Mongo, 48v 1000w 'Magic Pie' hub on a Mongoose 'Snarl'

BarelyAWake

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Well... I didn't think I'd ever be makin' an ebike thread - but here I am heh

A little background on this first I s'pose, I've been tinkerin' away on a suspended hybrid/tribrid tadpole trike on & off for about a year now: The Bent Zombie Tribrid Tadpole Trike & it occurred to me that it's electric drive was not only untested, but I was not terribly familiar with ebikes - the only one I'd ever had was years ago, a 12v SLA friction drive 'Zap' setup that was honestly a bit ridiculous, anemic to say the least it's woeful lack of power combined with it's incredibly limited range wasn't complemented by being a friction drive.

Fortunately, I held no grudge against the ebike concept because of it lol, even then I knew full well that wasn't a realistic system for anything other than the novelty factor.

Still, I figured I needed some time on a "real" ebike to see what I was getting into with the tribrid, I didn't have enough experience to know if it would be even worth the bother or what the problems may be - combined with the fact I needed a replacement commuter & winter beater I picked up a Mongoose Snarl mountain bike w/dual disc brakes to test out the electric drive (come winter it'll get an in-frame 2 stroke ofc).

The bike itself is surprisingly good for the price ($250) with beautifully fat, nicely lapped weld beads, 100mm travel forks w/adjustable preload and ofc the disc brakes, which while generic - actually have a centering adjustment feature. The rims themselves are unsurprisingly just the typical single wall alloys w/14ga spokes - those will be replaced & I've ordered some low cost ($22ea) fatty double wall rims w/that in mind: Weinmann Disc Bull Rim 26 x 2.00 36 Hole Black along w/another pair of my favorite cheap ($17ea) tires: Cheng Shin C1218 street tire, 26x2.125 - which w/a harder compound than you'd expect w/semislicks & very thick tread area, have proven to be very puncture resistant, durable tires that handle great.

The only actual disappointments w/the Mongoose 'Snarl' (other than it's silly name ofc lol) is it's kickstand is about 3/4" too short even w/o the added weight of motorization (it's b'cause of the long travel forks) & the stock seat is by far the most uncomfortable thing I've ever sat on - I suspect a splitting maul just might be worse, but I'm not going to experiment w/that to see & I just stole the comfy sprung seat off my old Stokvis for now.

BTW, while mine is a 26" (for the hub motor & wheel I already had), the Mongoose 'Snarl' is also available in a 29" if you're interested, I did a quick test fit w/a in-frame 2 stroke and it seems to fit w/o issue (knowing it's aluminum w/an oversized down tube ofc), but I should mention that w/these forks, even the 26" is a somewhat tall bike & you may not want the 29" if you're "vertically challenged" - I'm a hair over 6' and even the 26" is taller than I'm used to.

Anyhoo, on to the ebike stuff heh - to mount the Golden Motor 'Magic Pie' 48v 1000w hub I had to open the drop outs just a hair for it's oversized axle... not so much even "widen" them but smooth them just a little to allow the flat-faced axle to slide up & in there (prevents torque rotation). The only problem w/that is as the axle is slightly larger the disc rotor doesn't quite go all the way up into the caliper anymore, it's about 1/16" short of the edge of the brake pads which will cause uneven wear w/a "lip" developing on the pad. I'll hafta fix that ofc... but I'm going to wait till I've my new rims built. I'd already made a rotor spacer for the tadpole as it's caliper (Avid BB5) was too close to the hub - coincidentally & very fortunately the spacer jus' happened to be perfect for the Mongoose's caliper too so I didn't hafta mess w/that anyway.

I then stole my poor Schwinn's rear rack, which I'd already modified w/vertical supports to the dropouts (it was a seatpost clamp only design), bolted it up to the Mongoose (just needed one spacer for a support to clear the rear caliper) with a set of M-Wave Double Day Tripper Bicycle Panniers ($25) for the 48V 15AH LiFePO4 battery packs to go into. The M-Wave panniers are lined with plastic panels so while they're not "collapsible" the panels serve to spread the weight evenly. I'd custom ordered the LiFePO4s to be split into two battery packs for the tadpole, which has worked out well for this too - I just can't see having 16lbs mounted to the top of the rack like I'd hafta if it was a single pack... even split into two & mounted lower the handling w/the weight back there is noticeably... different - not bad, but defo different. I s'pose I'll get used to it, I'm just glad it's not the 30+lbs of SLAs lol

Then it was jus' a matter of routing the wiring & handlebar controls & I was ready for the first test ride - which went well for about 45 minutes, then things started to go badly... very badly. I started loosing connections, the throttle, the main power leads & the hub (internal controller) started beeping error messages - sometimes, when it felt like it... and it just kept getting worse until I had nothing at all.

