diff --git a/bincio/extract/writer.py b/bincio/extract/writer.py
index 592df8c..f4bd98d 100644
--- a/bincio/extract/writer.py
+++ b/bincio/extract/writer.py
@@ -261,6 +261,7 @@ def build_summary(
         "best_climb_m": metrics.best_climb_m,
         "climbing_vam_mh": metrics.climbing_vam_mh,
         "climbing_time_s": metrics.climbing_time_s,
+        "gear": activity.gear,
         "source": _infer_source(activity),
         "privacy": privacy,
         "detail_url": f"activities/{activity_id}.json",
diff --git a/bincio/render/merge.py b/bincio/render/merge.py
index e4c0b52..34c5db4 100644
--- a/bincio/render/merge.py
+++ b/bincio/render/merge.py
@@ -120,6 +120,8 @@ def _apply_sidecar_summary(summary: dict, fm: dict) -> dict:
         s["sport"] = str(fm["sport"])
     if "sub_sport" in fm:
         s["sub_sport"] = str(fm["sub_sport"]) if fm["sub_sport"] else None
+    if "gear" in fm:
+        s["gear"] = str(fm["gear"]) if fm["gear"] else s.get("gear")
     if "highlight" in fm:
         s["custom"]["highlight"] = bool(fm["highlight"])
     if "private" in fm: