The national advocacy group, People for Bikes, has created a walkscore style of scoring for bicycle infrastructure and access to amenities. Detroit does not rank well at 26 out of 100 points.
Major caveat here is that the analysis is based on OpenStreetMap data, which is sadly not robust for Detroit (Create a free account and help add data!). Things like bike lanes, speed limits, and other key data points are missing for much of the city.
Detroit is making great progress in bicycle infrastructure, but we need to do a better job of getting our data out there to show it!