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Thursday, 22 September 2016

Tech Talk: Specialized Roubaix 2017

Specialized Roubaix 2017

The original Roubaix featured a longer wheelbase and slightly shallower geometry than what was typically being ridden at the time. It also had generous clearance for big tires, and most distinctively, had polymer bumpers (called Zertz) molded into the frame to damp the ride and take the sting out of the cobbles. The head tube was taller than most road race bikes, putting the rider in a slightly more “heads-up” position. This latest iteration of the Roubaix bike is all of those things and none of them at once. The frame is a radical departure from the original model.

They stripped Zerts inserts from their frame and replaced by a mix of clever carbon construction and an innovative piece of front-end suspension. Specialized’s design team, led by engineer Chris D’Aluisio and head of applied technologies Chris Yu, set out to discover whether ‘smoother equals faster’, knowing that one of the major selling points of the Roubaix has always been ride comfort. Chris D’Aluisio continues: “As we were gathering the data, taking the bike and rider as one system, we started to see that a benefit of compliance was also traction. If you can keep in contact with the ground more of the time then you’ll have more control and be able to go faster.”

The head angle now matches that of the Tarmac, and the rider position is lower. The frame weight is lighter than the outgoing Roubaix. The fork borrows heavily from that found on the Tarmac, too, albeit with a longer axle-to-crown distance to better clear the tires. The whole frame is structurally stiffer than the previous SL4 Roubaix, with a massive new down tube and stout bottom-bracket area. It will accept tires up to 32mm wide, and it’s disc-brake only. 




There are two distinct types of front suspension. Splay relies on the fork being able to move fore-and-aft, and axial where the fork moves vertically up and down below the head-tube. For all-out efficiency, neither is perfect. Splay can slow you down, and the traditional ‘axial’ mountain bike-like bob when climbing wouldn’t work here either. On the Roubaix the effective suspension position was on top of the head-tube to reduce any bobbing effect and suspend the rider, not the bike. The new tech its calls The FutureShock, it’s composed of a tube-within-a-tube rolling on four sets of needle bearings and supported by three coil springs: two for support and one for tuning. It sits in the steerer tube (much like a traditional seatpost slides into a seat tube) and is clamped in place at the top of the fork. A traditional stem clamps to the outside of the cartridge. 



Specialized Future Shock Cartridge

The FutureShock offers 17mm of downward travel and 3mm of upward travel, effectively isolating the rider and lending a smoother feel at the bars. The front end can be tuned to your terrain or personal preference using three interchangeable springs – long, medium, and short. Shorter offers more compliance, and the longer is stiffer.


Seattube bigger than seatpost to aid a movement

The neat back-end’s design, which drops the seat stays 3.5in below the top-tube junction and incorporates the seat clamp into the seatstays ends via twin bolts, allows for much more movement from the seatpost. A rubber seal covers the top of the seat-tube, and the tube is significantly bigger than the slender post to allow for plenty of room to move. With the radical-looking C-GR seatpost, with its huge offset and built-in Zertz head to the seatpost too, you’ve got a back end that balances out and complements the front.

Not too racy in the front end
Glossary:

Headtube: The head tube is the part of a tubular cycle's frame that the front fork steer tube is mounted within

Head angle: Also called caster angle, is the angle that the head tube and hence the steering axis makes with the horizontal or vertical, depending on convention. The steering axis is the axis about which the steering mechanism (fork, handlebars, front wheel, etc.) pivots. In bicycles the head angle is measured clock-wise from the horizontal when viewed from the right side.

Seatstays: The tubes that rise from the rear axle to the back of the seat-tube

Downtube: The tube link between the headtube and bottom bracket,


Source:
http://www.bicycling.com/bikes-gear/reviews/first-ride-2017-specialized-roubaix
http://cyclingtips.com/2016/09/first-look-review-specialized-roubaix-2017/
http://www.bikeradar.com/road/gear/category/frames/road/product/specialized-roubaix-2017-review-50696/
https://en.wikipedia.org/wiki/Head_tube
https://roadcyclinguk.com/gear/buyers-guide-bicycle-geometry.html/5


Ride On!




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