  United States Court of Appeals
      for the Federal Circuit
                ______________________

                FOX FACTORY, INC.,
                     Appellant

                           v.

                     SRAM, LLC,
                       Appellee
                ______________________

                 2018-2024, 2018-2025
                ______________________

    Appeals from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in Nos. IPR2017-
00118, IPR2017-00472.
                 ______________________

              Decided: December 18, 2019
                ______________________

    ERIK R. PUKNYS, Finnegan, Henderson, Farabow, Gar-
rett & Dunner, LLP, Palo Alto, CA, argued for appellant.
Also represented by ARPITA BHATTACHARYYA, ROBERT F.
MCCAULEY; JOSHUA GOLDBERG, DANIEL FRANCIS
KLODOWSKI, Washington, DC.

   RICHARD BENNETT WALSH, JR., Lewis Rice LLC, St.
Louis, MO, argued for appellee. Also represented by
MICHAEL HENRY DURBIN, MICHAEL JOHN HICKEY.
               ______________________
2                                FOX FACTORY, INC. v. SRAM, LLC




    Before PROST, Chief Judge, WALLACH and HUGHES,
                     Circuit Judges.
PROST, Chief Judge.
    Appellant FOX Factory, Inc. (“FOX”) appeals the deci-
sions of the Patent Trial and Appeal Board (“Board”) in two
inter partes reviews (“IPRs”) of claims 1–6 and 13–19 (“the
challenged claims”) of U.S. Patent No. 9,182,027 (“the ’027
patent”). The Board found that the prior art references as-
serted by FOX disclose all the limitations of the ’027 pa-
tent’s independent claims and that a skilled artisan would
have been motivated to combine the asserted prior art. The
Board nevertheless concluded, based on its analysis of sec-
ondary considerations, that FOX had not shown that the
challenged claims would have been obvious. We have ju-
risdiction pursuant to 28 U.S.C. § 1295(a)(4)(A) (2012). For
the reasons below, we vacate and remand for further pro-
ceedings.
                             I
                             A
    Bicycle chainrings are the toothed disks to which the
bicycle crankarms are attached, collectively forming the
crankset. Pedaling the crankarms rotates the chainring,
which engages with and rotates the chain. Chains can be
susceptible to disengaging from the chainring. This prob-
lem is especially prevalent with geared bicycles, which can
experience severe changes in chain tension and energy mo-
tion of the chain, particularly when riding over rough ter-
rain. Bicycles have employed extraneous structures, such
as chain guides, to improve chain retention.
    SRAM, LLC (“SRAM”) owns the ’027 patent, which
generally covers an improved chainring structure that bet-
ter maintains the chain, obviating the need for extraneous
structures. For instance, the ’027 patent discloses a chain-
ring with alternating narrow and wide tooth tips, which al-
legedly improves chain retention because the narrow and
FOX FACTORY, INC. v. SRAM, LLC                               3



wide teeth better fit inside the inner and outer chain links,
respectively. In addition, the ’027 patent discloses teeth
offset from the center of the chainring, which also purport-
edly improves chain retention by providing “better guiding
of the chain to one side of the chainring.” Appellee’s Br. 8
(quoting ’027 patent col. 6 ll. 8–13).
    The independent claims of the ’027 patent—claims 1,
7, 13, and 20—recite a chainring with alternating narrow
and wide tooth tips and teeth offset from the center of the
chainring. Claims 7–12 and 20–26 generally cover tooth
tips offset toward the body of the bicycle (“inboard offsets”),
and claims 1–6 and 13–19 require teeth offset away from
the body of the bicycle (“outboard offsets”). Claim 1 is rep-
resentative of the “outboard offset” independent claims:
    1. A bicycle chainring for engagement with a
    drivetrain, comprising:
    a plurality of teeth formed about a periphery of the
    chainring, the plurality of teeth including a first
    group of teeth and a second group of teeth, each of
    the first group of teeth wider than each of the sec-
    ond group of teeth and at least some of the second
    group of teeth arranged alternatingly and adja-
    cently between the first group of teeth, wherein
    each of the plurality of teeth includes a tooth tip;
    wherein a plane bisects the chainring into an out-
    board side and an inboard side opposite the out-
    board side; and
    wherein at least the majority of the tooth tip of at
    least one of each of the first and second groups of
    teeth is offset from the plane in a direction toward
    the outboard side of the chainring.
’027 patent claim 1. Claim 7 is representative of the “in-
board offset” independent claims:
4                               FOX FACTORY, INC. v. SRAM, LLC




