Perfection would almost intimate a stasis. Whatever is truly perfect would have to be the last form of an evolutionary process. We know that this is just not possible with the current pace of technological advancements. However, at the moment there are a number of bicycles that must surely be nearing the top of the pinnacle. The BH Ultralight is one of those that deserve the distinction. Its performance is only overshadowed by its contempt for the traditions of the scale. As the name would imply, the Ultralight is just that. In a painted 54cm version, the frame weighs a mere 747 grams.Of course, light weight is nothing without performance. And who hasn't witnessed the laughable show bikes that simply aren't rideable as a normal road bike. Chris Cocalis of BH USA made the goals for the Ultralight very clear - make it the stiffest and lightest road racing frameset on the market. With a defined concept, BH was able to make the Ultralight just that by utilizing a number of key elements. These are the BB386 bottom bracket, their Formula 1 spec high modulus carbon fiber blend, and proprietary molding techniques. You might be wondering how the bottom bracket could relate to the performance of the bike. At 86mm in width, it shares that same dimension with a standard pressfit (BB86) bottom bracket. The benefit with either is that the shell has the real estate to accommodate larger diameter down and seat tubes. As the cross-section of a tube increases, so does the torsional stiffness for any given wall thickness. The difference between the two standards has to do with the inside diameter. Where a BB86 has a 37mm ID, the BB386 has a 46mm ID. And the reason that BB386 is superior to BB86 is that it allows the use of the newer cranksets with 30mm alloy spindles. They are roughly 40-50 grams lighter than their steel spindled 24mm counterparts in addition to offering greater torsional stiffness.The BH Ultralight is molded as a monocoque including ultra-high modulus carbon fibers. The fact that the materials meet Formula 1 specifications is not without merit. Comparatively, typical aircraft spec would be like the contrast between an Audi A6 Avant and a wood grained station wagon. The high modulus full-carbon blend afforded BH engineers the freedom to use less material to drop a significant amount of weight compared to their G5, yet still achieve the stiffness benchmarks they wanted. BH also uses a molding process that eliminates voids, wrinkles, and excess resin in the final, cured structure. And one of the nice benefits of an exacting lay-up schedule and molding process on a bike like this is that it's far removed from the wooden feel of many early composite bike frames. The result of the right amount of material and not an ounce more is a lively ride that inspires.While the G5 uses a complex, channeled down tube to hide away the under-routed derailleur cables, the Ultralight relies on more subtle tube shapes and exposed cables. The top tube is round,
Strengths: light, carries it's weight reasonably low, sart to use smaller diam seat post, good stiffness, stable geometry and light...
Weaknesses: rear drops could be made simpler and more accomodating. Should come with a chain catcher given the extremely thin walls near the BB,
Most bikes this light are more twitchy / jumpy feeling or give up stiffness for a smooth ride. BH did a great job here. Good finish quality front to back. VERY good performer. Not cheap, but this bike gets in the face of bikes that cost more. I would take this over the Tarmac, Venge, Prince all day on ride quality / smoothness. Nice and stable.
Many folks rave over the ride of latex tubes and i've read many of the test results on the web (wheel energy, biketechreview.com's tire testing, etc.) but i have yet to see a comparison of the Ultralight Butyl tubes vs similar weight Latex tubes.
I've been running Michelin Aircomp Ultralight Butyl ... Read More »
I'm in the market for a new frame/bike and the BH ultralight is at the top of my list. I'm also looking at the Tarmac SL4, Parleee Z5, Crumpton, and similar. I've read the magazine reviews but I would like some real world input if anyone has any.Read More »
Got to play around with one of the new BH Ultralights after dropping off a G5 I tested. I was shocked at both of these bikes. While they are different both had exceptional ride qualities. Anyone own one of the G5's long term?Read More »
Has anyone ordered from this wheel builder - he's in British Columbia - or built wheels with these hubs? A weightweenies.com forum has some posts re: the hubs but nothing re: their reliability over time.Read More »