime mantra here on CPF is that SureFire has great customer service. I would expect them to support the UM2 even though it seems to be somewhat of an orphan product.

If the price drops at some point, I'd be tempted to buy a couple more for gifts. Maybe I'll get those stickers and the ballcap next time.

 

[kssmith]

When the two primaries on mine began to weaken, the high output would begin to alternate between high and med high. New batteries fixed this, and I had no other issues on the lower outputs.