My mystery Mountain Chen bike !

Yeah it looks like an XM-3000. The rear wheel hub motor looks the same. It's definitely not an XM-2000. Was this a sample they ordered from Chen?

BTW, the 5th battery in the middle of the underseat storage is actually standard for this design and doesn't indicate that it was originally intended for LiFe's.

I wish the XM-3000's were packed like that rather than the metal frame it comes in (I think I'm one of the few folks who LIKED the fact that the packaging was cardboard not metal (the XM-2000 took a lot of flak and the packaging was replaced by metal - I wish they'd just improved the XM-2000 packaging a little).

it definitely looks like an xm3k.. but it has 33ah BB batts, instead of the greensaver silicons?

I agree with John about the packaging.. much better than mine! The steel frame won't protect it as much as the shipper's think.. they will drop it, ram it with a forklift, & think the steel frame will protect it.. it doesn't!

It should be fine, with the BB's.. let us know how everything works.

Hi,

The XM3K comes with Greensaver Silicone Batteries - they're marked 38Ah which is the 20 hr rate. At the 2 hr rate they are 27Ah. The replacement Greensaver battery has a model number of 27-12.

A lot of folks on this forum dislike Greensavers and prefer the BBs. However, personally I prefer the Greensavers. The BB's should work fine for you - you'll still need to either bank charge or fit a battery balancer. I've placed an order for 30 of the BattEQ (BEQ-LA-5-100) from SmartSpark which is a battery balancer that would be appropriate for your bike. I haven't gotten a delivery date yet. Drop me a line if you're interested in being notified when they arrive.

The motor on the XM3K is rated at 3000 watts. That's the motor's rating - not the peak power consumed. Peak power is closer to 3.3kW as the controller limits the current to around 55A and it's a 60V system (60 * 55 = 3300). Do a visual inspection of where the wires enter the rear hub - if you think it would benefit from extra protection then go ahead and wrap it in tape. I haven't wrapped mine.

Good luck and enjoy your ride (and make us all jealous by telling us just quite how good a deal you got!)

p.s. it's amazing how well these bikes can control the weather - when I got my first XM2K we had the first heavy rain in weeks!

My XM-3000 has a warped break rotor also, getting the chirp-chirp-chirp sound. The break caliper has a lot of slop in it compared to the front break, not sure which is the chicken or the egg. On trips the rear break always gets hot while the front one only gets warm.

make us all jealous by telling us just quite how good a deal you got!)

ok i'll tell ya :) $1750. brand new :)

OK, I'm not talking to you anymore. So there... ;-)

I wouldn't push it to go faster if I were you, the motor has terrible cooling properties. Plus after 40mph you need about a battery or two for every ~5mph increase, they will drain way faster too. I'd go for increased full throttle range if I were you, put more batteries in parallel with the existing ones. If you've got a nice budget for this hobby, buy a 65V 60AHr NiMH pack (two used Prius packs would do nicely), or a ~45-50amp hour lithium pack. Lithium can have less capacity since you'll be lighter.

Larger diameter tires might do the trick, some one else might be able to verify? I think the only real way to get more speed is to use another motor in the front wheel. I saw some ebicycles that have done that. It's a big project though.

I wouldn't push it to go faster if I were you, the motor has terrible cooling properties.

Why ?

Brushless motors are sealed because they do not require cooling for the windings, the magnets are the risk (debonding), windings are cooled via direct connection to motor case, unlike brushed which require airflow, that's one of the big benefits of brushless. And I have not seen one heat damaged XM-3000.

Larger diameter tires might do the trick, some one else might be able to verify?

SMALLER not LARGER, larger will slow the bike, heat the motor and controller and kill performance.

I think the only real way to get more speed is to use another motor in the front wheel.

LOL
No !
That won't make it go faster, the bike is only a few mph off its unloaded center stand top speed when loaded at full throttle on level ground, how is adding another motor going to get them to exceed their unloaded centerstand top speed?
It won't.
And would be very cost prohibitive and labor intensive.
Better off getting an EFUN-D 6 phase if you want more speed.
But they won't sell it to you.

Better off getting an EFUN-D 6 phase if you want more speed.
But they won't sell it to you.

"EFUN-D 6 phase? More speed? Do tell!

~ scott
My Blog: PetroZero.org
My Bike: 2007 Lashout Electric Scooter (12mph/12miles)
Considering: xm-3500Li

Just for fun let me try talking to you in your language.

