SR Suntour SP12-NCX Suspension Seat Post

A suspension seat post can be a useful thing if you are a hard-tail mountain bike rider. It is important too for the long distance cycle tourist to make the bike as comfortable as possible.

A good suspension seat post removes the lumps and bumps and generally makes the ride a bit more comfortable (together with the trusty steel frame). There are simple seat posts with a spring to absorb the rough stuff. SJS Cycles have a good range of suspension seat posts. There are also several makes of the parallelogram style post such as the Crane Creek Thudbuster and the SR Suntour SP12-NCX. The idea of the parallelogram design is to minimise the shortening of the operating distance between the saddle and the pedal. This improves contact with the bike as well as maintaining the position of the rider in relation to the geometry of the bike.

I decided to go for the SR Suntour SP12-NCX. It was redesigned in 2012 boasting improved brass bushings. Travel is 50 mm with a rider weight range stated as 60-100kg. The on-line reviews seemed good and the price was quite a bit less that the Thudbuster. I had also read that the Thudbuster can bounce up and down a bit depending on the combination of elastomers used. I have never used the Thudbuster but it also seems very popular. I was looking for a solid seat post that would only absorb the bigger bumps and pot-holes without loss of power transfer caused by a ‘bouncing’ saddle or saddle with springs.

Full technical details of the SR Suntour SP12-NCX, can be found on the Suntour web site.

The Suntour arrived in plain packaging which is how they are supplied in bulk to retailers. I purchased it from Practical Cycles in Lytham in Lancashire, England. They provide a wonderful range of utility bikes and bike parts. Service and delivery were excellent.

Seatpost top and Brooks B17 rails for comparison

On arrival I was a bit concerned about the fit. The above photograph shows the upturned Brooks and the seat post top. With the B17 Select saddle there is not much forward-aft adjustment possible with only about 6 mm of leeway available. Perhaps a small Suntour redesign would sort this out. I fitted it without a problem though. I was able to set up the bike into a comfortable riding position despite this limited adjustment with the Brooks saddle.

The point where the post would operate was tested by cycling over some bumps and pavement edges. The adjustment as delivered was almost ideal for my weight (71 kg). After tightening a little by adjusting the hex bolt in the seat post the correct setting was established. On numerous day rides I liked how the post would only absorb the larger bumps. There was no bouncing and in operation the post would absorb the bump and immediately return to a solid position in one action. I was happy with the purchase. A neoprene dust cover adds protection to the moving parts. This was purchased separately.

This Summer I set off to complete the North Sea Cycle Route. The seat post performed well on a variety of surfaces from smooth Norwegian roads, rough forest track in Denmark, tree roots under some Dutch and Belgian cycle paths, sand dune cycle paths, to pot-hole damaged sealed and gravel roads that we love to nurture in the UK. Really big bumps and holes were handled with confidence and no doubt prevented some serious back jarring and possible injury. The instant return to a solid seat post position after a bump helped in controlling the bike on rough terrain and complimented the Thorn Raven Tour’s inbuilt stability. It is a fit-and-forget item once the correct spring tension is set for your weight and preference.

Wear caused by rubbing against Brooks B17 rails

During the trip I examined the post a few times and discovered that the top had been rubbing against the Brooks saddle rails each time the post absorbed a bump. There was some wear to the corners of the post. There was no damage to the saddle rails other than the black paint having being worn off. There was no sign of any rust on the saddle rails. The wear in the photograph looks worse than in real life and has not affected the bushings.

Viewed from the right side …

Suntour SP12 NCX right view

… and from the left side of the bike …

Suntour SP12 NCX seatpost left view

After 14 weeks of daily use, and over 6200 km, the seat post performed very well. Initial spring tension remains as it was set before the tour. There were no indications of additional wear to the saddle rails or to the Suntour SP12-NCX. In operation the seat post now clears the saddle rails.
The neoprene cover did rub through as shown in the photograph …

Wear of the neoprene cover

The neoprene cover worked well. During and after the tour closer inspection of the mechanism showed little wear or signs of dust ingress. The bushings and contact points appear undamaged and intact.

