diff --git a/starpilot/assets/model_manager.py b/starpilot/assets/model_manager.py
index 13912eae2..ce574f12f 100644
--- a/starpilot/assets/model_manager.py
+++ b/starpilot/assets/model_manager.py
@@ -37,6 +37,7 @@ ACTIVE_BIG_MODEL_VERSION_PARAM = "ActiveBigModelVersion"
 ACTIVE_SMALL_MODEL_PARAM = "ActiveSmallModel"
 ACTIVE_SMALL_MODEL_NAME_PARAM = "ActiveSmallModelName"
 ACTIVE_SMALL_MODEL_VERSION_PARAM = "ActiveSmallModelVersion"
+DISABLED_MODEL_PROFILE = "none"
 MODEL_PROFILE_PARAMS = {
   "big": (ACTIVE_BIG_MODEL_PARAM, ACTIVE_BIG_MODEL_NAME_PARAM, ACTIVE_BIG_MODEL_VERSION_PARAM),
   "small": (ACTIVE_SMALL_MODEL_PARAM, ACTIVE_SMALL_MODEL_NAME_PARAM, ACTIVE_SMALL_MODEL_VERSION_PARAM),
@@ -154,7 +155,11 @@ def get_model_profile(params, profile: str) -> tuple[str, str, str]:
     raise ValueError(f"Unknown model profile: {profile}")
 
   key_param, name_param, version_param = MODEL_PROFILE_PARAMS[profile]
-  model_key = canonical_model_key(_params_text(params, key_param))
+  stored_value = _params_text(params, key_param)
+  if profile == "big" and stored_value.lower() == DISABLED_MODEL_PROFILE:
+    return "", "", ""
+
+  model_key = canonical_model_key(stored_value)
   requires_gpu = profile == "big"
   if model_key and model_uses_external_gpu(model_key) != requires_gpu:
     model_key = ""
@@ -203,6 +208,12 @@ def set_model_profile(params, profile: str, model_key: str, model_name: str = ""
   params.put(version_param, model_version or catalog_version or ("v15" if is_builtin_model_key(canonical_key) else ""))
 
 
+def disable_big_model_profile(params) -> None:
+  params.put(ACTIVE_BIG_MODEL_PARAM, DISABLED_MODEL_PROFILE)
+  params.remove(ACTIVE_BIG_MODEL_NAME_PARAM)
+  params.remove(ACTIVE_BIG_MODEL_VERSION_PARAM)
+
+
 def set_runtime_model_params(params, model_key: str, model_version: str = "") -> None:
   canonical_key = canonical_model_key(model_key) or DEFAULT_MODEL_KEY
   profile = "big" if model_uses_external_gpu(canonical_key) else "small"
diff --git a/starpilot/assets/tests/test_model_pipeline.py b/starpilot/assets/tests/test_model_pipeline.py
index e3ba5a871..f4ac17371 100644
--- a/starpilot/assets/tests/test_model_pipeline.py
+++ b/starpilot/assets/tests/test_model_pipeline.py
@@ -177,6 +177,40 @@ def test_active_small_and_big_profiles_migrate_from_legacy_selection(tmp_path, m
   assert model_manager.get_model_profile(big_params, "big") == ("big-one", "Big One", "v16")
 
 
+def test_disabled_big_profile_does_not_migrate_from_legacy_selection(tmp_path, monkeypatch):
+  monkeypatch.setattr(model_manager, "MODELS_PATH", tmp_path)
+  (tmp_path / model_manager.ARTIFACT_METADATA_CACHE).write_text(json.dumps({
+    "big-one": {"uses_external_gpu": True},
+  }))
+
+  class FakeParams:
+    def __init__(self):
+      self.values = {
+        "Model": "big-one",
+        "DrivingModel": "big-one",
+        "ActiveBigModel": model_manager.DISABLED_MODEL_PROFILE,
+        "ActiveBigModelName": "Big One",
+        "ActiveBigModelVersion": "v16",
+      }
+
+    def get(self, key):
+      return self.values.get(key)
+
+    def put(self, key, value):
+      self.values[key] = value
+
+    def remove(self, key):
+      self.values.pop(key, None)
+
+  params = FakeParams()
+  assert model_manager.get_model_profile(params, "big") == ("", "", "")
+
+  model_manager.disable_big_model_profile(params)
+  assert params.values["ActiveBigModel"] == model_manager.DISABLED_MODEL_PROFILE
+  assert "ActiveBigModelName" not in params.values
+  assert "ActiveBigModelVersion" not in params.values
+
+
 def test_runtime_model_metadata_does_not_overwrite_model_profiles(tmp_path, monkeypatch):
   monkeypatch.setattr(model_manager, "MODELS_PATH", tmp_path)
   (tmp_path / model_manager.ARTIFACT_METADATA_CACHE).write_text(json.dumps({
diff --git a/starpilot/system/the_galaxy/assets/components/tools/model_manager.js b/starpilot/system/the_galaxy/assets/components/tools/model_manager.js
index cd85704f6..690110771 100644
--- a/starpilot/system/the_galaxy/assets/components/tools/model_manager.js
+++ b/starpilot/system/the_galaxy/assets/components/tools/model_manager.js
@@ -473,8 +473,8 @@ function bindDomHandlers() {
     if (!(target instanceof HTMLSelectElement)) return;
     if (target.id === "mm-active-small-model-select" || target.id === "mm-active-big-model-select") {
       const modelKey = safeText(target.value, "");
-      if (!modelKey) return;
       const profile = target.id === "mm-active-big-model-select" ? "big" : "small";
+      if (!modelKey && profile !== "big") return;
       runAction(`select-${profile}`, modelKey).catch(() => {});
       return;
     }
@@ -669,7 +669,7 @@ export function ModelManager() {
         </select>
 
