Using the power of the motor on an eZip through the BB

[donob08]

Using the power of the motor on an eZip through the BB

I've had my 2008 eZip Trailz for about 7 wks. The odometer says my eZip and I have gone 783 miles. I'm a fat, bald guy eligible for Medicare in August, but I can still do 20 miles in less than an hour on a good road bike. My eZip is my hero. I can do all that stuff, I travel 30 or 40 miles on "work days" for my commitments, now I don't go to sleep when I get home.

I've added a 28, 38, 48 crank set and a front derailleur to my eZip. I needed higher gears on the downhill so I could pedal and keep up momentum for the ensuing uphill. Now 30 mph is just fast spinning.

I'm working on another mod.

I'm sure I read someone saying well 'if you don't use the gears then that's the best you can do'. I' m part/half way to hooking up a 1/8 drive chain from the motor on my 2008 TrailEZ up to a Stokers chain wheel on the driver's side (left side) so the power will go through the stock crank shaft over to the triple chain wheel, with front derailleur on the right that I have added and then back to the wheel through a theoretically possible 21 gear combination. My concern is to increase battery life, per charge, by allowing the motor the mechanical advantage of a two derailleur system.
I've figured a 55T stoker's chain wheel would center the motors abilities with equal shift capability one way for torque effectivity and the other way for speed, which would allow a good bit until the controller may shut it down.
What I have is a 40T stoker's crank so I won't get as much effective torque as I might want and probably more speed than I need.

I spent a little more time playing with this idea. I laid the chain in place. Almost all, looks good. The chain misses the kickstand while it's up. If it's down and the motor is driving there are probably other problems.

But, the freewheel/sprocket on the back wheel can't be there when the longer chain going forward is in place. Has anyone removed the rear wheel driver's side sprocket/freewheel? It looks like it's one nut after the wheel is out. I'm thinking of getting a second rear wheel, no driver's side sprocket, that would make it easier to return to the standard config. if things went amiss. I'd like a quick release axel anyway.

Thoughts?


Could the person who has done this, or something similar share the experience, please.

thanks, Don

 

[docnjoj]

I did something a little les complex, but it could be done with a 7-8 speed rear hub. I attached (crudely) a freewheel on the left side of a 3 speed hub. My Mongoose CX24 trailing arm has the chain drive for the motor on the left! U sound like U know bikes, so this may be a possibility for the regular E-Zip as well. Take a bit more engineering, though!
otherDoc

 

[donob08]

Doc

Thanks for the replies, private and here. I'm trying to answer both. My mother taught me ..... I guess I know some about bikes. Our Honey Moon in '71 was a bike camping trip around Nova Scotia. Unfortunately I think being, more mature, doesn't necessarily make you smart. I think I've forgotten more than I now know about bikes.
But , as you may know, rediscovering previously held knowledge feels just as good as the first time. Often it's not till the next day I say, wait I did that in '81. Life! I like it.
I don't quite understand your bike with the "internal", I think, transmission and THE Motor power applied on the left and the persons on power applied on the right, MIXED HOW?
I think you may have seen through me. I are an Enginer. But I never did anything practical as a professional.

I hope you and your bride continue to wheel
Don

 

[TylerDurden]

But, the freewheel/sprocket on the back wheel can't be there when the longer chain going forward is in place. Has anyone removed the rear wheel driver's side sprocket/freewheel? It looks like it's one nut after the wheel is out. I'm thinking of getting a second rear wheel, no driver's side sprocket, that would make it easier to return to the standard config. if things went amiss. I'd like a quick release axel anyway.

Hi Don,

Let's make sure I understand: You need to pull the LH freewheel? It's a bit of a pain if your hub is painted, but should be reasonable if not.

Any advice about a freewheel (clkwise power, cclkw free, next to zero impact on chainline) to mount on the Currie motor output shaft, that is the gear reduction part of the motor's output, (a clone of the Unite MY1018z), would be appreciated. I know I could change motors.

Driver's side (L), to drive the stoker-ring?

 

[donob08]

Tyler

You're everywhere, at every time.

"understand: You need to pull the LH freewheel? It's a bit of a pain if your hub is painted, but should be reasonable if not", yes. No paint involved, in the Currie thing it's kinda married to the spokes somehow, more formerly in the kits than now, I think.

"Driver's side (L), to drive the stoker-ring?" Yes driven by stoker ring, asleep when stoker is and motor is turning.

thanks for answers, Don

 

[TylerDurden]

Hmmm... sounds like a USPD drive, rather than a LH freewheel threaded onto the hub.

As for a freewheel that retains the chainline... that sounds custom. Other folks have used a "jackshaft": having the motor output shaft on the R-side coupled to a shaft leading to the L-side. Standard freewheel on the right eliminates cogging.

A custom motor-mount could preserve the chainline while using a LH freewheel.

 

[donob08]

Hmmm... sounds like a USPD drive, rather than a LH freewheel threaded onto the hub.

As for a freewheel that retains the chainline... that sounds custom. Other folks have used a "jackshaft": having the motor output shaft on the R-side coupled to a shaft leading to the L-side. Standard freewheel on the right eliminates cogging.

A custom motor-mount could preserve the chainline while using a LH freewheel.

Tyler I may have misled you. Mine is a vertical batt pack Currie eZip. I want to leave the motor where it is, on right, behind the rear wheel, at axle level. I won't be using the freewheel mounted on the wheel's axle. Since the power will be going forward, on the left to a Stokers chainwheel, so that the power goes thru the bottom bracket shaft and then sees a 21 speed gear system on it's way to the wheel in the coventional way.

All this says the freewheel on the eZip rear wheel axle has to get out the way, be gone AND a freewheel right at the motor's gear reduced output shaft is needed. I'm trying to keep everything pretty standard so a swap back to standard configuration would be easy.

 

[TylerDurden]

Ok Don, readin 'ya loud & clear.

Off the shelf freewheels will be about 3" in diameter and have about 17t.

If that can work, you might be able to get a bottom-bracket race (cup) and attach thet to the motor, then thread on a freewheel.

 

[donob08]

Ok Don, readin 'ya loud & clear.

Off the shelf freewheels will be about 3" in diameter and have about 17t.

If that can work, you might be able to get a bottom-bracket race (cup) and attach thet to the motor, then thread on a freewheel.

Tyler
I'm WAY impressed! I think you've done it. It seems to me your idea will work just fine. You must have done this stuff before.

I never realized a BB cup and freewheels were both 1.31 ", 24 tpi. I guess it makes sense, fewer tools at the foundry. I've dug out an old BB cup from the junk box. It looks like it and the motor shaft will get along, may need something to keep cup concentric with shaft.

Now that you got me by that block, I realize I don't even need a left hand side freewheel. The motor shaft is pointing to the right as an axle does. I'm putting in an order for one before shuteye. It looks like 16T is as small as I'll find easily. I'd like something like 9 or fewer, 16 will move the range of my 21 gears toward more speed, more torque required from the motor, fewer miles from a charge.

Thank you, thank you, thank you Don

 

[donob08]

Tyler
I think the last part of my last note was incorrect. I do need a left hand side freewheel, because the motor is the driver, not the driven like a wheel axle. Guess I'll wait til AM to order, let my brain settle.

thanks, Don

[/quote]
Tyler
I'm WAY impressed! I think you've done it. It seems to me your idea will work just fine. You must have done this stuff before.

I never realized a BB cup and freewheels were both 1.31 ", 24 tpi. I guess it makes sense, fewer tools at the foundry. I've dug out an old BB cup from the junk box. It looks like it and the motor shaft will get along, may need something to keep cup concentric with shaft.

Now that you got me by that block, I realize I don't even need a left hand side freewheel. The motor shaft is pointing to the right as an axle does. I'm putting in an order for one before shuteye. It looks like 16T is as small as I'll find easily. I'd like something like 9 or fewer, 16 will move the range of my 21 gears toward more speed, more torque required from the motor, fewer miles from a charge.

Thank you, thank you, thank you Don[/quote]

 

[TylerDurden]

You might try to graft a larger chainring onto the stoker ring, to keep the ratio sweet. I've seen numerous hacks where a large ring was drilled and bolted to the smaller. (doing the opposite is tougher).

:wink:

 

[TylerDurden]

I think the last part of my last note was incorrect. I do need a left hand side freewheel, because the motor is the driver, not the driven like a wheel axle. Guess I'll wait til AM to order, let my brain settle.

I think you'll be fine with a standard freewheel in the flipped orientation... since you are using the BB cup (not a wheel hub) you can thread the FW on and set it with locktite.



There is also another way using the standard FW orientation... run the motor in reverse & cross the chain on the way to the stoker. 8)

 

[donob08]

TD
I continue to be impressed. You must have done or seen everything about 2 wheel beasts.
'makes sense. I'd guess an ACS southpaw has left hand threads and would need a left handed dodad to thread onto. You go a long ways toward making my thinking clear in a much shorter cycle time than ordering the wrong part, discovering the problem and trying again.

thank you, Don

PS: ya know I even get the joke about the crossed chain. I feel like I'm experiencing a new awakening.

I think the last part of my last note was incorrect. I do need a left hand side freewheel, because the motor is the driver, not the driven like a wheel axle. Guess I'll wait til AM to order, let my brain settle.

I think you'll be fine with a standard freewheel in the flipped orientation... since you are using the BB cup (not a wheel hub) you can thread the FW on and set it with locktite.



There is also another way using the standard FW orientation... run the motor in reverse & cross the chain on the way to the stoker. 8)

 

[TylerDurden]

ya know I even get the joke about the crossed chain. I feel like I'm experiencing a new awakening.

No joke bro... if it don't hit the chainstay, it works.

 

[donob08]

TD
It seems like the chains would make sparks where they kiss at the crossing. How is the passion controlled?

Don

ya know I even get the joke about the crossed chain. I feel like I'm experiencing a new awakening.

No joke bro... if it don't hit the chainstay, it works.

 

[TylerDurden]

It seems like the chains would make sparks where they kiss at the crossing. How is the passion controlled?

:lol:
Perhaps the influence of a third party, such as a small sheet of teflon, tubes like recumbents use or maybe the slight deflection (5mm) of chains by jockey wheels.

8)