Seatpost wear after more than 7000km

All in all I would recommend the Suntour seat post for your touring or mountain bike. I hope to compare it with the Thudbuster one day. For the moment the SR Suntour SP12-NCX does the job!


  • Solid well-made construction
  • Micro-adjustable spring to obtain the right ‘bounce’
  • Good quality spring without any loss of tension on the tour
  • Quality brass bushings
  • Effective neoprene cover
  • Good value
  • Cool black colour


  • Tight fit with a Brooks saddle
  • Initial slight clicking sound until it wears in
  • Neoprene cover must be purchased separately
  • Not tried the Thudbuster yet

37 thoughts on “SR Suntour SP12-NCX Suspension Seat Post

  1. Danneaux

    Extremely helpful review, Richard; thanks so much for your efforts. A couple questions:
    1) Do you think the clicking sound during initial wear-in was the saddle rails hitting the ‘post link?
    2) Does the interference at the “corner” of the link prevent full travel?

    Thanks! Best,


  2. Richard Post author


    Yes, I have a hunch that the clicking was due to the rails clicking against the top of the seat post. The travel did not seem to be affected though. The sound soon disappeared which I can only assume meant that the seat post was clearing the saddle rails. I can confirm that the rails are free of the seat post now and travel is the same as it was when new.

  3. Sebastian Terts

    This Suntour seatpost is well worth the money. I have used the before previous model and am using the previous model right now, and am using a Crane Creek Thudbuster on a mountain bike, also to great satisfaction.
    The three models Suntour seatpost differ only in the attachment system and the pins of the moving parts. This last 2012/2014 edition seems the best to me. I lost a pin on the first seatpost in Germany, but could replace it with a screw. The second version saddle attachment, of which I use two now, really sucks! The incline is adjusted by a toothed half cylinder, so very rough. The new setup looks old skool but better. No teeth I hope.
    The pins in the parallelogram mechanism sticks out of the mechanism in the first and second version, thus limiting the movement of yes, Brooks saddles. That’s as much a problem of the brooks rails as of the seatposts construction.
    All in all I don’t favour a Thudbuster over a Suntour seatpost. The Suntour is 200 grams heavier, but heck, the price is good! I can buy three Suntour seatposts for one Thudbuster LT!

    For the record: I have used the Suntour posts on a mountain bike hard tail, on a trekking bike (the same bike, different tyres and road use, also very rough cobble roads in Germany and Poland) and am using it now again on the same hike, re transformed again to a non suspension mountain bike and the other on a light weight road race bike. Saddles: a Brooks with springs on the mountain bike and a Brooks B15 Swift on the Gazelle V5 Road racer.

    If money is an issue: buy the Suntour. If you like the looks or crave for another few ounces of weight, go for the Thudbuster. They perform both well. Perhaps the Suntour is somewhat smoother

  4. Richard Post author

    Thanks for your input Sebastian! I am still very happy with the Suntour suspension seatpost. Will probably give the Thudbuster a go in future so it will be interesting to compare the two one day!

  5. Ben

    Nice review and comments, thank you. Most of the reviews I’ve read are related to touring. I’m toying with the Suntour NCX and a Brooks C17 Cambium for a 29er hard tail used for trails and XC riding – mostly hard pack with some rocks and roots. Any thoughts on this? Any further comparisons wit the Thudbuster? Thanks…

  6. Richard Post author

    Ben – I have never tried the Thudbuster but hope to do so one day. I am very happy still with the Suntour seat post. It seems like it would take a lot of punishment so no problem for mountain biking I would say.

    The Brooks Cambium looks interesting but I love the leather B17 Special which is holding up well. There is a Brooks Cambium C15 on the horizon which I may look at for the road bike!

    Thanks for your feedback!

