When the US set up the 100:1 discrepancy between Cocaine and Crack sentencing was it recognized that the effects would be racially biased? Was the decision itself racially motivated?

If any discussion was had in Congress about the potential for a racially-based sentencing disparity, we would expect to see it in the legislative history: that is, the records of floor debates and committee reports generated during the lawmaking process. The U.S. Sentencing Commission has some public data available on this very subject, including the full text of a 1995 special report to the Congress. From Chapter 6:

The 1986 Act was expedited through Congress. As a result, its passage left behind a limited legislative record. While many individual members delivered floor statements about the Act, no committee produced a report analyzing the Act's key provisions. [. . . .]

Of particular relevance to this report, the legislative history does not include any discussion of the 100-to-1 powder cocaine/crack cocaine quantity ratio per se. Congress did, however, consider a variety of powder/crack quantity ratios before adopting 100-to-1. [. . . .]

The legislative history, as evidenced mainly by the statements of individual legislators, suggests four specific areas of congressional purpose. [List of factors omitted from this post for readability.] The legislative history, primarily in the form of member floor statements, shows (1) that Congress had concluded that crack cocaine was more dangerous than powder cocaine and (2) that this conclusion drove its decision to treat crack cocaine differently from powder cocaine.

From this, it seems the 100-1 ratio was driven by a genuine (if mistaken) belief that crack was just flat-out more dangerous, and more of an epidemic than cocaine generally. Race doesn't appear to have been an explicit part of the discussion. However...

(...and before I go on, let me give a neutrality/politics admonishment: the ACLU is an intellectually rigorous organization full of some of the country's best lawyers. Therefore, I would take their comments seriously, while bearing in mind that they come from an organization with clear reform goals when it comes to criminal justice...)

...the ACLU argued in a 2006 report that "powder cocaine’s prohibition had always carried a racial component" (see page 1 & n.23). From this, you could make a case that race is not text in drug sentencing laws, but it is subtext.