The 2015 race season is beginning to gather steam, which means that many of the top pros are spread out around the world to race national and local rounds in order to put in some runs against the clock. Some also use these races to evaluate new components or changes to their race bikes that they'd have to otherwise test in private - as anyone who's competed at a high level knows, you're going to take chances in a race run that you might not otherwise take during regular testing.
That fact makes these pre-season races, especially the hotly contested Fontana rounds, an ideal place to test anything that could give a racer an advantage when it really counts. That's exactly what Specialized's Aaron Gwin was doing at the last Fontana stop when his Demo race bike was spotted with a rather unique and definitely not production rocker link. A little digging showed that Troy Brosnan has also been using the prototype link, and he even won the Aussie Nationals with it on his bike. Reaching out to Specialized's Senior Engineer Jason Chamberlain, who actually designed the new link, revealed that there's quite a bit going on with it, and that both Brosnan and Gwin are fans of the changes.
How is it Different?
The production S-Works Demo, as well as the bike the team has been racing on up until recently, is fitted with an impressive carbon fiber link that's mostly hollow expect for some internal carbon ribs and a small amount of foam, and it's said to be 240 grams lighter than the aluminum version on the less expensive models. The rocker link pictured here on Gwin's bike, as well as the one Troy has been using, is actually a CNC'd aluminum unit that has been machined right in Specialized's Morgan Hill headquarters, and Chamberlain explained to me that it's just a few grams heavier than the S-Works carbon fiber link.
And speaking of weight, the prototype link rotates on smaller sealed bearings than what you'll find on the production bike, which helps to save a handful more grams. There's always a tradeoff, though, and the flip-side here is that the smaller diameter bearings aren't going to hold up as well compared to what's used on the bikes that the average consumer can buy, but that's not a concern to the Specialized Word Cup racers.
Gwin's FOX RAD DH shock - which looks like it came off of a production line, by the way - is the same length as stock, as is the RockShox Vivid that Troy uses, but the altered mounting locations mean that a short extension has to be used at the bottom end to compensate for the changes and preserve the bike's geometry.
The other big difference is the built-in adjustability the team now has compared to the non-adjustable shock mounting on the S-Works carbon link. Chamberlain actually employed the eccentric flip-flop chip from the old Demo, making for three different geometry possibilities, although he also said that both Gwin and Troy have stuck with the stock settings for now. The other two options give them a range of +/- 6mm of bottom bracket height, and less then +/- half of a degree of head angle adjustment if they choose to tinker with them. What Does it Do?
Specialized is not machining the prototype rocker link for the team to have more geometry adjustments, but rather for added bottom out control. ''The top ten pros do things with bikes that no one else in the world does,
'' Chamberlain explained ''And one thing we have found is that they generally need and like more progression than the rest of the world, so this link has more progression built in. That means the shock does not have to handle bottoming with compression damping as much.
'' The revised rocker link also provides increased sensitivity at the beginning of the stroke and also allows the bike to ride higher in the travel, all things that Gwin and Troy have really liked about the switch. ''Troy and Aaron have both been riding it for some time now and they like it better. They're faster on it, according to our testing, and more confident, which is the most important thing,
'' he says of the World Cup team's feedback so far.
I know what you're thinking: is your nearly brand new Demo already getting updated? Very doubtful. ''Your average consumer wouldn't be able to tell the difference,
'' Chamberlain replied when I asked him if production bikes will eventually employ a forged version of the CNC'd prototype link. ''We design for the ninety-nine percent, and then fine tune it for our pros.
''Main image by Scott McClain