    7. A bicycle chainring for engagement with a drive
    chain, comprising:
    a plurality of teeth formed about a periphery of the
    chainring, the plurality of teeth including a first
    group of teeth and a second group of teeth, each of
    the first group of teeth wider than each of the sec-
    ond group of teeth and at least some of the second
    group of teeth arranged alternatingly and adja-
    cently between the first group of teeth, wherein
    each of the plurality of teeth includes a tooth tip;
    wherein a plane bisects the chainring into an out-
    board side and an inboard side opposite the out-
    board side; and
    wherein at least the majority of the tooth tip of at
    least one of each of the first and second groups of
    teeth is offset from the plane in a direction toward
    the inboard side of the chainring.
Id. at claim 7.
    The ’027 patent specification discloses additional
chainring features that are not recited by the independent
claims. Like the features claimed, each of the disclosed but
non-claimed features contribute to improving chain reten-
tion. For example, the specification discloses forwardly
protruding tip portions that “function[] to engage a chain
link earlier than a chain lacking the tip portion and pro-
vide[] better guiding of the chain.” ’027 patent col. 5 ll. 47–
51; see also id. at fig.5. The specification also discloses a
“hook feature 78 . . . that may be formed on the rear flank
70 of each” tooth and “may cooperate with the tip portion
76 to provide better guiding of the chain.” Id. at col. 5 ll.
52–55; see also id. at fig.5. The specification further dis-
closes “inner link-receiving recesses.” Id. at col. 5 ll. 26–44;
see also id. at figs.5, 7. Furthermore, the ’027 patent ex-
plains that the narrow and wide teeth preferably fill at
FOX FACTORY, INC. v. SRAM, LLC                                5



least 80% of the axial distance of the corresponding space
in the chain link (“>80% gap filling”). Id. at col. 4 ll. 19–41.
    SRAM also owns U.S. Patent 9,291,250 (“the ’250 pa-
tent”), which is a continuation of the ’027 patent and in-
cludes claims reciting a chainring with alternating narrow
and wide teeth and wide teeth with >80% gap filling. ’250
patent claim 1; see also J.A. 5270, 5282. In separate IPR
proceedings, SRAM stated that this “combination of fea-
tures” claimed in the ’250 patent, “amongst several others
disclosed in the ’250 patent, leads to a chainring that will
retain a chain in even the worst conditions.” J.A. 5282–83.
SRAM also explained that the >80% gap filling feature “al-
lows the inventive chainring to better retain the chain un-
der many conditions and amounts to the ‘heart’ of the
challenged ’250 patent claims combined with the narrow
and wide tooth configuration.” J.A. 5284. SRAM further
described the >80% gap filling limitation as “critical.” J.A.
5289.
    SRAM sells thirteen different versions of its “X-Sync”
chainrings. It is undisputed that twelve of the thirteen ver-
sions embody the inboard offset claims and the thirteenth
version embodies the outboard offset claims.
                               B
    FOX filed two petitions collectively requesting inter
partes review of claims 1–26 of the ’027 patent. One peti-
tion requested inter partes review of the outboard offset
claims, and the other requested review of the inboard offset
claims. Here, we discuss the Board’s findings in IPR 2017-
00472, which relate to the outboard offset claims. We note,
however, that the Board made similar findings in IPR
2017-00118 with respect to the inboard offset claims, in-
cluding with respect to secondary considerations. See FOX
Factory, Inc. v. SRAM, LLC, IPR2017-00118, 2018 WL
1633537, at *3–18 (P.T.A.B. Apr. 2, 2018).
6                              FOX FACTORY, INC. v. SRAM, LLC




    The Board found that Japanese Utility Model No. S56-
42489 (“JP-Shimano”) and U.S. Patent No. 5,285,701
(“Parachinni”) together disclose every limitation of the out-
board offset independent claims and that a skilled artisan
would have been motivated to combine the references.
FOX Factory, Inc. v. SRAM, LLC, IPR2017-00472, 2018
WL 1889561, at *3–7 (P.T.A.B. Apr. 18, 2018) (J.A. 1–70)
(“Board Decision 472”). The Board determined that JP-
Shimano discloses the claimed narrow and wide teeth, and
Parachinni discloses the claimed outboard offset. Id. at *3–
5. The Board also found that a skilled artisan would have
been motivated to combine the references because the
skilled artisan would have recognized that the combination
of the two features would improve chain retention better
than either feature alone. Id. at *5–7.
    Nevertheless, the Board determined, based on its anal-
ysis of secondary considerations, that FOX had not shown
that the challenged claims would have been obvious. Id. at
*21. SRAM submitted secondary considerations evidence
pertaining to its X-Sync products. The Board determined
that SRAM was entitled to a presumption of nexus between
the challenged outboard offset claims and secondary con-
siderations evidence pertaining to SRAM’s X-Sync prod-
ucts, subject to two limitations. Id. at *7–10.
    First, the Board stated that evidence of secondary con-
siderations “specifically directed” to either an inboard or
outboard offset X-Sync product is only entitled to a pre-
sumption of nexus with the claims reciting the same type
of offset. Id. Second, the Board explained that the pre-
sumption of nexus only applies when a product is “coexten-
sive” with a patent claim. Id. at *7. The Board interpreted
the coextensiveness requirement to mean only that the
claims must broadly cover the product that is the subject of
the secondary considerations evidence. Id. at *9–10.
Through that lens, the Board explained that SRAM’s sec-
ondary considerations evidence pertaining to a specific X-
Sync product or component (chainring, crankset, or
FOX FACTORY, INC. v. SRAM, LLC                            7