Knowing all the secondary connectors (throttle, cruise control etc) were cheesy, flimsy little bits with wiggly pins - I figured I had a loose connection somewhere & started my diagnostics. Interestingly, while those connectors are sad, pathetic lil things they weren't actually the problem... or problems as it turned out & thus began my three day headache of sorting out what the heck was going on.

First the main power plug had an intermittent failure on the negative pin (left plug in third pic) an easy fault to find & even easier to fix w/a new, far better connector, I'd already gotten a Delphi Weatherpack (weatherproof connector set) for the taddy's harness so I had a plug handy. The hub then worked fine... for about 5 minutes & then quit entirely again. This was a major setback as it obv wasn't the main power plug anymore I had to do continuity tests on the rest of the wiring - and the ends of those wires are ofc inside the hub, being a "spiffy" internal controller and all. This meant I had to pull the hub itself apart and that's no easy task as the side covers act as the armature's housing (centering & bearing mounts) and ofc it's sealed to protect the internals from the wet.

Searching around online I found only vague references to the disassembly procedure & what I found just couldn't be right - it was suggested that after removing all the fasteners from the cover to "pound on the other side of the axle with a mallet" and that "should free up the other side's cover" ...while I may be an ebike novice, I'm no stranger to electric motors or wheels & bearings for that matter and that recommendation filled my brain with horrid images of bunged up bearings, mangled C clips and other, even less pleasant suspicions. Fearing the worst, I just made my own puller - much like any gear/pulley remover it bolted into the brake rotor mounts and applied pressure to the axle, removing just the cover on the same side.

With the cover off finally many things became apparent - first, I would have done a number on the sealed bearings & retaining clips had I followed that "advice" & second, they were decidedly stingy with the solder... everywhere. Now able to do continuity tests I found that the main junction block (where all the separate wiring joins to become one cable, to then go into the axle) had faulty connections, problematic as it's a solid chunk of molded plastic (third pic, thing on the right). I tried for a while to gently cut it apart, but after succeeding only in cutting me apart I simply removed it and made my own (forth pic), after cleaning up the mess I made of my thumb ofc. Then I resoldered all the internal connections so I wouldn't hafta go in there again. While it isn't mine (I was too cranky for camera crap at that point), the fifth pic shows the internal controller, complete with it's shoddy soldering. Apparently this is common as every pic of the internal controller I found had similar issues, there's more examples here in the Mongo's photobucket album.

 
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BarelyAWake

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...so oddly, after replacing & resoldering all the connections except the ones I thought cheesy - everything tested out just fine... ok whatever, I can accept that lol, I've long distrusted electronics so I'll jus' chalk this up as another example why heh

I then reassembled everything again for another, hopefully more successful test run. I swapped out the lightweight tires the bike came with with the heavier duty tires the Schwinn was sporting, which turned out to be a mistake on my part as I hadn't noticed the sidewall damage from the Schwinn's maladjusted rim brakes & ended up with a wobble from the rear tire's broken belts. Oh well, just an excuse to get those spiffy new tires right?

Everything seemed to work well running it around the parking lot so I trusted it to get me to work, taking over the daily commute the now stripped Schwinn so faithfully ran for so long. Cruising a sustained 23, with a 25mph max (flat ground) and with decent acceleration I don't actually have to pedal to get started - I usually do anyway tho to lighten the load on the motor & battery reserve. After a coupla days of this and some playing around, I decided to do my weekly grocery run with it and that too went so well even laden down w/bachelor chow I decided to do a 15 mile lap just to see if that would make a dent in the seemingly endless battery reserve... and according to the (admittedly questionable) battery level lights on the throttle - it didn't, but there was no loss in power that I could see and as my lil 2A charger only took roughly two hours to top off the battery packs... I can only assume there was still quite a reserve. So this weekend I'm hoping to try twice that - to attempt a thirty mile trip, weather permitting ofc.




