Napsali o nás

(Přiložena originální verze stránky)

Mountain Bike Action's March 2000 Issue

The name Mrazek may not be familiar to you, but one glance at their radical looking frames would ring a bell. Mrazek's radical curved frame tubes and elevated chainstays have been a hallmark of the marquee for a decade. Once you have seen one, the image is burned into your memory-even if you can't remember the builder's name (or how to pronounce it). It's Mrazek (mer-as-ick), and you won't be shocked to learn that Mrazek is not an American company. Family head Bohumil Mrazek builds the frames in the Czech Republic. The frames are then sent to Portland, Oregon, where Bohumil Jr., distributes them to American customers. To celebrate the first ten years of their existence, the Mrazek family is building a limited edition of 100 "BOH FX" signature framesets-one of which ended up in the hands of the MBA wrecking crew.


Boh Jr. worked in a plastics factory in Czechoslovakia before fdunding a small Czech metal working company. On a trip to the USA in 1993, he experienced the booming mountain bike movement. Upon his return to Europe, he created a bike manufacturing facility in Vrbno, Czechoslovakia, headed up by his father.

Boh Jr. wanted a durable, compliant frame and claims that his now-classic frame design came to him in a dream. Those close to him say the graceful curving lines come from his background making custom sabers.


Mrazek uses 7020 Formax aluminum drawn by a very big European metal company called Decin. Grade 7020 is common in Europe, and for comparison's sake is similar to the 7005 alloy designation in this country.

 The Mrazek hardtail is available in two models: The FX LTD signature and the FX LT. Both share the same frame geometry, material and design, but the LTD's "Limited Edition's" welds are finished smooth. The frame is then polished and nickel plated.

Head and Seat angles are 71 and 73 degrees respectively, and the elevated chainstays measure 16.5 inches long. The $1400 signature LTD frame weighs 4 pounds-about a half pound less than the standard $939 BOH FX chassis. Since the frames are hand-built, there is more attention to detail. In addition to filed, the frames cable routing uses full-length housing, and a trick, replaceable derailleur hanger mounts to the back of the drop-out. An 'S" curve in the seat tube is employed so the bike can have short, 16.6-inch chainstays and a long front-center. The effective seat tube angle is 72 degrees.


Mrazek believes the lightweight craze of a few years ago is resurfacing, and that this time around most of the questionable products have faded away, leaving only high-performance, durable stuff.

 Fork. A good example is the Morati titanium fork. The 3/2.6 and 6.4 seamless titanium fork is TIG-welded in an argon atmosphere, then heat treated in a vacuum oven. The sleek fork weighs a mere 1.4 pounds. Wheels: The wheels are Chris King hubs with Mavic X-517 rims and Kenda Kosmik Lite tires. Most everything else is Morati titanium.

Seat post: The Morati titanium seat post has a simple yet effective one-bolt head.

Cranks: The Morati titanium cranks feature hollow cross-sections and a longitudinal weld along the axis of the arm. Crank weight is an airy 315 grams.

 Handlebar: The most eye-grabbing component on the bike is the "M-bar" handlebar. It is somewhat reminiscent of the old Ritchey Bullmoose bar, except Morati uses a non-triangulated shape.

Brakes: Mrazek's brakes are a storv of their own. The Mrazek "MOC Miracle V +" brakes weigh 105 grams per side, have minimal free-play and can haul the bike down from speed on a nickel. They are good! Mrazek actually licenses the design from Marinovative, originator of the modern vee-brake concept.

Weight: All-tallied, the Mrazek frame and componentry add up to an unbelievable 18.5-pound bike.


When Boh created the FX frame, he wanted a fast, strong, compliant design. Strong and fast we can believe, but making a big-tube aluminum bike compliant is a stretch. The Signature is one fast bike. On fire roads it climbed like a road racing machine, and it continued to feel that way on hardpack singletrack. Where traction can he found, you can push a big gear up any climb. The light weight is an inspiration under power. Part of this comes from the short chainstays. Jump out of the saddle, throw the bike from side to side, look over your shoulder and watch your riding partners fade away. When things get technical the Mrazek is only limited by its slick tires and its rider's skill. Descending on the Signature is a mixed bag. The bike is fast - very fast. This gets you into trouble when braking bumps appear or you inadvertently smack a bone-jarring bump. You may want to add a RockShox SID Race fork (this will add about a pound to the bike) and turn this rigid rocket into a true hardtail. The Mrazek, however, isn't your average hardtail, so why spoil this speed monster with an act ofconformity? Obviously, a fully rigid bike with slicks has its limitations in some situations. MBA test riders could ride all their usual training loops, but some of the rougher, steeper descents became exercises in steering precision-at slow speeds. Hey, this isn't a freeride bike, and any time we lost on the descents was retaken on the next climb. The LTD's light weight, precise steering and agile maneuverability made missing obstacles a breeze. The Mrazek responded to the slightest rider input. Once we exceeded speeds over 25 miles an hour, however, the quick, responsive Mrazek became a twitchy handful to control WhAT'S THE DEAL? Call the Mrazek what it is: a fast, light, exotic and rigid cross-country bike-no more and no less. It is a genuine winner that is amazingly fun to ride in almost every cross-country situation. Our resident racers fought over it because whoever was aboard the silver steed invariably won our training rides. On the other hand, our freeride/trailbike guys scoffed because of its limited descending ability. One thing everyone agreed on was the attention factor. Everywhere we went, heads turned to get a better look at the nickel-plated aluminum Mrazek with its titanium componentry. Sit down, please. The suggested retail price for a Mrazek LTD is a staggering $5999. A pricey way to insure you'll own the most exotic and lightest bike at your next group ride. Mrazek isn't a household name, but that's a large part of what makes the bike so cool. For more info call Mrazek at (541) 385-4748

