So how do manufacturers come up with
track designs? SnoWest Magazine asked Yamaha some of these
questions regarding its new 162-inch Ascent track found on the 2012
Nytro MTX 162 and not only did we get answers, Yamaha gave us a
little peek at how it’s done.
A Successful History
Yamaha and Camoplast have collaborated
on more than one innovative track design over the years. Among the
highlights is the Rip Saw, which has been one of the best short-lug
tracks on the market since it debuted in 2005. As soon as the
exclusivity agreement expired, pretty much every OEM had at least one
trail sled that spun this track as a stock part.
Yamaha also worked with Camoplast to
develop the Maverick deep snow track. The guys at Yamaha said the
Maverick track worked very well for what it was designed to do, but
suffered from poor public perception.
“The Maverick got a bad rap with the
mountain guys, which was unfortunate,” Yamaha snowmobile product
manager Rob Powers said. “It’s a great deep powder and soft snow
track and it climbs like crazy in those conditions. But under
extended trail and hard snow use, the lugs would bend and not give
the traction some guys were expecting on acceleration.”
It was a classic conundrum for product
engineers: the very design aspects of the track that led to its sweet
deep snow and climbing performance, the ability of the lugs to flex
and bend, were the same ones that turned out to handicap its broader
consumer acceptance. More specifically, the columns molded in the
track didn’t provide the forward acceleration riders were looking
for on hardpack.
Back To The
Collaborative Drawing Board
When Yamaha and Camoplast began work to
create the Maverick’s replacement, they knew they would have to
eliminate the unpopular aspects of the track but not abandon the key
design elements they felt made it work so well in deep snow.
In fact, there were many qualities of
the Maverick they wanted to retain.
“When the mountain development team
set out to design the next track, we knew we wanted to keep the
Maverick’s excellent soft snow performance, climbing ability and
light weight,” Powers said. “But there were definitely targets
for improving the track as well. We needed to have better durability,
especially in the base areas of the lugs, without losing that
flexibility that works well in powder. We also felt we could have a
more versatile, consistent track for riding on the trails when a guy
is heading up to his favorite bowls and hills.”
At its foundation the new track would
have the same specs as the Maverick, a 3-inch pitch, 162-inch length
and 2.25-inch lugs and it would be a single-ply design. Ideally the
track would keep the lift qualities of the Maverick track lug, using
the wide center belt of the track to provide lift, while improving
forward acceleration and durability.
Track Science
There is more to designing a track than
just sticking funky-shaped lugs on it. In fact, there’s a definite
science to it. For example, with the Ascent track the total area of
lug surface was figured into the design. To increase lug durability
the new design called for 400 square inches of lug surface vs. 338
square inches found on the Maverick. This basically spreads the load
across a broader area, taking stress off each individual lug.
The rubber compound figures in too, and
Yamaha took advantage of a new compound Camoplast had engineered that
showed better performance regarding “lug set” while retaining the
same durability. It was lug set that dogged the Maverick track. The
lugs folded over to provide lift like they were designed, but over
time they stopped wanting to return to their original shape. The new
compound is also less prone to cracking or heat issues.
A larger factor in eliminating the lug
set problem and hitting the lug durability target was a new V-shaped
notch design at the tips of the lugs designed to fold back at a
20-degree angle but not take a set. The lug shape would also be
designed so it would force snow to the center of the track for the
most flotation. Lastly, the towers that supported the lugs on the
Maverick would be redesigned to spread loads more evenly to mitigate
cracking and tearing.
Performance Is In The
Details
The Ascent is a track unlike any ever
designed. The first thing you notice is the lugs reach from the edge
of the track all the way to the center. There are no “center lugs”
or “side lugs.” The lugs are designed to force snow to the center
of the track and the track actually builds its own dense base of
packed snow to provide lift and acceleration in deep or soft snow.
One design element that is consistent
from Maverick to Ascent is the 3-inch pitch.
“Our testing showed us that the wider
pitch is the best design in terms of packing the snow for
acceleration and flotation,” explained Powers. “We also tried a
2.86-inch pitch version of the Ascent track and it did not perform as
well.”
The next thing you notice is there are
no pronounced columns like the Maverick had; it looks like there are
just lugs. But the lugs have support columns built into them that
provide support on the base two-thirds of the lug for forward
acceleration. This is a noted difference from the Maverick design
which placed its pronounced columns only at the ends of the lugs.
Also, the columns in the center of the Ascent track are designed to
“migrate” to the edge to reduce stress at the base of the lug.
Finally, the columns are only placed on the backside of the lugs to
limit tension effects when the track is under load.
The top third of the lug controls lift.
There are V-notches cut into the top third of the lug that allow the
tips to fold back at a 20-degree angle to provide lift, but the
notches and the lug are shaped such that the lugs will return to
their original shape and not take a set. As for weight, the total
package is every bit as light as the Maverick.
Proving It
Yamaha tested the Ascent side-by-side
with the Maverick and what it considered the best competitive track,
the Power Claw, and it consistently outclimbed both of them. Its deep
snow performance was notably better than them as well. In fact,
Camoplast and Yamaha reps both think the new track is a huge step
forward in the world of mountain tracks.
“You ride the Maverick, the Power
Claw and the Ascent side-by-side and you can feel how much better the
Ascent works,” Powers said. “Camoplast told us they feel this is
the best mountain track they make. On our end, we made a big
improvement with the Nytro MTX 162 basically with a simple track
swap, so that’s a big deal for us.”
During the photo shoots last February
and March, the SnoWest SnowTest staff was able to ride the
2012 Nytro MTX and we found the sleds to be the best-riding Yamaha
mountain sleds to date and at the top of the heap for pure climbing
machines.
What the Rip Saw track did for
flatlanders, we think the Ascent is going to do for mountain guys.
Yamaha and Camoplast have set another
highmark with the Ascent track.
