Okay guys I need some suggestions. I am building an older bike, don't know the manufacturer, most likely off brand from wards or something. I am to the point of designing the driveline. I am working with a 3.5 briggs with 11 clutch sprocket and 60 tooth wheel sprocket. Due to alignment problems, I am forced to use a jackshaft, got one from OldMiniBikes. here is my question, do I need to bother making the shaft adjustable to allow for chain stretch? I am limited on space and am already unhappy that I need the jackshaft because I am going for a real simple and clean look with as little clutter and bulk as possible. The bike is not going to see a lot of miles ( more of a novelty ) but does need to be fully functional because it will be ridden. I don't want to go to the extent of a tensioner or anything like that, how much chain stretch can I expect and how quickly? Like I said I am looking for old school clean and simple. What do y'all suggest? Can I get away with a non adjustable jackshaft?
Doc, one of the good things about the jack shaft is that the shorter chain sections allow you to get away with more alignment and tension issues. Given your stated aims, this may be okay for you. You'd just have to mess around getting the rear chain on with enough tension to make it work. (Connected chain on both sprockets, THEN slide the wheel axle through)
Otherwise, making the rear axle adjustable is easier than making the JS adjustable with space limitations.
Otherwise, making the rear axle adjustable is easier than making the JS adjustable with space limitations.
okay, after drinking it over a bit I have decided to go ahead and order the adjustable jackshaft mounting plates. I want to be able to change gearing if needed without having to change the chain length to the wheel. plus I can mount the shaft further from the rear tire (instead of close to it to reduce chain stretch) and have room for the scrub brake. thanks for the responses, much appreciated
I may consider the idea, fish. Actually though about it already a little. But then I either have two plates stacked together that the engine mounts to and/or don't have any adjustment between engine and jackshaft. Still an option though. My rear wheel is mounted using DOM tubing welded across the rear frame so there is no possibility for adjustment there.