         <label class="mm-filter-label" for="mm-active-big-model-select">Active Big</label>
-        <select class="mm-select" id="mm-active-big-model-select" disabled="${() => getInstalledModels("big").length === 0}">
+        <select class="mm-select" id="mm-active-big-model-select">
           ${() => {
             const orderedInstalled = getInstalledModels("big").sort((a, b) => {
               const aCurrent = safeText(a.value) === state.activeBigModel ? 0 : 1;
@@ -680,14 +680,14 @@ export function ModelManager() {
 
             return orderedInstalled.length > 0
               ? html`
-                ${state.activeBigModel ? "" : html`<option value="" selected>Choose an eGPU model</option>`}
+                <option value="" selected="${() => !state.activeBigModel || false}">None — always use Active Small</option>
                 ${orderedInstalled.map(model => html`
                   <option value="${safeText(model.value)}" selected="${() => safeText(model.value) === state.activeBigModel || false}">
                     ${safeText(model.label, model.value)}
                   </option>
                 `)}
               `
-              : html`<option value="">No installed eGPU models</option>`;
+              : html`<option value="" selected>None — always use Active Small</option>`;
           }}
         </select>
 
diff --git a/starpilot/system/the_galaxy/assets/mobile/js/api.js b/starpilot/system/the_galaxy/assets/mobile/js/api.js
index 19cfcda8a..2fb5de5bc 100644
--- a/starpilot/system/the_galaxy/assets/mobile/js/api.js
+++ b/starpilot/system/the_galaxy/assets/mobile/js/api.js
@@ -260,6 +260,7 @@ export const api = {
   sentryPushSubscribe(body) { return request("/api/sentry/push/subscribe", { method: "POST", data: body }) },
 
   getModelStatus() { return requestOk("/api/models/status", { cache: "no-store" }) },
+  setActiveModel(profile, modelKey = "") { return request("/api/models/active", { method: "PUT", data: { profile, model: modelKey } }) },
   startModelDownload(modelKey, allowGpuWithoutGpu = false) { return request("/api/models/download", { method: "POST", data: { model: modelKey, allowGpuWithoutGpu } }) },
   downloadAllModels(allowGpuWithoutGpu = false) { return request("/api/models/download_all", { method: "POST", data: { allowGpuWithoutGpu } }) },
   deleteModel(modelKey) { return request("/api/models/delete", { method: "POST", data: { model: modelKey } }) },
diff --git a/starpilot/system/the_galaxy/assets/mobile/js/views/ModelManager.js b/starpilot/system/the_galaxy/assets/mobile/js/views/ModelManager.js
index 3d3c13290..f9570ec3a 100644
--- a/starpilot/system/the_galaxy/assets/mobile/js/views/ModelManager.js
+++ b/starpilot/system/the_galaxy/assets/mobile/js/views/ModelManager.js
@@ -24,6 +24,8 @@ export const ModelManager = {
       allowGpu: false,
       models: [],
       currentModel: "",
+      activeSmallModel: "",
+      activeBigModel: "",
       summary: { installed: 0, missing: 0, total: 0 },
       status: {
         modelToDownload: "",
@@ -41,6 +43,12 @@ export const ModelManager = {
       const match = (this.models || []).find((m) => text(m && m.value, "") === key)
       return match ? text(match.label, key) : key
     },
+    installedSmallModels() {
+      return (this.models || []).filter((m) => m?.installed && !m?.requiresGpu)
+    },
+    installedBigModels() {
+      return (this.models || []).filter((m) => m?.installed && !!m?.requiresGpu)
+    },
     sorted() {
       const mode = this.sortMode
       const rows = (this.models || [])
@@ -95,6 +103,8 @@ export const ModelManager = {
         const p = await api.getModelStatus()
         this.models = Array.isArray(p.models) ? p.models.filter((m) => m && typeof m === "object") : []
         this.currentModel = text(p.currentModel, "")
+        this.activeSmallModel = text(p.activeSmallModel, "")
+        this.activeBigModel = text(p.activeBigModel, "")
         const s = p.summary && typeof p.summary === "object" ? p.summary : {}
         this.summary = {
           installed: Number(s.installed) || 0,
@@ -129,8 +139,9 @@ export const ModelManager = {
       this.busy = `${action}:${key}`
       try {
         let msg = ""
-        if (action === "select") {
-          const p = await api.updateParam({ key: "Model", value: key })
+        if (action === "select-small" || action === "select-big") {
+          const profile = action === "select-big" ? "big" : "small"
+          const p = await api.setActiveModel(profile, key)
           msg = p?.message || `Selected "${label}".`
         } else if (action === "download") {
           const p = await api.startModelDownload(key, this.allowGpu)
@@ -222,6 +233,21 @@ export const ModelManager = {
               <button type="button" class="gx-btn gx-btn--tonal" :disabled="!!busy" @click="runAction('refresh')"><i v-if="busy === 'refresh:'" class="bi bi-arrow-repeat gx-spin"></i><i v-else class="bi bi-arrow-clockwise"></i> Refresh</button>
             </div>
 
