Home > Long Term Reviews > Lüm-Tec “Bull45” Watch Review

Lüm-Tec “Bull45” Watch Review

By Rick Korchak


Updated on

Summary:  The A5 version of the Lüm-Tec Bull45 is a solid and very cool-looking wristwatch that has become my favorite all-around quartz timepiece.  The numbers are as easy to read in daylight as they are at night when the special glossy Lüm-Tec MDV GX3 lume is glowing brightly.


lum-tec-bull45-box-bI’m not a big fan of quartz watches, but they definitely have their place in my collection and I’ll have to admit — when I’m in a hurry or I need a watch that I can depend on without question, I’ll grab a quartz. Most of the time, it’s the A5 version of the Lüm-Tec “Bull45”.

I bought this watch sight unseen, with no prior experience of the brand. I saw the watch on the Lüm-Tec website, thought it was too cool and had to have it. Many of the Lüm-Tec designs are very limited editions, with small production runs the order of the day and a necessity for what is a small U.S.-based watch manufacturer.

The Bull45 was announced nearly one year before it reached final production, so all I had to go by were CAD illustrations and photos of mock-ups. Lüm-Tec typically offers a nice discount for early order deposits, so I sent my money and got in line.

lum-tec-bull45-clasp-bLike any small manufacturer of any product, they have to order enough cases and parts to make manufacturing a feasible evolution, while hopefully getting a price break on the quantity. But surely they don’t want to get stuck with leftover stock that doesn’t move, which is money tied up in dust-collecting inventory.

The black, somewhat sinister-looking A5 version of the Bull45 shown here was not my first choice. The Bull45 came in A1 through A4 versions also; combinations of stainless steel, PVD (physical vapor deposition) coatings, face types and lume colors.

I couldn’t decide and went back and forth between the non-PVD coated stainless steel case A1 with a black face and white numbers and the black/orange PVD A5 version shown here. The A5 eventually won and I’m glad it did…although I’d be happy to own any one of the Bull45 watches, because they all look great!

Only 100 of the Lüm-Tec Bull45 A5 watches were made and they are now all sold out. This one is number 58 of 100. So if you want one, you’ll have to haunt the classifieds on one of the various watch forums! They do come up occasionally though, so keep looking — and Lüm-Tec has a gaggle of new designs in various stages of development, so check it out and you may end up putting a deposit down on your own limited edition!

The Lüm-Tec Bull45: A5 Version

lum-tec-bull45-face-close-up-bOther than the color and coating variations, all of the Bull45 watches have the same specifications. The case is 45 mm square, although the 12-to-6 dimension looks slightly smaller due to the indents in the case design.

The case is made from 316L stainless steel, PVD coated in the A5 and A4. The A4 has white lume rather than orange, otherwise it is identical to the A5.

The “Bull45” name comes from the top crown and pushers, which is traditionally called a “Bullhead” watch design. The “45” in the name is derived from the 45 mm case width.

The watch has a sapphire crystal which is coated on both sides with anti-reflective coating. This is somewhat controversial, as the outer coating can easily attract fingerprints, dirt and oils or grease, but a quick breath and a wipe cleans it up nicely. I haven’t noticed any undue wear on the coating from doing so and I don’t baby this watch.

The Bull45 is depth rated to 100 meters (330 ft.), but the pushers and the crown feel a bit mushy to me on this one, so I wouldn’t advise taking in the water at all. More on that in a bit…

The bright orange lume has a glossy finish on the numbers and hash marks and a matte finish on the hands, which is rather strange. It’s obviously very easy to read against the black background during the day, and the lume at night is good, but again — more on that in a bit.

Lüm-Tec Bull45 Lume

lum-tec-bull45-face-aOne of the most notable marketing strategies of Lüm-Tec is, of course, the lume. The “MDV GX” lume was apparently developed by Lüm-Tec and it’s available in various colors and applications. For example, in addition to the orange GX3 version of the MDV lume on the Bull45 A5, the A1 featues white lume and the A3 has a reverse all-lume white face and black numbers and hash marks.

