Author Topic: Soliciting Suspension seatpost recommendations  (Read 14610 times)

Danneaux

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Soliciting Suspension seatpost recommendations
« on: August 15, 2013, 09:14:12 PM »
Hi All!

I'm considering a suspension seatpost for my Nomad Mk2 when I use it on logging roads without a load. Usually, I just post (stand up briefly) when hitting a bump with my unladen bikes on such terrain, but that is less-often possible when tootling along in low gears uphill with a full-on touring load. Despite what I initially thought, the front of the bike is not problem; I just bend my elbows and do fine with that. It is the compressive loads coming up my spine that have a whiplash effect on my neck and I can really feel that after several hours. Unlike when road riding, the size of the bumps makes tire cross-section and lower pressures less effective in absorbing the larger hits while seated. For road use or extended touring, I'd still choose a lower-maintenance rigid post, but a sus-post would really help when I'm riding the bumpy stuff in the hills and mountains that surround my town.

I have experience with two suspension seatposts on my tandem. The stoker gets a USE telescopic seatpost I heavily machined and modified to reduce stiction and uses a combinaton of elastomers and a repurposed automobile valve spring. It works well, but would not be to my taste for the Nomad because there is the slightest bit of rotation that can be felt while pedaling and I find that annoying. My stokers have all been very enthusiastic about it, and say it performs well even on the "bigger hits" experienced by stokers when going on rougher surfaces (the stoker sits nearer the rear wheel and so feel the bumps more than I do as Captain, suspended midway between a long wheelbase).

I have a different sort of sus-post at the Captain's saddle. It uses an elastomer in compression that works a bit like a broomstick in a door hinge. It is just the ticket for absorbing the little bit of "road buzz" that comes up through the long wheelbase to the captain's saddle. Its one drawback is it tips the saddle rearward on compression, so I have to set the saddle up with a bit more forward tilt than usual to compensate. Not a problem with the leather-covered Avocet Touring II saddle I use there.

I think I'd prefer a parallelogram seatpost on the Nomad for several reasons. For one, under compression, the saddle moves downward and rearward, making for a bit less vertical compression and so affects saddletop-to-BB distance a bit less. Second, the geometry seems likely to be a bit more responsive than a telescoping post, which is about halfway locked-out when examined in light of the compressive forces coming up through the rear wheel.

There's three leading candidates so far in my search, and all are available in 27.2mm to fit my Nomad's seatpost shim. Thudbuster has a long-travel parallelogram post with two tunable diagonally-placed elastomers. Thudbuster also offer a shorter-travel post whose parallelogram is filled with a single, shaped elastomer that comes in several durometers. These are both nice, have received stellar reviews for their respective intended usage, and are expensive.

Alternatively, SR-SunTour offer a parallelogram seatpost that has been freshly redesigned for 2012, the SP 12-NCX: http://www.flickr.com/photos/29976052@N08/8022574000/sizes/o/in/photostream/
...and...
http://www.srsuntour-cycling.com/index.php?screen=sh.detail&tnid=3731
The price is considerably less than Thudbusters', and the reviews have been uniformly good on this new model at German and Dutch online vendors and among the pedelec crowd, even in comparison to Thudbuster. Our own Stuntpilot has one on his Raven Torla, and was initially impressed by it and is gathering long-term data on its performance. In an earlier post, he mentioned setting his tension so his post was effectively a rigid until he hit a large bump. That appeals to me. At that time, the post made a clicking noise when it hit the rebound stop, but was infrequent enough to be no bother. The SunTour uses brass bushings and rebuild kits are readily available to keep them fresh.

One thing that concerns me about the SunTour post is the apparent lack of rebound control. It uses a very clever design where a roller vertically compresses a spring-loaded shaft. This makes for a low-friction, very responsive post, but I'm concerned its action might not be well-controlled. Here's a video showing it in action at a bike show: http://www.youtube.com/watch?v=hN8v_SEWPto

Wondering if any of you have experience with suspension seatposts, if you also prefer a parallelogram design over telescopic, and what you thoughts are on the SunTour versus Thudbuster(s) or perhaps some other model or design.
- - - - - - - - -
EDIT: I just came across another possibility by German component supplier XLC: http://www.xlc-parts.de/produkte_detail_de,854,33700,detail.html
Google-translated to English here: http://translate.google.com/translate?sl=de&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.xlc-parts.de%2Fprodukte_detail_de%2C854%2C33700%2Cdetail.html&act=url
It uses an elastomer with adjustable preload to produce only 25mm of travel inits parallelogram linkage.
- - - - - - - - -
I should note I'd like a seatpost with considerable layback/setback to get a good position on the bike while clamping the saddle rails midway to reduce breakage. I currently use a Thorn/Zoom long-layback 'post and it works fine. Thanks in advance for sharing your thoughts.

