TECH AREA
Tech Doctor
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The Kona Way

At Kona, our core group has spent a ton of hours owning, managing and working in bike shops.
And if there's one thing that's stuck with us from those days, it was servicing bikes that were
constantly breaking down. We don't want to tinker and fix, we want to ride. So we build bikes that
not only work well, but last a real long time.

That's why we're so attached to the Kona Walking Beam 4-Bar Linkage system, found across our
entire line of dual suspension bikes. Since we first introduced the platform in 1996, we've been tweaking
and honing, refining and testing, in the effort of perfecting what we feel is one of the most functional,
durable and performance-oriented dual suspension platforms ever invented. That’s why you see
versions of our 4-Bar linkage on everything from the Hei Hei XC Race Bike to our Stab Supreme.


Coilair

We've stood by it because it works damn good. Here's why....

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Cornerstone

works
At Kona, how well a bicycle works is extremely important.
We know this because our company is chock full of riders,
racers and freeride athletes. Whether it's Ryan Trebon or
Barry Wicks winning back-to-back US National
Championships, Paul Bass dominating a slopestyle
course, Andreu Lacondeguy hucking double backflips or
Fabien Barel winning two World Downhill Championships,
we know how a good bike should ride. It needs lateral
stability, good rear wheel tracking and supple travel. Not
only that, it must excel at the type of riding it was
designed for.

Durability
At Kona, it's also very important for us to design bikes
that perform at a high level for a long period of time. For
us, durability is critical. From the staggering amount of
vertical our fleet of bike park rentals has to endure every
year, to the kid who's saved all his lunch money to buy a
Stinky. Consumers deserve a bike that can go and go…
then go a little more.

 

Grant

Why
To start, 4-Bar suspension is fairly common. It's not solely
confined to the bicycle industry, which speaks to its range
as a suspension system. As it applies to bicycles, 4-Bar is
made of four components: the rocker arm, seat tube,
chain stay, and the seat stay. You can have 4-Bar systems
that are either internally or externally dampened. We choose
to externally dampen ours by having the shock positioned
outside of the linkage. At Kona, 4-Bar achieves our design
cornerstones of Function and Durability exceedingly well.

....Here's why

 

Why?

Pivot

Pivot
Anytime you have a pivot in anything, there's
side-to-side movement, or tolerance. It's what
allows the pivot to move freely. When you have
pivots that are close together, like in more
complicated multi-pivot designs, the side-to-side
movement in those pivots becomes amplified,
what's called tolerance stacking. Our 4-Bar system
allows us to keep the pivots as far away from
each other as possible thus minimizing tolerance
stacking. Ultimately, it equates to less lateral flex,
or slop in the rear end, as well a significant
decrease in bearing and bushing wear.

Shock
Another benefit of our 4-Bar system is minimized side load on the rear shock. If you've got close pivot points
and/or the shock positioned so that it is exposed to lateral forces, you've got side load on the shock. Side load
causes resistance, which negatively impacts performance. Side load also causes premature seal failures.
With our 4-Bar system the rear shock is protected from side-to-side forces. As a result, we have a super low
rate of shock problems, as well as a very responsive feel to the rear suspension.

Design
By making adjustments to the orientation of the rear shock, with
4-Bar we're able to fine-tune suspension characteristics. For XC
bikes, we're can take an inherently progressive air shock and make
the suspension more linear, allowing the rider to benefit from all of
the bike's travel. For downhill bikes, like our Stab, we can make an
inherently linear coil shock more progressive, reducing the chances
of bottoming out the suspension and damaging the bike. This
tunability—which is characteristic of the Kona 4-Bar design—
allows us to achieve the optimum performance of all our
suspension designs.

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Virtue

Faux
In some magazines you may see our 4-Bar linkage called, “faux bar”. Often, they call it faux bar because it
doesn't have a Horst-Link. The fact is, you don't need a Horst-Link to have a 4-Bar system. Here's why. The
Horst-Link is supposed to modify the wheel path by taking the dropout pivot and locating it on the chainstay, in
front of and below the rear dropout. This location is supposed to allow the wheel to travel a little more vertically.
However, the difference in wheel path is almost nothing—maybe 3 mm if you had a really exaggerated Horst-
Link. On top of that, if it really is a vertical path, you get more chain elongation, which leads to that uneven,
Biopace feel when pedaling.

As well, when you have pivots on chainstays, every time you put power or breaking force on the rear wheel,
huge forces go through those pivots. Keep in mind these pivots are already located on a weak part of the bike.
In our system, the rear pivots are located on the seatstays above the rear dropouts. Not only are they subjected
to less force, we're able to weld the dropouts directly to the chainstays, making the rear end much more stable.

Truth be told, Horst-Link suspension was originally designed for motorcycles. You won't find the system on
any motorcycles today, simply because it doesn't work


There are a lot of companies out there trying to minimize brake jack—when rear suspension is adversely
affected by rear braking. New pivot placements and suspension designs fueled by millions of dollars of R&D
fail to do what floating calipers do on our long travel bikes, which is to eliminate brake jack completely. You
don't want to simply reduce it by 15%-to-25% like most new suspension technologies claim. You want to
eliminate it entirely. From our research and testing, the only system that accomplishes this objective is a floating
caliper rear brake system. That's the fact Jack.

However, we realize that floating calipers aren't for everyone. You'll notice many of our Clump riders don't use
them. When World DH Champion Fabien Barel raced for us, his bike had two brake set-ups. one eliminated
brake jack, the other accentuated brake jack .


Brake Jack

 

Many riders find themselves in excessively rough terrain like
that found in bike parks. Floaters dramatically increase the
riding performance of our bikes in this environment because
they kill brake jack completely. And that's what our D.O.P.E.
floating caliper system is all about, providing different riding
characteristics to our long travel dual suspension bicycles.

Floating calipers are best suited for longer travel bikes designed
to be ridden in harsh conditions. Bikes designed for XC racing
and riding don't reap the same benefits from a floating caliper
system, that's why you won't find floaters on Kona bikes with less
than six inches of travel. (29-2 illustration or image of Hei Hei Supreme)

Experienced riders who tend to brake when the ground is smooth and let the bike roll through rough terrain,
doing 70% of their braking with the front brake, may also not find a need for a floating caliper system. No
problem. All our Kona long travel dual suspension bikes are available with or without floating calipers.

Bearings
Whether we use bearings or bushings has to do with pivot movement. If there's a lot of movement in the pivot,
we go with a bearing. If movement is minimal, we go with bushings, which are underrated these days. Bushings
are low on stiction, have incredible longevity and weigh significantly less than bearings. Because our 4-Bar
design distributes pivot forces so well, we've always had very limited replacement of bearings or bushings, even
on our bike park rental bikes.

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Work For Us
At Kona, we want our consumers to have a lot of good experiences without a lot of bad experiences. 4-Bar
delivers on this objective year in, year out. We haven't pursued more complicated, multilink suspension designs
because, in most cases, we don't see the need. They don't necessarily jive with our philosophy when it comes
to what a dual suspension bike should do.

At Kona we want the bike to remain active when you're climbing. When it attempts to incorporate a platform, we
find the rider can't use compression in the rear travel to get up and over something. You're either waiting for the
shock to get into the active part of the travel or forcing it to get there, making the bike less predictable. Not good.

There are a lot of bike designs out there that don't last, with a ton of bike consumers out there wondering why
they bought some overly complicated contraption that's outdated and beat down in a couple of years. But the
next time you're out on the trails, take a look around and see how many old Kona's there are out in the woods
of the world. You'll be surprised.

We, however, are not.

Magic Link
Kona's tried and true 4-Bar rear suspension. Click Here.

 


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