Aimed primarily at the gravel/adventure market, the Redshift ShockStop Suspension Seatpost does a good job of taking the sting out of a rough ride. It is fairly weighty and it ain't cheap either, but it is easy to set up and works a treat, which kind of outweighs the negatives.
I've mentioned this before, but I'll recap: I love gravel bikes because they remind me of the rigid mountain bikes I was riding around on when I was a teenager. For me it's all about using your elbows and knees as the suspension as you hone your bunny-hopping skills for potholes and tree roots while keeping the bike upright on a surface that is moving around beneath you.
You might think this doesn't really make me the best person to test the Redshift, but to be honest, I was intrigued.
The first thing you notice when you open up the box is the weight of the post – you're looking at 545g of aluminium and internal components. It is very nicely finished, though, and a sturdy piece of engineering.
I'll give you a few stats:
The post is 350mm long from the saddle rails to the base of the post, with about 170mm of round post available between the minimum insertion line and the start of the suspension system.
Diameter-wise it's 27.2mm, a pretty common size, but if you need to make it fit a 30.9mm or 31.6mm seat tube then you'll need a shim.
Inside the box is a very detailed set of instructions which shows you all of the components inside the seatpost including the main spring, two end caps, a spacer and the preload adjustment plug. In the box you also get an inner spring to sit inside the main spring should you prefer a firmer ride or are at the heavier end of the scale. There is a 110kg maximum rider weight limit.
The preload adjustment plug screws into the bottom of the seatpost and is numbered from 1 to 5 – the higher the number the firmer the ride, basically. On the instruction sheet Redshift provides a rough guide to your preload setting based on weight.
It is just that, though, a guide. It's a starting point basically, as you'll need to tweak it based on your riding style and how much you want the suspension to help.
For me it recommends a setting of 4 using just the main spring, and that was about right to achieve the 20% of sag required for when I was sat in the saddle. You check this visually by way of the silver linkage pivot shaft at the head of the post; if it just disappears, you're in the right ballpark.
To take into account the sag, Redshift also suggests that you should position your saddle 5mm further forward than normal, and 6mm higher.
Out on the bike I found the preload a little soft for me. There was a fair amount of bobbing around in the saddle from pedalling and on the tracks with dips and small potholes I was bouncing around all over the place.
One thing that did highlight, though, was just how smooth the ShockStop is in action. It feels fluid, there is no jerkiness at all as it moves through the 35mm of available travel. Here's a clip of it in action, when first introduced at Eurobike last year.
If you are out for a tough gravel race or longer adventure, this post is going to make a huge difference to comfort levels.
As I said, though, this setting was a little too soft for me. Redshift reckons that on the main spring alone a preload of 4 is the highest you should go, so I needed to add the inner spring to the mix. I had it with me and it was literally a five-minute tweak at the side of the trail.
I wound the preload plug back in to around 2.5 and job was a good 'un. It was firm enough that I could still feel everything going on with the rear wheel but just taking the edge off the roughness of the trail.
The ShockStop should be pretty much fit and forget, too. The main spring is covered in plenty of grease from new and as it all remains sealed away from the elements, it should stay that way.
To keep everything clean around the moving parts and the bolts for tightening the saddle clamp, Redshift has attached a neat 'fender', a cover that is held in place by a strong magnet with a back-up o-ring to keep hold of it should it come loose.
As for the competition...
Our in-house intrepid mile-muncher Dave Atkinson is a big fan of the suspension seatpost, using various offerings over the years for audax, the Dirty Reiver and the 25-hour epic that is Red Bull Timelaps.
He recently tested the Cane Creek eeSilk which uses an elastomer system rather than the springs found on the Redshift. It costs a heady £299.99, which is £70 more than the Redshift, but he was well impressed by the performance, and it weighs just 297g – over 245g lighter than this one!
While weight isn't as much a factor on a gravel bike as it is on a road machine, that is still quite a bit extra to be dragging around with you.
Another option is the Canyon S15 VCLS 2.0 CF seatpost. The post is split into two sections which pivot at the top, giving vertical compliance, and it works very well indeed. It came on the Grail CF SL 8.0 SL that I tested, and the added comfort was very noticeable.
It costs virtually the same as the Redshift, but again is a lot lighter. The downside is that you can't adjust it for rider weight to get that perfect ride feel.
Overall, I'm a big fan of this seatpost. I can overlook the weight issues purely because of how much adjustability it has, and the suspension action is just so smooth. It is really easy to tweak and set up, too, even out on the trail.
Heavy, but easy to adjust and gives a smooth suspension action you can set to your own personal taste
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road.cc test report
Make and model: Redshift ShockStop Suspension Seatpost
Size tested: 27.2 x 350mm
Tell us what the product is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
Redshift says, "The patent-pending ShockStop Suspension Seatpost provides 35mm of tunable, ultra-responsive suspension travel for the ultimate bump-eating comfort. 20mm of front suspension and 35 mm of rear suspension let you float over rough terrain - ride further, faster, and more comfortably on the bike you already own. The minimal, subtle design blends seamlessly with the aesthetic of modern gravel, road, and e-bikes."
It is a very good suspension solution for those who want a smooth ride.
Tell us some more about the technical aspects of the product?
Diameter 27.2 mm (shims available)
Length 350 mm (14 in)
Suspension Travel 35 mm (1.4 in)
Rearward Offset 7 mm (0.25 in)
Rearward Offset (@ 25% travel) 12 mm (0.4 in)
Spring Preload User Adjustable
Rider Weight Limit 110 kg (242 lb)
Material 6061 T6 Aluminum Alloy
Saddle Rail Compatibility 7mm round & 7x9mm oval
Di2 Battery Compatibility Yes (requires mount kit)
Tell us how the product performed overall when used for its designed purpose
The suspension action is smooth and barely noticeable.
Tell us what you particularly liked about the product
Easy to set up.
Tell us what you particularly disliked about the product
It's quite heavy.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
It's a fair bit cheaper than the Cane Creek option (although a lot heavier) and about the same cost as the Canyon, although that doesn't have any preload options.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your overall score
The Redshift ShockStop has a very impressive suspension action and shows some quality engineering, while being easy to use. The price isn't too bad against the opposition but it is heavier than most by quite a margin.
About the tester
I usually ride: This month's test bike My best bike is: B'Twin Ultra CF draped in the latest bling test components
I've been riding for: Over 20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: time trialling, commuting, club rides, sportives, fixed/singlespeed,
With 20 years of road cycling and over 150,000 miles in his legs it's safe to say Stu is happiest when on the bike whatever the weather. Since writing his first review for road.cc back in 2009 he has also had a career in engineering including 3D-CAD design and product development, so has a real passion for all of the latest technology coming through in the industry but is also a sucker for a classic steel frame, skinny tyres, rim brakes and a damn good paintjob.
His fascination with gravel bikes is getting out of control too!