MRAZEK BOH FX - mountain bike

march 1997

That first slug of room temperature Guinness is always a harsh bit of reality. But this foreign con- cdction is surprisingly tame once you get past appearances. Well, what a surprise-that just hap- pens to remind us of a bike we just happen to be testing this month. The elegant and alluring imported Mrazek Bho FX, from the Czech Republic. The long- time ad campaign says "Guinness is good for you." Guess what? So is the Mrazek. From his adopted hometown of Portland, Oregon, Bho (pronounced "bow") Mrazek's (pronounced "mrazek") childhood in the for- mer Eastern Bloc country of Czechoslovakia is something of a clouded memory. "The communism wasn't that bad, says Mrazek. "I don't remember having any big problems, but it's true that you weren't completely free to do as you wanted." This meant that to leave his job at a state-owned plastics factory and pursue his passion for metal working, Mrazek had to wait until after the Velvet Revolution of '89, which signaled the end of communism in Czechoslovakia and led to the country splitting into the Czech and Slovak Republics in '92. "So many things changed after the revolution. People were able to travel and do their own thing. And it was then, like '90, that I saw my first mountain bike." Mrazek had been helping around his father's metal shop since the age of four. He would help build the go-carts that his father was known for making. "I saw a mountain bike but I didn't have any money to buy one so I got some chromoly tubing from a friend of mine and built my first bike," says Mrazek. "People saw me riding it, around my hometown of Vrbno and asked me to make some for sale. That's how my business started-I never had to advertise."
Eventually Mrazek ventured to Portland to visit an American friend. He married an American girl and stayed in Oregon. Today; Mrazek
directs his small but blooming company from the U.S. while his father runs their small production facility back in the Czech Republic.
It's a little crazy that the Bho FX is made in the Czech Republic, so it's no real surprise that the bike itself is a little crazy. The frame is a swoopy construct of custom bent, squashed and shaped aluminum tubes. But Mrazek claims that the Bho FX is more than a fancy hardtail: It's really a fully suspended cross-country machine. According to Mrazek, the frame's bow-like elevated stays give it "up to one inch of rear-axle compliance." Really? We'll get to that later.
The Bho FX is completely handmade by a staff of 12 in Mrazek's Vrbno facility. They receive 7020 aircraft-grade aluminum tubes as raw stock, then bend and swage the tubes in-house. The prepped tubes are then TIG welded into a frame, which is sent to a nearby Czech facility for its distinctive translucent red, blue or green finish. We got the red for our test frame, and the blend of powdercoat and wet paint was every bit as good as the finish on handmade frames from small U.S. builders such as Ventana.
I was initially suspicious of the Czech 7020 aluminum tubing used on the Bho FX. Most of the aluminum we deal with is 6061 or 7075 and has Easton stamped right on it-a trademark that guarantees quality. I shouldn't have worried. All 7000 series alloys (such as 7020 and 7075) are high-strength, zinc-based composites that are excellent for frame building because of their low density and ease of manipulation. That's a good start. And the factory that produced the tubing, Decin, which is near the Czech-German border, is one of the oldest and largest aluminum facilities in Europe. Before the revolution, it was a major supplier for the Communist war machine, so it must know a thing or two about metal. Despite the aluminum's reputable quality, it's straight gauge so it lacks the advanced (and weight-shaving) butting of some- thing like a ProGram tubeset from Easton. This is clearly reflected in the frames weight-just more than 4 pounds.
Despite the budget frame-only price of $699, the Bho FX has the nice details you'd expect in a high-dollar handmade frame-quality
welds, a replaceable derailleur hanger and good tire clearance around the elevated stays. Hell, it even has two usable water bottle mounts. One stunning detail that might be overlooked is the sheer amount of hand work that goes into bending and manipulating the aluminum tubes. Every tube except the head tube has been tweaked in some way. The elevated chainstays are dimpled for added tire clearance, the top tube is ovalized for added torsional rigidity and the down tube is ovalized near the bottom bracket for increased lateral rigidity. It seems that where the craftsmen at Mrazek couldn't find tubes to fit their needs, they did things the old-fashioned way and made their own. That's customization that no small builder in the U.S. could afford to do on a frame for less than $700.