+            <div class="gx-row" style="border-top:none;">
+              <span class="gx-row__label">Active Small</span>
+              <select class="gx-field" style="flex:1;" :value="activeSmallModel" :disabled="!!busy || status.isOnroad" @change="runAction('select-small', installedSmallModels.find(m => m.value === $event.target.value))">
+                <option v-for="m in installedSmallModels" :key="m.value" :value="m.value">{{ m.label || m.value }}</option>
+              </select>
+            </div>
+
+            <div class="gx-row" style="border-top:none;">
+              <span class="gx-row__label">Active Big</span>
+              <select class="gx-field" style="flex:1;" :value="activeBigModel" :disabled="!!busy || status.isOnroad" @change="$event.target.value ? runAction('select-big', installedBigModels.find(m => m.value === $event.target.value)) : runAction('select-big')">
+                <option value="">None — always use Active Small</option>
+                <option v-for="m in installedBigModels" :key="m.value" :value="m.value">{{ m.label || m.value }}</option>
+              </select>
+            </div>
+
             <div class="gx-row" style="border-top:none;">
               <span class="gx-row__label">Sort</span>
               <select class="gx-field" style="flex:1;" :value="sortMode" @change="sortMode = $event.target.value">
@@ -294,7 +320,7 @@ export const ModelManager = {
                 <button type="button" class="gx-btn gx-btn--danger" :disabled="!!busy" @click="runAction('cancel', m)"><i class="bi bi-x-circle"></i> Cancel</button>
               </template>
               <template v-else-if="rowState(m) === 'installed'">
-                <button type="button" class="gx-btn" :disabled="!!busy" @click="runAction('select', m)"><i class="bi bi-play-fill"></i> Set Active</button>
+                <button type="button" class="gx-btn" :disabled="!!busy" @click="runAction(m.requiresGpu ? 'select-big' : 'select-small', m)"><i class="bi bi-play-fill"></i> Set Active {{ m.requiresGpu ? 'Big' : 'Small' }}</button>
                 <button v-if="!m.builtin" type="button" class="gx-btn gx-btn--tonal" style="color:var(--error);" :disabled="!!busy" @click="runAction('delete', m)"><i class="bi bi-trash"></i> Delete</button>
               </template>
               <template v-else>
diff --git a/starpilot/system/the_galaxy/tests/test_dashboard_stats.py b/starpilot/system/the_galaxy/tests/test_dashboard_stats.py
index 2d16a3d64..c2904dbdc 100644
--- a/starpilot/system/the_galaxy/tests/test_dashboard_stats.py
+++ b/starpilot/system/the_galaxy/tests/test_dashboard_stats.py
@@ -44,9 +44,17 @@ model_manager = ModuleType("openpilot.starpilot.assets.model_manager")
 model_manager.MODEL_LAB_DOWNLOAD_PARAM = "ModelLabModelToDownload"
 model_manager.canonical_model_key = lambda value: str(value or "").strip().lower().replace(" ", "-")
 model_manager.external_gpu_available = lambda: False
+model_manager.disable_big_model_profile = lambda params: (
+  params.put("ActiveBigModel", "none"),
+  params.remove("ActiveBigModelName"),
+  params.remove("ActiveBigModelVersion"),
+)
 def _stub_get_model_profile(params, profile):
   prefix = "ActiveBigModel" if profile == "big" else "ActiveSmallModel"
-  key = params.get(prefix) or ("rdf43" if profile == "small" else "")
+  stored_key = params.get(prefix)
+  if profile == "big" and stored_key == "none":
+    return "", "", ""
+  key = stored_key or ("rdf43" if profile == "small" else "")
   return key, params.get(f"{prefix}Name") or key, params.get(f"{prefix}Version") or ""
 
