https://www.amazon.com/UAUS-Adjustable-Tensioner-Motorized-Bicycle/dp/B07QJBSBYJ/ref=mp_s_a_1_19?crid=374PTZ9PZ380P&keywords=spring+tensioner+motorized+bike+uhaus&qid=1681088376&sprefix=spring+tensioner+motorized+bike+uhaus%2Caps%2C161&sr=8-19 I run this on one of my bikes it works well but the best way is to figure out how to run no tensioner https://www.amazon.com/Tensioner-Single-Adjuster-Converter-Racing/dp/B08B3W3GMH/ref=asc_df_B08B3W3GMH/?tag=hyprod-20&linkCode=df0&hvadid=475805715755&hvpos=&hvnetw=g&hvrand=17449613538883218819&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9033615&hvtargid=pla-1131060627273&psc=1 I use this on my other bike it takes the slack of the pedal chain and I run no tensioner on the drive chain