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Tech Bits, Cutaway Photos on Manitou Circus DJ Fork and Hayes Prime Disc Brakes

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SEA OTTER CLASSIC 2010 – Hayes Bicycle Group, which owns Manitou, Hayes and Sun-Ringle had all their new goodies on display.  We showed you the hot new Sun-Ringle wheels at Interbike last year, and we’ve covered the launch and tech specs of the Circus DJ fork and Hayes Prime hydraulic disc brakes (in order: 1, 2, 3, 4 and 5), so we took the opportunity to talk tech with them at Sea Otter and get a few updated details.

After the break, there are cutaway, internal photos of how the new Hayes Prime brakes work, but first, a few notes on the new Circus.

There are two models available, the Expert (left, with aluminum stanchions) and the Comp (chromoly stanchions).  The lowers and crown are identical, but the internals, controls and sliders are what make up the $50 price difference.


The Expert (left) gets Manitou’s “Jumpstack” Absolute+ damping system that’s been tuned for dirt jump and an air cartridge, the Comp gets a coil spring and less sophisticated damping. Manitou product manager Rich Travis said the other special feature is the dual bottom out bumpers inside the legs.  He says you basically aren’t going to have a harsh landing with the Circus.


These are the stock graphics, but the forks come with four sheets of custom decals so you can decorate them (or not) anyway you want.  Check our interview with the artist here.



The Circus comes only with 20mm thru-axle lowers, and you can get three travel options on the Expert (80, 100, 130mm) and two on the Comp (80 and 100mm).


The crown on both models is forged aluminum.


The Hayes Prime is their new do-everything hydraulic disc brake set.  There are no various models (not at launch, anyway), options or distractions.  What it does have is a fairly unique stroke adjustment they call the Poppet Cam and a new type of reservoir/piston arrangement.  In their other brakes (and those from competitors), brake fluid is held in a reservoir that’s open to flow when the lever is static, and closes to build pressure when the lever is pulled.


With the Poppet Cam, Hayes has replaced the small timing ports on the reservoir and simply made the piston hollow.  The “Poppet” is the silver bit on the left of the smaller internal coil spring in the photo above.  To build pressure and activate the pistons, the Poppet moves down (toward the right in these photos) and seals the hole.  The “Cam” is rotated by the dial on the outside that adjusts the position of the Poppet.  So, if you look at the photos above, the top image has the Poppet all the way “out”, and the bottom has it all the way “in”.  The bottom image would give you shorter lever stroke before the brakes were activated.


On the trail, this translates into two benefits.  First, as shown above, you can set how far in you want the lever to pull when the brakes are fully engaged.  At the same time, you’re setting how much distance the lever needs to travel before it starts engaging the brakes.  Note the 180º difference in the Cam’s dial compared to how close the lever is to the handlebar.

Hayes’ product manager Joel Richardson admits that for most riders, it’ll be a set-it-and-forget-it feature, but here’s where the second benefit comes in: it allows for power adjustment on the trail.  Let’s say the weather went to crap and you need more stopping power, or your pads are wearing excessively thanks to some bomber downhills.  Just dial it so the brakes engage earlier and you’ll essentially be increasing the amount of power you can apply.

For some riders, the dead throw (meaning you’re pulling the lever, but nothing’s happening) that you’ll get with the Poppet adjusted all the way out might be a little disconcerting…it does feel weird to pull the lever a good half-inch and not have anything happen.  For those riders, simply adjust the Poppet all the way in, then use the tool-free reach adjust to put the lever where you want it.  For those that like to ride with their finger on the brake lever but don’t want to accidentally engage it over bumps, then having that extra bit of free movement might be just about right.

Hayes Bicycle Group has been without an overall marketing manager for a while now, leaving the product managers to pull double time.  As of today, they’ve brought on Scott Struve as Director of Marketing and Product Management for their Hayes Disc Brakes, Sun Ringlé, Wheelsmith, Answer and Manitou Suspension Products. Scott will be charged with setting strategic marketing direction for the division including brand vision, communications and product management.

According to their press release, Struve brings a vast amount of experience to Hayes having held marketing leadership positions for several iconic North American brands including Cannondale, Burton Snowboards, Timex and Converse Footwear.

Media samples of the Prime are set to go out this Summer, and one of our test sets will be pummeled and beaten by Douglas, owner of Basque MTB Touring in Spain. To say he rides a lot would be an understatement, so we’ll be providing a thorough review of them later this year.

We also just received a test set of their new 29er BlackFlag Pro wheels to put their paces, too…which look totally sweet and come complete with adapters for 9mm QR, 15mm or 20mm thru-axle and valves, Stans’ sealant and rim tape to run them tubeless right outta the box!

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