  7. Sarah

    Hi there, just came across this post as I was planning to get a Thudbuster – many years of sciatica and two slipped discs does worry me a little for next years’ planned world cycle tour! Having now read loads about the Suntour, I am pretty much sold. But can you tell me how much clearance is needed between the saddle and toptube? I’m currently having my wheels built for my disc trucker, so am waiting for those to arrive in the next few days in order to work out whether I’d even have enough room for the TB-ST – I assume the Suntour needs more clearance than the TB-ST’s 98mm?

  8. Richard Post author

    Hi Sarah! Apologies for the late reply but I have been a couple of thousand km from my bike for the last three months! With the Suntour suspension seatpost set at its lowest point, the distance to the saddle rails is 108mm so its looks like it required only 10mm more that the Thudbuster ST. Hope that helps! All the best for your next tour!

  9. Richard Post author

    Thanks Andrew! I have done a quick search on-line and can find the Suntour NCX for about £61 – £75. The Thudbuster LT is about £140. Not sure if you are comparing to the Thudbuster ST?

  10. gren

    Great review thanks. I will try this SUNTOUR post after using thudbuster LT for many years on my MTB. I have been happy with the ride etc (saves my bad back from the abuse) but the problem with the thudbuster is wear: after a few 1000km of heavy use the bushes wear out. I got ripped off (beware of this) for a replacement bearing kit, but the problem is that the fixed steel parts (hollow 3/8″ spigots) wear flat, and they are not replaceable, being part of the seat post itself. I did actually machine some out of solid steel and replaced the hollow ones which lasted a bit longer, but overall very dissapointed with the durability and high wear rate for what are expensive items. Hope that helps!

  11. Richard Post author

    Thanks for your comment! My Suntour suspension post is still going well. I have seen that some cycle tourists are using the Thudbuster Short Travel (ST) version instead which may be more suitable for touring. I am sticking with the solid Suntour post for now though!

  12. Andrew F.

    Mine failed after 1500km. Split brass pivot bushes. Noisy (creak, creak, creak) and wobbly. I ride hard offroad. Seat was right back but within range. Noticed upon free replacement (thanks Moustashe NZ) some NCX had alloy pins and seat locks some had steel. Mine was steel. Awesome when new. Horid when worn. Great for urban and light trails only, recommended. Very very comfy. Other options for repeated hard loading out there to try.

  13. Richard Post author

    Hi Andrew! Over 8000km now on mine and still working well. Sounds like you were unlucky but good to hear you got a replacement. I agree – very comfortable suspension seat post! Thanks for your feedback!

  14. Andrew F.

    Yes, must be unlucky. Supplier said very odd. But, new NCX seat post may last longer as a 2015 Moustashe Samedi FS Race now takes up the slack from the same supplier. Luck is back. Ill change the Samedi HT Gold to a hybrid road bike with hybrid tyres and paniers for touring. Two batteries on long runs. The comfy Suntour NCX post should last the distance for me now with lighter use as a factor and from the long use reported consistantly from others and yourself Richard.

  15. Tim Chambers

    I think you might have your seat set a little too far forward so the post is making contact with the narrowest part of the rail. I have mine set closer to the middle where the spring mechanism will ease between the rails.

  16. Richard Post author

    Thanks Tim – I will have a look again. Though I found before that there was little space available to move the seat so that it did not contact the saddle rails.

  17. Owen Manning

    What actual clearance is needed between top of frame and saddle rails to fit a suspension post like the Suntour or other models? This information is essential but hard to find. Although my rebuilt tourer is near ideal, with tubeless 35mm tyres giving a superb ride, for medical reasons I still need to minimise jolting from humps and bumps; however the frame doesn’t leave much room at optimum saddle height.

  18. Richard Palmer

    Can anyone recommend a firm saddle that doesn’t hit the top bushing surround? How about the Cambium range?

  19. John

    What are your thoughts on initial set up? I have just installed mine. When I sit on the seat the mechanism compresses a little (hard to get a measure on that). I ride and it feels great floating over bumps. I have not bottomed out. Does that sound like the right setting?
    The other thing I wonder about is seat height. I am particular about seat height so given that the seat goes down somewhat I am going to raise the seat post to compensate. Any comments? Thanks. John

  20. Richard Post author

    Hi John. I have my seat post set so that it only operates when I hit a bump. Otherwise the seatpost operates as a solid seat post. I could make the setting softer like you have yours set, but as yet I am quite happy with how it is working. Maybe I will try experimenting a little!

