  Silicon tracking detectors provide excellent spatial resolution, and so can
provide excellent momentum resolution for energetic charged particles, even in
compact detectors. However, at lower momenta, multiple scattering in the
silicon degrades the momentum resolution. We present an alternate method to
measure momentum and alleviate this degradation, using silicon detectors that
also incorporate timing measurements. By using timing information between two
silicon layers, it is possible to solve for the the radius of curvature, and
hence the particle momentum, independent of multiple scattering within the
silicon. We consider three examples: an all-silicon central tracker for an
electron-ion collider, a simplified version of the CMS detector, and a forward
detector for an electron-ion collider. For a 75 cm diameter tracker in a 1.5 T
magnetic field, timing can improve the momentum determination for particles
with momentum below 500 MeV/c. In the 3.8 T CMS magnetic field and 1.2 m radius
tracker, timing can improve tracking up to momenta of 1.3 GeV/c. The resolution
is best at mid-rapidity. We also discuss a simpler system, consisting of a
single timing detector outside an all-silicon tracker.
