Mongoose CB 24V450 -Motor Only Range (SLA)- Pinkerton Park

[knightmb]

Yeah, I couldn't resist. It was on sale for only $279.99 + Tax, so I figured why not see how the generic e-bike from Wal-mart stacks up to everyone else's custom e-bikes.

• Weight: 70 lbs
• 26" Wheel Size
• 24 Volt 12AH - SLA Battery Pack
• 450 Watt Rear Brushed Currie Motor
• 7 Speed Rear Derailer
• Twist Throttle
• Kill Switch on Front Break (when you squeeze the front break it has a circuit break that cuts power to the motor even if you are giving throttle)
• 6 Hour Charger (smart charger)
• Front Shocks
• Seat Shocks
• Comfortable Hybrid Road Tires
• Kickstand (strong enough to stand up the bike that is)
• Aluminum frame, unisex

Range (claimed)
18 Miles (29 Kilometers)

Top Speed (claimed)
15 MPH (24 KPH)

Max Power (claimed)
450 watts

Test Conducted 12/2/2006 @ 1:30PM

Environment Stats

1. Weather: Mostly Sunny
2. Winds: NNE 7 MPH Gust on Occasion
3. Temperature: 48 F
4. Humidity: 40%
5. Barometer: 30.39

Rider Stats

1. Gender: Male
2. Weight: 172 lbs

Bike Stats

1. Bike Weight: 70 lbs
2. Tire Pressure: 53.5 PSI both Front and Rear Tires
3. Batteries: (2) 12V @ 12 AH - SLA Battery Packs, Full Charge
4. Battery Age: Purchased 11/30/2006 - Unsure of Age

Summary:

The day for this test run was sunny and clear. It was cold, so that might affect the test somewhat because the batteries lose some power when they get cold. But since it sat in the garage and it's such a short drive to the park, I ruled out the cold being a major factor, especially once I start driving around because that will heat up the batteries anyway. If anything, the cold weather would keep the motor and controller cool, so less resistance for the power to the motor.

I put on my coat and gloves because I knew this was going to be a cold ride. I started on laps around the park from the 1 mile marker (just like last time). The bike uses an instant start controller, so away I go for many laps around the park. During the ride, speeds stay steady between 15 and 17 MPH. The ride was very straight forward and the cold weather made the park a ghost town. Less people to avoid so it was easy to go full throttle the entire way. I had no problem going up and down hills, the bike had plenty of torque to maintain the 15 MPH speed that it's rated for.

The ride ended up being a little shorter than I thought it would be, the bike finally died at the last hill before another lap, so I pedaled it up the top and used what remaining battery power to get me the rest of the way. One thing to add to this summary, the charger gets really hot when charging. But it won't have a meltdown, so don't worry about the charger when it's doing a 6 hour charge on the batteries and gets hot to the touch.

It was a very comfortable ride, here are the results.

Test Ride Results:

• Total Ride Time: 48 Minutes
• Max Speed: 19.2 MPH (30.9 KPH)
• Level Top Speed: 17 MPH (27.4 KPH)
• Average Speed: 14.2 MPH (22.9 KPH)
• Total Ride Distance (unassisted): 11.5 Miles (18.5 Kilometers)

Pros:

1. Cheap
2. Good first "e-bike"
3. Everything included (batteries, charger, motor, controller, bike, already built)
4. Safety feature on brakes to prevent braking and motor at the same time
5. Sturdy design
6. Easy speeds to maintain
7. Gears top out at motor max speed

Cons:

1. Chain comes off front sprocket when shifting into really low gears (1st, 2nd, or 3rd). You basically have to get a chain guard for the front sprocket to prevent this.
2. Charger gets really hot, almost scary to anyone that's never used one before.
3. Low Speed - Debatable of course
4. Low Range
5. SLA Batteries, you have to be careful to charge the batteries as soon as you are done riding or you'll kill them if left in the uncharged state for too long

 

[Reid Welch]

Good report, well documented.

My bike, when its now-tired batteries were new-enough,
ran me for full throttle rides, with nearly no stops, for 11 miles.
At that time the red (empty) light would come on, and the top speed
would have reduced from 17 to about 16mph.

IF I had done a test track run exactly as you did,
I'd have gotten, quite surely, the identical range of 11.5 miles,
at which point it'd have pooped.

A month or so ago while it was yet on 36V I did a constant speed run
at the local high school's oval quarter mile track.

I have lost the figures in the old V's hackings, but as I recall,
I got just over twenty miles by holding, close as possible, to a constant
fifteen mph. It was a non-stop ride. I did a few full throttle laps at 24mph, and some laps were slower than 15mph due to joggers on the track. But overall, I held to 15 per and got a bit over twenty on 3x12/12ah of SLA.

The bike will definitely run quite fast on 36V. But as I noted elsewhere, the motor will require forced air-through cooling if it is to be run at full throttle for more than a mile or so at a time. The windings will fry, promise. But at 24V, it's pretty hard to overheat the motor, though a long, continued slog up hill should be sufficient to let out the blue smoke (my guess).

It's a great value for an entry level ebike!
I recommend these bikes for first-timers,
esp. for the fact that they are so easy to hot rod,
and so easy to fix--no hub motor problems--no cogging,
no pedal drag, no busted spokes, no bulky three phase hot running controller---and a motor that costs less than 50 clams to replace when it dies.

It's a good value! And your report above is the best, most scientificalistic (grin) that I have yet seen.

Much obliged!

Reid

 

[Reid Welch]

Yes, I had to push all those brushes back in when I put the cover back on. Thank goodness for scotch tape.

? How'd you manage that?

I had learned through lemmiwinks/Ashley of the old V forum,
to look for the tiny hole through the end of each brush holder.

Threading four strands of copper wire, one for each holder, after inserting the brushes, holds them in place.

Then put the cover on far enough to get the brushes over the commutator.

Pull out your four copper strands, and snick, it's done.

How'd you get the tape out? I guess you could, and if it worked, it worked!

It's an easy, easy motor to tear down and reassemble.

cheers,
Reid

 

[Mathurin]

Were your batteries broken in though?

I read SLA gain capacity over the first 20-ish cycles.

 

[knightmb]

? How'd you manage that?

I had learned through lemmiwinks/Ashley of the old V forum,
to look for the tiny hole through the end of each brush holder.

Threading four strands of copper wire, one for each holder, after inserting the brushes, holds them in place.

Then put the cover on far enough to get the brushes over the commutator.

Pull out your four copper strands, and snick, it's done.

How'd you get the tape out? I guess you could, and if it worked, it worked!

It's an easy, easy motor to tear down and reassemble.

cheers,
Reid

Well for some reason, they wouldn't stay in. The springs pushed them out completely, so while I could get one to stay in. Moving it around to position the next would make the previous pop out again. I was getting no where, so I thought about some scotch tape. Basically, I folded it in half in the middle so that the "smooth" side was wrapped around the brush while it was inserted. Then the tape sides were "taped" to the outside of the motor, so this basically held the brush in. Once all 4 sides were taped, I put the back of it on and then simple pulled the tape out because the smooth side of the tape would slide right out, no problem. Picture attached to show what I mean.

 

[knightmb]

Were your batteries broken in though?

I read SLA gain capacity over the first 20-ish cycles.

I know that NiMH and NiCad battery packs need to be conditioned for the first 4 or 5 charge cycles to get maximum range when new, but I've never heard of this being done for SLA batteries. Easy enough though, after a little while of riding it around and charging, I can do the experiment again and see if the results get better or if they remain the same.

 

[Mathurin]

Same, I measured in the early cycles ~10Ah capacity out of my lead bricks, they're now just over 10 cycles and by the time they'll reach 20-ish I should be able to determine if the capacity has gotten greater, probably around next weekend. Gonna have to limit the consumption to 700w to get comparable results, though.

 

[D-Man]

Knightmb,

Do you know what brand sla's they use in that bike? Just wondering if Reid's and yours are the same brand or are they using multiple brand

 

[knightmb]

Knightmb,

Do you know what brand sla's they use in that bike? Just wondering if Reid's and yours are the same brand or are they using multiple brands.

A good question, I'll take the thing apart today and see if I can figure out what they are using. The manual says they will only be good for 3 months (??) so I'm sure it's the cheapest they could find.

 

[notoka]

Did you purchase this online? I Was at a couple of walmart stores but they didn't have any?

 

[knightmb]

Knightmb,

Do you know what brand sla's they use in that bike? Just wondering if Reid's and yours are the same brand or are they using multiple brands.

I took it apart today, here's what is lurking inside :|
No idea if this brand is good or not, never used it before.

 

[knightmb]

Did you purchase this online? I Was at a couple of walmart stores but they didn't have any?

The store I went to had one. It has actually been sitting in that store for a couple of months (I'd always seen it passing through when it was more expensive). Of course, maybe they were selling like crazy and it was a new one every time, I'm not sure.

 

[knightmb]

As you can see, my 24 volt NiMH 12AH pack will fit perfectly into this case. This will reduce the weight of the batteries by half at the same voltage and AH. When the weather gets better this week, I hope to test the bike again with the NiMH battery pack to see well it performs.

 

[Elmweaver]

Walmart told me they did not have any in the store and told me to call walmart.com and ask for one to be sent to the store. I did that and they said they can not do that the store has to ask for them.

ok the round and round we go game at walmart.

Anyway I called today to speak to a store manager who did not know what to do but said the bike manager was standing next to him and what do you know he says ohhh sure we have those in stock for $279 ready to go.

So I am headed to wally world to grab one while the bike manager is there since no one else in the store seems to know they exist.

Wish me luck. :lol: :lol: :lol:

@notoka - call the stores and speak to the bike dept manager they seem to be the only ones that can give any real answers.

 

[knightmb]

So I am headed to wally world to grab one while the bike manager is there since no one else in the store seems to know they exist.

Wish me luck. :lol: :lol: :lol:

Cool, let us know how it goes. I know that I had to charge mine for 3 hours before it was ready to ride (batteries at half capacity I guess). I did have to tweak out the rear derailer shifting on mine and put some more air in the tires, but other than that, it was ready to go after charging.

 

[sabrewalt]

To get to 36 Volts did you just tape the battery to the side of the box??

 

[2k66ks]

hi all

knightmb,

how would your future batter pack connect to make the 3 prong outlet on the out side
also how much is the future battery pack in usd??
can u include some pics of how it is don if u do it ? ty