The gauge group of a principal G-bundle P over a space X is the group of G-equivariant homeomorphisms of P that cover the identity on X. We consider the gauge groups of bundles over $$S^4$$
S
4
with $${{\textrm{Spin}}}^{{\textrm{c}}}(n)$$
Spin
c
(
n
)
, the complex spin group, as structure group and show how the study of their homotopy types reduces to that of $${{\textrm{Spin}}}(n)$$
Spin
(
n
)
-gauge groups over $$S^4$$
S
4
. We then advance on what is known by providing a partial classification for $${{\textrm{Spin}}}(7)$$
Spin
(
7
)
- and $${{\textrm{Spin}}}(8)$$
Spin
(
8
)
-gauge groups over $$S^4$$
S
4
.