Freewheeling motor and coaster brake?

Ok so I have a Phantom and it is great but hub motor does have a few drawbacks.
I like the mid drive + internal gear hub setup for the fact that the motor can use the gearing also.
Here's the kicker- I like a good coaster brake hub.
Now I have read that the TSzd2 has an option for this, but I am cheap and a part of me thinks the motor hanging down below the crank is only OK.

So the frame I am looking at has space between the post and rear wheel.
My question is can i use a standard brushless motor bolted up on the frame in line with the chain with a forward freewheel on the motor shaft?
Does that make sense?
I want to do PAS so I figure I would need some sorta sensor for the controller?
Any experienced opinions much appreciated.
Brax

The Prodeco Phantom bike has vertical dropouts, which makes it incompatible with a coaster brake. Since your question is interesting, I'm going to address it with the assumption that you'd be willing to switch to a suitable frame with horizontal dropouts.

It would be tricky to get enough wrap around both the motor sprocket and the crank sprocket. If you check out the 500W Cyclone mid drive, you can see their approach to dealing with the problem. Their way doesn't meet industrial standards for such things, which dictate a minimum 120 degrees of engagement between a drive sprocket or driven sprocket and its chain.



If you can resolve that issue, it doesn't have any other show stoppers in principle.

Note that when the coaster brake is applied, the slack side of the chain becomes the taut side, so all idlers, drive sprockets, and mounting brackets must be able to withstand the tension that results from full pedal torque.

Can't activate a coaster with a freewheeling chain wheel.

Ah so not enough chain wrap.

Yea I have been trying to convert my phantom to a regular bike. Nightmare. I have a 16t ss sproket and it is just a half link too long. Going to try changing the crank sproket to a 40t or something maybe.

But yea I was thinking an extended tail bike with a long rear fork, motor behind the seat post above the kickstand mount. But yea there would only be a slight amount of wrap. Guessing it would slip under torque then huh.

I am back to eyeing the TSZD2.
Anyone with the TongSheng motor- one of the things I want to avoid is that with my Phantom (after 5 years and arseloads of miles)- my batt is done and so after a few miles it goes out and I am on a veritable exercize bike- pushing the pedals is a severe workout, esspecially since I ditched the derailer* for a 13t ss years ago.
Does the TSZD3 experience the same parasitic motor drag without current or does it "freewheel" somehow?

BullyB said:

Yea I have been trying to convert my phantom to a regular bike. Nightmare. I have a 16t ss sproket and it is just a half link too long. Going to try changing the crank sproket to a 40t or something maybe.

Click to expand...

Have a look at this tool: http://eehouse.org/fixin/fixmeup.php

It will allow you to figure out what combination of sprocket sizes will work for your bike. Keep in mind that chains elongate by about 1/4" as they wear, even if you replace them before they exceed specifications. So if your setup depends on a just-right-sized chain, your going to have to replace it often, while it's still plenty good.

Does the TSZD3 experience the same parasitic motor drag without current or does it "freewheel" somehow?

Click to expand...

The TSDZ2 and other crank drives have one-way clutches so that the pedals don't drag the motor or vice versa. But that means no coaster brake, like Grantmac said.

I have a 16t ss sproket and it is just a half link too long.

Click to expand...

You can get a half link for most chains, that would solve this little problem.

Rassy said:

I have a 16t ss sproket and it is just a half link too long.

Click to expand...

You can get a half link for most chains, that would solve this little problem.

Click to expand...

Maybe. Chain length is sensitive to differences much smaller than half a chain link.

Would you believe i hacked my chain to male a diy "half link", still slips off on corners. (Initially I thought I had invented some spectacular new thing {I'm gonna be RICH!} :lol: , then I read about them on Sheldon Brown )

The chainline isnt ideal either. I know Prodeco sells this bike unpowerd but it must necessitate a gearset. I refuse to have one of those goofy tensioners.

Gonna check out that link rite now Chalo, big ups!
Oh btw, apparently the TongSheng is available in a special order coaster break version.
Did a little more digging through the forum and one user says there is a bit of drag without power but that it "wears in" eventually. Who knows?

Cheers,
Brax

holy cows eggs this website is the tits
http://eehouse.org/fixin/fixmeup.php

I just love old HTML websites.
Does anyone remember old webpages with code embedded to make your windows pointer into a wand or excessive flashing text or stars and snow glitering all over the page?!
What happened to that?
Damn CSS and smartphone compatabilty.