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Redshift ShockStop Suspension Seatpost



Heavy, but easy to adjust and gives a smooth suspension action you can set to your own personal taste
Smooth suspension action
Easy to adjust the settings

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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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.

> Find your nearest dealer here

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.

Redshift ShockStop Suspension Seatpost - detail.jpg

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.

Redshift ShockStop Suspension Seatpost - top.jpg

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.

Redshift ShockStop Suspension Seatpost - base.jpg

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.

> 9 ways to make your bike more comfortable

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.

> Buyer's Guide: 6 of the best comfort-boosting seatposts

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 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?

Redshift lists:

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)

Rate the product for quality of construction:
Rate the product for performance:
Rate the product for durability:
Rate the product for weight (if applicable)
Rate the product for comfort (if applicable)
Rate the product for value:

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

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.

Overall rating: 8/10

About the tester

Age: 41  Height: 180cm  Weight: 76kg

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,

As part of the tech team here at F-At Digital, senior product reviewer Stu spends the majority of his time writing in-depth reviews for, and ebiketips using the knowledge gained from testing over 1,500 pieces of kit (plus 100's of bikes) since starting out as a freelancer back in 2009. After first throwing his leg over a race bike back in 2000, Stu's ridden more than 170,000 miles on road, time-trial, track, and gravel bikes, and while he's put his racing days behind him, he still likes to smash the pedals rather than take things easy. With a background in design and engineering, he has an obsession with how things are developed and manufactured, has a borderline fetish for handbuilt metal frames and finds a rim braked road bike very aesthetically pleasing!

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Mushroom | 4 years ago

I was wondering... can you use suspension Seatpost while bikepacking? I'm not sure how it would work with a seat pack...

ktache | 4 years ago

How does it compare to the Cane Creek Thudbuster ST ?

I know one of you has one of those.

Little bit lighter, little bit cheaper, similar travel.

And mines been going a good 15 years.

dave atkinson replied to ktache | 4 years ago
1 like

yeah, i have an ST and i've used it for gravel riding including the dirty reiver, and it's excellent for that. they're not dissimilar; i've been saying for ages that the thudbuster is due a big resurgence thanks to gravel riding becoming popular. 

ktache replied to dave atkinson | 4 years ago

Cheers Dave, I remember seeing pictures, and that you'd replaced stuff with big bolts.

aOaN replied to ktache | 4 years ago
ktache wrote:

How does it compare to the Cane Creek Thudbuster ST ?


I have the RedShift ShockStop, a ThudBuster ST, have had a number of ThudBuster LTs on various bikes, have a bySchultz LT 2.0, and have ordered, set up and ridden a SunTour NCX on my interim girlfriend's bike. 

 I prefer the CNC machined surface of the ThubBusters (i.e., the fine ribbing, the polish) of the ThudBusters to all of them. The finish is superior to any other suspension seatpost's that I've experience with. Of course, that ThudBusters' CNC machining bears no effect on its ride quality. 

 The ThudBuster ST (gen. 3 and earlier) has so little effective suspension that it barely smoothens the ride at all. There's surely marginal improvement compared to a rigid seatpost, but it's barely perceptible. 

 The new ThudBuster ST (gen. 4) has a different design and a longer travel (50mm, I believe, as opposed to 33mm of its predecessor). It also has a different design and, while the suspension mechanism is eqally as long as predecessor's, it is designed to take an up to 150kg load, as opposed to the 115kg of its predecessor and the LT and a lamentable 110kg of the RedShift ShockStop. Part of the reason for this is the supposedly improved (indeed, quite different) suspension mechanics that has less backward curvature in suspension action amplitude than the version 3 has. It has a number of other supposed advantages too (for instance, the elastomer removal is now toolless and takes a couple of seconds). It is expensive (at least in Europe, where it costs close to €200 - €30 to €70 more than its predecessor). 

 While I prefer the finish of ThudBusters and the price tag of the SunTour NCX, the ShockStop provides the best suspension of all suspension seatposts I have ever ridden. Even when dialled down to ca. 110kg (My actual weight at the present is 118, but it's as turbulent as precipitation in Germany & The Netherlands, as I'm working on getting back to shape (ca. 83kg.), but catch myself reaching for sweets every opportunity I happen upon), the ShockStop suspension feels superb - entirely incomparable to ThudBuster ST's (at least, 3-rd generation one's). On paper, it reads 2mm travel difference. In reality difference is night and day. It feels better than the vastly more comfortable than the ST, ThudBuster LT. The angle of suspension, the tolerances, the rebound, the travel - it's literally perfect for anything short of heavy-duty mountain biking. 

 To illustrate, I'll ask you to take Apple's Lightning plug and plug it into a Lightning port. Feel the delightful tactility (like the finest spring-loaded action there is)? Now, take a USB / USB Mini / USB-C cable and stick it into a corresponding port. Zero tactility, zero haptics or the like.  

 Or press the iPhone's home button or MacBook's / iMac's trackpad. Feel that delightful tactile click? Compare to flimsy trackpads of early 2000 and earlier cheap plastic Windows laptops? 

 In other words, the ShockStop suspension is superb! It's incomparable to anything else save for a perfectly tuned full-suspension bike's suspension action, except the ShockStop has zero stiction, doesn't (at least, not perceivably) slow you as you pedal - and has a shorter travel (you do not really need longer than ShockStop's) and will only work when seated. And weighs less, too. And is compatible with any bike that takes cylindrical seatposts. 

 The ShockStop seatpost suspension is easily the best of all the others I have used, followed by a somwhat under-tuned 50mm travel SunTour's, then the by.Schultz (also ca. 50mm travel) & ThudBuster LT (the two are roughly on par and only very slightly inferior to SunTour's). The ThudBuster ST (3-rd gen and older) practically feels rigid (it sags a bit when you sit on it, and limits the effect of the elastomer significantly). The ShockStop doesn't appear to sag - it's optimally springy. 

 Also, the suspension travel is superior to others, in My opinion - just the right angle: not to vertical and not too backward-sloping, but right in between the two. It is an engibeering marvel. Much better than the boring, uninspired and ineffective in comparison, ShockStop stem 9which works, but lacks tactility. I'm fairly certain, the Kinekt stem (just out of KickStarter phase) is a better match to teh ShockStop seatpost in efficiency 9by the way, it is a good idea to pre-order one)!  


 The ShockStop's finish is of sandblasted variety, but it's much finer than most sandblasted surfaces. ShockStop sandblasting is comparable to most modern non-CNC stems'. Seat angle adjustablity is comprehensive (as most seatposts', including 3-rd gen.ThudBuster ST's and LT's, but not the handier 2-bolt systems (which I somewhat prefer, despite their marginally more limited adjustability), such as the by.Shultz LT 2.0, the newest (4th-gen) ThudBuster ST & the SunTour). 

 The ShockStop weighs ca. 50 grams more than a 3rd-generation ThudBuster ST in the same size, but it is still much lighter than all others (ca. 350grams lighter than the by.Schultz Lt 2.0 and roughly ca. 200grams lighter than the SunTour).  


 To summarise, I'll rate teh ShockStop seat post properties below: 


 Comfort: 9.5-10 out of 10 (while the competitors range from 3-4 to 8-8.5). Superior to competition, including longer-travel competition.  

 Effect on pedalling performance / speed: ca. 9.5 out of 10. The best on this count, too. 

 Weight: at ca. 500 grams (claimed 497 grams for 27.2mm one), it's on the light side, compared to competition: 7 out of 10. 

 Max. load rating: At 110kg, it's mediocre. 4 out of 10. For lighter fighter, entirely a non-issue. 

 Adjustability: 7 out of 10. While both the seat angle and the suspension properties are adjustable, they do require tools and, in the case of the latter, removal of the seatpost from the frame. 

 Finish: 8 out of 10. The tolerances, etc. are excellent. The finish is very good, but in My opion, not quite as fine as CNC machining.  

 Value: 6 out of 10. Like the Kinekt / Cyrrus, it's quite expensive. But then again, it is about the best. 

 Overall: 9 out of 10. 

 Would I buy it again? Yes, absolutely! After riding it for a couple of days, seating on a rigid (or even suspension in many cases) seatposts feels terrible. 

 Good luck. 

mdavidford replied to aOaN | 4 years ago
aOaN wrote:

have ordered, set up and ridden a SunTour NCX on my interim girlfriend's bike.

Does she know she's only an interim girlfriend?

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