Madara probably has more chakra. Chakra is amplified by connecting physical, spiritual, and optionally natural energy. Madara on his own has Indra's exceptional spiritual energy, and with Kabuto's modifications he also has Asura's exceptional physical energy, and after absorbing Hashirama's sage mode he has natural energy as well. His chakra levels should be well in excess of any non-jinchuuriki, Sasuke included.
One might argue that Sasuke's chakra is still of a higher quality due to the power he received from Hagoromo, but Madara also possesses that same type of chakra as a fellow Rinnegan user. That's not necessarily to say he'd win in a fight, but he's definitely not to be written off.