diff --git a/ebikes/README.md b/ebikes/README.md
index 8495fae..7e6404b 100644
--- a/ebikes/README.md
+++ b/ebikes/README.md
@@ -72,6 +72,8 @@ Display Working Temperature: -20-80C
 
 #### power transmission
 
+https://www.elecycles.com/blog/post/how-much-do-you-know-about-the-e-bike-motor-parameters/
+
 ### battery
 
 ### charger