Light Weight: With the additional strength of
the SC7000 material, we were able to push the
limits of light weight aluminum alloy tubing. In
general, you will see about a 10% reduction in
frame weight when compared to our full UltraLite
frame. Remember too, that the UltraLite frame
is one of the lightest, most durable aluminum
frames you can get.
Durability: While light weight is good, durability
is paramount. Because SC7000 material is so
strong, and was designed for additional compliance,
the durability is excellent. Eastons fatigue
and impact testing shows a remarkable increase in
durability over standard frames.
With aluminum, fine elongated grains means
high performance. The photo-micro-graphs in
Figures 1 and 2 (next page) are cross sections of
welds using SC7000 welded with Scandium Filler
Rod and 7005 welded with 5356 filler rod. The
effects of Scandium in both the base metal (tube)
and weld bead are readily visible. The base metal
of the SC7000 material has extremely fine elongated
grains while the weld bead is characterized
by equally fine equiaxed grains. These fine grains
promote optimum properties including exceptional
yield strength and fatigue life.
Fabrication Instructions for Scandium Tube Sets
EASTON SPORTS, INC. 7800 HASKELL AVENUE, VAN NUYS, CA 91406 TEL: 818 782-6445 FAX: 818 782-2435 EASTONBIKE.COM
2
Sc7000
BASE
MATERIAL
WELD
BEAD
Figure 1: SC7000 Base Material and Scandium
Weld Rod
7005
BASE
MATERIAL
WELD
BEAD
Figure 2: 7005 Base Material and 5356 Filler Rod
SC7000 is indeed a remarkable product. The proprietary
Scandium alloys that Easton uses are just the
beginning. Eastons proprietary TaperWall process,
and extensive cold working take this material to a
higher level. Grain refinement, precise manufacturing
processes, and years of experience in frame tubing,
all add up to the most refined tubes available.
On top of all of this, the design of these tubesets is
beyond all others. Easton researched every element
of frame design when creating these tubes. The
engineering and design investments in these tubesets
is overwhelming.
Advanced materials, proprietary manufacturing
processes, and superior development and design all
add up to the Easton Advantage!
2.0 Frame Building Technical Information
SC7000 can be used successfully to build durable,
smooth riding frames. To ensure such characteristics
several safe-guards, construction techniques,
and thermal processes must be carefully followed.
2.1 Cleanliness
Cleaning tubes properly immediately prior to welding
is paramount to ensure joints with sufficient
structural integrity. Recommended practice is to
Scotch-Brite the ends of the tubes a minimum of
1.5 inches from the tube end. This should be followed
by chemical treatment with any of the commercially
available acidic solutions for aluminum.
Product: Aluma Kleen
Manufactured by: ABBOT CHEMICALS
11706 Sheldon Street
Sun Valley CA 91352
(818) 982-2707
Available from: Gordon Woods (and other Weld
Supply Distributors Nationwide)
7254 Coldwater Canyon
North Hollywood CA 91605
(818) 759-6900
If the tubes are left for more than one hour without
having been welded, it is advisable that they be
acid cleaned again. This
time is only a rough guideline
and may increase or decrease depending on
variables such as temperature and humidity.
2.2 Straightening
SC7000 is considerably stronger than either 7005
or 6061 and will therefore require more effort to
straighten. The thin wall SC7000 tubes can wrinkle
when high straightening loads are applied so
frames should be tacked/welded as straight as possible
to reduce the amount of post weld straightening
required.
Minor alignment after welding should be performed
as soon as possible while material adjacent
to the weld is in its softest state. SC7000 age-hardens
rapidly making alignment more difficult as
time advances. As tubes re-age-harden the force
necessary to straighten frames increases. This can
lead to damage to either the tube or the weld that
will not be easily detected and can shorten the life
of the frame.
EASTON SPORTS, INC. 7800 HASKELL AVENUE, VAN NUYS, CA 91406 TEL: 818 782-6445 FAX: 818 782-2435 EASTONBIKE.COM
Less than six hours is the recommended time for
frame alignment. If frames are built in sub-assemblies,
alignment should be done on each subassembly
within six hours.
To promote welding straight frames all mitered
gaps should be less than .030 inches.
2.3 SC7000 Filler Rod
The entire frame must be welded with Easton
Scandium Filler Rod, which has been formulated
to optimize the properties of the Scandium Tube
Kit. This includes the rear triangle. SC7000 frames
require different thermal processes than complete
7005 frames necessitating the use of Scandium
Filler Rod throughout the frame.
2.4 Weld Bead Treatment
2.4.1 Double Passes
Double passes across the weld bead (a technique
sometimes employed to smooth the bead look)
should not be employed. Violating this recommendation
will result in a dramatic decrease of tensile
properties in the area around the heat affected
zone.
2.4.2 Filleting Joints
Sanding or filing weld beads smooth is also not recommended.
2.4.3 Starts and Stops
Through rotary beam fatigue testing conducted in
Eastons Sports Lab of aluminum alloys that were
circumferentially welded, it was determined that
in nearly all cases, fatigue cracks leading to joint
failure will initiate at the weld starts/stops. Good
design and fabrication practice is to have start and
stop placement offset from the plane of the frame
where the stress is the highest by 90 degrees.
For example, at the head tube-down tube junction
the stress is the highest at the bottom of the head
tube. Therefore the starts and stops for this weld
should be placed on the side of down tube.
2.5 Frame Construction
2.5.1 Seat Tube Bottom Bracket Connection
As with any high-performance aluminum tube set,
it is imperative that the seat tube be completely
welded 360 degrees to the bottom bracket prior to
attaching the down tube or chain stays (see Figure
3). If this is not done, failure of the joint is likely.
2.5.2 Down/Top/Head Tube Connection
If there is any overlap between the Down and Top
Tubes at the Head Tube (as there may often be on
small frames) the Down Tube must be completely
welded to the Head Tube 360 degrees before attaching
the Top Tube (see Figure 4).
Figure 3: Proper Attachment of Seat Tube to
Bottom Bracket
Figure 4: Proper Attachment of Down Tube to
Head Tube
2.5.3 Weld Vent Holes
Vent holes should not drilled in any SC7000 tube
or 7005 Chain and Seat Stays. Venting of tubes
should be done at the intersection of two tubular
sections. For example, Chain Stays should be vented
through the Bottom Bracket Shell and Seat Stays
should be vented through the Seat Tube.
2.5.4 Cable Guides
If cable guides are to be welded on the tubes, they
must be a minimum of two inches from the
edge of
weld bead. They should also be placed on the thick
sections of the tubes. If attachment to thin wall is
3
EASTON SPORTS, INC. 7800 HASKELL AVENUE, VAN NUYS, CA 91406 TEL: 818 782-6445 FAX: 818 782-2435 EASTONBIKE.COM
necessary, it is recommended that rivets instead
of welding be used. Easton does not recommend
welding or riveting mounts on the underside of the
down tube.
2.5.5 Tube Crimping and Cold Working
SC7000 Main Tubes and 7005 Chain and Seat
Stays should not be cold worked in any manner.
Examples include crimping or dimpling Chain Stays
for more tire clearance or crimping tubes elliptical
at tube junctions. Easton tubing is supplied in
a thermal state that is designed for a post weld age
only. Cold working tubes prior to welding will dramatically
increase the susceptibility of the frame to
Stress Corrosion Cracking (SCC).
2.5.6 Frame Size Limits
SC7000 Road and ATB Tube Kits are designed
to accommodate a specific size range of frames.
Exceeding the size recommendations will compromise
frame life and stiffness. Frames larger than
those defined in Table 1 should not be fabricated
with SC7000 Catalog Tube Kits.
TABLE 1: SC7000 FRAME SIZE LIMITS
SC7000 Tube Kit Type Large Size Limit
Road Small Down Tube 56 cm
Road Large Down Tube 61 cm
ATB 20 in.
Note: Frame Size is measured Center Bottom Bracket
Shell to Top of Top Tube along Seat Tube axis.
2.5.7 Rivet Nut Installation
Due to the thin wall thickness in the center of the
SC7000 Down and Seat Tubes, proper installation
of Rivet Nuts used for water bottles is essential to
insure frame integrity. The following items must be
addressed:
Rivet Nuts must be designed to work on the grip
range of the SC7000 Tubes (see Table 2 for wall
thickness)
Rivet Nut Manufacturers installation torques must
be followed. Rivet Nuts must not be too loose or
too tight (see Figures 5 and 6 for an example of an
over-torqued Rivet Nut that lead to frame failure).
TABLE 2: CENTER WALL THICKNESS OF SC7000 TUBES
SC7000 Tube Description Center Thickness (in.)
ATB Down Tubes .035
ATB Seat Tubes .035
Large Road Down Tube .028
Small Road Down Tube .032
Road Seat Tubes .035
NOTE: Some Rivet Nuts may be installed on thicker
walls due to tube trimming and mitering. Always check
Easton Tube Drawings to verify wall thickness at rivet
nut location.
Figure 5: Example of Over-Torqued Rivet Nut that
Lead to Frame Failure
Figure 6: SEM Photograph Showing Mechanical
Deformation Caused by Over-Torqued Rivet Nut
NOTE: Some race frames use a Rivet Nut in the Top
Tube for Racing Number Attachment. The thin wall
of Road and ATB Top Tubes is .030 in.
4
EASTON SPORTS, INC. 7800 HASKELL AVENUE, VAN NUYS, CA 91406 TEL: 818 782-6445 FAX: 818 782-2435 EASTONBIKE.COM
WARNING!! Scandium Road and Mountain Tube
Kits are not designed for use with Water Bottle
Cage Mounted Lighting System Batteries.
2.6 Frame Identification
If stamping is to be used to identify frames (i.e. to
mark builders ID, customers name, or any other
serial number or identification) it should only be
applied to the bottom of the Bottom Bracket Shell
at least 1 inch from any weld beads. Stamping
should never be done on any other areas of the
frame.
2.7 Post-Weld Thermal Processing
2.7.1 Post Weld Age
Correct Post Weld Aging is absolutely critical!!
Failure to do so will result in reduced properties
and a susceptibility to Stress Corrosion Cracking
(SCC). The required post weld age is:
Step 1: Allow oven temperature to reach 275° F
+/- 5° F
Step 2: Insert frame for 5 hours +/- 5 minutes at
275° F +/- 5° F
Step 3: Change oven temperature to 300° F +/- 5°
F. Note: Oven must ramp to 300° F in no more
than 10 minutes.
Step 4: 2 hours +/- 5 minutes at 300° F +/- 5°.
Step 5: Remove frame from oven and allow to
cool to ambient without fan assist.
WARNING!!! Failure to conduct the recommended
age will lower frame strength and may promote
frame cracking, which can cause premature frame
failure.
2.7.2 Solution Heat Treatment
Due to the alloy mix and material properties, post
weld solution heat treating should not be performed.
SC7000 frames can not be water quenched,
the most common heat treating process path. The
only way that SC7000 frames can be solution heat
treated is with a company that has a great deal of
experience performing forced air quenches. If this
process is to be employed Easton recommends
using a source that has been qualified to perform
this service.
Newton Heat Treating Company
19235 E. Walnut Dr. North
La Puente CA 91748
(626) 964-6528
Contact: Greg Newton
Easton assumes no responsibility for solution heat
treating of SC7000 frames at other sources.
2.7.3 Checking Thermal Processing Using
Conductivity Measurement
Checking material hardness is not the recommended
way to correlate correct thermal processing and
material properties as they can often be misleading.
Easton recommends using an electrical conductivity
meter to verify frame thermal processing. These
meters can be purchased from:
HOCKING NDT Ltd.
Inspec House
Camp Road
St. Albans, Herts
UK, AL1 5HL
Tel.: +44(0) 1727 795500
FAX: +44(0) 1727 795400
To find a distributor near you check the World
Wide Web at:
http://www.hocking.com
Product: AutoSigma 3000
STAVELY NDT
Customer Support: (509) 736-2751 or email:
[email protected]
World Wide Web:
http://staveleyndt.com
Product: Nortec 1700
K.J. Law Engineers, Inc.
42300 West Nine Mile Rd.
Novi Michigan 48375 USA
Tel.: (248) 347-3300
Toll Free: (800) 521-5245
FAX: (248) 347-4113
E-Mail:
[email protected]
World Wide Web:
http://www.kjlaw.com
Product: Verimet M4900C
5
EASTON SPORTS, INC. 7800 HASKELL AVENUE, VAN NUYS, CA 91406 TEL: 818 782-6445 FAX: 818 782-2435 EASTONBIKE.COM