Thats some smart thinkin right there. As far as room goes though my frame will prob be something like 15 inches wide on account of 11 inch wide tires. I still need to run down and hold these parts in my hand and think about what ill do. Nothing is set in stone yet, just a few tack welds on a mock.
First scratch build, off road mini bike.
- Thread starter jared8783
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mckutzy
Well-known member
Id say dont tackweld any drive line products until your sure, If they are "used or modified" the store might/most likely not take them back.
Yeah I've thought about that. I'll be as careful as I can but this is my first scratch build so I might end up buying parts that I can't use or return. Oh well I'm really looking forward to this. If I have extra parts they can just be used for future projects. As soon as I'm done with this post I'm going to be parking my car outside and covering it so I can set up a mini starter fab shop in the car's space.
I'm still trying to figure out the details to the two speed manual shifting thing. And I'm still considering scrapping that Idea and just gearing it out for 15 mph (instead of 10mph and 20mph). But I just really want to do it since even on a one speed set up I will still need to use a second jackshaft for gear reduction.
I'm still trying to figure out the details to the two speed manual shifting thing. And I'm still considering scrapping that Idea and just gearing it out for 15 mph (instead of 10mph and 20mph). But I just really want to do it since even on a one speed set up I will still need to use a second jackshaft for gear reduction.
Ok progress update. I haven't really done anything more for the bike except built a steel stand for the frame to hold it while I build it and weld it. I have also decided to use a different method of engaging sprockets on the jack shaft. I'm going to have a sprocket hub machined to accept a sprocket on both sides. Honestly Ill prob have two hubs machined down so they aren't as wide, but welded together wider than a single hub. Then take two sprockets and weld them on the hub. As thick of steel as that is Ill take it to work to weld that. Ill grind the teeth off so that they are just discs. Drill several holes in the discs for rods, and matching holes in the idlers so that my home made gear engage can engage them.
As of right now I plan on drilling and tapping the hub and shaft and using a big bolt and a ratchet on the trails to shift. I figure I will use first gear rarely and kinda think it would be cool to use a wrench to shift. Plus that system ought to never break. Though I am open to Ideas on how to shift using a lever that maybe has a skateboard bearing on the end that contacts the discs. Just don't know I would keep the gear locked in with a lever.
Last weekend I spent 24 hours in my garage between two days setting up my first shop (gotta put a pic of this in the baby book). I had to boot my rust free 90 miata outside for this but it's worth it. I'll get a cover for her and perhaps warehouse it for the winter. Unfortunately I still stay with my mother so yeah, I only can have one stall. And I got two cars, two work benches, standard tool chest, drill press, band saw, and a mountain of parts for the miata. Bought a parts car years ago, stripped it and scrapped the chassis. Anyways now I have a decent work shop. Bought the steel a few days ago to build a big welding table. The top will be 3'x6'. Got two sheets (3/32" i think) and am doubling them up. I have 60 feet of 11 gauge 1.5x1.5 that I will use for the framing and I am trying to find some side crank rv jacks for cheap to install on each leg of the table so I can not only adjust level but have a foot or so of play in table height. You know where I can pick those up for cheap Rick?
I will build the table for the shop this weekend and hopefully have time left to work on the bike as well. I plan on buying the torque converter pulleys and jack shafts this weekend if I can find them.
this is the small stand you see in the pic of the garage that the mock frame is sitting on
As of right now I plan on drilling and tapping the hub and shaft and using a big bolt and a ratchet on the trails to shift. I figure I will use first gear rarely and kinda think it would be cool to use a wrench to shift. Plus that system ought to never break. Though I am open to Ideas on how to shift using a lever that maybe has a skateboard bearing on the end that contacts the discs. Just don't know I would keep the gear locked in with a lever.
Last weekend I spent 24 hours in my garage between two days setting up my first shop (gotta put a pic of this in the baby book). I had to boot my rust free 90 miata outside for this but it's worth it. I'll get a cover for her and perhaps warehouse it for the winter. Unfortunately I still stay with my mother so yeah, I only can have one stall. And I got two cars, two work benches, standard tool chest, drill press, band saw, and a mountain of parts for the miata. Bought a parts car years ago, stripped it and scrapped the chassis. Anyways now I have a decent work shop. Bought the steel a few days ago to build a big welding table. The top will be 3'x6'. Got two sheets (3/32" i think) and am doubling them up. I have 60 feet of 11 gauge 1.5x1.5 that I will use for the framing and I am trying to find some side crank rv jacks for cheap to install on each leg of the table so I can not only adjust level but have a foot or so of play in table height. You know where I can pick those up for cheap Rick?
I will build the table for the shop this weekend and hopefully have time left to work on the bike as well. I plan on buying the torque converter pulleys and jack shafts this weekend if I can find them.
this is the small stand you see in the pic of the garage that the mock frame is sitting on
Cole Tallerman
Cole Tallerman
I recently built a machine exactly like your trying to build. I just used a centrifugal clutch and geared it down with a jackshaft so it tops out at about 20 mph. I was originally planing on upgrading to a TC but I found that with this gearing i was doing burnouts on pavement and it will haul 3 people up a pretty steep hill! I was impressed. If you would like some pictures I can probably get them this weekend.
robbie
New member
I'm going to build a fat tire bike with a centrifugal clutch as soon as I can buy a few more parts. Can you tell us your tooth count and tire size?
Well since my last post there has been little to no progress on the bike. Been setting up shop and building a solid welding table to work on. And my cvt pulleys have come in. I went with comet series 20 symmetrical with a 7" driven pulley. Now I can start mocking up the drive system and them mock the frame around it.
rmm727
New member
This may help you. I don't think this pic belongs to porschedude so I don't think he will mind. He posted this on OMB the other day. I ran across your thread and thought, man that sounds familiar.
firemanjim
Just kartin' around....
Uhhh, where can someone buy one of those? That's pretty fancy!
mckutzy
Well-known member
So what is that from?
Looks like a scrub brake and 2 speed all in one on the swing arm.
Looks like a scrub brake and 2 speed all in one on the swing arm.
firemanjim
Just kartin' around....
About 4" down......
Nice work!! Did you cut, bend and weld those bends
OzFab
Well-known member
It appears so; that's what I call dedication 
Yes, yes I did cut and bend. Thank you. I got this build on a motorized bicycle forum also cause I used to be active there years ago. Someone living 20 minutes away from me saw the thread and we met up. He is teaching me lots of tricks for building these sorts of things from scratch.
OzFab
Well-known member
Cool, sweet deal when you can find someone who can teach you all the little tips & tricks.
My buddies Kurt & Pete are like that, we're all on similar wavelengths but, we all specialise in different areas so, we sort of teach eachother.
One example: Pete was having trouble with the tailstock on his lathe not clamping properly so, I pointed out the big nut underneath it; he hasn't had a problem with it since...
The simple things make the biggest difference...
My buddies Kurt & Pete are like that, we're all on similar wavelengths but, we all specialise in different areas so, we sort of teach eachother.
One example: Pete was having trouble with the tailstock on his lathe not clamping properly so, I pointed out the big nut underneath it; he hasn't had a problem with it since...
The simple things make the biggest difference...
Update with pics and vids
By the way I will be using belts and pulleys for the two speed set up.
http://www.youtube.com/watch?v=yI3x136SQWw
By the way I will be using belts and pulleys for the two speed set up.
http://www.youtube.com/watch?v=yI3x136SQWw
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