I’m a little disappointed in the luminosity of the MDV lume on this watch, however. It is very slow to charge and seems to have lost a great deal of its “power” in the few months I’ve owned the watch. In fact, I can’t get it to charge at all, even when shining my very powerful Clearwater “Andie” LED flashlight on the face.

The MDV GX lume seems weak compared to other watches I own with Superluminova (SL) brand lume. The SL seems to charge very rapidly when its new and I can see the glow even in daylight.

I’m not sure if this is a fault in this particular watch or not, because this is my only Lüm-Tec product. But based on this experience so far, my opinion is that it is simply not as good as Superluminova.

Fortunately, I’m not all that big on lume anyway. Some collectors are fanatics about lume, while I’m more interested in how easy it is to read in the daytime when I’m awake. Going to bed at 21:30 or so does that to you I guess…

The Bull45 Chronograph Function

lum-tec-bull45-rear-aI’m getting ahead of myself actually here, because if it wasn’t for the lume, which is one of the primary marketing features of the watch, I would have mentioned first that the Bull45 is a chronograph. Lüm-Tec is also developing a non-chrono version of the Bull45, using the same case with the crown at the top. But all five versions of the Bull45 are chronos.

The watch uses the Miyota OS10 quartz chronograph movement that is very accurate, gaining only a second in about a week. As in most chronographs, the sweep seconds hand only moves when the chrono function is started. The right-hand subdial at 3 o’clock is the actual seconds counter that always runs (unless the crown is pulled out to set the watch).

The minutes are accumulated up to 60 (one hour) on the left-hand subdial at the 9 o’clock position, while the bottom subdial at the 6 o’clock position accumulates the hours up to 12.

I’m not a big fan of this traditional chronograph action; I’d much prefer a sweep seconds hand that runs all the time, with the right-hand subdial activated to count the seconds when the chrono function is initiated.

lum-tec-bull45-wrist-aBut I’m apparently in the minority here, as almost every chronograph made does the opposite. I bet many first-time chrono buyers think the chrono function is cool, so they buy the watch, and then are disappointed to find out that the seconds hand just sits there motionless until the chronograph is started!

This probably isn’t as much of a problem on a quartz chrono as it is on a mechanical chrono; indeed, some classic chronograph movements like the two-dial Poljot 3133 are supposed to be run only briefly or they will wear out prematurely, a strange attribute of a chronograph for sure!

Here’s something else to note: if you’re buying a chronograph, chances are pretty good that you’re planning on actually using the timing function. I use the Bull45 to time specific trips, and on the first trip I discovered that because the minutes on the subdial are incremented by 5, it’s very difficult to know the exact duration of the timing.

This is important and taught me a lesson: when buying a chronograph, make sure the subdials are functional and not stylish. My next chrono will have seconds, minutes and hour markings clearly delineated so I can tell exactly how much time has passed.

The crown on this watch does not have a solid “snap” feel when it’s pulled out; in fact, it’s rather mushy and sometimes it’s difficult to tell whether it’s in or out. Same with the chronograph pushers, which have a surprisingly mushy feel with no detent to alert the user when the chrono is engaged. I find the crown and the pusher quality to be the most disappointing aspects of the Bull45.

Other Bull45 Features

lum-tec-bull45-lumeThe watch comes with a slightly thin rubber or synthetic rubber (not sure which) strap. It has some stretch, which is good, because the watch does feel top heavy, so the strap must be cinched up pretty tight to keep the watch from sliding around on the wrist.

I tried an accessory “oyster” style strap, shown in some of the photos, but I didn’t like the look so I went back to the original. The original strap also has a black Panerai-style PVD coated buckle (stainless steel) and two keepers.


The original list price of the A5 version was $599.99, with a 15% discount for early deposits. Other Bull45’s are still available, with prices starting at $545.00.

It’s up to the individual as to whether or not that constitues a value. I’m pleased with the watch and think I got a good deal on a very unique, rare and great-looking timepiece.

By the way, Lüm-Tec also provides a lifetime battery replacement warranty on their quartz watches.

