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The Cane Creek Thudbuster ST G4 is the fourth generation of the iconic short travel suspension seatpost (which also happens to be one of my favourite suspension posts of all time). This time round it's marketed at e-bike audiences and commuting, with 50mm of travel and a comprehensive mechanical makeover. It's also claimed suitable for riders up to 150kg.
This incarnation of the ST (short travel) Thudbuster still employs the parallel linkage design, using hard anodised axles and flanged PTFE bushings for slick, low-maintenance service.
This time round, the elastomers are a tool-free press fit, so relatively easily switched to suit a softer or firmer action, depending on your weight and, possibly, where you ride. I say relatively, since the firmest stock model required very strong thumbs; the softer was very compliant.
Ours came with the medium fitted, which ultimately ticked all the boxes for me, but it's worth checking Cane Creek's guide and choosing what's suitable for you – not that they're difficult to exchange: simply press the inner elastomer until it pops out, then slot in your substitute. (Soft and hard are included in the box; extra soft and extra hard are available to order separately.)
Elastomers do like the occasional lick of rubber-friendly grease, too – think along the lines of Judy Butter, Green Oil Ecogrease or Muc Off Silicon Shine. Avoid old fashioned greases designed for classic cars and motorcycles; these, like PTFE greases, will do horrible things to modern elastomers. I speak from first-hand experience...
The previous G3 Thudbuster had 33mm of travel and was available in five diameters, 25.4, 27.2, 30.9, 31.6 and 33.9mm, but I wasn't surprised that the G4 now comes in only three – 27.2, 30.9 and 31.6mm – as things have become largely standardised. Shims are available separately.
The single-bolt saddle clamp design is intended to make alignment and adjustment easier – and it does. However, it seems a curious choice for a system designed to support heavier riders.
It's designed to accommodate both round and oval rails – just slacken the cradle with a 5mm hex key, click your saddle into place, then wind it up to 16Nm with a torque wrench.
The science behind the design keeps it in the direct path of the rear wheel. As a bump shoves the bike's rear wheel, the Thudbuster reacts downward and rearward, theoretically absorbing force at the same rate. Hence zero saddle movement and why it doesn't feel like a pogo stick.
The concept does rely on at least 100mm of exposed seatpost, which shouldn't be an issue for most, but is something to consider if the post is used by riders of different heights, like tandem stokers. (It's also something to bear in mind when fitting luggage – some larger saddle/seatpacks might not fit.)
Before installing the post, treat it to a light coating of compatible grease (metal frames) or gripper paste for carbon frames.
From the outset, the linkage design offers a very progressive, subtle movement, which damps out smaller ripples without impeding a decent cadence. My fixed gear winter/training bike could never be described as harsh but there was a discernible difference between a rigid post, even a titanium one, and the Thudbuster over the same sections.
Switching to 38mm gravel tyres and meandering along dirt roads, the linkage compressed progressively, absorbing the shock without any weird rebound or annoying bob. This was also true when alternating between sitting and climbing.
Ultimately, I felt a whole heap fresher than usual, after 50-mile mixed terrain loops. This bodes well for the latest generation of e-bikes, which seem to be stiffer in order to support increasingly powerful engines and not handle like a blancmange.
I've experimented with switching to a softer elastomer off-road and benefited from the increased sensitivity; the softer setting is too responsive on metalled roads and smoother tracks, but the simplified system means road/trailside switching is a practical possibility.
One thing I was surprised to discover was the need to snug the cradle bolt down each time after three 25-mile road outings. Most of us will appreciate that things settle a bit during the first few rides, and thankfully this hasn't proven an issue in the subsequent weeks, but I'm only 70-odd kilos... I'm not entirely sure it's optimal for riders exceeding 100kg.
Aside from running the original Thudbuster ST for a few years, I've also done a few hundred miles on the Redshift Shockstop Suspension post. The latter feels a little plusher than the Thudbuster ST G4, though the Thudbuster has 50mm of active suspension travel (the Redshift 35mm) and without any loss of manners.
The Redshift is a little more enclosed in its design, which may be a consideration if you're running a gravel bike through the depths of winter, but aside from the odd cursory wipe-down, there's been no call for more involved maintenance with the Thudbuster through a dry and dusty testing period.
The Redshift is also £229.99, so although £169 is a sizeable investment for a seatpost, the Thudbuster is competitive in its market. Both weigh in at 545g apiece.
If your riding is predominantly on the road and you want some compliance without the heft or complication, something like Specialized's CQ-R Carbon Seatpost might be a better option, but it's also more expensive at £185 rrp.