Best,

Dan. (...who <Ungh!> could use something to help with the <Ungh!> larger bumps while touring on <Ungh!> really rough roads)
« Last Edit: October 14, 2014, 08:13:08 PM by Danneaux »

martinf

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Re: Soliciting Suspension seatpost recommendations
« Reply #1 on: August 16, 2013, 05:55:21 AM »
Maybe try a Brooks Flyer saddle instead? Similar top to B17, but with fairly stiff springs.

I generally prefer B17 for my bikes, but have a B66 Champion (the twin-rail predecessor to the Flyer) on my old 5-speed. On off-road riding I find this smooths out the worst of the bumps without noticeably compromising on-road pedalling efficiency.

Had the B66 Champion since 1984, done over 60,000 kms with it, the leather is a bit cracked now but the saddle is still very comfortable.

Downsides of a sprung saddle - extra weight, and may make creaky sounds. But probably simpler than a suspension seatpost, and doesn't develop sloppiness with wear over time.

Danneaux

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Re: Soliciting Suspension seatpost recommendations
« Reply #2 on: August 16, 2013, 06:50:36 AM »
Quote
Maybe try a Brooks Flyer saddle instead? Similar top to B17, but with fairly stiff springs.
Thanks for the thoughtful suggestion, Martin! I really wish this would work as a solution for me, as it is simpler and more direct, just as you say.

I tried a Flyer some years ago, and sadly ended up selling it to my neighbor. I found the springs were just too stiff to provide much (any) suspension effect for me even on larger bumps with my back at a 45° angle.

Similar experiences here: http://www.bikeforums.net/showthread.php/227872-Brooks-saddle-springs-%96-is-ride-softer-with-use

I really liked the idea, and wished very much I could have substituted slightly softer springs to make it work on muting the Big Bumps without bouncing much on the smaller ones. The B.17 is the perfect match in width and shape for my needs, and the Flyer felt the same. I really wouldn't want to go wider or narrower in the Brooks line, or to a different shape when this works so well for me.
Quote
Downsides of a sprung saddle - extra weight, and may make creaky sounds. But probably simpler than a suspension seatpost, and doesn't develop sloppiness with wear over time.
All very true. I'd sure be willing to give a Flyer another try if I could just source the slightly softer springs I would need -- and then get then installed.

Best,

Dan. (...who may give this some more considered thought, as it is a Preferred Solution™)
« Last Edit: August 16, 2013, 07:21:14 AM by Danneaux »

geocycle

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Re: Soliciting Suspension seatpost recommendations
« Reply #3 on: August 16, 2013, 09:23:36 AM »
I think a lot depends on your saddle.  I didn't get on well with combining my B17 with a suspension post.  I think it slowed down the break-in process.  Also, for me getting the height of the saddle just right is critical for a Brooks and also for my knees.  We are talking mm here!  With a suspension post the height and geometry becomes variable.  i suppose a sprung flyer or B67 would have some of the same issues but not tried them.
 

martinf

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Re: Soliciting Suspension seatpost recommendations
« Reply #4 on: August 16, 2013, 01:00:35 PM »
According to this reviewer, the springs in recent saddles are stiffer than those in my old saddle:

http://swhs.home.xs4all.nl/fiets/tests/zadels/index_en.html#Brooks_b66_champion

Danneaux

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Re: Soliciting Suspension seatpost recommendations
« Reply #5 on: August 16, 2013, 05:30:56 PM »
Quote
...for me getting the height of the saddle just right is critical for a Brooks and also for my knees.  We are talking mm here!
Hi Geo'!

I think you've touched on the "stopper" that has been lying in the back of my mind wrt suspension seatposts.

After injuring my knees in that car wreck at age 16, I've had to be really careful not to re-aggravate them, and -- just as you said -- even mm of difference in saddle height start the bone-deep aching again. My recent adventure trying clipless shoes knocked me right off the bike, made even walking difficult, and I've lost a lot of sleep due to the knee pain resuming. I never figured the lightest pedal spring-release tension and heel-out movement could possibly aggravate such ancient injuries. I seem to have found my solution in multirelease cleats and "baby-mode" Shimano T400 pedals dialed back to minimum tension.

I'm not sure I would fare as well wrt to dynamic changes in saddle height -- at least not while I'm still icing my knees. Best to wait and let things settle down, then re-evaluate the sus-post thing.

It may well be the "best" sus-post solution for me is one that can be tuned to act as a rigid post in all circumstances except when encountering the Big Bumps -- as Richard (Stuntpilot) has set his. Adjusted that way, the saddle would "give" only momentarily when really needed and my knees wouldn't have to deal with much change in height.

Martin, I have to agree...Brooks' springs have become thicker and less responsive in recent years.

Thanks, fellows; really helpful input.

Best,

Dan.

Andre Jute

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Re: Soliciting Suspension seatpost recommendations
« Reply #6 on: August 16, 2013, 05:50:05 PM »
I thought yesterday of suggesting a Brooks extra-spring saddle ("extra" because the leather hammock is already a spring) but refrained because the ones with the right springs, with progressive suspension, are the helical coil-sprung models, and the best ones among them are wider than the B17 — and Dan had earlier in another thread ruled out saddles wider than the B17.

I like the B73, which I bought on a halfprice sale at SJS as a wild experiment and loved so much that I have ridden nothing else since, even giving up my beloved Cheeko90 (a seat rather than a saddle) for the Brooks. The street myth from people who haven't ridden the triple-coil sprung Brooks that it sways from side to side is rubbish; it doesn't because the springs are too stiff. But they are tempered just right to keep the road buzz out of your coccyx and thence your spine, so the ride is very relaxing. On washboard and brandnew cheap chipseal surfaces they're too stiff to help much (I use the B73 in a complete system with 60mm low pressure balloons), or perhaps one just notices more because the rest of the ride is so plush. But they shine in crashing through potholes, which here is inevitable, the more so if you ride fast on my narrow roads and lanes, when you often have to ride through the pothole as the alternative might be an incident with a car or a spill. At my age I can't afford a broken hipbone, so a saddle that helps keep you on the road regardless of potholes is worth twice the full price of the Brooks.

Unfortunately the B73 is the third heaviest of the current Brooks saddles (the B135 and B190 are heavier than the B73 by more than the weight of the B72!). But there's a lighter version called the B72, very rare but listed by SJS. It doesn't have the full helical springs of the big brother B73 (now revealed as a brilliant compromise!), but what makes the coiled springs so good isn't their coiling but their length; coiling is not an operating function but a space-saving device. This B72 has a pair of extra-long sprung rails with a single longitudinal coil in each. See the frame at http://www.sjscycles.co.uk/page/find/?name=Brooks%20B72&page=1 The B72 should thus be lighter -- compare with the B73 components and assume heavier leather too at http://www.sjscycles.co.uk/page/find/?name=Brooks%20B73&page=1 -- than the B73 by a good deal (1100 - 690 = 410gr), and almost as stiff/compliant under the relevant conditions as the B73, because of the very long effective rail. Also, probably important to a dyed in the wool traditionalist like Dan, the B72 looks more like a proper fast touring cycle saddle than the B73, which is clearly designed for the middle-aged sybarite's sitzplatz.

I wouldn't use any of the Brooks saddles, including the B17, with a sprung seat post. The B17 is itself already a double suspension medium of leather and slightly flexible rails. Brooks lucked out with the combination because the leather is so extremely adaptable. But adding a third suspension medium with yet another set of frequencies is a recipe for introducing disastrously tiring microfrequencies into your bum and thence into your spine and nervous system even on good roads, while doing nothing to make bad roads more tolerable.

