comfort seatpost Testing

Seatposts: Often Overlooked Yet Critical For Your Comfort (Lab Testing)

A very good seatpost is the important thing to attaining a cushty experience. That’s as a result of along together with your tyres, seatposts truly make up the majority of your bike’s comfort – actually, a well-designed carbon seatpost flexes at a price 7x higher than a metal body!

The Ergon CF3 carbon seatpost requires 69N of pressure to flex one vertical millimetre (0.04″). To put that into context, the CF3 will flex 7mm (0.Three″) once you merely sit in your saddle. As compared, a typical bike body requires greater than 500N of drive to flex one vertical millimetre, demonstrating how much a seatpost (and how little a frame) plays in the comfort equation.

Briefly, flex seatposts are a good way to realize an excellent snug journey as they:
(a) Scale back high-frequency street vibrations, and;
(b) Deal with the larger impacts (assume rough filth roads) because of their 20mm+ (0.89″) of vertical flex.

On this article, we’ll talk about the totally different seatpost varieties and supplies, before wanting at the distinction between vibration damping and seatpost deflection. We’ll then take a look at a few of the lab testing that’s been accomplished and can end up with my seatpost suggestions.

Word: This text was originally revealed July 2015, however has been updated in Might 2019.

Very few individuals think about the journey quality of a seatpost, which is exactly why I feel they’re probably the most missed bike element. They’re arguably even more necessary for bike travel as touring and bikepacking bikes are often set up with larger handlebars, resulting in a larger proportion of our physique weight on our saddles (normally 80%+). Couple that with our penchant for looking for rough roads, and seatposts actually are the important thing to unlocking all-day consolation on your bike.

Bikes fitted with narrower tyres have probably the most comfort to realize from using a flex seatpost. It’s because a bigger proportion of the overall shock and impacts will have to be taken up by the seatpost. Bikes with wider tyres still have lots to realize too, as flex posts assist to take the edge off greater impacts.

Trek’s IsoSpeed Decoupler permits the seat tube to flex independently of the highest tube.

During the last decade, bike manufacturers have been optimizing their bikes round consolation, and the seat tube has been the primary focus. Trek have developed what they name an ‘Isospeed Decoupler’ which is integrated into their seat tube, providing round 20mm of vertical compliance. Big created a singular seatpost shape referred to as D-Fuse which can flex round 12mm underneath you. And Cannondale has caught with one thing a bit extra conventional, utilizing a smaller-than-usual seatpost diameter paired with a flat-section carbon layup to realize an excellent snug journey.

The excellent news is that you simply don’t need to buy a flowery new bike to realize a high degree of consolation. A handful of aftermarket seatposts can match the vertical flex and vibration damping of the Trek, Big and Cannondale designs, permitting you to rework no matter you journey into something that rides ultra clean.

Carbon, Aluminium and Titanium Seatposts
Seatposts are manufactured utilizing three totally different development supplies. The bulk are constructed from aluminium which is lightweight, dependable and really low cost to manufacture. Titanium seatposts are much less widespread and are sometimes paired with titanium frames for a pleasant aesthetic. Carbon seatposts are lighter and costlier, but more importantly, they are often optimized utilizing totally different layering methods to realize an unparalleled experience high quality.

Suspension Seatposts
There is a handful of suspension seatpost manufacturers, however perhaps the most typical is Cane Creek. The benefit of a suspension seatpost is that it’ll assist take in massive hits and different impacts from the bottom under, allowing you to pedal by way of bumps while also decreasing the fatigue in your body. Suspension seatposts have been measured to be a number of occasions simpler than any rigid seatpost. The primary disadvantage is the increase in weight.

Elastomer Seatposts
Specialised has been incorporating elastomers into their flex seatposts for over a decade in order that they will achieve their desired journey traits. The newest-generation carbon elastomer publish (pictured on the proper) is claimed to offer 18mm of vertical flex, is fairly light-weight and can also be reliable as there are not any shifting elements.

Straight and Setback Seatposts
Seatposts can be found in several offsets starting from Zero levels to 35 degrees. A setback submit places you further behind your crankset and a straight seatpost moves you nearer. The amount of setback or offset is greatest determined by means of a primary bike fit at a collaborating bike store. They’ll take a look at the relationship between your knee and pedal axle, as well as your hip angle/mobility and will determine how far it is best to sit behind your crankset. You’ll be able to read extra about bike geometry HERE and about getting a customized bike fit HERE.

Microbac Laboratories’ check jig for comparing the totally different traits of seatposts. Image: BikeRadar

Damping is the velocity at which a seatpost will transfer over repeated bumps, and it’s probably the most essential attribute for cycling on smoother surfaces.