 
@@ -1851,6 +1859,12 @@ def test_model_profiles_can_be_selected_without_external_gpu(monkeypatch, tmp_pa
   assert status["activeBigModel"] == "big-one"
   assert status["activeSmallModel"] == "small-one"
 
+  disabled = client.put("/api/models/active", json={"profile": "big", "model": ""})
+  assert disabled.status_code == 200
+  assert params.values["ActiveBigModel"] == "none"
+  assert disabled.get_json()["model"] == ""
+  assert client.get("/api/models/status").get_json()["activeBigModel"] == ""
+
   wrong_profile = client.put("/api/models/active", json={"profile": "small", "model": "big-one"})
   assert wrong_profile.status_code == 409
 
diff --git a/starpilot/system/the_galaxy/tests/test_ui_vue_frontend.py b/starpilot/system/the_galaxy/tests/test_ui_vue_frontend.py
index 28b3dc048..589bdb32f 100644
--- a/starpilot/system/the_galaxy/tests/test_ui_vue_frontend.py
+++ b/starpilot/system/the_galaxy/tests/test_ui_vue_frontend.py
@@ -425,7 +425,7 @@ def test_ui_all_remaining_classic_tools_native_no_embed():
   # Shared API surface added for the second batch of ported pages.
   for method in ["selectTestingGround",
                  "getSentryStatus", "getSentryEvents", "deleteSentryEvent", "sentryPushSubscribe",
-                 "getModelStatus", "startModelDownload", "downloadAllModels", "deleteModel", "saveModelPreferences",
+                 "getModelStatus", "setActiveModel", "startModelDownload", "downloadAllModels", "deleteModel", "saveModelPreferences",
                  "getPlotsLive",
                  "getGalaxySession", "deleteNavigationKey",
                  "getThemeList", "saveTheme", "applyTheme", "deleteTheme", "downloadTheme",
diff --git a/starpilot/system/the_galaxy/the_galaxy.py b/starpilot/system/the_galaxy/the_galaxy.py
index 66d52fb39..d3351b17b 100644
--- a/starpilot/system/the_galaxy/the_galaxy.py
+++ b/starpilot/system/the_galaxy/the_galaxy.py
@@ -55,6 +55,7 @@ from panda import Panda
 from openpilot.starpilot.assets.model_manager import (
   MODEL_LAB_DOWNLOAD_PARAM,
   canonical_model_key,
+  disable_big_model_profile,
   external_gpu_available,
   get_model_profile,
   is_builtin_model_key,
@@ -6450,7 +6451,21 @@ def setup(app):
 
     model_key = canonical_model_key(str(data.get("model") or "").strip())
     if not model_key:
-      return jsonify({"error": "Missing model key."}), 400
+      if profile != "big":
+        return jsonify({"error": "Active Small cannot be disabled."}), 400
+
+      lab_config = normalize_model_lab_config(params.get(MODEL_LAB_CONFIG_PARAM, encoding="utf-8") or "")
+      if lab_config["enabled"]:
+        lab_config["enabled"] = False
+        params.put(MODEL_LAB_CONFIG_PARAM, lab_config)
+        params.remove(MODEL_LAB_RUNTIME_PARAM)
+
+      disable_big_model_profile(params)
+      return jsonify({
+        "message": "Active Big disabled. Active Small will be used even when Chestnut is connected.",
+        "profile": profile,
+        "model": "",
+      }), 200
 
     catalog = {model["value"]: model for model in get_model_catalog()}
     model = catalog.get(model_key)
diff --git a/system/hardware/hardwared.py b/system/hardware/hardwared.py
index 9463df11d..648350c3a 100644
--- a/system/hardware/hardwared.py
+++ b/system/hardware/hardwared.py
@@ -428,7 +428,8 @@ def hardware_thread(end_event, hw_queue) -> None:
     if chestnut is not None:
       chestnut.update(started_ts is None, last_hw_state.usb_state)
       model_lab_config = params.get("ModelLabConfig")
-      chestnut_expected = bool(params.get("ActiveBigModel")) or (
+      active_big_model = params.get("ActiveBigModel", encoding="utf-8") or ""
+      chestnut_expected = active_big_model.lower() not in ("", "none") or (
         isinstance(model_lab_config, dict) and bool(model_lab_config.get("enabled"))
       )
       chestnut_state = sm["chestnutState"]