drivetrain) is only coextensive with the claims broadly cov-
ering that particular component. Id. at *10–11. For in-
stance, in the Board’s view, SRAM’s independent claims,
which cover a chainring, are only coextensive with sales or
industry praise of X-Sync chainrings, not sales or industry
praise of X-Sync cranksets or drivetrains. Id. at *11.
    FOX argued that SRAM’s products are not coextensive
with the challenged claims because the products include
numerous unclaimed features. Id. at *9. The Board re-
jected this argument, reasoning that “[u]nclaimed features
do not prevent the presumption of nexus, but they may be
the basis for rebutting the presumption.” Id.
    FOX also argued that, under this court’s decision in
Therasense, Inc. v. Becton, Dickinson & Co., 593 F.3d 1289
(Fed. Cir. 2010), vacated on other grounds, 374 F. App’x 35
(2010), SRAM’s products are not coextensive with the inde-
pendent claims because the X-Sync products also embody
the claims of additional patents that cover a different in-
vention than the claims of the ’027 patent. Board Decision
472, at *9. The Board also rejected this argument. The
Board reasoned that, under Therasense, presuming nexus
is only inappropriate if the products also embody one or
more claims of a prior art patent. Id. However, the Board
observed that FOX relied only on continuations of the ’027
patent.
    Weighing the evidence, the Board determined that
FOX could not rebut the nexus presumption, and due to
SRAM’s “extremely strong overall showing of objective in-
dicia of non-obviousness,” FOX had not shown by a prepon-
derance of the evidence that the challenged claims would
have been obvious. Id. at *21. FOX appealed the Board’s
obviousness determinations.
                             II
    “We review the PTAB’s factual findings for substantial
evidence and its legal conclusions de novo.” Redline
8                                 FOX FACTORY, INC. v. SRAM, LLC




Detection, LLC v. Star Envirotech, Inc., 811 F.3d 435, 449
(Fed. Cir. 2015) (citation omitted). “Substantial evidence
is something less than the weight of the evidence but more
than a mere scintilla of evidence,” meaning that “[i]t is such
relevant evidence as a reasonable mind might accept as ad-
equate to support a conclusion.” In re NuVasive, Inc., 842
F.3d 1376, 1379–80 (Fed. Cir. 2016) (internal quotation
marks and citations omitted). “If two inconsistent conclu-
sions may reasonably be drawn from the evidence in rec-
ord, the PTAB’s decision to favor one conclusion over the
other is the epitome of a decision that must be sustained
upon review for substantial evidence.” Elbit Sys. of Am.,
LLC v. Thales Visionix, Inc., 881 F.3d 1354, 1356 (Fed. Cir.
2018) (internal quotation marks, brackets, and citation
omitted). Obviousness is a legal question based on under-
lying fact findings. In re DBC, 545 F.3d 1373, 1377 (Fed.
Cir. 2008).
                              A
    On appeal, FOX contends that the Board applied the
wrong standard for determining whether SRAM was enti-
tled to a presumption of nexus between the challenged
claims and SRAM’s evidence of secondary considerations.
We agree.
                              1
    A patent claim is invalid “if the differences between the
claimed invention and the prior art are such that the
claimed invention as a whole would have been obvious be-
fore the effective filing date of the claimed invention to a
person having ordinary skill in the art to which the claimed
invention pertains.” 35 U.S.C. § 103 (2012). 1 Obviousness



    1   Congress amended § 103 when it enacted the
Leahy-Smith America Invents Act (“AIA”). Pub. L. No.
112-29, § 3(c), 125 Stat. 284, 287 (2011). Because the ’027
FOX FACTORY, INC. v. SRAM, LLC                               9



“is a question of law based on underlying findings of fact.”
In re Gartside, 203 F.3d 1305, 1316 (Fed. Cir. 2000). Those
underlying findings of fact include: (1) “the scope and con-
tent of the prior art,” (2) “differences between the prior art
and the claims at issue,” (3) “the level of ordinary skill in
the pertinent art,” and (4) the presence of evidence of sec-
ondary considerations, such “as commercial success, long
felt but unsolved needs, failure of others,” and unexpected
results. Graham v. John Deere Co. of Kan. City, 383 U.S.
1, 17 (1966); see United States v. Adams, 383 U.S. 39, 50–
52 (1966). In assessing the prior art, the PTAB also “con-
sider[s] whether a [skilled artisan] would have been moti-
vated to combine the prior art to achieve the claimed
invention and whether there would have been a reasonable
expectation of success in doing so.” In re Warsaw Orthope-
dic, Inc., 832 F.3d 1327, 1333 (Fed. Cir. 2016) (internal quo-
tation marks, brackets, and citation omitted).
      In order to accord substantial weight to secondary con-
siderations in an obviousness analysis, “the evidence of sec-
ondary considerations must have a ‘nexus’ to the claims,
i.e., there must be ‘a legally and factually sufficient connec-
tion’ between the evidence and the patented invention.”
Henny Penny Corp. v. Frymaster LLC, 938 F.3d 1324, 1332
(Fed. Cir. 2019) (quoting Demaco Corp. v. F. Von Lang-
sdorff Licensing Ltd., 851 F.2d 1387, 1392 (Fed. Cir. 1988)).
“The patentee bears the burden of showing that a nexus
exists.” WMS Gaming Inc. v. Int’l Game Tech., 184 F.3d
1339, 1359 (Fed. Cir. 1999). “To determine whether the
patentee has met that burden, we consider the correspond-
ence between the objective evidence and the claim scope.”
Henny Penny, 938 F.3d at 1332.
    As first recognized in Demaco Corp. v. F. Von Lang-
sdorff Licensing Ltd., a patentee is entitled to a rebuttable


