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545g £229.99

The Redshift Shockstop Suspension Seatpost is aimed primarily at gravel/adventure audiences and may also appeal to rough stuff tourists and tandem stokers. It’s pricey compared with high-end elastomer models but is very progressive and requires virtually no maintenance.

Pros: well-engineered, refined and nigh on maintenance free.

Cons: Relatively expensive and weighty.

bike bicycle cycle seatpost suspension sadlle seat

Materials/Specification 4/5

The post is made from 6061 aluminium alloy with a commensurate satin black anodized finish. Measuring 350mm, rails to base, it’s perhaps a little short, if you’re running a smaller MTB frameset (such as my Univega), especially given you need to raise it 6mm or so higher than usual, to account for some sag.

In practice we’re talking 170mm of useable length. In terms of diameter, any you like, 27.2 but shims are available to cater for 30.9 and 31.6mm seat tubes. Keeping to a single, common size keeps costs lower, while still catering for most modern framesets. However, owners of higher end, old school mountain bikes will need to look to something like Cane Creek Thud buster ST: a system that I really rate. Ours remains rude health several years down the line.

Staying with compatibility a moment, maximum recommended rider weight is 110kilos, but with an adaptor, the system is di2 compatible and the clamp will entertain standard saddle rails up to 7mm and 7x9mm oval.

redshift suspension seat post bike bicycle cycle

The all metal linkages require no servicing/ maintenance and offer 35mm of travel, which should be adequate for most contexts.  Look closely and you’ll notice a magnetic rear flap, complete with O-ring to prevent loss. This protects the internal mechanism from grit, silt and ingress thrown up by the rear wheel.

Setup 3/5

Set aside twenty minutes, to digest the instructions and get familiar with the system and correct adjustment. It’s not overly complex, or difficult to set up but not quite plug n’ play either. I found their thorough and engaging You Tube video the most accessible way of understanding the design and setting the preload.

You set this up by screwing a pre-load adjustment plug into the post’s base then winding it home. The plug has a number between 1 and 5. There is also a second spring, which sits inside the main one, should you need a firmer action. 

Instructions give useful “at a glance” reference points, based upon rider weights, but these are approximate, so expect to fine-tune this, during the first couple of rides. You are looking for 20% sag. Again, the silver linkage pivot shaft is a useful visual gauge. If this just slips out of sight, you’re close to the mark.

I initially set ours at 4, using the standard spring and this proved the magic number for my 70-kilo frame and mixed terrain riding. I measured ours against the existing posts added a thin layer of Park PPL grease and slid it inside the seat tube 15mm higher, THEN gently eased it down, taking sag into account. Not that the anodizing is poor, rather scratches are more obvious in black finishes. 

Test Bikes/Considerations

My fixed gear winter trainer is essentially a cyclo cross bike with track ends and spacing, and racks up big mileages along lumper roads. Despite the weight penalty, I was also very keen to see how it performed on my TT bike, which is based around a plain gauge 531 frame and large flange hubs. Though responsive, this combo can feel surprisingly direct. My rough stuff tourer was a non-starter, most obviously due to seat tube diameter but the Redshift is also a little too short.

My fixed gear winter-trainer typically sports a Carradice SQR Carradry, which requires a minimum of exposed post. This typically precludes suspension models, including The Cane Creek Thudbuster ST. However, while I’d expect the latest generation of bike packing bags to be compatible, SQR type luggage is a less exact science.

bike seat pack beam seatpost suspension cycling bicycle bike

Designs such as this Altura which use a frame will be fine. Carradice and SQR Tour are likely to be non-starters, unless you’re running the post at minimum insert, or a bigger, horizontal geometry frameset. 

Performance 4/5

Fitted to my Holdsworth, I wound the preload to 5. Adjusted correctly, the gentle movement is barely noticeable, even when I’ve sat down, following a long climb, or aggressive sprint. Though the Holdsworth’s ride quality would never be considered harsh, it can feel a little direct-especially with static aluminium alloy models.

The linkage design’s gentle, progressive damping just ironed out the buzz from washboard, “rumble strip” tarmacs and similarly small, unavoidable imperfections. No bounce, or power robbing flex to impede a steady 85-95rpm cadence. Not the most obvious host but one that presented an excellent way of assessing preload etc., before porting to my fixed gear winter/trainer.

Having done so, the post’s additional zing really came into its own, on long, steady day rides that often involved some dirt road fun (when I’d shod the bike with these Soma Fabrications Shikoro tyres) . This time round, I dropped the preload to 4.

The action is, like for like, plusher than the Thudbuster ST (or indeed, the G4, its latest incarnation) and it can be dialed very precisely to match rider weight and taste. Factors that give it a slight, but potentially very definite edge (although the G4 has evolved to tool-free, press fit elastomers. Even so, uprating to a stiffer unit requires strong thumbs).

bicycle bike cycle suspension seat post saddle redshift

Even when I’d selected the softer settings and hit some bigger lumps, the Shockstop has never felt like a pogo stick, let alone bottomed out. Qualities that lend themselves particularly well to tandems, especially mtbs. At the other extreme, it’s possible to lock the unit out by inserting the second, inner spring inside and winding it out to 5.       


Value 3/5

£229 is a sizeable amount to part with. Cane Creek Thudbuster ST G4 is £169.99, offers 50mm of travel for the same weight. There’s a decent saddle’s worth of cash between them. If you’ve deeper pockets and your bikes are on a calorie-controlled diet, Cane Creek eeSilk is another elastomer system a penny shy of £300, but 297g.



At 70 odd kilos, I don’t tax components to the same degree a 95-kilo rider might. Personally, Cane Creek Thudbuster ST ticks all my suspension boxes and is a good bit cheaper, albeit not a great deal lighter. That said, I’m not sold on the G4’s single clamp bolt, given its marketed at riders up to 150 kilos. Redshift opt for a twin bolt cradle and set a 110 kilo maximum. Weight aside, whether the Redshift Shockstop is right for you, will depend on several factors. 

E-Bike frames have become stiffer to support increasingly powerful motors. The Redshift would be an obvious choice, if you were taking advantage of their bigger range and wanting to improve comfort. Similarly, gravel/adventure/bike packing enthusiasts should also have the Shockstop high on their list.

3.75/5 Refined and extremely tuneable post, tempered by price and weight.

Michael Stenning




Ryton On Dunsmore

Coventry  CV8 3FH


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