Could an Ukaku ghoul beat a Rinkaku ghoul?
If an experienced Rinkaku and equally experienced Ukaku went for each other, Rinkaku would have a higher chance of winning. They are only weak against Bikaku. In Chapter 13 of Tokyo Ghoul, 


  Shinohara explained this to Suzuya: 


Furthermore, on the same chapter,


  Shinohara said that RC cells of ghouls acts as an effective 'poison' to the types that are weak against them.