diff --git a/nhf/parts/test.py b/nhf/parts/test.py
index 5685978..0610f8f 100644
--- a/nhf/parts/test.py
+++ b/nhf/parts/test.py
@@ -23,26 +23,27 @@ class TestJoints(unittest.TestCase):
     def test_joints_comma_assembly(self):
         joints.comma_assembly()
 
-    def test_torsion_joint(self):
-        j = joints.TorsionJoint()
-        assembly = j.rider_track_assembly()
-        bbox = assembly.toCompound().BoundingBox()
-        self.assertAlmostEqual(bbox.zlen, j.total_height)
-
-    def torsion_joint_collision_case(self, joint: joints.TorsionJoint, slot: int):
+    def torsion_joint_case(self, joint: joints.TorsionJoint, slot: int):
         assembly = joint.rider_track_assembly(slot)
         bbox = assembly.toCompound().BoundingBox()
         self.assertAlmostEqual(bbox.zlen, joint.total_height)
         self.assertEqual(pairwise_intersection(assembly), [])
 
-    def test_torsion_joint_collision(self):
+    def test_torsion_joint(self):
         j = joints.TorsionJoint()
         for slot in range(j.rider_n_slots):
             with self.subTest(slot=slot):
-                self.torsion_joint_collision_case(j, slot)
-    def test_torsion_joint_collision_right_handed(self):
+                self.torsion_joint_case(j, slot)
+    def test_torsion_joint_right_handed(self):
         j = joints.TorsionJoint(right_handed=True)
-        self.torsion_joint_collision_case(j, 1)
+        self.torsion_joint_case(j, 1)
+    def test_torsion_joint_covered(self):
+        j = joints.TorsionJoint(
+            spring_hole_cover_track=True,
+            spring_hole_cover_rider=True,
+        )
+        self.torsion_joint_case(j, 1)
+
 
 
 class TestHandle(unittest.TestCase):
@@ -63,7 +64,7 @@ class TestMetricThreads(unittest.TestCase):
 
     def test_major_radius(self):
         major = 3.0
-        t = metric_threads.external_metric_thread(major, 0.5, 4.0, z_start= -0.85, top_lead_in=True)
+        t = metric_threads.external_metric_thread(major, 0.5, 4.0, z_start=-0.85, top_lead_in=True)
         bbox = t.val().BoundingBox()
         self.assertAlmostEqual(bbox.xlen, major, places=3)
         self.assertAlmostEqual(bbox.ylen, major, places=3)