I have a few RiR that have just hit 18 weeks, and they have the same sized combs. But I do think that of the 3 straight run, 1 is a roo. Any thoughts?
Notice the longer, pointier feathers on the neck...
...and pointier tail than the other...
Possible RiR in the middle-right, likely hen middle-left.
I was hoping he would be a meatier bird, I'd like to start breeding RiRs but he's pretty scrawny. I've got several other hens that are pretty big, but a big rooster is critical for a quality dual-purpose, or so I've read.
The real reason that your birds are scrawny and not meaty is because they are not Rhode Island Reds. They are production reds, a generic term for a red colored layer. True Rhode Island Reds will have a "brick" shape to them, and will be dual purpose birds. If you are looking to breed them, please get some good quality, true RIR stock.