manual

I'm currently building a 125cc 4 speed manual motor onto a bicycle but I'm unsure what sprocket sizes I should chose. I want to have a decent amount of top speed (80kmh should be easy with a 4 speed transmission) but still have acceleration around the city. Any help is appreciated.

Hello, I'm trying to install an engine kit on my Mongoose Excursion 27.5". This bike is 21 speed, and has this assembly on the back of the bike. In order for this engine kit to work, it needs to have one large gear on the pedals, and the shifter on the back wheel needs to go. I was wondering...

Hello, I'm trying to install an engine kit on my Mongoose Excursion 27.5". This bike is 21 speed, and has this assembly on the back of the bike. In order for this engine kit to work, it needs to have one large gear on the pedals, and the shifter on the back wheel needs to go. I was wondering...

Hey everyone, I've been a lurker here for quite a while and it's ridiculous how great this community is. Anyway, I've found several sites selling what seems to be a manual clutch. The build quality of the product itself and the sites that it's sold on look a little sketchy, but if the product...