After finding Redshift‘s Shockstop suspension stem very effective, I’ve been testing the 6061 T6 aluminium alloy Shockstop suspension seatpost, which is designed to replace standard round seatposts.
It’s 350mm long and 27.2mm in diameter, and a Di2 battery holder is also available.
Unlike existing designs, the Shockstop uses springs to provide its suspension. Its larger main spring is pre-installed and a smaller diameter inner spring is supplied – to be fitted within it if a stiffer spring rate is necessary.
Redshift suggests that riders up to 80kg should only use the main spring and those from 90kg to 110kg must install the inner spring as well. With the main spring fitted, my unit weighed 538g.
A preload adjusting plug in the base of the seatpost tunes the suspension. Numbers one to five are printed within its thread pitch and relate to rider weight and the spring(s). Turn the preload plug to the required position and fit the post.
Its two-bolt saddle clamp remains level atop a parallelogram linkage pivoting on dry-lube bushings. When weight is added to the post a link compresses the internal spring(s), creating user-adjustable sag, which Redshift recommends should be around 20 per cent of the 35mm total travel.
The small unweighted saddle height increase needs a slight adjustment when mounting up for the first time. At the suggested preload setting, I immediately felt neutrally suspended and didn’t notice any negative effect on seated pedalling.
With the knowledge that my tyre volume and pressure could cope with the sort of impacts I normally try to avoid, I steered towards the roughest patches of tarmac, potholes, ancient cobbles and uneven gravel.
The result was simply extraordinary comfort. I was aware of surface undulations, but the Shockstop is so reactive that no impacts or vibrations made it to the saddle.
There’s no doubt the Shockstop reduces bump-induced fatigue and with a good saddle it will increase rider comfort.
At around twice the mass of the aluminium post I replaced, it’s not for the weight-obsessed, but for commuters, all-road explorers and ebike riders such supreme float could be well worth the extra grams.
Redshift Shockstop Seatpost details
- Cover: The saddle clamp bolts and rear part of the parallelogram linkage is protected from most of the rear wheel’s spray by a magnetic cover
- Diameter: The 27.2mm diameter requires the addition of optional shims for seat-tube diameters up to 31.8mm
- Sag: To allow for the sag’s rearwards linkage path, position the saddle 6mm higher and 5mm further forward than usual