patent has an effective filing date after March 16, 2013, the
AIA applies. See id. § 3(n)(1), 125 Stat. at 293.
10                            FOX FACTORY, INC. v. SRAM, LLC




presumption of nexus between the asserted evidence of sec-
ondary considerations and a patent claim if the patentee
shows that the asserted evidence is tied to a specific prod-
uct and that the product “is the invention disclosed and
claimed.” 851 F.2d at 1392 (emphasis added). That is, pre-
suming nexus is appropriate “when the patentee shows
that the asserted objective evidence is tied to a specific
product and that product ‘embodies the claimed features,
and is coextensive with them.’” Polaris Indus., Inc. v. Arc-
tic Cat, Inc., 882 F.3d 1056, 1072 (Fed. Cir. 2018) (quoting
Brown & Williamson Tobacco Corp. v. Philip Morris Inc.,
229 F.3d 1120, 1130 (Fed. Cir. 2000)). Conversely, “[w]hen
the thing that is commercially successful is not coextensive
with the patented invention—for example, if the patented
invention is only a component of a commercially successful
machine or process,” the patentee is not entitled to a pre-
sumption of nexus. Demaco, 851 F.2d at 1392.
    We have reaffirmed the importance of the “coextensive-
ness” requirement in subsequent opinions. See, e.g.,
SightSound Techs., LLC v. Apple Inc., 809 F.3d 1307, 1319
(Fed. Cir. 2015) (“If a product both embodies the claimed
features and is coextensive with the claims at issue, a
nexus is presumed. In other words, a nexus exists if the
commercial success of a product is limited to the features
of the claimed invention.” (citation and quotation marks
omitted)); Therasense, 593 F.3d at 1299. 2 Whether a prod-
uct is coextensive with the patented invention, and there-
fore whether a presumption of nexus is appropriate in a
given case, is a question of fact.



     2  Although the panel opinion in Therasense was va-
cated by an order granting appellants’ petition for rehear-
ing en banc on the issue of inequitable conduct, 374 F.
App’x 35, the portions of Therasense addressing obvious-
ness—which are the portions we rely on in this case—were
reinstated. 649 F.3d 1276, 1276 (Fed. Cir. 2011) (en banc).
FOX FACTORY, INC. v. SRAM, LLC                            11



     A finding that a presumption of nexus is inappropriate
does not end the inquiry into secondary considerations. See
In re Huang, 100 F.3d 135, 140 (Fed. Cir. 1996). To the
contrary, the patent owner is still afforded an opportunity
to prove nexus by showing that the evidence of secondary
considerations is the “direct result of the unique character-
istics of the claimed invention.” Id.
                                 2
    The parties dispute whether the X-Sync chainrings are
coextensive with the independent claims. 3 In finding that
the independent claims would not have been obvious, the
Board did not address the dependent claims in its obvious-
ness analysis. Board Decision 472, at *20. Accordingly, we
only address the Board’s application of the presumption of
nexus to the independent claims. Because no reasonable
fact finder could find otherwise, we conclude that SRAM’s
X-Sync chainrings are not coextensive with the independ-
ent claims.
    The independent claims cover a chainring that includes
wide and narrow teeth and either inboard or outboard off-
set teeth. It is undisputed that the X-Sync chainrings in-
clude unclaimed features. See generally Appellant’s Br.;
Appellee’s Br. 24–25. For example, SRAM does not dispute
that its X-Sync chainrings embody the independent claim



    3   Because neither party disputes the Board’s finding
that the X-Sync cranksets and drivetrains are not coexten-
sive with the independent claims, the only issue before us
is whether the X-Sync chainrings are coextensive with the
independent claims. See Appellee’s Br. 24. In any event,
because the X-Sync cranksets and drivetrains each include
an X-Sync chainring, our conclusions as to whether nexus
can be presumed between the independent claims and the
X-Sync chainrings also extend to the X-Sync cranksets and
drivetrains.
12                             FOX FACTORY, INC. v. SRAM, LLC




of a different patent—the ’250 patent—which, as explained
previously, covers a chainring with both wide and narrow
teeth and wide teeth with >80% gap filling. See J.A. 5282–
85 (Preliminary Patent Owner Response). As discussed in
more detail below, because the independent claims of the
’027 patent do not recite this >80% gap filling feature, the
independent claims are not coextensive with the X-Sync
chainrings.
     To be sure, we have never held that the existence of one
or more unclaimed features, standing alone, means nexus
may not be presumed. Indeed, there is rarely a perfect cor-
respondence between the claimed invention and the prod-
uct. As we explained, the purpose of the coextensiveness
requirement is to ensure that nexus is only presumed when
the product tied to the evidence of secondary considerations
“is the invention disclosed and claimed.” Demaco, 851 F.2d
at 1392 (emphasis added). Thus, if the unclaimed features
amount to nothing more than additional insignificant fea-
tures, presuming nexus may nevertheless be appropriate.
    Put differently, the degree of correspondence between
a product and a patent claim falls along a spectrum. At one
end of the spectrum lies perfect or near perfect correspond-
ence. At the other end lies no or very little correspondence,
such as where “the patented invention is only a component
of a commercially successful machine or process.” Id. Alt-
hough we do not require the patentee to prove perfect cor-
respondence to meet the coextensiveness requirement,
what we do require is that the patentee demonstrate that
the product is essentially the claimed invention. See id.
While coextensiveness is an issue of fact that should ordi-
narily be decided by the fact finder in the first instance, no
reasonable fact finder could conclude, under the proper
standard, that the X-Sync chainrings are coextensive with
the patent claims.
    It is undisputed that the X-Sync chainrings include un-
claimed features that the patentee describes as “critical” to
FOX FACTORY, INC. v. SRAM, LLC                             13



the product’s ability to “better retain the chain under many
conditions” and that go to the “heart” of another one of
SRMA’s patents. See J.A. 5284, 5289. In light of the pa-
tentee’s own assertions about the significance of the un-
claimed features, no reasonable fact finder could conclude
that these features are insignificant. As an initial matter,
the fact that SRAM obtained the ’250 patent covering the
combination of wide and narrow teeth and >80% gap filling
leads us to conclude that this combination of features
amounts to more than an insignificant feature not claimed
by the ’027 patent. See Therasense, 593 F.3d at 1299 (find-
ing that the patentee was not entitled to a presumption of
nexus because the product embodied at least two patented
inventions, and the burden thus remained on the patentee
to show that the product’s success was due to the invention
claimed in the patent asserted in the case). Moreover, in a
separate IPR proceeding pertaining to the ’250 patent,
SRAM touted this “combination of features” as, “amongst
several others disclosed in the ’250 patent,” one that “leads
to a chainring that will retain a chain in even the worst
conditions.” J.A. 5282–83. SRAM further described this
gap filling feature as “critical” and one that “allows the in-
ventive chainring to better retain the chain under many
conditions and amounts to the ‘heart’ of the challenged ’250
patent claims combined with the narrow and wide tooth
configuration.” J.A. 5284, 5289. A patent claim is not co-
extensive with a product that includes a “critical” un-
claimed feature that is claimed by a different patent and
that materially impacts the product’s functionality by
“lead[ing] to a chainring that will retain a chain in even the
worst conditions.” See J.A. 5282–84, 5289.
    In short, because the independent claims do not include
the >80% gap filling feature, we cannot say that the X-Sync
chainrings are the invention claimed by the independent
claims. Accordingly, the Board erred in presuming nexus
between the independent claims of the ’027 patent and
14                              FOX FACTORY, INC. v. SRAM, LLC




secondary considerations evidence pertaining to SRAM’s
X-Sync chainrings.
     The lack of coextensiveness between the independent
claims of the ’027 patent and SRAM’s X-Sync chainrings
appears to extend far beyond the gap filling feature to ad-
ditional unclaimed features. More specifically, FOX con-
tends, and SRAM does not contest, that the X-Sync
chainrings further include the following unclaimed fea-
tures: (1) forwardly protruding tooth tips, Appellant’s Br.
22–26; see also ’027 patent col. 5 ll. 45–51, fig.5; (2) hook
features on the teeth, Appellant’s Br. 22–26; see also ’027
patent col. 5 ll. 52–55, fig.5; and (3) mud-clearing recesses,
Appellant’s Br. 22–26. As to the first, the ’027 patent spec-
ification explains that forwardly protruding tooth tips
“function[] to engage a chain link earlier than a chain lack-
ing the tip portion and provide[] better guiding of the
chain.” ’027 patent col. 5 ll. 45–51; see also id. at fig.5. As
to the second, the ’027 patent specification explains that
such hook features “cooperate with the [forwardly protrud-
ing tips] 76 to provide better guiding of the chain.” Id. at
col. 5 ll. 52–55; see also id. at fig.5. As to the third, SRAM’s
marketing materials explain that these recesses “get rid of
mud so the chain remains in place no matter what condi-
tions you’re up against.” J.A. 5316. 4 In sum, the ’027 pa-
tent and SRAM’s marketing materials confirm that the
forwardly protruding tooth tips, hook features, and mud
clearing recesses each materially impacts the functioning



     4  FOX further contends that these recesses appear to
be the same as the inner link-receiving recesses discussed
in the ’027 patent. It is unclear on this record whether
FOX’s contention is correct. If these features are different,
SRAM’s chain links further appear to include inner link-
receiving recesses. Appellant’s Br. 22–26; see also J.A. 219
(’027 patent col. 5, ll. 26–44). Compare J.A. 5344 with J.A.
211–12 (’027 patent figs.5, 7).
FOX FACTORY, INC. v. SRAM, LLC                                15



of a chainring. For each of these features that the Board
confirms is included in the X-Sync chainrings, nexus can
only be presumed between the X-Sync chainrings and a pa-
tent claim if the claim includes limitations relating to these
features.
                                 3
    SRAM’s counterarguments are unpersuasive. First,
SRAM argues that the existence of unclaimed features in a
commercial product is irrelevant to the question of whether
nexus can be presumed between that product and a patent
claim. 5 Rather, according to both SRAM and the Board,
unclaimed features are only relevant on rebuttal, 6 and the
coextensiveness requirement is met if the patent claim


    5    For this position, both the Board and SRAM rely on
our decision in PPC Broadband, Inc. v. Corning Optical
Communications RF, LLC, 815 F.3d 734, 747 (Fed. Cir.
2016).
     6   In addition to challenging whether the Board erred
by presuming nexus in this case, FOX also contends that
the Board imposed too high a burden on FOX to rebut the
presumption of nexus by requiring FOX to show that the
claimed invention had absolutely no relevance to SRAM’s
evidence of secondary considerations. Appellant’s Br. 51–
53; see, e.g., Board Decision 472, at *14 (“Petitioner fails to
direct us to where the industry praise is directed only to
the inboard-offset feature.”); id. at *15 (“Moreover, none of
the articles that include the references to the ‘tall,’ ‘hooked,’
and ‘asymmetric’ teeth purport to attribute all of the bene-
fits of the X-Sync chainring to those attributes.”); id. (“As
for the fact that some of the articles only mention wide nar-
row teeth, we do not agree with Petitioner that this estab-
lishes that the praise was only directed to the features
found in the prior art.”). Because we determine that the
Board erroneously presumed nexus, we do not reach this
issue.
16                            FOX FACTORY, INC. v. SRAM, LLC




broadly covers the product that is the subject of the evi-
dence of secondary considerations. See, e.g., Appellee’s Br.
50–56. As previously explained, we agree with both the
Board and SRAM that the mere existence of one or more
unclaimed features does not necessarily mean presuming
nexus is inappropriate. In this case, however, because
there are one or more features not claimed by the ’027 pa-
tent that materially impact the functionality of the X-Sync
products, including the >80% gap filling feature claimed in
the ’250 patent, nexus may not be presumed.
    On a broader note, if we were to agree with the posi-
tions taken by both SRAM and the Board—i.e., that the co-
extensiveness requirement is met so long as the patent
claim broadly covers the product that is the subject of the
secondary considerations evidence, irrespective of the na-
ture of any unclaimed features—then the coextensiveness
requirement would rest entirely on minor variations in
claim drafting. For instance, suppose a patent includes
some claims specifically covering novel “brake pads” and
others directed to an “automobile” in which the body of the
claim recites little more than the novel brake pads. It is
beyond dispute that the “brake pad” claims would not be
entitled to a nexus presumption with any secondary con-
siderations evidence tied to commercially sold automobiles
containing those brake pads (e.g., commercial success or
praise of the automobiles). In SRAM and the Board’s view,
the “automobile” claims would be entitled to a nexus pre-
sumption with such secondary considerations evidence.
They reach this view even though the automobiles sold con-
tain hundreds if not thousands of different components be-
yond just the novel aspect of the claimed brake pads, and
even though only minor variations in patent claim lan-
guage (i.e., whether the word “automobile” is included in
the claims) differentiate the “brake pad” claims and the
“automobile” claims. Resting the coextensiveness inquiry
on nothing more than minor variations in patent claim
FOX FACTORY, INC. v. SRAM, LLC                            17



