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Discussion Starter · #1 ·
http://www.electricmotorsport.com/store/ems_ev_parts_motors_me1003.php
http://store.kta-ev.com/Motors-DC-motors/AMD_Motor_L91-4003.aspx
http://store.kta-ev.com/Motors-DC-motors/AMD_Motor_K91-4003.aspx
I got a recommendation from Raul at Electric Motorsport. The RT-200 moto=
r. I =

was thinking the same thing that if I kept the amps below 200 & the voltage=
near =

72 by limiting the 1221C it shouldn't overheat. I mean what are ratings =
and =

limits for? Does any one have experiences with all these motors or any o=
f them =

and could let me know the characteristics? It seems the RT-200 is a lot =
more =

powerful than the old ETEC of which I melted one myself. I'm a little sk=
eptical =

of the RT-200 because it is only 39 pounds. I'm leaning toward the K or =
L91. =

Lawrence Rhodes....
http://www.evalbum.com/1043

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Discussion Starter · #2 ·
On 8 Mar 2011 at 20:03, Lawrence Rhodes wrote:

> I'm a little skeptical of the RT-200 because it is only 39 pounds.

You're trying to get lots of torque from your motor at something like 1500
rpm, IIRC. That doesn't come naturally to a 39lb motor. If you're not
going to gear it down further, you need a low speed motor. However, low
speed motors are usually BIG, as in hundreds of pounds. That might make
sense for a truck or large car, but not for a bike.

Even the old 1500lb Comuta-Car had lower gearing than you're using, 6.38:1.
That had a 65lb 6hp GE motor. Mine had the optional 5.19 (IIRC) speed axle.
That was OK for flat Florida, but I kept burning up brush pigtails trying to
climb hills here in gently rolling northern Ohio (let alone SF). Then I put
in a controller with a 350a current limit. That stopped the brush burning,
bur I couldn't climb hills any more.

WIthout much lower gearing, you're going to need a motor that's hopelessly
big and unwieldy for a bike. I'm no bike expert so I don't know what the
right gearing would be. However, you have examples. Look at what the
commerical E-bike / big scooter builders are doing and emulate that.

Good luck.

David Roden - Akron, Ohio, USA
EVDL Administrator

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Discussion Starter · #3 ·
One additional thing about the Comutacar - it came stock with 135R13 tires, and
the motorcycle probably has a significantly larger diameter rear tire - so even
7:1 may be too low with a small motor.

My Citicar (older than the Comutacar) has a 7.125:1 axle. Works OK for going up
hill, but tops out at about 45.

Tom Keenan



----- Original Message ----
From: EVDL Administrator <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Tue, March 8, 2011 10:35:32 PM
Subject: Re: [EVDL] 3.5 to one gear ratio chopper. Motor recommendations.

On 8 Mar 2011 at 20:03, Lawrence Rhodes wrote:

> I'm a little skeptical of the RT-200 because it is only 39 pounds.

You're trying to get lots of torque from your motor at something like 1500
rpm, IIRC. That doesn't come naturally to a 39lb motor. If you're not
going to gear it down further, you need a low speed motor. However, low
speed motors are usually BIG, as in hundreds of pounds. That might make
sense for a truck or large car, but not for a bike.

Even the old 1500lb Comuta-Car had lower gearing than you're using, 6.38:1.
That had a 65lb 6hp GE motor. Mine had the optional 5.19 (IIRC) speed axle.
That was OK for flat Florida, but I kept burning up brush pigtails trying to
climb hills here in gently rolling northern Ohio (let alone SF). Then I put
in a controller with a 350a current limit. That stopped the brush burning,
bur I couldn't climb hills any more.

WIthout much lower gearing, you're going to need a motor that's hopelessly
big and unwieldy for a bike. I'm no bike expert so I don't know what the
right gearing would be. However, you have examples. Look at what the
commerical E-bike / big scooter builders are doing and emulate that.

Good luck.

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
EVDL Information: http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Note: mail sent to "evpost" and "etpost" addresses will not
reach me. To send a private message, please obtain my
email address from the webpage http://www.evdl.org/help/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =


_______________________________________________
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
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