Watch Size and Weight

lum-tec-bull45-side-strapAt 45 mm wide by 45 mm top-to-bottom, the Bull45 is definitely a large watch. It fits on my 7.25″ wrist, but just barely. It does feel top-heavy, as mentioned above, so anyone with a wrist size of less than 7″ or so will probably feel overwhelmed wearing it.

The watch weighs 131 grams with the Lüm-Tec supplied strap. It’s a solid piece and the flat, wide strap does help keep the square watch in place. But a square watch can not really be allowed to “float” on the wrist as a round lighter-weight watch with a bracelet might.

The underside of the Bull45 is slightly curved, which does help the fit. The lugs are very short, which helps, and the watch has a lug tip-to-tip distance of 52 mm. The overall height of the Bull45 is 13.1 mm. It looks and feels thicker than that, probably because of the flat square sides.

The lugs are about as wide as they get, at 26 mm. This also helps make the flat strap to have as much surface area as possible to keep the watch planted on the wrist. See the Watch Straps page for a listing of my favorite watch strap retailers.

Movement, Setting and Accuracy

lum-tec-bull45-crowns-175The Miyota quartz OS10 is a very common movement, used in many inexpensive watches. On one hand, it’s a bit disappointing to find a movement that is common in sub-$100 watches powering a $600 watch, but on the other hand, the OS10 is considered reliable, it’s accurate and Miyota is owned by Citizen, one of the most respected mass-marketed watch brands in the world.

Quartz is quartz, more or less, until you get into the thermocompensated movements in Omegas and Breitlings. Even the $1500+ TAG Heuer quartz watches use pedestrian quartz movements. So I guess all of the money went into the development of the case and the lume in the Bull45.

lum-tec-bull45-oyster-face-175Pull out the crown to the first mushy position to set the date by turning the crown anti-clockwise (when looking down in it from above). Pull to the second position to set the time. The hands spin freely, but it is slightly difficult to get the minute hand precisely lined up with a mark and to see the tiny seconds hand rotating in the subdial when hacking the watch.

However, once everything is set, the watch is very accurate. I let it go for a couple of weeks, then when the seconds hand is 2-3 seconds fast, it’s an easy matter to pull the crown, watch the Casio “Atomic” watch, wait until it matches the Bull45, then push the crown in. All set and perfectly timed for another few weeks; the beauty of quartz!

lum-tec-bull45-oyster-strap-175I have no idea how long the battery will last in the Bull45; I assume for several years, although I use the chronograph fuction quite often, which probably runs the battery down faster than normal. Lüm-Tec has a free battery replacement service as part of the warranty, but by time I ship it back to them with insurance, I could probably replace 2-3 batteries myself (read the webWatchWorld battery replacement article with video).

So the bottom line here is that the Bull45’s Miyota movement is very easy to maintain and very easy to set and, like all quartz movements, should provide years of reliable, trouble-free service.

Readability and Face

lum-tec-bull45-side-175The big, flat, double-sided, anti-reflective coated sapphire crystal on the Bull45 virtually eliminates all reflective glare, albeit at the expense of some blue reflections due to the coating. This is a very easy watch to read, due in no small part to the flat crystal, the anti-reflective coating and the big, bold orange on black numbers on the black background.

I’m sure the white lume version on black background is just as easy to read.


The Lüm-Tec Bull45 is the nicest quartz watch I have ever owned. It has a few idiosyncrasies, and I’m 60/40 on the quality of the lume, which seems a bit over-hyped to me, especially when Superluminova is available.

I find myself reaching for the Bull45 quite often, because it’s simple and fast and accurate and it looks great — certainly not like your average, run-of-the-mill quartz beater from the local Big Box store!

Even with its few issues, I will be looking at Lüm-Tec again to see what they have to offer. Perhaps I’ll try one of their new automatics next!

Avatar photo
About Rick Korchak

Rick has been an avid watch collector for decades. His first watch was a Zorro manual wind from 1957 and he still owns it today. Learn more about WYCA's Editorial Process.

Leave a comment