diff --git a/lerobot/common/motors/dynamixel/dynamixel.py b/lerobot/common/motors/dynamixel/dynamixel.py
index b3e11053..b0f9556f 100644
--- a/lerobot/common/motors/dynamixel/dynamixel.py
+++ b/lerobot/common/motors/dynamixel/dynamixel.py
@@ -16,7 +16,6 @@ import logging
 import math
 from copy import deepcopy
 
-import dynamixel_sdk as dxl
 import numpy as np
 
 from ..motors_bus import (
@@ -172,24 +171,21 @@ def convert_degrees_to_steps(degrees: float | np.ndarray, models: str | list[str
     return steps
 
 
-def convert_to_bytes(value, bytes, mock=False):
-    if mock:
-        return value
-
+def convert_to_bytes(value, n_bytes: int):
     import dynamixel_sdk as dxl
 
     # Note: No need to convert back into unsigned int, since this byte preprocessing
     # already handles it for us.
-    if bytes == 1:
+    if n_bytes == 1:
         data = [
             dxl.DXL_LOBYTE(dxl.DXL_LOWORD(value)),
         ]
-    elif bytes == 2:
+    elif n_bytes == 2:
         data = [
             dxl.DXL_LOBYTE(dxl.DXL_LOWORD(value)),
             dxl.DXL_HIBYTE(dxl.DXL_LOWORD(value)),
         ]
-    elif bytes == 4:
+    elif n_bytes == 4:
         data = [
             dxl.DXL_LOBYTE(dxl.DXL_LOWORD(value)),
             dxl.DXL_HIBYTE(dxl.DXL_LOWORD(value)),
@@ -199,7 +195,7 @@ def convert_to_bytes(value, bytes, mock=False):
     else:
         raise NotImplementedError(
             f"Value of the number of bytes to be sent is expected to be in [1, 2, 4], but "
-            f"{bytes} is provided instead."
+            f"{n_bytes} is provided instead."
         )
     return data
 
@@ -255,6 +251,8 @@ class DynamixelMotorsBus(MotorsBus):
         super().__init__(port, motors)
 
     def _set_handlers(self):
+        import dynamixel_sdk as dxl
+
         self.port_handler = dxl.PortHandler(self.port)
         self.packet_handler = dxl.PacketHandler(PROTOCOL_VERSION)
 
@@ -486,6 +484,8 @@ class DynamixelMotorsBus(MotorsBus):
         return values
 
     def read_with_motor_ids(self, motor_models, motor_ids, data_name, num_retry=NUM_READ_RETRY):
+        import dynamixel_sdk as dxl
+
         return_list = True
         if not isinstance(motor_ids, list):
             return_list = False
@@ -519,6 +519,8 @@ class DynamixelMotorsBus(MotorsBus):
             return values[0]
 
     def _read(self, data_name, motor_names: str | list[str] | None = None):
+        import dynamixel_sdk as dxl
+
         motor_ids = []
         models = []
         for name in motor_names:
@@ -566,6 +568,8 @@ class DynamixelMotorsBus(MotorsBus):
         return values
 
     def write_with_motor_ids(self, motor_models, motor_ids, data_name, values, num_retry=NUM_WRITE_RETRY):
+        import dynamixel_sdk as dxl
+
         if not isinstance(motor_ids, list):
             motor_ids = [motor_ids]
         if not isinstance(values, list):
@@ -575,7 +579,7 @@ class DynamixelMotorsBus(MotorsBus):
         addr, bytes = self.model_ctrl_table[motor_models[0]][data_name]
         group = dxl.GroupSyncWrite(self.port_handler, self.packet_handler, addr, bytes)
         for idx, value in zip(motor_ids, values, strict=True):
-            data = convert_to_bytes(value, bytes, self.mock)
+            data = convert_to_bytes(value, bytes)
             group.addParam(idx, data)
 
         for _ in range(num_retry):
@@ -590,6 +594,8 @@ class DynamixelMotorsBus(MotorsBus):
             )
 
     def _write(self, data_name: str, values: list[int], motor_names: list[str]) -> None:
+        import dynamixel_sdk as dxl
+
         motor_ids = []
         models = []
         for name in motor_names:
@@ -611,7 +617,7 @@ class DynamixelMotorsBus(MotorsBus):
             )
 