Mrazek offers its frames wrapped in several component packages-most are a pretty good value. For example, Mrazek sells a Shimano LX/XT bike with Rock Shox Indy SL for $1,449. We tested a $1,699 Sachs Quarz bike with a Judy XC. Compare that with a handbuilt frame from the U.S. with ?he same parts kit and you'll see that the Czech machine is a pretty sweet deal. Mrazek is flexible and is continually updating its spec list, so check with the company for updated availability and pricing.
We don't get to test a whole lot of Sachs equipment. It's not that we don't like the German-manufactured components, it's just that
after Shimano and Grip Shift eat their helping the buffet is all but cleaned out. The Sachs Extreme twist shifters work as well as top
twist shifters from SRAM better if you consider that the Sachs shifters have on-the-fly spring-tension adjustment. We've used and had favorable results when pairing the Sachs shifters with both Sachs and Shimano derailleurs.
The brakes on the BOH FX are made by Mrazek and are based on the original V- brake design from Marinovative. In fact, Mrazek is so above-board that it's officially licensed the design from Marinovative-one of the only such agreements that we've heard of. The Czech-made brakes come in two versions: a $79 aluminum-arm model that came on our test bike, and a $119 version with light magnesium arms. They're a bit more complicated to install and set up than Shimano's V-brakes, but they work with equally staggering results.
COMPLIANCE, NOT SUSPENSION Let's get back to that one inch of pivotless suspension that Mrazek claims from the cantilevered Bho FX design. In our July '96 issue we tested the thermoplastic Scott Pro Racing, which that company claimed had one inch of deflection from a similar cantilevered type of pivotless design. We disagreed. Sure, the bike was comfy and we could even feel some give in the stays, but it sure as heck wasn't moving an inch. The Bho FX is the same deal. It's more comfortable than a typical diamond rear triangle, but not in this world or any other does it move an inch. If the Bho FX did get one inch of travel with no pivot, the fatigue life of the frame would be ridiculously short. (You've probably bent an aluminum beer can back and forth a few times and seen it tear in half with very little effort.) Aluminum is less ductile than either titanium or steel, so it's not really cut out for this.
The Bho FX is just like the other two bikes in this test-sure and rock steady. Laterally, it's stiffer than a cigar- store Indian. It's a beauty of a climbr. A steel, titanium or carbon bike with elevated stays would probably be soft in the bottom bracket during out-of-the-saddle climbs, but the Mrazek's stout bottom bracket held its own, even under our big and beefy test riders.
FIRE ROADS: Despite its bizarre look, the Bho FX has simple, tested geometry. A medium (18-inch) Bho has 71/73- degree
head/seat angles, a 42.5-inch wheelbase, short 16.7-inch chainstays and a low 11.6-inch bottom bracket. The low bottom bracket helps the Bho stay stable on speedy corners but some riders thought the short chainstays and wheel- base undermined the bike's stability. Despite the compliance of the rear stays, a long titanium or even a suspension seatpost on this bike would've made it more comfortable and dependable on fast, rattling corners and cratered-out straightaways.
The short chainstays are beautiful in the twisties, especially on technical climbs where the Bho pops up and over rock piles, ledges and roots. On tight downhills, the short front center of 25.5 inches and the tight wheelbase give the Bho an easy maneuverability and lively cornering feel. If the bottom bracket were a bit higher, say 12 inches instead of 11.6, the Bho would be a complete singletrack machine.

There are so many bizarre things going on that it's tough to get an angle on the Mrazek. Like a Milan Kundera novel or a pint of
Guinness, it's a bit cloudy and complex on the surface. But if you can get through the first chapter or initial swig you'll find the Boh FX to be of a pretty simple character It's a handmade aluminum hardtail bike that rides like it looks-a little better than your average frame. If it makes you feel good to sup port a small 12-person business (and one in a former Communist state), this could be your bike. Serve at room temperature.

Zprávy o dění kolem kol MRAZEKNapsali o násFan Club MRAZEKNaše výrobkyDoporučené sestavyVolejte, faxujte, mailujteCo pro Vás připravujeme novéhoHomeAktuální cenové bomby...Aktuální cenyHistorie a současnost