Well if you bridge the second router to the first then the second router will be on the same network as router #1. So you lan addresses will be on the same network (example 192.168.1.xxx where x is the computer ip) and all traffic wil be routed to the first router.
Or use the second router and have a different network address (example 192.168.2.xxx), bridge the third router to the second and all computers on that network will be on 192.168.2.xxx and the first router will use a network address of 192.168.1.xxx.
Am I following what you are trying to do?