34
by Eric Horn
SUDOCE
I
OLD MAN WINTER PART II
What to do if you never had a ramp in the
first place.
The winter months are upon us, meaning
less time to terrorize on the stick and more
time to rake leaves or shovel snow. Have you
ever thought about what you are going to do
on a rainy day? Your mom has already for-
bidden finger-skating on porcelain surfaces,
claiming you leave little black grind marks
on the lips. The new Powell video isn't out
yet, so I guess you could watch "I Dream
of Jeannie" or "Gun Smoke" reruns.
Nahhhhh. What about thinking? Heavy con-
cept? What about using your noggin to en-
vision and design a ramp of the near future?
Winter is an opportune time to start design-
ing a new ramp. In this article I'll go over
several design aids that may be helpful to
you when daydreaming about springtime
ramp construction.
SURFACE DISTANCE: COPING TO
COPING
Surface distance from lip to lip will be ab-
breviated as "So" to avoid further hyster-
ical confusion. The terms I will use involve
high school geometry. Give geometry your
best shot, as it is the key to any ramp design.
So is the actual surface distance along the
contours of the ramp from one lip edge to
the other (see illustration #1 below). The
physical components of ramp surface
distance are: two transitions, one flat bottom
section and two vertical sections. The key
point when calculating So is that the total
should be divisible by 8' (or as close as
possible), in order to minimize wasted 4' x
8' plywood sheets. Wasted plywood is
wasted money is wasted time and is simply
wasted. Below is a formula to calculate So:
So +2y + Zr
So Surface distance lip to lip
r
Don't ask, it's a button on your calculator.
Radius of transition y Amount of vertical
Z Flat bottom constant
When calculating the So of your propos-
ed ramp, you must keep these variables in
mind: radius of transition, amount of vertical
and flat bottom length. These variables are
usually decided upon by you and your
skating abilities as well as your wallet. If
you're a beginner, you'll probably want less
flat bottom and less vertical. If you're quite
the ripper, you'll probably want a lot of ver-
tical and proportionately more flat bottom.
Surface Area:
The surface area of a ramp is the actual
riding surface of the ramp. Surface area
becomes important when you start thinking
ILLUSTRATION #1
VERT
TRANSITIONS
FLAT BOTTOM
VERT T
about how many 4 x 8 sheets of ply are
needed to cover a ramp with one layer. To
calculate surface area, use the following
formula:
SA SoX (width of ramp)
When you decide how wide your ramp will
be, all standard factors should influence
your decision: money, space, skating abili-
ty, etc. Choose a width divisible by 4 to,
again, minimize wood waste. After you
calculate SA, divide the total SA by the total
square footage of one 4 x 8 sheet of ply,
which is 32 sq. ft.. This will give you the
number of 4' x 8' sheets needed for one
layer of whatever you choose to surface your
ramp with, whether it be exterior grade ply,
smooth masonite, polished steel or a com-
bo of all three.
SAMPLE CALCULATION:
radius-91. width 24t y 2' vert z=2
So (9)+2(2)+(29)
So 50.27 (round to 50.3)
Sa
So x width SA 50.3 x 24 SA 1207.22
of ply needed for 1 layer:
SA
1207.2
32
38 pieces of plywood for one layer.
37.72 (round to 38)
The tables at right will help you decide
how big you want your ramp to be and how
many sheets you'll need. A flat bottom con-
stant between 1 and 2.5 is given, which is
multiplied by transition radius to achieve op-
timum flat bottom length in relation to ver-
tical height. Since bigger transitions,
ellipses and cycloids are the present day
rage, I've listed calculations for ramps with
a 9' transition. Many different designs are
possible, but some may not be desirable or
economically feasible to you. Look them
over. If you desire a different transition.
raidus you can make your own tables using
the basic equations given above.
TRANSITION RIB SPACING:
Another important factor in design is tran-
sition rib spacing. I could bore you to death
with uniform building code restrictions,
deflecting calculations and all sorts of other
complicated stuff, but I won't. The editor
said, "Give it to them straight."
The critical impact zone for a ramp is the
lower % of the transition. It is here that the
spacing should be no larger than 8" on-
center (OC). I recommend 6". On the up-
per ½ of the ramp, the rib distance should
be 8" to 10" O.C. When making this deci-
sion, think of flexibility and strength, and use
a spacing that is a happy medium between
them. Also, when putting in 2 x 4 ribs make
sure you do it the right way. See illustration
#2. For ramp uprights, span-length between
centers should be no more than 6" O.C.
So there you have the basic ramp design
concepts. On that certain rainy day when
you pull the Ferris Bueller trip on your
parents, pull out that geometry book and let
your mind germinate the seedlings of a
modern-day ramp. Remember to deviate
from the norm and build what suits you and
your needs. After all, skaters are deviates of
the norm and always do what they want to
and not what is traditionally accepted. Un-
til later, thanks for your time, and
remember-geometry rips.
VERTICAL 1 ft.
Const
Surface So-s
Bottom Dat
9.0
1.25 11.25 415 52
1.75 15.75 46.0 58
2.25
VERTICAL 1.5 ft.
Botion
Const
10
20
35
21 26
37
"
41
4
45
47
40
Surface So-wide 20' wide 24 wide 28 wide
31
36
22
23
34
40
и
44
25 225 538 67
VERTICAL 2.0 ft.
27
41
47
Surface So-wide 20 wide 24
32
37
1.25 11.25 435 54 22
33
30
40
3
42
2.0
2.25 20.25 525 66 27 33
54.8
6.9
35
25
ILLUSTRATION #2
BACK VIEW OF RAMP
UPRIGHT SPACING
40
47
CONCRETE
JUNGLE
AIN'T DEAD YET
ALL MODELS INCLUDE
BEAST
FINAL SOLUTION
ALTERNATE TRUCK CHOICE:
POSTAGE AND HANDLING:
INDEPENDENT 159
LAND
AIR
..$39.95
TRACKER SIX TRACKS U.L.B.P.
GULL WING PRO.
$110.00
CLOTHING
DECK
$2.00
COMPLETE SET-UP $6.00
$6.00
$12.00
HOODED SWEATSHIRTS
.$24.00
SWEATSHIRTS
.$17.00
LONG SLEEVE T-SHIRTS
$13.50
T-SHIRTS
$10.00
STICKERS
$1.00
CALIFORNIA RESIDENTS ADD
6.5% SALES TAX
RIGHT
MODELS
AIN'T DEAD YET 9%" x 30"...$39.95
BEAST 9" x 29¾"
FINAL SOLUTION 9% x 30%".$39.95
NEW AND IMPROVED SHAPES,
CONCAVE AND GRAPHICS
COMPLETE SET-UPS:
ANY MODEL
THUNDER 159 OR VENTURE TRUCKS
VARIFLEX HARDWARE
GRIP TAPE
TRACKER RISER PADS
GMN ABEC 1 BEARINGS
BEARING SPACERS
POWELL RAT BONES 90A ....$100.00
SCREEN CHOICE:
AIN'T DEAD YET, BEAST,
FINAL SOLUTION
AIR ONLY AND PRE-PAID ONLY:
HAWAII, P.R., ALASKA, PO. BOXES,
APO'S, FPO'S
NO C.O.D.'S
PLEASE INCLUDE:
NAME, FULL ADDRESS, ZIP, AREA
CODE, PHONE
CONCRETE
JUNGL
1717 WALLER STREET
SAN FRANCISCO, CA 94117
(415) 751-8829
BEYOND
LAME
WAY
SKATE SHOP
(415) 386-0188
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