StreetFighter Rear Diff Setup

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Apr 22, 2021
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Yes, that is correct, the fixed gears would be at the ends of the axle to drive both wheels at the same time. The drive wheels would be a single speed freewheel like a BMX or cruiser bike, the crank powers the axle via a freewheel cassette or single speed. Now that I am thinking about it the fixed gears on the end of the axle might need to be replaced with freewheel single speed or the slower wheel might get a little jittery in a corner, kind of like a positraction that doesn't like to disengauge fully, either way the consept is the same.
Ok, so 4 freewheels, all single tooth and same tooth count and the cassette assembly?
 
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The other question that just came to mind is how do I get the freewheel to rotate in reverse on the left "driver side" wheel because isn't it a thread on and just ratchet click otherwise?
 
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If you're using the freewheel adapters, just have it face the same direction, so all three adapters with the threaded side facing towards the right side, pretty simple
 
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It would be on both, the problem would be to allow the "slip" smoothly wh ile pedaling during a corner. Thechnically you could go with a fixe hub or fixed gear on the wheels, but the freewheel hubs/wheels are easier to find, basically with the freewheels on the axle it should work like a differencial, just kind of backwards. If you just coast through a corner the freewheels on the drive wheels would let the wheels turn at different rates because they would be in freewheel/coasting "mode", under power the slower wheel or inside (to the corner) wheel would be getting the power while the outside ot faster wheel would freewheel the gear on the axle, a normal differencial power would be applied to the outside or faster wheel. I had to do a test on my current trike as I was overthinking and something didn't add up right, And if you have disk brakes on both drive wheels it would increase the stopping power, or if you have then set up with a lever for each wheel while coasting you might be able to use it to make sharper turns, but that would be more for stunts and fun then cruising around.
 
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It would be on both, the problem would be to allow the "slip" smoothly wh ile pedaling during a corner. Thechnically you could go with a fixe hub or fixed gear on the wheels, but the freewheel hubs/wheels are easier to find, basically with the freewheels on the axle it should work like a differencial, just kind of backwards. If you just coast through a corner the freewheels on the drive wheels would let the wheels turn at different rates because they would be in freewheel/coasting "mode", under power the slower wheel or inside (to the corner) wheel would be getting the power while the outside ot faster wheel would freewheel the gear on the axle, a normal differencial power would be applied to the outside or faster wheel. I had to do a test on my current trike as I was overthinking and something didn't add up right, And if you have disk brakes on both drive wheels it would increase the stopping power, or if you have then set up with a lever for each wheel while coasting you might be able to use it to make sharper turns, but that would be more for stunts and fun then cruising around.
It's going to take the characteristics of a real car as far as each wheel having a brake, etc. I think the only thing confusing me is having fixed cogs or freewheels on the axle that shares the cassette for power to the wheels
 
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Yes, that is correct, the fixed gears would be at the ends of the axle to drive both wheels at the same time. The drive wheels would be a single speed freewheel like a BMX or cruiser bike, the crank powers the axle via a freewheel cassette or single speed. Now that I am thinking about it the fixed gears on the end of the axle might need to be replaced with freewheel single speed or the slower wheel might get a little jittery in a corner, kind of like a positraction that doesn't like to disengauge fully, either way the consept is the same.
Wanting to clarify what's in bold
 
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Wow, that was back when Brad had more Hair than Worries. ;)
 
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I don't understand the question. You need a setup simular to how Brad's bike is, just don't need to have the jackshaft/axle as far away as he does. The gear on the end of the axle just needs to be a few inches away from the drive wheels. I'll try yo give an oversized visual, so imagine two of the same bike with from the seatpost forward cut off and where the crank goes still intact. Put the drive wheels in each one just like it would be if it was stilll a whole bike and place them parallel to each other say 24 inches apart (the distance doesn't matter, just using it as a referance), so both of the back halves are side by side with the seatpost facing towards the front of the bike. Next you have an axle with two single speed gears at either end of the axle and inline with the gear on each drive wheel going through where the crank would be at. put a multi speed cassette or single speed gea in the middle of the axle inline with a crank at the front of the bike, now the only other thing is to tie the two back halves together using framing, but make sure it doesn't interfear with any of the chains. If you put the freewheels on the drive wheels, the axle will have to be completely in front of the drive wheels, if you have the fixed gears on the drive wheels the axle can be put inbetween the srive wheels with clearance for the gears, but the drive wheel on the right would have to be fliped over so the gears of both drive wheels would be in the inside to be inline with the axle gears. There use to be a freewheel hub and gears that would run on the left side of the bike instead of the right side, but I don't know if they are still around or how hard they may be to find.
 
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I don't understand the question. You need a setup simular to how Brad's bike is, just don't need to have the jackshaft/axle as far away as he does. The gear on the end of the axle just needs to be a few inches away from the drive wheels. I'll try yo give an oversized visual, so imagine two of the same bike with from the seatpost forward cut off and where the crank goes still intact. Put the drive wheels in each one just like it would be if it was stilll a whole bike and place them parallel to each other say 24 inches apart (the distance doesn't matter, just using it as a referance), so both of the back halves are side by side with the seatpost facing towards the front of the bike. Next you have an axle with two single speed gears at either end of the axle and inline with the gear on each drive wheel going through where the crank would be at. put a multi speed cassette or single speed gea in the middle of the axle inline with a crank at the front of the bike, now the only other thing is to tie the two back halves together using framing, but make sure it doesn't interfear with any of the chains. If you put the freewheels on the drive wheels, the axle will have to be completely in front of the drive wheels, if you have the fixed gears on the drive wheels the axle can be put inbetween the srive wheels with clearance for the gears, but the drive wheel on the right would have to be fliped over so the gears of both drive wheels would be in the inside to be inline with the axle gears. There use to be a freewheel hub and gears that would run on the left side of the bike instead of the right side, but I don't know if they are still around or how hard they may be to find.
I'm still confused. Am I using fixed gears or freewheels on the axle that shares the cassette? The whole concept of freewheel and fixed single gear doesn't make sense terminology wise. Can I just use 4 of these? https://www.hutchseugene.com/product/odyssey-bmx-freewheel-319753-1.htm

To clarify what I was asking, the unit itself needs a way to stay put so that the rear end doesn't come out like when an overpowered muscle car loses it's rear diff when launching too hard.

Possible solution:

I think I might just weld some bolts to the axle end and call it good. My logic last night was to cut the head off the bolt and weld it directly in the center of the axle shaft, as it appears solid, and use the rear forks welded to the frame to keep the axle in place
 
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You can use 4 of those, but 2 is enough.
As long as each wheel is on one of those, it is OK.
The wheels keep spinning as you stop peddling.
That is why, the rest doesn't need it.
 
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You can use 4 of those, but 2 is enough.
As long as each wheel is on one of those, it is OK.
The wheels keep spinning as you stop peddling.
That is why, the rest doesn't need it.
But what about the potential jittery ness in turn from the fixed gear that was mentioned? I think I'll run 4 freewheels to be on the safe side. Great, now I just need to get a machine shop to make a few parts for me to make it work.

Regarding my idea on welding a bolt on the axles to keep in place. Will it work?
 
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As you make a corner, the other will turn faster, but that is no problem because it can spin free with one of them. The other will be powered.
It is just as that one way diff from that we side. Only instead of 1 chain to the back, you have 2 chains.
You can keep the rear drive system the same as on the street fighter. That is probably also a one way with the gears, but that is no problem and you can keep that.
 
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