    As my Suntour seat post is set to absorb only bigger bumps, I have set my seat as I would with a solid seat post.

  21. Richard Post author

    The saddle rails on the Cambium look similar to the B17, though don’t quote me on that! Anyone using a Cambium with the Suntour seat post?

  22. Michael S.

    Hi Richard

    I have purchased the same setup, a Suntour NCX seat post with Brooks B17 saddle and have encountered the same issue until some quick googling leading me to this blog post.

    I find that the clicks changes the angle too dramatically. One click higher than the seat post rails touching is too high for me to be comfortable. Also I find when it scrapes, the suspension feels “sticky” since it is rubbing.

    In any case I had to stop using the NCX seat post unfortunately. Have you figured out any workarounds?

  23. Richard Post author

    Michael, I have been lucky in that the height of the seat worked out fine for me. I assume you are using a Brooks saddle like me. Other saddles may be better or worse with the seatpost.

    After a bit of forward and back movement of the Brooks B17 saddle, I found a position where rubbing was only a minor issue and soon the clicking stopped. It did however result in the wear shown in the photographs.

    The only workaround I would suggest is to find that ‘sweet spot’ where there is minimal rubbing with the seat post and put up with the clicking until is stops.

  24. Shaun D

    If you read the manual for it you are supposed to service it every 300 miles, pulling the threaded piece from the tube and regressing it. I do it every 1,000 or so but oil the bushings when they start squeaking. You can pull it all apart with Allen wrenches and a ounce to knock the cylinders out and that takes a bit of time but worth it after a few thousand miles.

  25. Richard Post author

    Shaun – I did clean and re-oil the bushings after my last tour. I have only today tracked down the manual on-line for the seatpost and yes – service every 500km. Thanks for bringing that to my attention. I will remove the seatpost and spring sometime soon to re-lube as recommended in the manual. Will also look at removing the bushings too as you do.

  26. Mario Mario

    Hi You could put some rubber of a bike tube between the rails of the brooks seat and the suspension suntour metallic part , and renew it from time to time

  27. John C

    The post doesn’t work with a Brooks B17S unfortunately. It might just work with the B17 but the stoker on the tandem (my wife) has a ladies version is just too short get any clearance.. Such a shame as the post is a wonderful piece of engineering.

  28. Jerry

    I am very interested in Marc’s suggestion however the Instagram link doesn’t seem to work.
    Is he suggesting to rotate the entire assembly 180 degrees?
    Has anyone tried this? I would really like to purchase one of these seat posts for a trip that is coming up soon but wold like some reassurance that i can make it work properly with my B17.

  29. Igor Štimac


    Is it possible that the Brooks saddle bends a little and rubs against the seatpost while bending. I can see that the rails on the Brooks saddle are longer than standard rails and also tend to bend (according to some reviews). I have my seat mounted just a few mm from the top of the seatpost and it seems to me that the clearance stays the same no matter how much the seat drops… So to maybe explain it better, the part that is damaged (as seen in the pics from your review) drops as much as the seat/rail thus keeping the same distance between the rails and the top of the post
    I bought the seatpost a few weeks ago and have driven with it just once but this is what I observed. Maybe I’m missing something…

  30. Ted

    This review is very helpful and informative, thanks for this as i just purchased mine just now. You mentioned that straight out of the box, the seatpost is already adjusted to a 71kg setting, how do you know if you still need to adjust it to positive or negative? Is there a chart for this?

  31. Dan

    Hi, I know this is an old post but I’m literally about to buy the b17 then came across this now I’m second guessing if it’s a good idea or not, I’ve had the suntor ncx for about 2 weeks and I love it and as far as I can see the the half moon clasp holds the seat rails quite away from the pivot arms no matter the tilt angle could this be an old issue that’s been fixed?

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