  Double-lined spectroscopic binaries (SB2) allow us to determine a lower limit
of the masses of their components directly to test stellar models. In this
work, our aim is to derive the orbital and physical parameters of GJ1284, a
young SB2. We also revise the membership of this system and its two wide
co-moving companions, GJ898 and GJ897AB, to a young moving group to assess,
along with other youth indicators, their age. Afterwards, we compare the
results from these analyses and the photometry of these systems with several
pre-main-sequence evolutionary models. We determine the orbit of the GJ1284
system alongside its systemic velocity from high resolution spectra.
Additionally, we use TESS photometry to derive the rotational period of the
GJ1284 and its two wide companions. GJ1284 is a binary system located at
approximately 16 pc with an eccentric orbit ($ e = 0.505 $) of 11.83 d period
made up of an M2-M2.5 + M3-M3.5. The revised systemic velocity of $ \gamma =
0.84 \pm 0.14\,\mathrm{km\,s}^{-1} $ suggests that it is a member of the Local
Association. The kinematics together with other activity and youth indicators
imply an age of 110-800 Myr for this system and its two companions. The
isochronal ages derived from the comparison of the photometry with several
evolutionary models are younger than the age estimated from the activity
indicators for the three co-moving systems. The masses for the components of
GJ1284, derived from their luminosity and age using the different models, are
not consistent with the masses derived from the photometry, except for the
PARSEC models, but are compatible with dynamical masses of double-lined
eclipsing binaries with similar ages and spectral types. The effect of magnetic
activity in the form of spots can reconcile to some extent the photometric and
dynamical masses, but is not considered in most of the evolutionary models.