It has TERRIBLE COOLING PROPERTIES, and I'm sticking to it. Yes, very good Einstein the outside gets HOT FIRST. Are you expecting to get a PhD thesis out of that? That outside has a nice INSULATING LAYER OF RUBBER around it. But please, don't listen to me, the XM-3000 has a bigger motor than the XM-2000 JUST FOR FUN!! You haven't seen one XM-3000 with heat damages only because people haven't been pushing them, duh. You might get away with 5mph more but after that I'd be worried. If you boost it up to 240V and 54A you'll be able to hit 100mph I bet! Ever go 80mph on a scooter with XM scooter sized tires? I have!!! It's tempting fate when you hit the pot holes!!! Real thrill ride 4sure!!

Larger diameter tires was a question, you know circumference = Pi * diameter. So one RPM of a larger tire would cover more ground if the diameter was larger. It does this by demanding more torque at each speed. At the highest motor speed the torque it can deliver is very low. So somewhere in between max speed and max torque is your target. Where are your motor calculations Singlow? Is the math too difficult for you? Don't worry Singlow, you can PM me and I'll help you solve the equations, nobody has to know.

I think the only real way to get more speed is to use another motor in the front wheel.

LOL
No !
That won't make it go faster, the bike is only a few mph off its unloaded center stand top speed when loaded at full throttle on level ground, how is adding another motor going to get them to exceed their unloaded centerstand top speed?
It won't.
And would be very cost prohibitive and labor intensive.
Better off getting an EFUN-D 6 phase if you want more speed.
But they won't sell it to you.

Ohh, you know what they say about people who assume things don't you? LOL!!!! The point of the second motor is to lower the torque requirement of each motor. Then you can raise the unloaded speed if you want to without fearing a MELTDOWN!

Buzzz... wrong on many counts including who I am.

And I am riding what you say should melt, and its over 90 outside today, but I am fairly comfortable with a 53 mph breeze.

Such hostility, don't know why, but I was warned.

Anyhow, my info comes from what I have seen someone do and then riding what they did.

Where does you speculation come from, a book ?

It is not important to me really, the proof is in the bikes that are riding down the road the defy what you state, so I will leave everyone with that.

So somewhere in between max speed and max torque is your target. Where are your motor calculations Singlow? Is the math too difficult for you?

After reading your posts I understand now where your opinions originate, they all appear to be based on math and theory and perhaps some experience yet some of your hypothesis are flawed at the core because you lack the engineering data for the controller and motor including their core manufacturing components and operational data and limitations, as do the people I am watching, who took a different approach, they actually road tested these scenarios and found that smaller is better, bigger is slower and hotter and more detrimental to component lifecycle, at least as they apply to the particular vehicle referenced above and elsewhere.

As for the hypothesis that two motors would make this work, it didn't work out that way on the XM-3000 type trike they made by attaching two swingarms to the bike. It has lots of accel and climbs hill like crazy, but top speed only increased a few mph.

Yes, they probably could have increased voltage, lowered the stress on each motor by virtue of having two motors and gone that route to increase speeds and lower motor controller stress, as I think you are describing, but rather than build a complex unproven concept vehicle, wouldn't it be much simpler to just buy a motor controller deisgned and proven to provide the operational characteristics one is striving for in the first place ?

By the way, you have posted a lot of stuff here, are you actually working at doing any of it or are you just putting it out there ?

I think we are all interested in seeing some of the projects in your posts come to life so we can see the outcomes as they are all very interesting.

I just wanted to try acting like you once. Just to see how it felt. I felt a little like I'm making a fool of myself in public for showing everyone I have the emotional intelligence of a 4th grader. You know, that I'm a genius and you all are newb idiots role you play so well. I'd call it Tracy speak, but poppa bear Bill O'Reilly does it much better than you.

If the motor controller can deliver so many more amps then it does, it would stand to reason, having a motor that delivers more torque with a larger tire would be the way to go. I know a 72V mod will get the top speed to about 45mph, if you lower the tire diameter, you MIGHT get to 50 XM miles/hour. What do you make out of the center stand speed being not much faster than the fully loaded speed? I'd bet you we're running into the switching speed limit of the controller. More volts + same amps = more torque. The 72V mod doesn't make the switching speed faster, it just gives the scooter the power it needs to reach that center stand unloaded speed.

I found company in Tiwan willing to build hub motors to my specs. Here is their questions to me:

It depends, could you provide more information for motor design :
1- What kind of vehicle you plan to install dc hub motor ?
2- What are the curb weight and max. pay load ?
3- What are the required acceleration, max. speed ?
4-What are the torque and rpm expected from one 60V 10KW hub motor ?
5-Can you provide drawing for the requirement dimension , position to install
with your vehicle ?
The 7KW or 10KW dc brushless motor are about 280mm Dia. x 130mmT
for 13" and 15" hub , if make to 10" hub, may need widen th 130mmT, but all depend on above your asnwers.

Regards
Raymond

Heh Raymond- and my name is Shan (mountain in mandarin). I bet we could find enough people with XM motors who would like a drop in replacement. The retailers might want to stock a few as well.

I don't understand why bigger motor is hotter and slower? Can you elaborate?

I'm working strenuously on my GreenBMS. I answer posts when I think I have something useful to contribute, instead of just bragging that I got up to 53mph without saying how. You're right, at this step I can only speculate about how to get the scooter to run faster. It's just the first step in problem solving. I agree we all have the same goals. I thought it was sad Tracy so often acted the opposite of a southern gentleman when people disagreed with him, he was often the most insightful one in the group. After we get over being SHOUTED AT and our uncertainty ridiculed we kinda miss that guy.

>>Such hostility, don't know why, but I was warned.

I have greatly enjoyed your tech input "singlow" , but wondering why someone would respond to your previous post with "hostility" implies that your are unaware of how it sounded , so as an objective third party - let me say I thought your logic and science interesting but I to took the the format of YOUR reply as insulting and not worth the technical content.

It was a shame to loose USATrace's fantastic insight and intellect on this board , but as a "rank & file" reader I must say that for me the tradeoff of loss of his technical contribution for a more congenial atmosphere has been worth it.

I love discourse, but I would ask that you please disagree with logic and science without being insulting

If you hold the DC motor completely still and apply 50 V but your source can only supply 1 mA. Then you'll feel minimal torque. If your supply can provide amps of current, your motor will fight you hard. When the motor is in steady state, the back-EMF will ALMOST equal the applied voltage hence back EMF == proportional to voltage. You can derive it all, or look it up in a power electronics book. www.geocities.com/CapeCanaveral/Lab/8679/motor.html

This form calculates k and n for the equation: torque = k * current^n Examination of the circuitry shows that arbitrary nonlinear source B1 produces a voltage which is the argument of the above integral expression, and integrator device A1 performs the integration to produce a value for w. Now of course the Tl and the J inputs are also voltages.

The motor torque is equated to Kt*Ia, where Kt is the motor torque constant, and Ia, really ia(t) is the motor current. The back EMF is created by arbitrary nonlinear voltage BVBEMF as the product of the angular velocity and Kv, a motor voltage constant. Note that in the model there is no ground for the primary motor winding. It left floating for generality, and it assumes that the external circuitry will provide the necessary connection to

http://www.beigebag.com/case_dc_motor_t1.htm

Make sense?

With less windings, and thicker wire we can get more amps drawn from the motor controller while keeping it within it's operating parameters. With that increased torque we can use a larger diameter tire, and get the target of 55-60mph. I went with more torque and not more rpms for power because the controller tops out at 72V but can supply a hell of a lot more current then it currently does. 80A peak @ 60V and a 13" tire should do the trick! I didn't do that calculation, that's what the Efun-D uses to achieve that speed :-P

sparc5 - don't feed the trolls. I have, and it never works. Even the feel good factor of blasting back is short lived. BTW, I know the guy who owns beigebag! :-) He's here in Ann Arbor.

singlow - OK, you're a bright guy. You've posted some good stuff but you've not revealed who you are nor your source of info (I asked about the apparent dyno data you posted on another thread). You say you're not Tracy - but I dare say there's some link there. There's nothing wrong with being associated with Tracy - why the need for secrecy?

This scooter has been a steep learning curve to make it do everything I want. Here was the advice I got from an experienced motor winder:

I believe you take the desired increase in current as a percentage (60 to 80A = 33%), divide it by 3 (# of phases) = 11% and reduce the number of turns by that percentage. This means unwinding the motor, making sure to count the number of existing turns as you do. You need to appreciate whether it is terminated Star or Delta and which teeth are wound in which direction and form part of which phase.

You calculate the cross-section area of the existing wire and buy wire that is 11% thicker to compensate for fewer turns. You then rewind the motor exactly as it was but with fewer turns and measure current again. The formula is seldom perfect so if 80A is getting close to your controller's max then you should be consevative in the changes you make, eg: make a 5% change first.