***

Dan, I've had the USE in two or three of the cheaper models (no better in use than really cheap stuff with a one-year lifespan, though more tuneable), a Suntour NCX and the smaller Thudbuster because it was all that would fit on that bike. The Suntour works just as well at half the price of the Thudbuster and better than the more expensive USE. Both the parallelograms are superior to the USE in use. I can't tell you anything about longevity because I kept none but the USE very long and that only for a year. In my opinion, suspension seat posts aren't a solution or in many cases even an amelioration but the cause of further complications and problems.

Andre Jute

StuntPilot

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Re: Soliciting Suspension seatpost recommendations
« Reply #7 on: October 01, 2013, 08:19:52 PM »
I have just posted a review of the SR Suntour SP12-NCX on my blog. Detailing my experience of the seat post, it adds comments on the good and bad with plenty photos.

Despite the down sides, I love the SR Suntour post and how it performs on a long tour ...

http://www.touronabike.com/sr-suntour-sp12-ncx-suspension-seat-post-review/

Hope that provides some input for those deciding to buy or not.

Danneaux

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Re: Soliciting Suspension seatpost recommendations
« Reply #8 on: October 01, 2013, 08:21:24 PM »
Wow! Richard! Is that ever helpful; thanks so much for this.

All the best,

Dan. (...who will re-read as he ponders further)

Andre Jute

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Re: Soliciting Suspension seatpost recommendations
« Reply #9 on: October 01, 2013, 10:57:20 PM »
http://www.touronabike.com/sr-suntour-sp12-ncx-suspension-seat-post-review/

Thank you so much for that. Makes me want to try it again -- the last time I had one, briefly, was before the recent redesign with brash bushings etc, though I hasten to add I didn't sell it on for any quality issues but simply because it wasn't in use after I changed bikes and saddles and someone else lusted after it. But now Julian has sent me his adaptor for Brooks twin rail to micro-adjustable seat post, so I could conceivably fit any seat post. Mmm...

That's a really good point in the article about a one-motion return to the original position, and the effect on control of the bike over rough roads or in unexpected situations.
« Last Edit: October 01, 2013, 11:03:54 PM by Andre Jute »

honesty

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Re: Soliciting Suspension seatpost recommendations
« Reply #10 on: October 03, 2013, 09:17:53 AM »
Specialized have recently released a carbon suspension post called the COBL G0BL-R> You can read info on it here: http://www.cxmagazine.com/specialized-cobl-goblr-ergon-cr3-suspension-seatposts-cyclocross-road

I find it interesting as it has no moving parts, its basically a leaf spring.


Etienne

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Re: Soliciting Suspension seatpost recommendations
« Reply #11 on: October 03, 2013, 02:37:43 PM »
 ;)  how nice to share .... remain interesting for all of us on 27,2 and .. for the familly !

NZPeterG

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Re: Soliciting Suspension seatpost recommendations
« Reply #12 on: October 07, 2013, 07:03:51 PM »
Specialized have recently released a carbon suspension post called the COBL G0BL-R> You can read info on it here: http://www.cxmagazine.com/specialized-cobl-goblr-ergon-cr3-suspension-seatposts-cyclocross-road

I find it interesting as it has no moving parts, its basically a leaf spring.



YES its very cool and works well.

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jimmer

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Re: Soliciting Suspension seatpost recommendations
« Reply #13 on: October 19, 2013, 03:13:22 PM »
Dear Dan,

I use a Cane Creek Thudbuster LT when the Catalyst is carrying me over MTB trails with a Rock Shox Reba RLT 100mm fork up front. It works well to smooth out the small, high frequency bumps that can sap energy and pummel the derrier over a day's riding (no innuendo free way of expressing this, let's not let things slide into a mire of innapropriate smuttiness, eh?). It affords somewhat greater traction over such sections when taken, at speed. This effect seems to be enhanced by the rearward actuation of the suspension which throws ones weight over the rear wheel. The compression is responsive, smooth and progressive. The movement keeps the seat - pedal distance constant which contributes to the natural feel of the system.

Drops greater than 6" or so and technical sections still need to be negotiated standing up on the pedals. The post does not give the big hit, freeride capability you may be looking for on the fully loaded Nomad dragging the extrawheel.

The first post I brought was replaced under warranty by CRC when one of the bolts securing the halves of one of the parallelogram arms sheared. I am just within the upper weight limit for the system (100kg of solid lard vs 105kg) but was disappointed that it failed so soon after moderate riding. The new post has lasted the past five years with no trouble.