A seatpost that dampens vibrations effectively will insulate a rider from much of the street buzz arising by way of their bike. Seatposts with the most effective damping traits have been tested to be more than twice as efficient than those which perform poorly.

We presently have two damping lab checks to draw some conclusions from:

Seatpost Damping

Velo Journal’s damping check outcomes with 14 totally different 27.2mm seatposts.

Velo Magazine’s 2012 check results present that:
– Virtually all carbon seatposts carried out higher than the aluminium or titanium choices.
– Straight seatposts (carbon, titanium & aluminium) are worse at damping shock than setback seatposts.
– The Cane Creek suspension seatpost was surprisingly not as efficient at mitigating street buzz as two carbon seatposts.

Microbac Laboratories collected knowledge on most of the newer flex seatpost fashions. This check consists of the Ergon CF3, Ritchey WCS Carbon Flexlogic, Canyon S13 VCLS, Specialised CG-R and Syntace P6 Hi-Flex. Picture: BikeRadar

The Microbac Laboratories’ 2016 check outcomes show that:
– The Ergon CF3 leaf-sprung seatpost absorbs 2-3x extra shock than other flex carbon seatposts.
– The one aluminium seatpost in the check (Thomson) is just no match when it comes to damping.
– The Specialized submit is somewhat underwhelming on the street contemplating its radical design.

There is a caveat here! This knowledge solely applies to bikes without baggage fitted. Why? Rear panniers and bikepacking seat packs are extremely effective at mitigating vibrations, so you gained’t notice an enormous difference between a carbon or aluminium seatposts when travelling with baggage.

Deflection is the whole movement that a seatpost will move after an influence.

A seatpost with more deflection will scale back the fatigue in your physique because it protects you from more durable jolts like sudden potholes or filth street corrugations. It’ll additionally permit you to pedal via bumps on rougher terrain.

When testing seatpost deflection, two axes of measurement are often taken – vertical and horizontal – however they virtually all the time monitor proportionately. The Velo Journal lab check knowledge exhibits that beneath the precise drive utilized, some seatposts have been capable of deflect twice as a lot as others.

Seatpost Flex

Velo Journal’s deflection check outcomes with 27.2mm seatposts.

The results are a bit onerous to read, so let me sort that out:
1. Cane Creek Thudbuster ST (13.7mm, 19.3mm)
2. Ritchey Carbon Straight (5.8mm, 4.8mm)
Three. Ritchey Carbon Setback (5.5mm, 5.0mm)
four. Cannondale Carbon (5.4mm, four.3mm)
5. Zipp Straight Carbon (4.9mm, 4.2mm)
6. Ritchey Setback Aluminium (4.8mm, four.5mm)
7. Specialised FACT Carbon (four.8mm, four.4mm)
8. FSA Straight Carbon (4.8mm, 4.2mm)
9. Thomson Straight Aluminium (four.8mm, four.2mm)
10. FSA Setback Carbon (4.3mm, 4.2mm)
11. Moots Straight Ti (four.3mm, four.2mm)
12. Moots Setback Ti (4.2mm, 4.0mm)
13. Zipp Setback Carbon (Three.9mm, 4.0mm)
14. Thomson Setback Aluminium (Three.5mm, Three.6mm)

The conclusions we will draw from the Velo Journal check:
– One of the best performing common seatposts supply 50-60% extra flex than the worst performing.
– Carbon is ready to deflect more than both aluminium and titanium.
– Setback seatposts are typically worse performing, making up locations 10, 12, 13 and 14 on this check.
– In another league altogether is the Cane Creek Thudbuster suspension seatpost which presents Three-4x more flex than a daily seatpost. It’s also value noting that this is underneath half of what it could possibly flex (33mm).


The Microbac Laboratories deflection check utilizing the minimum and maximum seatpost insertions at totally different rates of drive.

The conclusions we will draw from the Microbac Laboratories check:
– There is a linear relationship between deflection and pressure (for a small vary), serving to us to predict flex at totally different pressure charges.
– Lighter riders are higher suited to the Ergon/Canyon seatposts and heavier riders the Syntace/Ritchey.
– The minimal (high seatpost) and maximum insertions (low seatpost) impacts the amount of deflection by 1.5-2x.
– The Ergon CF3 is the king again, outperforming all other seatposts at the most and minimal insertions.
– The Ritchey and Syntace seatposts depend on a excessive seat peak to realize their flex (2x larger flex).
– The Specialised CG-R was once more quite underwhelming, flexing underneath half as much because the Ergon CF3 and Canyon S13 VCLS.