All in all I've really mixed feelings regarding the Golden Motor 'Magic Pie' setup... while it was a nightmare of shoddy soldering & cheesy connectors, with only very basic repairs it's turned out to be a decent hub drive that's very feature rich, the only other issue is the rim wasn't trued properly, but that's not unexpected w/any wheel purchase. Given it's relatively low cost ($240 for hub & wheel w/controller) I can't really recommend against it as it should be a really easy, simple ebike kit for the novice yet still having all the "bells and whistles" such as integrated lighting & horn, cruise control, true and adjustable regenerative braking, variable voltage compensation, anti theft, etc., etc., even reverse... not that such is needful with a bicycle lol

Thing is, I can't really recommend it either given the problems... I do suspect it would have been covered by the warranty had I tried it when I first got the thing and sent it back, Gary from http://www.goldenmotor.ca/ is reportedly good about such - but I didn't bother as I made the purchase about a year ago & I didn't feel like bothering with S&H and the wait times *shrug*

Anyway, here's a movie of some of my fifteen mile test run, just the four miles of the only bike path around here... I don't run the path with my stinky, loud & fast gas bikes, but I figured it'd be OK with the stealthy "clean" ebike lol, besides it was freezing cold & 6am - I figured there wasn't going to be many other riders, and there wasn't ;)

vid: http://www.youtube.com/watch?v=tcGdt44KP0s

better vid: http://www.youtube.com/watch?v=PNhS5FJCqNo



 
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haste

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how do you like it compared to a 2 stroke kit? Less top end im sure...until you go 72v!
 

BarelyAWake

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It's growing on me TBH, while roughly 10mph slower than my gasbikes the near silent cruising & "plug & play" simplicity is very addictive... but I don't think I can really compare the ebike to my 2 smokers fairly as they're very different "tools" for different applications.

For example, there's no way it could outright replace ICE bikes for me as it's isn't so much a speed issue, but the all-season application - there's no way in heck I'm gonna subject electronics to the evil devil's brew of rock salt & calcium chloride they use on the roads around here in the winter lol, and ofc while the 2 stroke kits don't have the HP advertised, they've still more than 1000w (roughly 1.3hp) of this hub drive... which would struggle to plow through any of the snow & shush I ride in. I've also a habit of 100 mile wanderabouts on nice sunny summer weekends, which the battery reserve hasn't a prayer of dealing with *shrug*

So while the ebike is fine as a supplementary summer work commuter & while this was a "economical" ebike build (about $1100 for everything - the upgraded LiFePO4s being the costly bit), only time will tell if it's actually "worth it" for my use. ;)
 

haste

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right, and if you moded a HT you can easily get 3-4hp out of them, and minimum 50 mile cruising distance.

I want an ebike but cant justify to spend 700 dollars on a kit...
 

BarelyAWake

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Have you tried the PC tuning feature yet?
No, not yet... I seem to have misplaced the silly USB adapter, perhaps that's not a surprise tho lol

right, and if you moded a HT you can easily get 3-4hp out of them, and minimum 50 mile cruising distance.

I want an ebike but cant justify to spend 700 dollars on a kit...
The distance cruising ability of gasbikes is indisputable... but I hafta say I think the HP rating of the in frame two stroke kits has been grossly overestimated through a lack of unbiased, substantiated data - simply put, most of the "specs" available are for advertisements, they seem wont to tack on another 1/2hp or more than their competitors, then they do it again, ad infinitum.

I've done a lot of testing, preformance mods & yet more testing - competing against myself, other gasbikes but perhaps more importantly, factory mopeds & scooters, ones made by reputable manufacturers w/known specifications. There's simply no way our sloppy & primitive HT kits have equal or even greater HP than an equivalent displacement two stroke made by Honda, Puch, Tomos, Morini, their clones & etc. - & while they can be improved, I doubt greatly we can "easily get 3-4hp out of them" ...at most & even after extensive mods I suspect they're far closer to 2-2.5hp.

As an example, the only (noncommercial) person I'm aware of to do comprehensive testing with validated speed & dyno runs was foureasy: http://motorbicycling.com/showpost.php?p=150605&postcount=80 and he just barely nicked the 5hp mark - but his motor was so modded as to not be a HT anymore w/a true 79cc Puch preformance top end, mikuni, reeds & more... basically customized everything with just the HT's case left over. Even so, it blew up more often than not: http://motorbicycling.com/showthread.php?t=14204

Don't get me wrong, I really do love the in-frame Chinese kits & in fact the only thing I dislike about them is all the hype & straight out lying their retailers are known for & the false expectations & "information" that result. They're wonderfully simplistic, easy lil engines to deal with, near perfect for motorizing a bicycle - but they are not and never will be competitive in anything other than price & even then I suspect for the money foureasy spent trying - he could have just gotten a motor w/4-5hp stock... I'd be willing to bet he spent more than 700 bucks w/his experimentation ;)

An interesting example of price comparison including mods & aftermarket parts is that my '43 Rollfast (HT, shiftkit, expansion chamber, CNS, P&P, comp mods, etc) and the Mongoose ebike above cost almost exactly the same overall, they both ran me just about $1100 when all was said & done;



...is one "better" than the other - or even a "practical" expenditure? lol, those are impossible questions, apples & oranges I figure & the 2nd I'd rather not dwell on :p
 
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BarelyAWake

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So, more testing of some of some the taddy's components - this time lighting.

With any electric vehicle, power reserves are of paramount importance even with a hybrid like the Zombrid as even though it's ofc got an onboard charging system - every watt counts. Lighting can be a power hog, particularly if it's spiffy halogens so they're out of the question.

So after some shopping around I got a pair of LED MR16 Halogen replacement cool white spotlights (12V 4W/440 Lumen - 50 Watt Equivalent), one with a 30° beam angle (high beam) and one with a 60° for the low. Conveniently for the Mongoose, they just fit in the old headlight from my now stripped Schwinn (it's one of Norm's wonderful bullet housings), so I stuck the 30° beam one in there. Ofc not being 48v I have to use a DC to DC step down converter (60-48V in, 12V out) to power it and the LED taillight, which is simply a trim/marker light, commonly available at most auto parts stores - tho this too came off my ol' Schwinn, it was also part of the lighting systems Norm used to offer.

After a coupla hours fiddling around with soldering connectors, more shrinkwrap & wire routing I was pleasantly surprised to find that it works really well! There's some peripheral efficiency loss w/e you use a converter, so the consumption wouldn't be as ideal as using 48v lights, but the loss is marginal - very marginal when you consider what 48v LEDs cost & their limited selection & availability lol

I should prolly point out that if you're looking for a low cost, reliable & effective lighting system for your own bike these 12v LED MR16 halogen replacement bulbs and the red trim/marker lights are commonplace & cheap (anywhere from 4-10 bucks ea), you'd just hafta come up w/your own 12v battery - a small SLA or better yet, a 12v ni-cd replacement power tool battery.

The MR16 is most commonly used for indoor track lighting BTW & while unusual for LEDs, the MR16 replacements are usually not polarity sensitive so you don't hafta worry if you wire it backwards;

 
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BarelyAWake

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This past Sunday it was simply gorgeous out, so I hopped on the ebike & found some hilly, twisty back roads to go play on... I only ended up doing just under 20 miles this time, but given some of the terrain I encountered I was quite impressed - no battery fade & I found no hill that couldn't be conquered ;)

Some of the run: http://www.youtube.com/watch?v=PNhS5FJCqNo&hd=1

Sadly, Mongo's down for about a week as I'm having a new wheelset built w/some decent aluminum double walled rims, stainless spokes & a set of fatty (2.125) semislicks...

...and I was jus' starting to really enjoy myself lol
 

haste

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thatt looks really fast... i mean even if you get a ht running that smooth..it gives you issues after 50 miles.
 

haste

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also how does pedaling a DIRECT DRIVE hub work after battery is dead. If i have a single speed mtb bike..am i screwed?
 

BarelyAWake

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TBH haste, the feeling of speed is primarily because the camera is so close to the ground. While I find the ebike impressive, it's speeds I've encountered so far are;

32mph max (downhill/vid)
25mph sustained (level ground/vid)
10mph (uphill - not in vid)

...and I've gotten my HTs running as smooth as you can expect, I'll sometimes do up to 100mi weekend wanderabouts w/o issue (once broken in and dialed ofc), thing is the one I use for that has a shiftkit - which keeps the cruise RPMs down & gives a "smoother" ride, limited only by my stamina, the noise & rough roads at speed get to me after awhile.

