Dropper Seatpost
New technology and deviation from the norm are often met with
reticence among those who have charged themselves with upholding
cycling’s “traditional values.” Two recent examples include the furor
over mountain bike wheel sizes and resistance to the inevitable change
to road bike disc brakes. One technological advancement which has been
whole-heartedly welcomed, however, is the adjustable-height, or
“dropper”
seat post.
In fact, dropper posts have been embraced so enthusiastically that
riders are willingly shelling out hundreds of dollars to add up to a
pound of weight to their bike. Can the expense, both in cash and grams,
be worth the performance gains? Well, once you try one, you’ll likely
never want to ride without one again; which is why we present this guide
to dropper posts, with the goal of helping you decide which one is
right for you.
While the advantages of using a dropper post are many, there are only
two real negatives, but
they are notable: cost and weight. With the
most affordable posts costing $260, and the high-end offerings hovering
around $500, the price of entry into the dropper post market makes any
argument moot for many riders. Also, the act of weighing down your bike
with an extra 400 grams of metal and hydraulic fluid by replacing a part
that already does its job just fine is anathema to the dedicated XC
riders among us.
If you have been saving your pennies and don’t keep track of your
bike’s weight to the gram, then you are probably ready to enjoy the
benefits bestowed by dropper posts. In this writer’s opinion, the
dropper post is no less a game-changer than sticky rubber tire
compounds, enabling
increased overall speed, flow, and fun on any ride.
Lowering
seat posts for descending is nothing new, as the added clearance allows
you to get lower and farther back on your bike for better high-speed
control, the ability to use the length of your bike for optimal weight
distribution, and clearance on jumps and whoops. Dropper posts allow you
to lower your saddle on the fly, and also fine-tune saddle height for
“in between terrain,” which is flat enough to pedal but requires
maximized bike handling for the most fun. Plus, when short, steep,
technical sections appear on the trail, instead of dismounting before
and after to lower and raise your seat post, or conversely fumbling
through with a raised saddle, a flick of the thumb will have you
crouched and able to attack the section and immediately get on the gas
after. When climbing, instead of sliding up to the saddle’s nose on
short steep efforts, which effectively lowers your saddle height, some
riders drop the saddle a touch in order to stay seated on the
comfortable end of the saddle. Dropper posts enable you to optimize your
position on the bike in any situation, enabling better traction,
increased responsiveness, and maximizing fun!
While there are several important distinctions between dropper posts,
the most important feature to consider is the difference between fixed
and infinite positioning. Fixed posts generally have three preset
positions to choose from; fully extended, fully lowered, and somewhere
in the middle, usually closer to the top than the bottom. While three
positions is the norm, there is at least one manufacturer with a
four-position fixed post. Conversely, seat posts with infinite
adjustability can be positioned anywhere in the post’s range of travel.
These posts allow minute differences in saddle height for varied
terrain, and don’t require “hunting” to find the middle spot. Most fixed
position posts have to be finessed into the middle position—time which
could be spent pedaling—while infinite posts will immediately go
wherever you want them.
In
addition to deciding on an infinite or fixed travel post, you’ll have
to choose between internal/stealth versus external cable routing and
remote or post-mounted actuation. Here’s a hint for the latter—go with
the remote option. Remote actuation levers are mounted on the handlebars
next to the grips, making raising or lowering the post a risk-free,
immediately executable operation. Conversely, actuators mounted on the
seat post require you to take one hand off the bars and reach under your
saddle to lift a lever. This makes fine-tuning saddle height much
harder than it should be, discouraging use of the post. While actuator
location is up to you, your frame largely decides between internal or
external cable routing. If it’s equipped with an internal cable path, go
with a compatible post. Your frame will look much cleaner and you won’t
have to worry about cable rub marring your bike’s finish. If you decide
to go with an externally routed post, there are a few factors to weigh.
First, which location attachment is best? Generally, cables are either
attached at the seat post’s saddle clamp or on the seat post tube
itself, usually just above the frame’s seat post clamp. Attachment
points at the saddle clamp force the cable housing to move up and down
with the saddle. This can cause the housing to rub against your frame
during movement, or possibly make the cable to bend outward and contact
your leg or catch trailside debris when the post is compressed.
Attachment at the post’s tube fixes the cable housing in a permanent
position, free from movement when the saddle is raised or lowered. This
attachment lets you precisely fit housing to your frame and ensures the
housing will never rotate outward.
Next, decide on your travel needs, determined by frame size and
riding style. Longer travel bikes benefit from a longer travel seat
post. These bikes will
usually be tackling varied and technical terrain, which is easier to
negotiate with a lower center of gravity coupled with the ability to get
farther off the back of the bike. Larger sized frames will almost
always require longer travel posts to facilitate proper leg extension in
the raised position. Sometimes, 150 millimeter travel posts will be too
long for smaller sized frames. If weight is a concern, seat posts with
less travel, thus shorter, are generally lighter as well.
By now you are probably ready to lay down your credit card and wait
for your new post to arrive, but there’s one more item to discuss, and
that is the internal mechanism of your post; hydraulic, mechanical, or a
hybrid of the two. Full hydraulic systems, like the
Rock Shox Reverb,
require bleeding to maintain long-lasting, like-new performance. Don’t
let this scare you off, however, because the bleed procedure is easier
than a brake bleed. Hydraulic posts make up for the necessity of
bleeding by offering smooth, infinitely adjustable travel, and do not
require the use of a shift cable between the remote lever and post.
Mechanical posts use springs and locking mechanisms to vary travel, and
are usually in the fixed position category. Hybrid seat posts, such as
the
Kind Shock LEV and Integra, along with
Thomson Elite Dropper Posts
use mechanical actuation to open and close a hydraulic cartridge for
height adjustment. This set-up offers infinite adjustment, smooth
travel, and easy maintenance, since the hydraulic cartridge is closed
and does not require bleeding. Some hybrid posts, like the
Kind Shock e10,
feature an air/spring hybrid system. Cables are used to remote actuate
hybrid and mechanical posts, and are subject to the same degradation's in
performance as shifter cables. When deciding between hydraulic,
mechanical, or a hybrid post, consider whether you would rather change
cables every few months or perform a bleed twice a year.
Mountain biking is possibly the most fun you can have on two
wheels. There’s something incredibly satisfying about discovering new
trails from an altered vantage point while giving your knees and running
muscles a bit of a reprieve.
