Technology

Teaching an Old Material New Tricks

Renovo introduced advanced manufacturing technology to wood bikes in 2007. With state-of-the-art adhesives, finishes and manufacturing techniques, Renovo has produced high performance, lightweight wood bicycles so durable and beautiful that they become treasured heirlooms that will last for a century, not just a few 100 mile races.

Renovo's owner is a woodworker of a very unusual kind… a woodbender. With a background in the arts, industry, and sciences, Christo Mroz uses wood like a sculptor. Wood is his medium for creation. And a way to produce bikes that are almost living things.

Christo started Pure Timber LLC in 2005 to bring solid wood bending to an architectural scale. That expertise is also applied to Renovo, a brand of Pure Timber. The “Extreme wood bending” that was developed for Pure Timber is used in architectural fabrications, musical instruments, fine studio furniture, sculpture, civic arts projects and Renovo bikes. Pure Timber bends wood further than anyone else on the planet. And that extreme wood bending is also in every Renovo bike.  

Durability

"As bicycle companies compete in the arms race to make even lighter, stiffer bikes, safety and durability are pushed to the limit. High modulus (66 Msi and greater) carbon fiber is being used to make stiff yet thin walled tubing. When slightly damaged from a pebble thrown up by a passing car, or an unfortunate event during a group ride or race, a thin walled tube can rapidly degrade to an unsafe condition". (Calfee Designs, one of the original carbon frame producers) Calfee's very popular carbon repair business is evidence of this common failure.

A Renovo is perhaps the most durable of frames. Our relatively thick-wall hardwood frames are extremely damage resistant and the easiest, least expensive frames to repair. They withstand Northwest rain, Desert heat, Alaska cold and Belize humidity. We know because we have customers in all these places.

"Yesterday I was driving to ride at the Chico Wildflower Century. Driving down a backroad at about 50MPH, my hitch-mount rack broke, dumping my bike to the pavement. The end of the carbon bar was broken, the pedal and rear derailleur were scraped, the hanger was bent and the frame had 2 dings where it struck the hitch.  I am certain if the frame had been carbon it would have been un-ridable." After replacing the parts, Eric Olsen rode the bike for 6 more months after the accident before sending it back for the very minor frame repair.

Frame Longevity

Wood is one of the most fatigue resistant materials on earth, simply because it used to be a tree. As a result, wood has a remarkable fatigue life that exceeds steel and aluminum and rivals carbon. We can design our frames with adequate margins to assure a long life against normal loads, and still have a light-weight frame. But not fragile-light. That belongs to other business models. Our frames will last a century, not just a few century races.

We use eight different adhesive formulations to meet our requirements of withstanding high temperatures, resisting moisture and bonding complex joinery. Our adhesives are moisture proof and the frames are heat cured to withstand the temperature and humidity range anywhere bikes are ridden on earth. 

We have bikes that endure extreme weather in Alaska, Norway, Belize, Singapore, Dubai and of course the rainy Northwest with never a failure from these conditions. To ensure consistent and good bond quality, we follow industry standard practice: meticulous surface preparation, good process control and good training—pretty much the same set of criteria to ensure good bonds on carbon bikes or good welds on metal bikes. All bonding is done in a climate-controlled room and the frames are heat cured to achieve the highest possible bond strength.

The Right Boards

The appearance of each bike is unique simply because grain, color and figure vary, even within the same board. Our wood selection process for each and every bike is painstakingly conducted by obsessive people. We spend ridiculous amounts of time searching for and choosing the perfect lumber to achieve stunning results. Selecting your frame materials is way more fun than just ordering another Reynolds tubing set.

Finishing

Our finish coating is two applications of at least three layers each of automotive clear coat, the same as on your Audi, BMW, Porsche... Your bike is as well protected as any car, boat or airplane. 

Heat, Cold and Moisture are Not Problems

Wood, in a  properly designed structure, properly sealed and bonded, is unaffected by hot, wet or cold outdoor environments; modern wooden boats live in the water, wooden aircraft and wooden propellers fly through it. 

• Moisture content. Unsealed wood seeks moisture equilibrium with its environment, so its moisture content varies by season. This can range from about 6% to 12%. Sealed wood has a much narrower range of moisture content, with no structural or cosmetic consequence.

• Heat/cold effects. Wood gains strength as it gets colder, and loses strength with heat, but the Renovo frame is designed for temperatures in the range of human activity, so heat or cold has no material effect.

• Warping, Cracks. These problems occur in wood from improper early drying. There is no checking or cracking possible in our bikes, because the time for that to happen would have been months before we chose our lumber for your frame. All wood used in the Renovo is kiln-dried before parts are assembled. Curved parts are bent with partially dried wood, then baked in a kiln to fix the shape forever.

Metal Sleeves in the Frame

We use metal sleeves in the head tube, upper seat tube and bottom bracket. All bonded aluminum is abrasive blasted, acid etched and alodined for maximum bonding strength.

Maintenance and Repair

No more is required than any other painted bike. A quick fix for deep scratches is clear nail polish. A more thorough repair is simple and unlikely to require a pro. Should any major repairs be required, you can send your frame to us for full service.