US company Redshift Sports is aiming to produce a new stem with a hinge and elastomer insert to aid road vibration damping

Suspension and compliance features for road bikes are becoming a hot ticket, with many brands building shock absorption features into their endurance frames to increase comfort and control and reduce rider fatigue.

Getting more comfort into the front end without adversely impacting steering and control is more difficult and innovative solutions are being tried such as the suspension fork on Cannondale’s Slate gravel bike.

Now Philadelphia-based Redshift Sports has launched a campaign on Kickstarter to fund the production of a road bike stem called ShockStop with built in shock absorption.

The stem has a pivot built in at the headtube end, which moves up and down as the wheels are displaced vertically by road imperfections. Shock absorption is mediated by elastomer inserts and each stem will come with a range of these, which can be swapped out to fine tune the degree of displacement to suit the rider.

Redshift's stem is designed to replace the bike's standard stem

Redshift’s stem is designed to replace the bike’s standard stem

Vertical travel will be between 1 and 2 cm and the stem will come in lengths from 90mm to 120mm and Redshift claims a weight starting at 238 grams, dependent on length. It is 3-D forged from aluminium.

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Fitting the ShockStop stem is just a matter of unscrewing your existing stem from the headtube and the bars and replacing it with the new one. The stem is designed for 31.8mm bars but spacers can be used to fit it to 25.4mm and 26mm bars too. More details of the product can be found on Redshift Sports’ Kickstarter page.

Funding is due to close at the end of September, with delivery to backers scheduled for March 2016. Prices are set at $89 for the first 50 backers, then $99.

  • Stephen Ahnert

    Mark – 3D Forging is a term for a forging process where one or more internal mandrels are used to smush (smoosh?) the material outward into its final shape. It’s commonly used to produce stems, seatposts, and other bike parts with internal cavities, and it eliminates welded joints, which creates a much stronger part. I’m one of the creators of the Shockstop, so let me know if you have any other questions or comments!

  • Stephen Ahnert

    Paul – I’m one of the creators of the Shockstop. We had a lot of fun testing out both the Softride and Flexstem during our development process, and indeed, there’s a good reason they were supplanted by suspension forks for MTB riding. Our goal with the Shockstop was to create a stem that was specifically tailored for road riding. The travel range is much smaller than the old stems (it rotates through about 6°), and actually, on a drop bar, the travel feels much more linear because your hand contact point is further from the pivot.

  • Stephen Ahnert

    Adam – Hi, I’m one of the creators of the Shockstop. Thanks for the feedback! Interestingly, the compliance provided by the stem is much more pronounced than switching to 28mm tires. The feel is more akin to going from a 23mm tire at 110psi to a 32mm at 50 psi, but without the additional rotating weight or rolling resistance.

  • cahern1968

    The Flexstem had a single pivot. You must have had the Softride stem which had the parallelogram design.

  • Mark V

    “3-D forged”?

  • cahern1968

    This new stem looks like it has only a single pivot at the stem end, which is quiet similar to the Girvin in many ways. The new stem stem is more streamlined because it doesn’t need a brake hanger like the mountain bikes of old did. But let us not forget the Softride stem which was a parallelogram design.

  • Adam Beevers

    How about special tyres – say 28mm? Oh, already thought of…

  • Adam Beevers

    Exactly, hardly original.

  • Paul

    Flexstem had dual linkage so bars moved up and down only – this design has a single pivot point so the angle of the bars with change, not good when riding on the hoods.
    I had a Flexstem copy that worked this way on my MTB 25 years ago – I threw it away soon after I bought it. I can only imagine it will be worse on drop bars.

  • David Ritchie

    Had a Flexstem on my 1st mountain bike nearly 25 years ago!!

  • Wc

    Girvin flexstem?