diff --git a/router/router.py b/router/router.py
index da4a36d..fb2b6e1 100644
--- a/router/router.py
+++ b/router/router.py
@@ -181,8 +181,8 @@ def route(rd, tier):
         if "qwen3.6-27B-code" in avail and not is_gpu_busy("qwen3.6-27B-code"):
             return {"model":"qwen3.6-27B-code","reason":"simple_conv_fallback"}
     
-    # TIER 3: Heavy reasoning — very large context or very long conversations
-    if t > 12000 or turns > 15:
+    # TIER 3: Heavy reasoning — extremely large context or very long conversations
+    if t > 50000 or turns > 25:
         candidates = [m for m in ["qwen3.6-27B-code","qwen3.6-35B-A3B","qwen3.5-9b-vlm"] if m in avail]
         result = select_best_gpu(candidates, "heavy_reasoning")
         if result: return result