Being so hefty I had to order the appropriatly firm purple elastomers seperately which cost a further £10 or so. The included elastomers allow tuning of the suspension to accomodate riders between about 60 - 90 kg in 5kg increments.

The neoprene cover is necessary to protect the bearings which are simple bronze bushings with open ends. Mine has developed abrasion holes so I'll need to think of a repair approach. £20 for a replacement is an affront even to my fairly primitive economic understanding.

Overall it was £90 well spent when I got it six years ago. I notice that they are double that now.

Yours, James





 

Danneaux

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Re: Soliciting Suspension seatpost recommendations
« Reply #14 on: October 19, 2013, 07:12:43 PM »
Hi James!

Your post is really timely as I have turned my focus increasingly toward the Thudbuster LT.

I have been looking for the sort of performance you describe -- the smoothing of high-frequency bumps -- figuring I would still have to post (stand) over more rugged stuff. I see Andy Blance continues to offer the Thudbuster LT as an option in the Nomad brochure, though he says he and Fiona use it on their MTBs and not their touring bikes.

On the one hand, I dislike the idea of adding extra weight (unlikely to be noticed in the 20kg weight of the bike and the weight difference between the LT and original post isn't much) and complexity (one more thing to wear and potentially break), but it would be really nice to have something to "take the edge off" when touring largely unladen on rough logging roads, fire trails, and such where many miles of large-ballast rock (see attached pic) must be traversed before hitting the really rough-stuff. It is the ballast that is proving a bit problematic on the unladen bicycle. It reminds me of Belgium's cobbles -- nothing in the way of a really hard hit, but just lots and lots of constant vibration. Putting a touring load on the bike of course smooths things out considerably, the Nomad really coming into its own with an expedition load (exactly what I need for full-on backcountry touring). My preferred option was a Brooks Flyer, but I found the springs almost completely unresponsive for my riding position and sold it on in disappointment. If only the springs had been softer and more responsive for my use! This is what caused me to turn toward sus-posts. A telescopic model works fine for my tandem stokers, but I want to avoid changes in leg-length, so parallelogram models hold greater appeal for me.

I'm a little unnerved by your breakage, but hope my 78kg and 45° back angle won't press the bolts unduly in service. Makes me think it would be Very Wise to carry a spare bushing and bolt with me on longer tours if I go this route. I'm guessing the forward lean of drop 'bars will help a bit as well. Bike4Travel partner Chantal Kwakkelstein in Rotterdam published an encouraging review of her experience in Dutch here: http://www.bike4travel.nl/article_info.php?articles_id=25 summarized in translation:
Quote
...I am now on two bikes, but the Thudbuster is simply moved along. The suspension is perfect! So subtle that you do not feel it, but the bumps on the paths not. And after long days on unpaved trails, no problems with my back! Now after 25,000 miles he still works perfectly and no play!

I'm hoping the parallelogram linkage will indeed work to keep saddle-to-BB distance fairly constant, at least compared to telescopic posts. Jimmer, do you find the downward-and-rearward movement has you really reaching for the handlebars, or is it pretty tolerable and largely unnoticeable? I read about the LT having as much as 76mm/3in of travel and wonder how much of that is rearward. I'm guessing about half the total travel? Any interference between Brooks saddle rails and linkage as Richard found initially on his SR-SunTour?

I'm still unsure whether the LT is the route to go or the ST...or something with similarly short travel like Richard's SR-SunTour ( http://www.srsuntour-cycling.com/index.php?screen=sh.detail&tnid=3731 ) or the Tamer PivotPlus XC (http://www.amazon.com/Tamer-Pivot-Plus-Suspension-Seatpost/dp/B00A214PR6 ).

Stateside, I can get the current Thudbuster LT for as little as USD$139, equivalent to £86, so the price isn't as bad as I'd feared. I would definitely want the neoprene cover. I wonder if ShoeGoo or McNett SeamGrip would make a good patch for the holes?

Thanks again for your thoughts, James. Anyone else out there running a sus-post?

All the best,

Dan. (...who would like to travel in a less ehm, shocking manner)
« Last Edit: October 19, 2013, 11:52:22 PM by Danneaux »