Should you’re on the lookout for a agency journey on the street (much less saddle motion), you’ll need to choose a seatpost with a decrease deflection however a better damping means. In line with the Velo Journal results, that’s something just like the FSA Okay-Pressure or Zipp Service Course SL, while the Microbac Lab results recommend the Ritchey WCS Flexlogic is the go. That stated, this info is applicable principally to street driving – you’ll find a bikepacking seat pack or rear panniers will dampen street vibrations appropriately with whichever seatpost you select.

For dust street use, deflection is king. Straight carbon seatposts supply the very best diploma of vertical flex on huge bumps, nevertheless, they are typically a bit extra jarring on the high-frequency small bumps. Suspension seatposts are merely on one other degree in all regards, with numerous deflection as well as wonderful damping talents.

Carbon seatposts are tuned with set spring rates.

For instance, at 300lb pressure, the Ergon CF3 would theoretically flex its maximum amount of 20mm whereas the Specialized CG-R will only be halfway via its travel. Primarily, lighter riders can be much better suited to the Ergon or Canyon seatposts, whereas heavier riders should look in the direction of the Ritchey, Syntace or Cannondale choices.

Riders with less exposed seatpost may also profit from the Ergon or Canyon seatposts, as they’re shown to flex twice as a lot on the maximum seatpost insertion. But then again, seatpost peak reduces the deflection by half, so a suspension seatpost is a superb choice for riders with less seatpost uncovered. However more on that under.

best bikepacking bikes

There’s no use to fit a flex seatpost to a fat bike as a result of the tyres take in nearly all of the overall shock.

Tyres do an exceptional job of damping vibrations and absorbing greater hits.

In the wider widths, tyre sidewalls can flex as much or even more than the perfect seatposts. When you’ve acquired tyres which are slender (30mm to 50mm broad), you’ll benefit quite a bit from a seatpost with extra flex like the Ergon CF3 or Canyon S13 VCLS. Between 2.Zero″ and a couple of.5″, flex posts are nonetheless really effective but you possibly can often get away with a little less flex in the event you like (eg. Cannondale SAVE or Ritchey WCS Flexlogic). The consolation effects begin to diminish when you get into the plus-size tyre vary (3.0″) or wider (four.Zero-5.0″) the place the tyres are absorbing a lot that aluminium posts work effective.

One cool factor a few flex seatpost (and matching Redshift Shockstop stem) is that it permits you to use narrower tyres without sacrificing any comfort. The good thing about this setup can be that you might scale back your rolling resistance and general bike weight while nonetheless travelling in comfort.

The Cane Creek eeSilk is a contact heavier than a carbon seatpost yet has five totally different spring rates out there.

Ok, so both carbon and suspension seatposts are sounding pretty good right here. But how would you go about choosing between the 2?

There are two disadvantages to using a carbon submit:
– There is only one spring fee obtainable, and;
– The consolation depends on the quantity of seatpost protruding of your body.

By having a set spring price, a heavier rider will take pleasure in a more snug experience, whereas a lighter rider will feel extra vibration and large hits. Carbon seatposts additionally carry out a lot better with extra exposed seatpost (2x extra flex), which arms the better performance to taller riders.

A suspension seatpost is able to clear up both of these issues. A lot of the suspension options have four or five totally different spring rates, which permits each mild (45kg/100lb) or heavy (150kg/330lb) cyclists to realize the equivalent journey really feel, regardless of the seatpost peak. With a suspension submit, you may as well tune the journey quality based mostly on the surfaces you experience: a stiffer elastomer/spring for the street, or a softer one in the event you like rougher terrain. Most suspension seatposts have an adjustable pre-load too, which allows you to change the quantity of drive required to make the saddle begin shifting.

The primary draw back to picking a suspension seatpost is the load. Most of them tip the scales between 450-550 grams (1.Zero-1.2lb) which is more than twice the load of most carbon seatposts out there. That stated, there’s one really light-weight suspension seatpost…

The Cane Creek eeSilk is probably the last word seatpost. At 295 grams, it’s barely heavier than most of the carbon choices. With 5 totally different spring charges, riders of any weight can tune it to realize the right experience high quality. And it’ll work simply as effectively whether or not set high or low in your frame. The worth isn’t low cost – it’s round US $300, however then again, that’s the identical worth as a top-end carbon seatpost.

There’s definitely some extent the place you’ll discover excessive seatpost flex, however that may rely upon the terrain you journey, your physique weight, your seatpost peak and your personal preferences.

If in case you have a great amount of seatpost exposed, have a mean body weight and need a flexible however agency experience, three appropriate seatposts come to thoughts right here: Cannondale SAVE, Ritchey WCS Flexlogic or Syntace Hi-Flex P6. These posts will nonetheless flex between 5-15mm on impression but are in any other case tuned to be fairly agency.

