it says 4.2 in in the pictures but in reality it's 5.2 inches. I've had good interactions with this company in the past Their customer service is also really good. The only reason it's not one star is because they have crazy fast customer service. Read more

Anyone have any idea how to fix this????? The motor takes super long to get up to speed and has 0 torque PLEASE HELP Read more

Amazing kit for the price! I put it in my e bike build and it works so good! It fit right in with no problems all I had to do is drill new holes in the plate. It has pretty good torque but not too much. This is amazing for what comes in the kit. Would 100% buy again Read more

Very little modifications to fit mx500 with great results! Read more

Comes with t8F sprockets, 2 of them for the drive shaft on the motor. I am using this to power my mobility scooter. It has great control, doesn't get hot, and works great. BUT...It is a slow start. Top speed with the 11 tooth drive, and a 28 tooth driven sprockets driving 10 in wheels is still 28mph. But, no torque. I'm gonna have to gear it way down , so it will have more power for hills. All in all, a good value. I don't see this powering a bicycle. A go cart, for sure. And going almost 30mph on a mobility scooter is kinda nuts, too. My old motor only got me 15 mph, but It would do wheelies for a block. No way this is 2000 watts, but the price reflects that. My old motor was 800 dollars, but it lasted 10 years. UPDATE: I got a 54 tooth sprocket for the drive wheels. Still does 25 mph on speed three, 7mph, on speed one, and 15mph on speed two. I can now go right across grass, and do wheelies! Read more