There was a day when suspension seatposts were all the rage in mountain biking and cyclocross. At the time, tires were narrower, and suspension was limited and typically constrained to front forks on mountain bikes or flimsy rims and 28c tubulars for cyclocross. Racing on a bumpy “Jungle Cross” course? A suspension seatpost would help you stay seated while pedaling, and options from Rock Shox, USE and Cane Creek were quite common sights in the 90’s out on the cyclocross or cross-country course.
As full-suspension mountain bikes have gained popularity, the suspension seatpost has become an endangered item in racing. While the Cane Creek Thudbuster remains a popular and relatively unchanged product, thanks to advancements in carbon fiber and the popularity of dirt road, gravel and cyclocross racing and riding, the whole suspension seat post segment has gotten a shot in the arm and there are now several new lightweight, short-travel options for the cyclocross racer. [Update: More video of the Specialized CGR (COBL-GOBL-R) added below]
Ergon Unveils Dual Leaf Spring CF3 Carbon Fiber Suspension Seat Post
Ergon has developed the 200-gram carbon fiber CF3 seat post to smooth out the road, trail or cyclocross course, and the new seatpost simplifies the company’s old CR1 suspension seat post design but utilizes a simpler pivoting saddle clamp and more carbon fiber to keep the weight down.
Ergon CF3 Pro Carbon. © Cyclocross Magazine.
Ergon’s two VCLS (Vertical Comfort Lateral Stiffness) carbon fiber leaf springs are designed to flex, not in an up-and-down motion like a telescoping post, but down and back to offset the bike’s motion when the rear wheel hits a large bump. The post flexes to offset the catapult motion of a rear wheel bump, but the saddle angle doesn’t change because Ergon’s floating “Flip Head,” thanks to the two bearings it sits on, rotates with the travel to keep the saddle at a consistent angle. The travel isn’t measured in inches but in mm (more than 1cm) and should be plenty or road and cyclocross – all without losing “road feel,” according to the company.
The post doesn’t appear to have much setback, but the Flip Head’s saddle rail clamp is quite short to allow for a lot of adjustment. Furthermore, the head can be reversed to allow for a further forward or back saddle position.
Especially in this day of ultra-stiff and oversized carbon fiber frames, the Ergon CF3 seat post might be just the thing to smooth out the bumps during races and on longer rides.
Ergon’s Sonya Looney and Specialized’s Chris Riekert Talk Suspension Seat Posts:
Specialized Brings Boonen’s CGR (Formerly CobL GobL-R) Suspension Post to Cyclocross and the Masses
A carbon leaf spring provides up to 18mm in travel and should withstand the rigors of cyclocross and remounts. ©Cyclocross Magazine
Specialized developed the carbon CGR carbon seatpost (formerly called CobL GobL-R, pronounced cobble gobbler) suspension seat post to give Tom Boonen an advantage on the cobbles at Paris Roubaix this spring. While Boonen ended up not racing with the post on his way to winning the classic, he reportedly appreciated it in all of his cobble training prior to the race. Developed by long-time cyclocross racer and Specialized engineer Chris D’Alusio to flex with big bumps, the post may be a useful component to make a cyclocrosser faster on bumpy courses.
Specialized’s CobL GobL-R carbon suspension seat post for pave, dirt and cyclocross. ©Cyclocross Magazine
Just as with the Ergon CF3 post, carbon leaf springs handle the suspension, but the Specialized CobL GobL-R post employs just one giant FACT carbon spring that allows the bike to move up with a rear wheel bump, while the saddle stays stationary, connected to the rider. The leaf spring offers a generous 18mm of travel.
Specialized doesn’t employ a pivoting head like Ergon does, but does insert a Zertz elastomer in the spring for additional (minor) vibration absorption. Specialized’s Chris Riekert said that the elastomer is not an essential component of the suspension, but riders have already requested the ability to replace it in order to “tune” the flex to their liking and it’s something the company might consider.
The CobL GobL-R comes in a 27.2mm diameter and 350mm length – plenty long for most mountain bikes – and yet weighs just around 200g. The post comes as standard equipment on the S-Works Roubaix road bike models, and should be available as an aftermarket accessory next spring.
More video of Chris Riekert demonstrating the CGR suspension action:
Stay tuned as we test early versions of both of these posts.
