A recent Bicycling article claims that "[c]onsuming protein and after rides can help stave off muscle loss". The article even references a study published in Sports Medicine as support. Unfortunately, there is no link to the study itself so it is difficult to comment on the specific support claimed by the author. However, a quick search of recent scholarly articles across multiple journals tends to conclude the opposite.
A recent meta-analysis in the Journal of the International Society of Sports Nutrition concludes that their study "refute[s] the commonly held belief that the timing of protein intake in and around a training session is critical to muscular adaptations and indicate that consuming adequate protein in combination with resistance exercise is the key factor for maximizing muscle protein accretion." See http://link.springer.com/article/10.1186/1550-2783-9-54 A 2009 study concludes: Results indicate that the time of protein-supplement ingestion in resistance-trained athletes during a 10-wk training program does not provide any added benefit to strength, power, or body-composition changes. See http://www.ncbi.nlm.nih.gov/pubmed/19478342
Of course, protein intake is important. You should be ingesting at least 0.8g protein per kilogram of body weight per day. This is a global consensus figure for the adequate amount to satisfy the protein needs of a healthy adult. There is less agreement as to whether athletes require more protein, and if so, how much. There are negative effects associated with excessive protein consumption (and counter-examples as well), so "more is better and can't hurt" probably doesn't apply. Also, if you are at all concerned about body weight, excessive protein ingestion could contribute to weight gain (assuming you continue to consume the same amount of fat and carbohydrates). Also notable, studies indicate that female athletes tend to under-consume protein as compared to men.
The bottom line, 1.2g/kg/d to 1.6g/kg/d is probably a reasonable range for most training cyclists. Adjust your diet to this range and then stop thinking about it.
As always, caveat lector.