language would turn the inquiry into one of form over sub-
stance.
    We reject SRAM’s attempt to reduce the coextensive-
ness requirement to an inquiry into whether the patent
claims broadly cover the product that is the subject of the
evidence of secondary considerations. Such an interpreta-
tion is inconsistent with Demaco’s requirement that nexus
can only be presumed where the evidence of secondary con-
siderations is tied to a specific product that “is the inven-
tion disclosed and claimed.” Demaco, 851 F.2d at 1392
(emphasis added). Nor is such an interpretation consistent
with Demaco’s explanation that nexus cannot be presumed
where, for example, “the patented invention is only a com-
ponent of a commercially successful machine or process.”
Id. We are bound by Demaco and decline to depart from it.
     Second, SRAM also argues that because the ’250 patent
is a continuation of the ’027 patent, failing to presume
nexus in this case “would result in the absurd situation
that multiple continuations on a patent would prohibit a
presumption of nexus.” Appellee’s Br. 50. SRAM continues
that “[t]his Court has recognized time and again that re-
lated patents can share a presumption of nexus.” Id. at 53.
Where a product embodies claims from two patents, a pre-
sumption of nexus can be appropriate only if the claims of
both patents generally cover the same invention. In each
of the cases SRAM cites for the proposition that the claims
of multiple patents can share a presumption of nexus with
the same product, the claims of each of the patents covered
essentially the same invention. See, e.g., WBIP, LLC v.
Kohler Co., 829 F.3d 1317, 1324–25 (Fed. Cir. 2016) (pre-
suming nexus between a product and the asserted claims
of two related patents where the patents covered essen-
tially the same invention, and the court identified a single
claim as representative of both patents); PPC Broadband,
815 F.3d at 737–39 (presuming nexus between a product
and the asserted claims of three patents where the asserted
claims of all three patents recited the same essential
18                             FOX FACTORY, INC. v. SRAM, LLC




features); Gator Tail, LLC v. Mud Buddy LLC, 618 F. App’x
992, 995, 999–1000 (Fed. Cir. 2015) (presuming nexus be-
tween a product and all of the asserted claims where “the
[related] patents essentially claim the same invention”);
Media Techs. Licensing, LLC v. Upper Deck Co., 596 F.3d
1334, 1336–39 (Fed. Cir. 2010) (unclear as to whether
nexus was presumed, and in any event the related patents
were drawn to the same invention). 7 Conversely, here, the
independent claims of the ’250 patent and ’027 patent do
not cover the same invention. In particular, these patents
cover different combinations of chainring features.
    In addition, although the fact that SRAM separately
sought patent protection for the combination of wide and
narrow teeth with this >80% gap filling feature is alone
probative of whether this combination of features adds up
to more than an insignificant additional feature, see The-
rasense, 593 F.3d at 1299, a presumption of nexus might
well be inappropriate in this case even if SRAM never
sought such patent protection. In particular, the X-Sync
products are not coextensive with the independent claims
of the ’027 patent because the products include a “critical”
unclaimed feature not covered by the independent claims
of the ’027 patent that materially impacts the product’s
functionality by “lead[ing] to a chainring that will retain a
chain in even the worst conditions.” See J.A. 5282–84,
5289. This is true regardless of whether SRAM included
these unclaimed features in other patents.



     7  The additional cases on which SRAM relies do not
address the presumption of nexus at all. See Acorda Ther-
apeutics, Inc. v. Roxane Labs., Inc., 903 F.3d 1310 (Fed. Cir.
2018); Merck Sharp & Dohme Corp. v. Hospira, Inc., 874
F.3d 724, 730–31 (Fed. Cir. 2017); Transocean Offshore
Deepwater Drilling, Inc. v. Maersk Drilling USA, Inc., 699
F.3d 1340, 1354–55 (Fed. Cir. 2012); Star Sci., Inc. v. R.J.
Reynolds Tobacco Co., 655 F.3d 1364, 1368 (Fed. Cir. 2011).
FOX FACTORY, INC. v. SRAM, LLC                            19



    We note that the Board’s determinations in these IPR
proceedings on the ’027 patent and the IPR proceedings on
the ’250 patent highlight one reason why nexus may not be
presumed under these circumstances. Between these two
proceedings, the Board presumed nexus between the inde-
pendent claims of both patents and the secondary consid-
erations evidence submitted by SRAM, see J.A. 6458–62,
even though (a) SRAM relies on essentially the same evi-
dence of secondary considerations in both proceedings; J.A.
5455–76, 6363–88; see also J.A. 5282–84, 5289; and (b) the
’027 and ’250 patent claims cover different inventions. The
same evidence of secondary considerations cannot be pre-
sumed to be attributable to two different combinations of
features. See Therasense, 593 F.3d at 1299. In such situa-
tions, the patentee retains the burden of proving the degree
to which evidence of secondary considerations tied to a
product is attributable to a particular claimed invention.
See, e.g., WMS Gaming, 184 F.3d at 1359.
                                 4
    Because the Board erroneously presumed nexus be-
tween the evidence of secondary considerations and the in-
dependent claims, we vacate the Board’s obviousness
determination and remand for further proceedings. On re-
mand, SRAM will have the opportunity to prove nexus be-
tween the challenged independent claims and the evidence
of secondary considerations. More specifically, SRAM will
bear the burden of proving that the evidence of secondary
considerations is attributable to the claimed combination
of wide and narrow teeth with inboard or outboard offset
teeth, as opposed to, for example, prior art features in iso-
lation or unclaimed features. See, e.g., Ethicon Endo-Sur-
gery, Inc. v. Covidien LP, 812 F.3d 1023, 1034 (Fed. Cir.
2016) (for patent claims covering a combination of prior art
features, to establish nexus, patentee must show that the
evidence of secondary considerations is attributable to “the
combination of the two prior art features . . . that is the
purportedly inventive aspect of the [challenged] patent” as
20                             FOX FACTORY, INC. v. SRAM, LLC




