Bests & Worsts Reviews from Amazon

This kit is very basic, and minimal, but with a Twist throttle, and a low price, it's one of the better basic kits out there. It comes with almost everything you need, except the battery wiring, batteries, and Battery bag. If you're looking to emulate a small displacement motorcycle, this is the kit that will do it well. The literature sucks, it's not a reliable source of information. The pictures are very small, and for their intent, are almost useless. It is best to search youtube or look up guides of people building these kits to get a good reference. This thing is an absolute pain in the butt to install. It took me having to take off the rear Derailleur, removing the right side locking washer, and then trying to hold the rear frame open wide enough to get the inside washers into the rear wheel mount. 20 minutes of fighting with this and then having to go back and remove things just to get the wheel into place. Then slowly adjusting and tightening the bolts to align the wheel. The low speed torque and acceleration is not there so, if you want a hard acceleration off the line, you need to pedal a bit to help it get moving. The Cassette gears(it's a free Freewheel) is 6 speed, so if your bike is a 7 speed rear shifter, you will not be able to align the shifter to this new freewheel. You will need to swap to a 6 speed shifter. It's also an absolute struggle to get the rear derailleur realigned to use the gears. It took a while to get it aligned to use the low gears, and the freewheel is incredibly difficult to adjust the shiftier too, but you can use the largest freewheel gears without scratching the wheel. You will need be careful about derailleur travel distance limits. Once the low gears are aligned, and you can pedal off the line, the bike can accelerate well and maintain speed, and yes it will break the 25mph city speed limit. This kit comes with the Cassette(Freewheel AKA the gears) attached already, but it is a 6 speed setup. It is not 7 speed and if you want the shifter to work you will need to redo the rear gears with a 6 speed shifter setup. If you don't do this you will still be able to align the shifter to use the highest gears and the lowest gears but anything in between will be problematic will not shift well. You cannot change the gears out for a 7 speed either as the 7 speed freewheels are too wide. The battery connection wires are 12 Gage, so you will need 12 or 10 gage terminals and wire crimpers. The Twist throttle is only half of the grip, the entire grip handle included does not twist. Throttle uses a 3 light system to show battery life, and available power, and the red button is system on/off. Depending on your stock brakes, you may need to replace the lines with larger heads. The loop for the brake head is slightly larger than your standard Mountain bike brake line head. Spokes, Rim, and motor casing is weaker and less shock resistant than your standard bicycle rim, it will not take the same stresses as a mountain bike rear tire. This kit is really meant for the road and paved trails, not at all for anything offroad or unpaved. The spokes needed to be tightened up out of the box. If you do not check the spokes the wheel might fail and you will get hurt. The rim is slightly wider width than a standard MTB Bike rim, so you will need to adjust the rear cable. None of the cables are sleeved well, and need to be cautiously bound up with electric tape up to their connectors. Some of the wires are flimsy feeling so be careful with them. The bag it comes with is very small and can only fit the controller inside. It will not fit the wiring in with it. The little Blue connector on the controller is a Speed Limiter that limits the system to 20 mph. Leave it disconnected for higher speeds. Top speed of this system is 31mph regardless of weight below 210lbs total gross weight(Bike and Rider) Under load this kit will handle 31mph cruise speeds with a 48volt Lithium battery. This limitation is on the battery voltage and amperage for the controller for this kit, and not the motor. The controller handles a maximum of 60volts, so do not use a battery above a 48volt rating.(52volt rated Battery maximum.) DO NOT USE LEAD BATTERIES WITH THIS KIT, YOU WILL KILL THEM VERY QUICKLY. Do not order a set of SLA, or AGM or any lead primary battery to go with this kit, you will get about 100miles of good usage, and 300 miles of true usage. You will be replacing the lead batteries every few hundred miles. Get a LiFePO4 48Volt or Li-ion 48volt Battery pack instead. Do not make the same mistake I did, get a Lithium battery! The tire(that my kit came with preinstalled) is a terrible road oriented tread, with side grips. They're awful for anything other than going in a straight line. I suggest replacing them immediately with proper road tires. Inner Tube is schrader valve. I use KENDA 838 motorcycle style tires with 60PSI Rear pressure, 45PSI Front. GET A REAL TORQUE ARM FOR THIS KIT, OR YOU WILL DESTROY YOUR BICYCLE. DO NOT RUN THIS KIT WITHOUT ONE. DO NOT USE THE CHINESE ONE. Get the Grin Tech V4 torque arm. Grin Technologies Universal Rear Torque Arm V4 Overall, great kit with terrible documentation. Requires basic knowledge of how to do electrical wiring, and intermediate knowledge of Bicycle technical know how. Does not require any specialist tools. Requires batteries and battery bag that will fit batteries and controller inside, and a means to cover and protect all the wires for the controller and kit. 1000 Mile Update: Ticked over 1000 Miles on the bike, now and the kit is holding up well. I upgraded the brakes to Koolstop Dual Compound, they have enough stopping force to throw you over the handle bars. Personal experience after a Prius cut me off and tried to kill me. Kool-Stop Dual Compound Mountain Pads Updated the pictures.