Open to Interpretation

Open to Interpretation

I was reading Padraig’s review of the Masi Evoluzione and was nodding in agreement as he detailed the reason for the drop off of his road bike reviews. The adventure/gravel/multi-surface has been for me as well, the more interesting, more exciting category to ride, talk about and review. And by the way, Masi has some entries in this class that are worthy of examination. But the bike in this category that raised my level of excitement in a significant, “I gotta ride that thing,” sorta way, was the machine you see pictured here. Open cycles and its U.P. (Unbeaten Path) boldly said with the introduction of this bike, “There’s a better way to explore roads and trails previously inaccessible on a drop bar bike, and it is the Open U.P.”

The lineup of bikes from Open (there’s just three) comes from the mind of Gerard Vroomen. In a previous bicycle life, Vroomen launched Cervelo into the stratosphere by designing the fastest TT bikes, curving seat tubes, thinning seat stays and putting the Cervelo name under eventual Tour de France winner Carlos Sastre. But Open is a much different company and the U.P. a much different bike. Instead of designing bikes that others ride to victory, Vroomen says the U.P. is a representation of the kind of riding he likes to do: a mix of tarmac, dirt paths and gravel.

Before there was a U.P., Vroomen rode whatever he could get away with on his favorite, unimproved surfaces. He even would take out Thor Hushovd’s Paris-Roubaix  Cervelo. But the big gears and limited tire clearance proved to be, well, limiting. And then he got to talking to another bike braniac, the late Steve Hed. The two were sharing a ride to the Almanzo 100 gravel race in Minnesota and started talking wheel size. It was Hed who alerted Vroomen to the fact that the outer diameter of a 650b mountain bike tire and a 700c road tire were pretty close and that if one could fit in a rear triangle than the other could too. The problem was how to squeeze wider tires yet retain a chainl stay length that was close to road spec.

When the U.P. was just an idea, Vroomen wanted angles and lengths familiar to a road bike because says Vroomen, road geometry gives you speed. The rider can get lower and the shorter stays are more pedal efficient. The head tube angle is 72.5 on all four sizes. The HT lengths are aggressive to achieve an aero position. The large I rode was 155mm. But the back half of the U.P. is the real mind blower. Those chain stays are just 420mm. Incredibly there’s room for a mountain bike tire yet those stays stay out of the way of a road chain set.

The secret sauce is the right chain stay. Vroomen curved it down as it moves away from the bottom bracket. The drop allowed him to keep the stays wide enough to clear off-road tires (27.5 x 2.1 or 700c x 40mm) but also give a 50t, road chain ring (that’s the maximum) room to operate. We’re talking a few millimeters between those big ring teeth and a coating of orange paint, but it’s enough.  At the back, those stays meet up 142mm apart at a thru axle to keep power transfer efficient.

The pay-off is an off-road worthy bike that responds like a road bike. The U.P. goes from slow to go in a matter of a few turns of the crank. Its pedal response is particularly useful on techie trails where a sudden acceleration is needed to clean a rough patch or clear a steep pitch. And on a long, steady road climb, the U.P. was a willing ascender.

I put the the U.P. through the paces at the Redlands Strada Rossa, a mixed surface event held half way between Los Angeles and Palm Springs. The trails were lush and overgrown. Handlebars were turned into weed whackers. Looking up trail was of no use and instead riders reacted to what was directly under their front wheel. The U.P. gave me a distinct advantage in this situation. When an obstacle suddenly appeared, a fast turn of the cranks got me around ruts and over rocks. And on the RSR’s paved sections, I found myself riding the front with relative ease. It certainly wasn’t me, it had to be the machine.

Open sells the U.P. as a frame fork only. Consider it a canvass. Or if you’re not the artsy type, a pizza dough. Paint your picture or add the toppings of your choice. The U.P. is “open” to your interpretations of what art or food or riding is. The U.P. accepts 650b or 700c, 1x or 2x, electronic or mechanical. Run the stock 3T fork or thrown on a Lauf. Drop bars or flats? Maybe. It’s a Monet or a Margherita or whatever you decide.

My tester came kitted with Ultregra DI2 and 3T carbon, 650b wheels with the eye catching, WTB Horizon slicks in 47c. In the dirt, the tires were short on bite but soaked up the rough stuff with ease. On the road, the girth took a few more pedal strokes to get those tan sidewalls spinning but when up to speed, they were cruisin’, even uphill.  Like I said, there are many ways to set up the U.P., this was just one. If the budget is there, best to have a couple wheelsets.

Oh yeah, the budget. Asking price for a frame and fork is $2900. Open has taken some flack in the press who have said a frame made in China shouldn’t cost that much. “The press is out of their mind when they say that, and you can quote me on that,” responds Vroomen. “I think for a frame that is completely unique, designed from the ground up, without any reference to previously available product, that is built in low quantity, I think that’s a pretty reasonable price, it might be a little low.”

Imagine what they’ll say about Open’s new horse in the stable. The Upper is also a “Gravel Plus” platform. It’s lighter by 230g, accepts flat mount disc brakes and has a much heftier price tag: $4500. “The introduction of the Upper will not push aside the original,” says Vroomen. “It’s just the more expensive, lighter brother.”

Colors are few and paint schemes subdued: brown, orange and raw. Vroomen says paint was not a priority. He wanted to keep Open focused on design, manufacturing, distribution and sales. They don’t do marketing or sponsorship or paint that takes a lot of time. Small and nimble is the mantra of Open.

That said, if you wind up on one, be prepared to explain. Humble paint job or not, the Open U.P. is a talking point. People will ask about it. My go to description: fast and steady. A serious machine that is all about having fun.

The thought of a “quiver killer” bike is both exciting and ridiculous. The minimalist side of me says, “I’m in. One bike instead of the six or so I have now.” (Of course if I really was a minimalist, that one bike would have one gear and no brakes). Another side of me says narrowing my inventory to just one machine is crazy. I love both my road bikes and both my mountain bikes and my ‘cross bike. I mean variety IS the spice of life, especially when it comes to what I ride. One bike to rule them all, oh yeah! – yeah right.

, , , , , , , ,


  1. GeekonaBike

    Pertty Trick, but I’ve been doing something very similar with a Surley Karate Monkey for a decade. It’s weights a bit more, but can be built with 650b plus size wheels. I like to call this build “Bluto’s road bike”.

    1. Author
      Michael Hotten

      Surly is doing some great stuff with their dropouts. They have a couple of bikes that will accept just about any wheel axle. Light is not their thing but having fun (like Open) is.

  2. Jonathan Collins

    After your review of the T5 Gravel, I purchased the next generation Litespeed Gravel. Absolutely love the bike. For me it checks all the boxes. Went with a 48/32 praxis crank and a 11-32 in the rear. Hed wheels with maxis 40 ramblers. The bike only seems to be limited by my abilities. Thanks for all the hard work you 3 put into the paceline, it shows. Love the show.


    1. Author
      Michael Hotten

      Ron- you are correct, the smaller sizes have slacker angles up front. I rode the large.

      I wish I could make that comparison for you. Padraig is one of the few to have ridden the Allied Alfa all-road so the best you can do is read his preliminary review on it and compare that with the many reviews on the interwebs on the Open, including ours of course.

  3. Nik

    I have to admit I am mostly ignorant about bike geometry. Could you try to explain why short chainstays are more efficient ? With longer chainstays, where does the lost power/watts go ?

    1. Author
      Michael Hotten

      Shorter usually means stiffer. So the power the rider delivers has less opportunity to escape due to flex. Shorter stays also usually equate to a shorter wheel base, so the bike should flick back and forth easier during out of the saddle efforts.

    2. Mark

      Nik, there’s no good studies of the mechanical efficiency regarding any watts lost due to flex in the frame. Subjectively, though, most riders who have ridden otherwise similar bikes agree that shorter chainstays make the bike *feel* more responsive. It’s particularly apparent when climbing out of the saddle: the bike with the shorter chainstays will feel like it jumps forwards with each pedal stroke, while the bike with longer chainstays doesn’t have the same “pop” to it.

      A physicist or mechanical engineer would (rightly) ask where the energy is going, if it is “lost” and not going into forwards motion. That’s an open question…

      (I’m assuming you’re asking the question seriously, and not rhetorically; there’s a small subset of cyclists who actively discuss the question you’re asking. Check out Grant Peterson and Rivendell bikes, or Jan Heine of Compass, if you’re curious for the counter-discussion and the supposed merits of “planing”.)

  4. Shawn

    I would love to see someone do a full comparison btwn. the Open UP to the 3T Exploro. (I’m sure I would be happy, if either one magically appeared in garage.)

    1. harris

      Shawn: a bike shop owner friend of mine has ridden extensively both the Open and the Exploro. He said that Open is more like a gravel bike for MTB enthusiasts, while Exploro is more like a gravel bike for road bike enthusiasts. That said, as a road bike enthusiast that rides a cross bike off-road, the Open blows my skirt up more than the Exploro; particularly the brown Open.

Leave a Reply

Your email address will not be published. Required fields are marked *