StreetFighter Rear Diff Setup

Joined
Apr 22, 2021
Messages
50
I plan on adding a posi diff to StreetFighter, but not sure exactly how to go about it as it will be motor free. I have an image, just need help implementing it. Thanks

 
Joined
Jan 14, 2019
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Location
Great Mills, MD
If all you're interested in is driving both rear wheels you could use a freewheel differential. It involves mounting single speed freewheels on the end of each axle and connecting with rods and spacers as depicted in this drawing by Savarin. You can leave out the drive sprocket if you're using a multispeed freewheel per the plans. You'd need to keep the axles longer to mount the differential and looking at Figure 62 in the streetfighter plans there may be enough room to insert a differential between the freewheel and left axle.


If you don't want to make your own Utah Trikes and Staton-inc both make ready made solutions.

Utah Trikes UTCustom Freewheel Posi Differential
Staton Freewheel Differential 3/4" OD shafts
Staton Freewheel Differential for 5/8" OD shafts
 
Joined
Apr 22, 2021
Messages
50
If all you're interested in is driving both rear wheels you could use a freewheel differential. It involves mounting single speed freewheels on the end of each axle and connecting with rods and spacers as depicted in this drawing by Savarin. You can leave out the drive sprocket if you're using a multispeed freewheel per the plans. You'd need to keep the axles longer to mount the differential and looking at Figure 62 in the streetfighter plans there may be enough room to insert a differential between the freewheel and left axle.


If you don't want to make your own Utah Trikes and Staton-inc both make ready made solutions.

Utah Trikes UTCustom Freewheel Posi Differential
Staton Freewheel Differential 3/4" OD shafts
Staton Freewheel Differential for 5/8" OD shafts
I'm going with UtahTrike's parts as I've been on their site for the last few days. Great stuff! I think I have everything accounted for now regarding how this project will play out. I meet with the welder this week, so we'll go from there after that.
 
Joined
Apr 22, 2021
Messages
50
If all you're interested in is driving both rear wheels you could use a freewheel differential. It involves mounting single speed freewheels on the end of each axle and connecting with rods and spacers as depicted in this drawing by Savarin. You can leave out the drive sprocket if you're using a multispeed freewheel per the plans. You'd need to keep the axles longer to mount the differential and looking at Figure 62 in the streetfighter plans there may be enough room to insert a differential between the freewheel and left axle.


If you don't want to make your own Utah Trikes and Staton-inc both make ready made solutions.

Utah Trikes UTCustom Freewheel Posi Differential
Staton Freewheel Differential 3/4" OD shafts
Staton Freewheel Differential for 5/8" OD shafts
I met with the welder today and it sounds like the posi diff will be a little more complicated than I thought, so I might have to go with the one you suggested on here. I'm planning on using the Timberwolf rear end so I can have the rear shock.
 
Joined
Sep 16, 2018
Messages
848
Location
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Sorry, something like this.


You can do it with 3, but 4 is best. 2 in the middle and than the other 2 on each axle.
Than you only need to connect it to a chainring on one side and you are ready.
Very simple system.
You don't need any freewheel gears, only a couple of bearings.

This system, but with a chain afcourse.
 
Last edited:
Joined
Apr 22, 2021
Messages
50
Sorry, something like this.


You can do it with 3, but 4 is best. 2 in the middle and than the other 2 on each axle.
Than you only need to connect it to a chainring on one side and you are ready.
Very simple system.
Spider gears... Now I understand 😁

Do I need a cage for it? I understand the concept, just not how to install it.
 
Joined
Sep 16, 2018
Messages
848
Location
Netherlands
In India they just weld 4 strips together and drill holes in it.

Just copy the lego diff but than bigger.
Make sure that the axle can't move from left to right.
 
Joined
Sep 16, 2018
Messages
848
Location
Netherlands
You can take a square tube with thick enough walls. Cut a piece off and use that as cage.
You only need to check the size of the gears.
You can always ad some spacers.
Weld on each side a round pipe that can hold a bearing for the axle.
You can do the same for the 2 in the middle. You can mount them on there own axle. They don't need to be locked, because they can't go out as they are on the axle fixed. Just a small spacer so it only toughest the bearing and not the rest.
Make sure that the bearings don't fall out.

Mount on one side where one of the axles for the wheels come out a gear for the chain.
You ccan make an enclosure so no durt can get in.
 
Joined
Apr 22, 2021
Messages
50
You can take a square tube with thick enough walls. Cut a piece off and use that as cage.
You only need to check the size of the gears.
You can always ad some spacers.
Weld on each side a round pipe that can hold a bearing for the axle.
You can do the same for the 2 in the middle. You can mount them on there own axle. They don't need to be locked, because they can't go out as they are on the axle fixed. Just a small spacer so it only toughest the bearing and not the rest.
Make sure that the bearings don't fall out.

Mount on one side where one of the axles for the wheels come out a gear for the chain.
You ccan make an enclosure so no durt can get in.
Do I need to cage the axles though or can I just run the pillow block bearings? I would still need 17mm wheel hubs/axles to mount the brake rotor to the wheel directly or can I get away with 15mm? The UtahTrike's diff uses 15mm, but 17mm for disc on wheel. The welder thinks the UtahTrike's posi diff is overengineering, so I have alot running through my brain. If I can't get those two things figured out or if it's not an easy task, I'm not building this quad as I don't want to sink anymore than about 1800 in parts and labor, especially since it's my first and I don't want this hobby to leave a bad taste in my mouth like others have in the past.
 
Joined
Sep 16, 2018
Messages
848
Location
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You can use the pilo blocks.
15 is enough.
Do you make the wheel hubs yourself, or do you buy them?

As soon as I have time, I will make a drawing.
There are different ways to do it, but I don't know what you can get made, so I keep it as simple as possible.
You can always change things, but than you have a base to work from.
I will make the drawing on my pc. Better visible than as I draw it on paper.
 
Joined
Apr 22, 2021
Messages
50
You can use the pilo blocks.
15 is enough.
Do you make the wheel hubs yourself, or do you buy them?

As soon as I have time, I will make a drawing.
There are different ways to do it, but I don't know what you can get made, so I keep it as simple as possible.
You can always change things, but than you have a base to work from.
I will make the drawing on my pc. Better visible than as I draw it on paper.
I was originally going to have the welder make them, but then I found the UtahTrike's parts, so was going to do that, but I'm still open to having my welder do it, though I'm already at about an estimated grand in labor 😳

My welder doesn't have much experience with CAD, but he is still skillful, albeit young (guessing 20s), so as long as it's fairly easy/straightforward for him, the better (which is exactly how your details seem to be, so I'm looking forward to that drawing).

This just came to mind for a future build: is it possible to run a 17mm axles long enough to have a threaded end to put a lug nut on to make tire removal easy without having to remove the whole axle with?
 
Joined
Apr 22, 2021
Messages
50
Freewheel system. That is easy to make yourself.
I'm failing at grasping this concept, especially since I'm having a hard time finding good images with parts list, etc. If I weld two freewheels to a cage, how does that prevent the "welded diff" effect when going through a corner? Also, as far as locating the gears for the diff, where do I look for that? Seems like commercial stuff online that wouldn't work for me, but I don't know.
 
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