Today I took 41st to Webster to 29th to Broadway to 25th to Webster going there, Franklin to 22nd to Broadway to Piedmont going back.
Google Maps suggests a very complicated inbound route: Piedmont to Broadway to 27th to 24th to Waverly to Harrison to Grand to Valdez to 21st to the Kaiser Building parking lot to Harrison. In reverse they take 19th to Harrison to 27th to Broadway to Piedmont.
The main problems with my chosen route: Webster is steep going under the freeway and ends at 29th Street before picking up again with an awkward left turn at 25th, and Franklin is all but useless as a through street because of the way it ends at 22nd.
Franklin could be fixed by opening 22nd to two-way traffic, at least for bicycles, between Franklin and Webster, and opening Webster to two-way traffic between Grand and 22nd. (Or opening Webster to two-way traffic between Grand and 21st, since 21st goes the right way.) Downtown Oakland is full of streets that are one way for no reason at all except to make obvious routes difficult.
I don't know how to fix Webster. Probably the best thing would be to forget about it entirely on the southern part and turn Valdez into a usable street between 21st and 28th. But there is no way to bridge the gap between 28th and 29th.