I do hafta admit I'm becoming addicted to the serine silence of the ebike tho, just the slight whine from the motor shortly drowned out by the hum of the tires on the road as I pick up speed. It's an aspect of bicycling I'll admit I'd forgotten lol

The electric hub has some drag ofc, I've not managed to run the batteries dead yet - but pedaling w/o engaging the electric drive isn't difficult at all... a comparison would be roughly like the difference between pedaling with semislicks vs pedaling with knobbies, the weight of the hub & batteries is far more noticeable than the drag of the hub. Yet it is on a 24sp mountain bike & I've not yet tried to pedal it in it's top gear w/o the electric assist & as the drag is exponential I'd imagine it could get pretty difficult.
 

Mike B

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This thread has inspired me.

I have a Giant Revive which is a 20" semi recumbent, very comfortable with backrest seat but very heavy and not so much fun to pedal.

Ordered up the 20" magic pie rear wheel kit w/o battery and will motorize this sucker - :)
 

BarelyAWake

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Something like this?



If so, that seems ideal for an ebike conversion, perfect actually lol (^)

What are ya thinking for batteries?
 

Mike B

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Yup, that's it.

Wierd lookin' thing eh? Not cheap either, I think I paid $700. I've looked at that thing for a year at least thinkin' how am I going to put a motor on it?

Thanks for whackin' me up side the head - :)

Yes, batteries. That Ping 48V, 15 AH looks like it would fit nice on the rack.
 

Goat Herder

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I have to do more reading and get a little more educated on these electrics myself. This electric of yours is very inspiring. Even with it's weaker output so to speak it seams to me very hard to complain. I want a systems about double this perhaps in power? Still this really is not bad. Especially the distance you are getting with it. Pretty darn nice!
 

BarelyAWake

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The "duct tape" packs are defo the way to go Mike, while you'll need to create your own case & mount I think it's worth it given the price difference... I mean the prefab batteries in cases offered w/the kits are nice n'all - but I'd rather get a few more amp hours ;)


Thanks Goat :) As ya prolly figured, w/the hub drives double the power is easy;

(not my pic)


...but double the speed is not. I'm not sure what you want, but these hubs are limited in the RPMs they can reach so while having two of them would seriously improve acceleration/hill climbing - it'd still only get to about 25mph flat ground (27mph reported w/duals). There's a huge selection of motors out there ofc, I'm sure you could find others w/a higher wattage rating - ya prolly know this but 1000w = 1.34hp so obv yer after higher wattage ratings than the 'Pie offers.

I'm sure there's hacks, I could prolly mod/change the controller to take more... at the cost of potential damage ofc. Unfortunately I'm pretty much an ebike novice so I can't offer much advice if you want raw speed. Just 2x the power should be easy enough, but you'd be venturing into DIY external drive territory if you're lookin' to smoke your Morini... possible w/o doubt, but even jus' thinkin' about that gave my poor lil wallet a heart attack lol :p
 
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POPS

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Cheers Barely

Really good job bro.
Great build. Can't wait to see more vid.
You must be haveing a blast.

Hey, Goat
If you want to go fast on your first E bike,
go to Endless Sphere and look up anything
Greyborg on the site.
There is a new hub just being sold for $600.00.
You can run it at 10K watts.
It's crazy fast.
One guy hit around 110 kph.
Nothing out of a box can kill this one off a set of lights.
Check it out Guys. You can find the hub in "New" stuff for Sale.
I think I'm going to go for one on my Chopper.

Sorry Barely if I jacked your thread a bit but I thought you
guys might like to see it.

Again..Super build Barely and I can't wait to see more.

POPS
 
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Goat Herder

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That looks extremely promising Pops! Like that a lot!! I will be building one in my future just my wallet say's no right now. That hub sounds like a dream come true! I would need a hefty controller for that rig? Was thinking about B.A.'s hub as a duel hub set up. Two wheels slipping in the snow could prove very interesting to try on snow and ice. Bet it would be fun as all heck to coordinate! A whole new territory to explore for sure!:) This hobby never ends!! Just cannot beat how fun all these bike are to ride...
 

Mike B

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Ordered up the Ping 48V, 15 AH pack and (2) 20 x 1.95 Hookworms.

When all this stuff comes in I'll start the "Electric Revival" thread - :)

Looking forward to making some good use of this rather unique bike that's been hanging from the rafters in the garage for years now.

Here's an old pic of mine I took a long time ago.

 
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