The Thudbuster ST G4 should satisfy those looking for some sophisticated compliance without breaking the bank. E-bike and cargo bike riders, especially those riding over longer distances, arguably have most to gain, though it's still a very good bet for cross/adventure-biased riding, not forgetting tandem stokers.
Iconic suspension post updated with tangible benefits, save perhaps for the cradle
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road.cc test report
Make and model: Cane Creek Thudbuster ST G4 suspension seatpost
Size tested: 27.2mm
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?
Cane Creek says "For over 20 years, Thudbuster has been the bicycle industry-standard in suspension seatposts by providing unequaled comfort and reliability to riders around the world. We are now proud to announce the latest evolution to that legacy with the all-new Thudbuster ST. The new Thudbuster ST is superior to its predecessor in every way. Building on Thudbuster's proven parallel linkage technology we have completely re-designed the seat post for increased durability, a higher rider weight limit, and additional suspension travel, as well as ease of use through tool-free elastomer change and a single-bolt seat clamp design. By improving on this already legendary design, we're confident to say that the newest generation Thudbuster is the most advanced suspension seatpost ever made."
I'm not sure it's the most advanced ever made, and given the increased weight limit I'm not completely sold on the single clamp. That said, it's still my all-time favourite.
Tell us some more about the technical aspects of the product?
Cane Creek lists these specs:
SETBACK 0mm (unweighted)
POST Forged aluminum
SEAT CLAMP Single bolt fastening and angle adjustment design
PIVOTS Threaded, serviceable, hard anodized aluminum axles flanged PTFE bushings
ELASTOMER Medium firm elastomer pre-installed from the factory. Soft and Firm elastomers included. Extra Soft and Extra Firm elastomers sold separately
TRAVEL 50mm / 1.97in
LENGTH 27.2 - 345mm. 30.9 + 31.6 - 375mm
WEIGHT 580 grams (31.6)
MAX. RIDER WEIGHT 330lbs / 150kg
EXTENSION Minimum - 100mm / Maximum - 274
DIAMETER (DIRECT FIT) 27.2, 30.9, 31.6 (additional diameters available with shim)
Engineered and finished to a very high standard.
Very simple to set up; refined action is easily tailored to suit your riding and personal taste.
Well made but will be interesting to see how durable the single clamp cradle design pans out in the longer term, for heavier riders.
Weighty, relative to standard posts, but typical of the more sophisticated, higher quality suspension designs. Not the biggest consideration on a tandem/gravel/cargo bike.
Efficient and subtle movement insulates against lower level and more intense bumps, without robbing power or impairing cadence.
Definitely an investment but still competitive.
Tell us how the product performed overall when used for its designed purpose
Overall, I've been very impressed by this latest generation of the Thudbuster. I've never needed the full 50mm of travel but found the medium elastomer offered just the right balance of damping, insulating against intrusive low-level vibration and bigger bumps alike. Even when alternating between climbing in/out of the saddle, sag was very subtle and I've only noticed it in the most positive way.
Tell us what you particularly liked about the product
Loved most things about it. From the subtle, precise and efficient action, to the quirky, industrial looks.
Tell us what you particularly disliked about the product
I'm not completely sold on the single cradle bolt. Ours settled down within a few rides but I'm only 70kg.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
The Redshift Shockstop weighs the same but costs £229.99. Specialized's CQ-R Carbon Seatpost is £185.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? For tandem stokers, gravel riders and cross-country mountain bikers, definitely.
Use this box to explain your overall score
The Thudbuster ST is probably my favourite suspension post of all time, and for the most part the minor revisions have only served to improve it. While the single-clamp cradle isn't causing me any problems, I'm not sure its the best option for a design intended to support riders weighing close to 150kg. It offers more travel than the Redshift Shockstop, and is a good bit cheaper.
About the tester
I usually ride: Rough Stuff Tourer Based around 4130 Univega mtb Frameset My best bike is: 1955 Holdsworth Road Path and several others including cross & traditional road
I've been riding for: Over 20 years I ride: Most days I would class myself as: Experienced
I regularly do the following types of riding: cyclo cross, commuting, touring, fixed/singlespeed, mtb,
Shaun Audane is a freelance writer/product tester with over twenty-eight years riding experience, the last twelve (120,000 miles) spent putting bikes and kit through their paces for a variety of publications. Previous generations of his family worked at manufacturing's sharp end, thus Shaun can weld, has a sound understanding of frame building practice and a preference for steel or titanium framesets.
Citing Richard Ballantine and an Au pair as his earliest cycling influences, he is presently writing a cycling book with particular focus upon women, families and disabled audiences (Having been a registered care manager and coached children at Herne Hill Velodrome in earlier careers)