For lighter or shorter riders, a seatpost with a lighter spring price will yield comparable amounts of deflection. That’s where the Ergon CF3 and Canyon S13 VCLS are nice. These posts are also suitable for taller/heavier riders that favor extra flex relatively than much less.

On notably bumpy surfaces it’s fatiguing on your body to cycle for lengthy durations of time. That’s why I fit my Cane Creek suspension seatpost to my bikes once I know the terrain will probably be rough – the additional 10-20mm of deflection is usually a godsend.

Flex Submit w/ Wider Tyres: Cannondale SAVE (208g/7.3oz)
I’ve used a Cannondale publish in my mountain bikes for years, and assume it offers the right quantity of flex across all varieties of terrain, from clean roads by way of to bumpy gravel roads. I feel it’s the decide notably in the event you’re using 40mm or wider tyres. Should you’re coming from an aluminium seatpost, it is going to utterly rework your journey! The SAVE is considerably firm in comparison with a suspension seatpost, however it actually does an ideal job of taking the sting off all the things. Highly advisable for $199 on Amazon.

Flex Submit w/ Narrower Tyres: Ergon CF3 or Canyon S13 VCLS (each 220g/7.8oz)
In the event you’re utilizing narrower tyres (eg. 700x30c to 700x40c), it’s value choosing up a seatpost with a bit extra flex to make up for the very fact your tyres don’t deform as much. The Ergon CF3 (US $299) is definitely the most effective performer right here because it has 20mm of vertical flex and weighs just 220 grams. A ‘flip head’ package is out there for the Ergon publish, supplying you with the option to increase or decrease the setback to fit your needs. The Canyon S13 VCLS performs virtually as properly and is considerably cheaper (US $170), so it had to make the listing too.

Vibration Absorbing Submit: FSA Okay-Drive Mild (210g/7.4oz)
For one thing that gives a agency experience however still does an excellent job at absorbing street buzz, you’ll be able to’t go past the FSA Okay-Pressure seatpost. This is the right improve for a street bike with none bike baggage hooked up. Yow will discover the Okay-Pressure Mild for $199 on Amazon.

Suspension Submit: Cane Creek Thudbuster ST (454g/1.0lb)
My Cane Creek seatpost performed flawlessly on my massive bike journey from Europe to Australia! Whereas 250 grams heavier than a carbon publish, you’ll be able to benefit from greater than twice the vertical journey, plus five totally different spring fee options so you possibly can tune your experience from smooth to agency. It really works out lighter than all comparable suspension publish choices and can also be great value at $143 on Amazon.

Cannondale SAVE – My general decide, an ideal performer for each vibration damping and absorbing massive hits – $199 on Amazon
Canyon S13 VCLS – 2nd greatest deflection results, good at max insertion, nice for lighter riders – US $170
Canyon VCLS 2.Zero – Greatest deflection/damping results, nice at max insertion, well-suited to lighter riders – US $299
Ergon CF3 – The same submit because the VCLS 2.Zero as it’s a shared product between corporations – US $299
FSA Okay-Drive – The Velo Journal best-tested seatpost for vibration damping, great for street driving – $199 on Amazon
Ritchey WCS Carbon Flexlogic – Respectable deflection outcomes, nice at damping vibrations, light-weight – $199 on Amazon
Specialized CG-R – The Specialised CG-R could be the go for heavier riders with its heavy spring price – US $199
Syntace P6 Carbon Hello-Flex – 3rd greatest deflection outcomes, but doesn’t perform properly at max insertion – $198 on Amazon
Zipp Service Course SL – Like the FSA seatpost, this provides great vibration damping for the street – $133 on Amazon

Cane Creek eeSilk – 20mm of suspension travel, 5 spring charges, 295g – $310 on Amazon
Cane Creek Thudbuster ST – 33mm of suspension journey, 5 spring rates, 454g – $143 on Amazon
Cane Creek Thudbuster LT – 67mm of suspension journey, five spring charges, 540g – $127 on Amazon
Kinekt 2.1 Aluminium – 35mm of suspension travel, 4 spring charges, pre-load adjustment, 525g – $249 on Amazon
Kinekt Three.1 Carbon – 35mm of suspension travel, 4 spring rates, pre-load adjustment, 471g – $329 on Amazon
Suntour NCX – 50mm of suspension journey, two spring rates, pre-load adjustment, 765g – $114 on Amazon
Redshift ShockStop – 35mm of suspension journey, eight spring charges, pre-load adjustment, 497g – US $199