         for idx, value in zip(motor_ids, values, strict=True):
-            data = convert_to_bytes(value, bytes, self.mock)
+            data = convert_to_bytes(value, bytes)
             if init_group:
                 self.group_writers[group_key].addParam(idx, data)
             else:
diff --git a/lerobot/common/motors/feetech/feetech.py b/lerobot/common/motors/feetech/feetech.py
index c62f63d6..a0bcc083 100644
--- a/lerobot/common/motors/feetech/feetech.py
+++ b/lerobot/common/motors/feetech/feetech.py
@@ -15,7 +15,6 @@
 from copy import deepcopy
 
 import numpy as np
-import scservo_sdk as scs
 
 from ..motors_bus import (
     CalibrationMode,
@@ -185,24 +184,21 @@ def adjusted_to_motor_ticks(adjusted_pos: int, model: str, motorbus, motor_id: i
     return ticks
 
 
-def convert_to_bytes(value, bytes, mock=False):
-    if mock:
-        return value
-
+def convert_to_bytes(value, n_bytes: int):
     import scservo_sdk as scs
 
     # Note: No need to convert back into unsigned int, since this byte preprocessing
     # already handles it for us.
-    if bytes == 1:
+    if n_bytes == 1:
         data = [
             scs.SCS_LOBYTE(scs.SCS_LOWORD(value)),
         ]
-    elif bytes == 2:
+    elif n_bytes == 2:
         data = [
             scs.SCS_LOBYTE(scs.SCS_LOWORD(value)),
             scs.SCS_HIBYTE(scs.SCS_LOWORD(value)),
         ]
-    elif bytes == 4:
+    elif n_bytes == 4:
         data = [
             scs.SCS_LOBYTE(scs.SCS_LOWORD(value)),
             scs.SCS_HIBYTE(scs.SCS_LOWORD(value)),
@@ -212,7 +208,7 @@ def convert_to_bytes(value, bytes, mock=False):
     else:
         raise NotImplementedError(
             f"Value of the number of bytes to be sent is expected to be in [1, 2, 4], but "
-            f"{bytes} is provided instead."
+            f"{n_bytes} is provided instead."
         )
     return data
 
@@ -268,6 +264,8 @@ class FeetechMotorsBus(MotorsBus):
         super().__init__(port, motors)
 
     def _set_handlers(self):
+        import scservo_sdk as scs
+
         self.port_handler = scs.PortHandler(self.port)
         self.packet_handler = scs.PacketHandler(PROTOCOL_VERSION)
 
@@ -340,6 +338,8 @@ class FeetechMotorsBus(MotorsBus):
         return values
 
     def read_with_motor_ids(self, motor_models, motor_ids, data_name, num_retry=NUM_READ_RETRY):
+        import scservo_sdk as scs
+
         return_list = True
         if not isinstance(motor_ids, list):
             return_list = False
@@ -373,6 +373,8 @@ class FeetechMotorsBus(MotorsBus):
             return values[0]
 
     def _read(self, data_name, motor_names: str | list[str] | None = None):
+        import scservo_sdk as scs
+
         motor_ids = []
         models = []
         for name in motor_names:
@@ -420,6 +422,8 @@ class FeetechMotorsBus(MotorsBus):
         return values
 
     def write_with_motor_ids(self, motor_models, motor_ids, data_name, values, num_retry=NUM_WRITE_RETRY):
+        import scservo_sdk as scs
+
         if not isinstance(motor_ids, list):
             motor_ids = [motor_ids]
         if not isinstance(values, list):
@@ -429,7 +433,7 @@ class FeetechMotorsBus(MotorsBus):
         addr, bytes = self.model_ctrl_table[motor_models[0]][data_name]
         group = scs.GroupSyncWrite(self.port_handler, self.packet_handler, addr, bytes)
         for idx, value in zip(motor_ids, values, strict=True):
-            data = convert_to_bytes(value, bytes, self.mock)
+            data = convert_to_bytes(value, bytes)
             group.addParam(idx, data)
 
         for _ in range(num_retry):
@@ -444,6 +448,8 @@ class FeetechMotorsBus(MotorsBus):
             )
 
     def _write(self, data_name: str, values: list[int], motor_names: list[str]) -> None:
+        import scservo_sdk as scs
+
         motor_ids = []
         models = []
         for name in motor_names:
@@ -465,7 +471,7 @@ class FeetechMotorsBus(MotorsBus):
             )
 
         for idx, value in zip(motor_ids, values, strict=True):
-            data = convert_to_bytes(value, bytes, self.mock)
+            data = convert_to_bytes(value, bytes)
             if init_group:
                 self.group_writers[group_key].addParam(idx, data)
             else: