Crankbrothers Cobalt SL Headset
Crankbrothers has been known to think outside the box. Innovative designs spurred the success of such Crankbrothers products as the Egg Beater pedal and their Multi-series tools. But, the first thing we noticed when we had the opportunity to review the Crankbrothers Cobalt SL Directset was, well -- the box. While Momma always told us not to judge a book by its cover, attention to detail on package design can often indicate a similar level of care spent on the goodies inside. Crankbrothers didn't disappoint with this one.
Let's review some basics -- the headset is that oft-neglected tidbit that ties together the fork, stem, and bike so that when you turn and yank on the bar, the front wheel goes where you want it to, and you and the rest of your bike follow shortly behind. Ideally this is accomplished with a minimum amount of weight and a maximum amount of rigidity and robustness. Way back in ancient times folks used persnickety threaded headsets that required some big ol' wrenches and voodoo magic to adjust properly. Then came the five-lined skink from Cane Creek with the threadless Aheadset back in the early 90s that revolutionized the whole bicycle front end (with a little help from Mr. King out west). And now, Crankbrothers have dropped their Directset on the world. Naturally, our curiosity was peaked.
Most threadless headsets consist of an outer cup on top and bottom, with cartridge bearings pressed in. So, from the outside in: fresh air, head tube, headset cup, outer race, ball bearings, inner race, steerer tube, old air. Crankbrothers took this idea and threw out one of the chunks of metal, machining the cups to also serve double duty as the outer races (definitely another one of those "Why didn't I think of that?" situations). In short, the upside is a lighter, more compact, sexier headset. Potential negatives include questions about strength, longevity, and some installation issues.
Crankbrothers took care of the strength question by crafting most of the bits out of 440c stainless steel and tossing 28-ball sealed retainers in each race while still keeping the weight down to a jaw-dropping feathery 65 grams. The top cap and cobalt blue colored dust cap both get the aluminum treatment. For those of us that live by the credo of "get light or get out," you can drop a little more change and pick up the titanium version to shave about 7 grams off the SL. The bearings have rubber seals that are easily removable for service. Just pop them off with something sharp, drizzle some degreaser inside, dry everything out, regrease, replace the seals, and be on your way. This can even be done without removing the cups from the bike.
Like any good headset, the Crankbrothers Cobalt SL Directset led us and our Ventana El Padrino mule down many-a-local trail including the IMBA Epic Womble during the Ouachita Challenge marathon with nary a peep. The weather gods have been pretty active this spring in Arkansas and all the resulting mud didn't seem to faze it one iota. The rubber o-rings, protective aluminum shield on top, and bearing seals all worked together solidly to keep all the little nasties out while still allowing free movement for steering. While it's a bit too early for us to know if it'll live up to the manufacturer's 5-year warranty, we found no reason to think that it won't. We've seen a few raised eyebrows around these parts, but the quality stainless steel and tight construction appear to come together in a headset that should give years of trouble free service.
The only real trouble we had with the Crankbrothers Cobalt SL Directset had to do with installation. We've pressed several of these into frames recently and each time we've struggled to keep them from cocking sideways on the way in. With proper head tube reaming, a steady hand on the headset press, and patience, they'll eventually drop in, but it can't be rushed. It seems that Crankbrothers made these with a slightly larger outer cup diameter than the good ol' trusty Chris Kings we're so used to. "What's a few thousandths of an inch among friends," you ask? Well, when you're dealing with a press fit joint it can mean the difference between gallivanting down your favorite trail on Saturday morning or turning your cracked-head-tube-inflicted-frame into a bad lawn sculpture that will scare away small children. We recommend that you take yours to a reputable bike shop that has all the proper tools and have the folks there install this for you. You might even gently point out the included 1-1/8" installation tool if they've never dealt with a Directset before. The head tube must be reamed out, and the top and bottom cups should definitely be pressed in one at a time. Crankbrothers recommends using a rubber mallet to set the cups prior to pressing them in.
Other than the finicky initial setup, the Crankbrothers Cobalt SL Directset represents a solid evolution of headset technology. Quality materials matched with a slimmed down design result in a component that carries the same price and about half the weight of comparable headsets from other manufacturers. If you are looking to shave some grams and don't mind trying something new, this is a great headset. If you're running everything maxed out at ten and really want to crank that "lightness knob" to eleven, go for the gusto, and spring for that Cobalt Ti. While there's no reason to doubt the effectiveness of the Crankbrothers design, if you're more comfortable with something a little more tried and true, even if it weighs a little more, go with a Chris King. Just don't complain when we pass you on the trail!