opposed to unclaimed features or either prior art feature in
isolation).
                              B
    Separate from the issue of nexus, in its response to
FOX’s statement of the case, SRAM briefly contends that
we can enter judgment in favor of SRAM on an alternative
ground: that substantial evidence does not support the
Board’s conclusions that a skilled artisan would have been
motivated to combine the asserted prior art to arrive at the
independent claims. Appellee’s Br. 20–23. Notably, SRAM
does not mention this argument in its summary of the ar-
gument or argument sections of the brief. See generally
Appellant’s Br. We have previously declined to address ar-
guments that appear in the statement of facts but not the
summary of the argument or argument sections of the
brief. See Kao Corp. v. Unilever U.S., Inc., 441 F.3d 963,
973 n.4 (Fed. Cir. 2006) (declining to consider appellee’s ar-
gument that only “appear[ed] in the appellee’s brief’s sec-
tions ‘Statement of the Facts’ and ‘Standard of Review,’”
but not the “statement of issues presented, nor the sum-
mary of argument, nor the argument section” of the brief);
see also SmithKline Beecham Corp. v. Apotex Corp., 439
F.3d 1312, 1319 (Fed. Cir. 2006) (“Our law is well estab-
lished that arguments not raised in the opening brief are
waived.”); Becton Dickinson & Co. v. C.R. Bard, Inc., 922
F.2d 792, 800 (Fed. Cir. 1990) (holding we have discretion
to consider arguments that are not properly raised in the
opening brief).
     Even if this argument is properly preserved, it is mer-
itless. Substantial evidence—including the declarations
submitted by FOX’s expert—supports the Board’s conclu-
sion that a skilled artisan would have been motivated to
combine the asserted prior art because the skilled artisan
would have recognized that the combination of prior art
features would better address chain drop than either fea-
ture in isolation. See, e.g., J.A. 4492–4513, 5219–27, 5762–
FOX FACTORY, INC. v. SRAM, LLC                           21



89, 6099–6106. Therefore, we affirm the Board’s determi-
nation that a skilled artisan would have been motivated to
combine the asserted prior art.
                             III
     FOX also raises a SAS-based remand request. In one
of the underlying inter partes review proceedings, IPR
2017-00118, the Board instituted review of only two of the
eight grounds of unpatentability raised by FOX. Three
weeks after the Board’s final written decision, the Supreme
Court issued its decision in SAS Institute v. Iancu, 138 S.
Ct. 1348 (2018). Shortly after this appeal was docketed,
and before any briefs were filed, FOX moved to terminate
the appeal as to IPR2017-00118 on the ground that the
Board failed to follow the requirements set forth in SAS by
failing to institute review of all eight grounds FOX raised.
Motion of Appellant FOX Factory, Inc., for Remand of Ap-
peal No. 2018-2024 (IPR2017-00118) in View of Interven-
ing Authority at 1–2 (Sept. 28, 2018), ECF No. 22
(“Motion”). Although we chose not to terminate the appeal
as to IPR No. 2017-00118, we now remand to the Board to
consider the non-instituted grounds.
     SRAM contends that FOX waived its right to a remand
(and to terminate the appeal) pursuant to SAS because
FOX failed to raise its SAS objection before the Board. Ap-
pellee SRAM, LLC’s Opposition to Appellant’s Motion to
Remand at 2 (Oct. 2, 2018), ECF No. 24. This argument,
however, is unavailing because SAS issued after the
Board’s final written decision, and we have not required
filing a request for reconsideration to preserve a SAS-based
remand. See BioDelivery Scis. Int’l, Inc. v. Aquestive Ther-
apeutics, Inc., 898 F.3d 1205, 1208 (Fed. Cir. 2018) (“We
also declined to find that a party waived its right to seek
SAS-based relief due to failure to argue against partial in-
stitution before the PTAB.”).
   SRAM also argues that FOX waived its right to a re-
mand because FOX failed to explicitly raise its SAS
22                             FOX FACTORY, INC. v. SRAM, LLC




objection in its Notice of Appeal. We have found that a pa-
tent challenger can properly preserve an SAS objection by
requesting remand in its opening brief. See Google LLC v.
Ji-Soo Lee, 759 F. App’x 998, 1002 n.2 (Fed. Cir. 2019).
Here, FOX did more than that: it filed a motion to remand
even before its opening brief was due. See Motion. Accord-
ingly, we conclude that FOX did not waive its right to a
remand.
                             IV
    We vacate the Board’s obviousness determinations in
IPR 2017-00118 and IPR 2017-00472 and remand for it to
reevaluate the import of the evidence of secondary consid-
erations with the burden of proving nexus placed on the
correct party. We also remand IPR 2017-00118 for the
Board to consider the non-instituted grounds.
              VACATED AND REMANDED
                           COSTS
     The parties shall bear their own costs.
