- Hey everyone.
My name is Seb Stott.
You're watching Pinkbike
and this is the Polygon Mt Bromo.
(upbeat techno music)
You may have already spotted that it's an E-bike
and I know you all love E-bikes
but the thing that's really interesting
about this one is the suspension.
Polygon have opted not to go
with their Naild REACT 2PLAY suspension system
seen on some of their previous models, but rather than going
for a Horse-link four-bar like everyone else,
they've actually gone for a six-bar suspension system.
It's got a pair of short links just there above the motor
which connect the mainframe to the swing arm
and form a four-bar linkage.
But then it's also got the seat stay and the rocker link
which are purely there to drive the shock.
They bring the total number of frame members up to six.
Although it looks different, the idea is somewhat similar
to the specialized Enduro or the Canyon Sender, for example,
and that there's a four-bar linkage
which purely dictates the axle path
and therefore the anti-squats
and anti rise that go along with that.
And then the other two links,
which in this case are the seat stay and the rocker link,
are designed purely to optimize the leverage curve
and so the progression of the suspension.
What that means in theory is that polygon can separate
the design constraints of how the bike pedals
from how the suspension kind of ramps up
as it goes through its travel.
Those two short links give it an instant center,
sometimes called the virtual pivot point,
which sits somewhere inside the motor housing.
And because there's no need for a physical pivot
behind the motor and along with that elevated chainstay,
that means they can shorten
the rear center quite considerably.
At 435 millimeters, this is about
the shortest rear center you'll find on any E-bike.
And in fact, if you look at the gap
between the tire and the motor,
this is probably as short as you could go
with the 29-inch rear wheel.
Now obviously a short chainstay has its downsides
in terms of keeping the front wheel loaded,
particularly on steep climbs or flat corners,
but with all that weight upfront
and with the really very long chainstay lengths
on some E-bikes, they can make riding
dynamically very difficult indeed.
And because there isn't a pivot point sat on top of
the motor, the anti-squat values aren't crazy high
so there's about 100% anti-squat or a bit more,
depending on what gear you're in and in my opinion,
you really don't want too much anti-squat on an E-Bike
because being able to pedal smoothly over rough terrain
is really half the fun.
It's 29-inch only, front and rear, in all four frame sizes
and there's 160 mm of travel at either end.
This is the top-spec model, the N8,
which retails for $5,000 USD.
For that you get a performance elite Fox Float X2 shock.
You get a Fox 38 with a grip damper
and you get pretty much a full XT drivetrain and brakes
just with a derailleur cassette.
You also get Shimano XT hubs
which is something you just don't see very much nowadays.
And then there's 35 mm internal width rims
with Schwalbe magic Mary tires in the 2.6 inch width
and the super gravity casing.
That's a big thumbs up for me.
I think too many bikes come
with lightweight tires that just
aren't tough enough for the job.
And I think the extra cushioning you get
from a 2.6 over the 2.35 inch version,
I really like that whether on an E-bike or not.
It uses the Shimano EP8 motor
with a 504 Wh internal battery
so you won't get quite as much range
as many of the latest E-bikes,
many of which have a 630 Wh battery or more.
Don't think that smaller battery makes it lightweight though
because this XL weighs 25 kilos exactly on my scales,
that's 55.1 pounds.
It's a full alloy frame with pretty sturdy wheels and tires.
So I don't think that weight is overly surprising.
It's in the same sort of ballpark
as other E-bikes in this category.
Geometry wise it's bang up-to-date, but nothing too radical.
You get a 64.5 degree head angle
and a 77 degree effect to seat angle, which is fairly steep.
It should help offset those short chainstays when climbing.
The reach figure goes up by 20 mm increments between sizes.
So there's 450 mm for the small,
then 470, 490 and 510 for this XL.
The wheelbase on this XL is 1,280 millimeters
so it's not outrageously long, but it's not short either.
So how does it ride?
Well, I've not had a chance to put much time on it yet
so stay tuned for a full review further down the line.
So that's the Polygon Mt Bromo.
Let us know what you think in the comments
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(upbeat techno music)