Hey guys, some people have said that in order to mount your sprocket right, you need what's called a "sprocket holder hub". I've seen one on Amazon and they look alright, but I was thinking I could just take the sprocket and weld on a really wide piece of iron pipe and then weld that to wheelbarrow rim. I wanted to know if anybody has experience with this type of thing or if it's not a smart thing to do :shrug: any advice is welcome. Thanks
you don't want to use a wheelbarrow wheel on a mini bike. they are not designed for anything over a few mph (like pushing a wheelbarrow) and are not safe.
i did a search on "sprocket holder hub" and that's something used for a live axle set up. you're still going to have to get a wheel that you can mount a sprocket to. i'm lost on where the iron pipe would come into play here.
i did a search on "sprocket holder hub" and that's something used for a live axle set up. you're still going to have to get a wheel that you can mount a sprocket to. i'm lost on where the iron pipe would come into play here.
If you can come up with a rim that runs true enough for a minibike the next challenge would be to weld to it without distorting it. Miging a number of tacks would be the most likely way to pull that off. The hub would need to come off the rim concentric and perpendicular. Mount a proper tire and you've done it.
I've thought about the same thing --I would pull the bearings out --sleeve the pipe to the outside of the bearing extention--check for squarness then mig--don't make the hub too long so you can get the bearing back in. If you weld a sprocket flang to the pipe before you weld to the rim then you can reject any attempt to put the flange on square that didn't end up square. Once you've got a pipe with a flang that is true--- then weld it to the rim. Might want to drill that flange before you weld it to the pipe too. It has to be really good work as far as square and concentric or it will just toss chains.
I've thought about the same thing --I would pull the bearings out --sleeve the pipe to the outside of the bearing extention--check for squarness then mig--don't make the hub too long so you can get the bearing back in. If you weld a sprocket flang to the pipe before you weld to the rim then you can reject any attempt to put the flange on square that didn't end up square. Once you've got a pipe with a flang that is true--- then weld it to the rim. Might want to drill that flange before you weld it to the pipe too. It has to be really good work as far as square and concentric or it will just toss chains.
In my humble opinion a guy will never get the sprocket run-out within acceptable limits unless the sprocket adapter is lathe turned with concentric surfaces. The stock sprocket will have a hole in the center that must fit reasonably close on a shoulder on the adapter. That register MUST be concentric with the axle bearings. In the absence of this register the several bolts that attach it to the adapter WILL NOT suffice in keeping it running true so that the chain does not get radically looser and tighter as the sprocket rotates. That would be just one of the problems to overcome if the job is to be a chop saw and welder project. Adapters are available but not for all applications when the bolt circle on the rim, the distance between rim and sprocket, the sprocket I.D. and bolt circle can be very different on different bikes.
Wow, this project just got a lot more technical and complex. But thanks for all of the help guys, I really appreciate it. I think I might go out and buy a set of small moped wheels or something so that they have stronger ball-bearings and see if I can find some that are easier to mount a sprocket to. But this has all been helpful. I'll see about getting a flange, or I'll improvise. Thanks again
So since I'm a newbie and I'm building everything from stock, I wanted to know how you guys (minibikers in general) mounted your sprockets. Do the wheels come with a mount for the sprocket or what? And to mini bikes generally use 'live axles" like on a go-kart with the sprocket mounted TO the axle???
given your lack of mini bike parts availability you mite be better of going with a live axle . you could take the drive tire off a riding mower or some powered cart . mount that to the shaft the get a gear flange and mount that .
the gear hub like this AZ2037 - "B" Type Hub 5/8" Bore. P5256 pattern.
the wheel would have a key way to mount it to the shaft .
you could pull parts out of farm machines processing stuff . you would nee to use pillow block bearings but it mite be easier then making a hub with limited tooling and supplys :shrug:
the gear hub like this AZ2037 - "B" Type Hub 5/8" Bore. P5256 pattern.
the wheel would have a key way to mount it to the shaft .
you could pull parts out of farm machines processing stuff . you would nee to use pillow block bearings but it mite be easier then making a hub with limited tooling and supplys :shrug: