I am not exactly sure I understand your topology or what you are trying to accomplish, but you can add a static route with a "track" object. This would allow your static default to go away if the track object fails.
If, for example, you have two next-hop routers and you want to use one as primary and the other as a backup, you could do something like this, assuming 192.168.1.1 is primary and 192.168.2.2 is secondary. It will ping the primary router every 15 seconds. If the ping fails, the route is removed and the floating static route will take over to the secondary router.
ip route 0.0.0.0 0.0.0.0 192.168.1.1 track 100
!
ip route 0.0.0.0 0.0.0.0 192.168.2.2 200
!
track 100 rtr 1 reachability
!
ip sla 1
icmp-echo 192.168.1.1
frequency 15
timeout 30
!
ip sla schedule 1 life forever start-time now
!
Check out this doc for more info.
http://www.cisco.com/en/US/docs/ios/12_3/12_3x/12_3xe/feature/guide/dbackupx.html
HTH,
-Rob
Please rate if helpful. Thanks