HOTEBIKE electric bikes have adjustable stems installed on a 26-inch e-bike to make it a 27.5 electric bike. They are more flexible than standard stem risers. Tyres should match the wheels. Or.... Based on your needs, you may choose 26"x1.95" tyre size. To increase the speed of the e-mountain bike, a 500W motor is used. The rear wheel had a motor, so it could go fast like 35-40 mph. Since the electric bike always has enough power for riders, the 500W will get the job done no matter how you use it. This bike has a 48-volt lithium battery. Fully charged, it has a range of 40-60 km. It has a removable battery so it's easy to recharge. Charge the battery by removing the key and plugging it in Charge the battery with the supplied charger, then wait 5-7 hours for it to recharge. The handle bar has an LCD display that displays the battery level and time. It's cool. Get 2.35 inch tyres to fit 26 inch wheels. Bigger than regular tyres, which are 1.95 inches. You can ride on them. Better stability.