Author Topic: Cheap Electric fatbike  (Read 95748 times)

Beasho

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Re: Cheap Electric fatbike
« Reply #60 on: August 25, 2016, 11:57:45 AM »
There's nothing wrong with hubmotors in a low-end electric bike. . . .

OK got it.  So my bike is a Piece O Crap :o

That said maybe I have been like a dumb animal and don't realize what I have been missing.

So what is the build time on this Mongoose set up?  (Question for GotWavz, or Pono)

How heavy is the whole thing?  Do you care or is there just so much juice it doesn't matter?

I was wary of building my first electric bike because of all the components needing to be compatible AND I wanted it to start as my Surf Caddy IMMEDIATELY.

5 years later, and with a few successful builds on this thread, I am more excited to try.  I might even learn something to benefit my current rides.  Alternately if I really like the setup it doesn't look like much to swap out a nicer fat bike or modify over time.

PonoBill

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Re: Cheap Electric fatbike
« Reply #61 on: August 25, 2016, 06:31:10 PM »
The new BaFang motors are a cinch. The controller electronics are in the motor housing and the cabling is coded, snaps together, and is waterproof. It's mostly a matter of fitting the motor to the bottom bracket. If you keep the derailleur rear end you need to get the sprocket of the drive more or less centered on the middle of the gear cluster. You also need to pull all the guts out of the bottom bracket. The cheesy Mongoose bike is particularly easy to do because it doesn't have a bearing cassette, just old school races and loose balls. You basically just knock all the stuff out, make up any shim you need to center the sprocket, and bolt it up. I did mine in less than a day. I'd suggest the battery option that GotWavz settled on. It looks like he did a cleaner job than I did on his bike, so it might have taken longer, but I'd guess a day for both, especially since once he did one he knew all the things he should and shouldn't do with #2.

How much do you have into yours Gotwavz? $1500 each?

Opps, just looked at Gotwavz post--I get $1474.

A good place to start is to read all the stuff from Lunacycle. these guys are pretty hot on the Bafangs, and have been hacking them a long time. On their recco I boosted mine to 1600 watts and was terrorizing the neighborhood. they tell me it runs all day like that, but I'd be getting stopped by the cops for nutjobbery, so I'm back to 1000watts.
« Last Edit: August 25, 2016, 06:49:28 PM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

GOTWAVZ

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Re: Cheap Electric fatbike
« Reply #62 on: August 25, 2016, 06:54:33 PM »
The Mongoose was really easy, we did two of them in about 5 hours. Even went thru and upsized the wires with a lower gauge between the motor and the battery receiver, soldered (removed quick connects, shortened excess wire) and went thru and put sealer on all the possible water entry points. Overkill but worth it.  No shims were required on the Mongoose, it fit perfectly.  I had a friend who built his a month earlier and he helped me big time, so that helped but there are lots of videos on the build on Lunacycles web site.
HB, CA, Oahu, HI
JK 7'-8' x 28"x 4" = 99L
JK 7'-10" x 41/4" = 106 L
Joe Blair Gun 8-10" x 28 x 4 1/4
198 lbs - 5'-9"

1tuberider

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Re: Cheap Electric fatbike
« Reply #63 on: August 26, 2016, 06:53:31 AM »
Is the mongoose strong enough for the electric motor? What about weight with this choice?
Nashbar has a nice fat tire bike on sale, as well as the house and REI. I would also look for a frame
that is gusseted. Workman cycles builds this tyoe of frame but they are heavy. I would not want my bike
frame to fail at speed. Also consider a front shock, because on the beach it can get rough and the frame bouncing
is punishing the battery. My battery is fine but the housing cracked.

I went with an aluminum framed bike(origin 8), added the bafang 1000 hd kit and a bottle battery 13.5 ah.
The nice thing about my choice is that it included the nuvinci hub. I paid 1200 for the bike, 700 for
the motor kit and 435 for the battery.  So for under 2400 I have a nice fat tire beach bike (around 60 lbs)that weighs
less than my evelo arias e bike (around 70lbs) that I commute on. My evelo cost around 2800.

The fat tire bike has opened up miles of beach to collect on. So far I have put over 100 miles of beach
riding and have collected over 40 lbs of agate and jade. I have only had to come back on my own power
twice as the rides were in soft sand for many miles.

The fat tire bike is not much of a street bike. Its the tires. The evelo is not much of a beach bike. Its the tires. They both have their roles. I do plan on hunting next month with my fat tire bike. Nothing like stealth out in the woods.
I have been really happy with the bikes. They get used. So far the garage has not gone up in flames.

I guess my bikes are not what you would call cheap. But put in perspective, e bikes prices range from around 1800 (look at luna cycles) to 10k. So I feel I am at the lower end of the spectrum. Both bikes are crank driven motor setups.  The bafang likes to rev where the evelo is a low speed torque setup. I like the advantage of gearing. I can do rooster tails in the sand.

Why do it? Every person who has ridden either of my bikes squeals like little kids with joy. No insurance. No license,
fewer restrictions (try taking a motorcycle on the beach), commuting at 20 mph around town and of course
exercise.

You should try one sometime just to check it out if you have not done so yet.

stoneaxe

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Re: Cheap Electric fatbike
« Reply #64 on: August 26, 2016, 08:55:12 AM »
OK...a pair of these just went into the do this sometime soon box.
Bob

8-4 Vec, 9-0 SouthCounty, 9-8 Starboard, 10-4 Foote Triton, 10-6 C4, 12-6 Starboard, 14-0 Vec (babysitting the 18-0 Speedboard) Ke Nalu Molokai, Ke Nalu Maliko, Ke Nalu Wiki Ke Nalu Konihi

PonoBill

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Re: Cheap Electric fatbike
« Reply #65 on: August 26, 2016, 12:00:11 PM »
Onetube -- The mongoose frame is a stout piece of work--steel, oversized tubing, double-butted in a few places. The cheap stuff is the components--the crank isn't a sealed cassette, it's loose bearings. Who cares, you're throwing it away. The rear derailleur is low end shimano, but it looks stout. I flailed the crap out of mine on Maui, doing the cane road from hell to the Peahi lookout, riding in soft sand, doing the mud and root trails near my house. No problem. It's heavy, but with three Lance Armstrongs doing the pedaling who cares.

Still, I looked at doing the Kawasaki aluminum framed el-cheapo. But it was heavier! Most importantly, the Mongoose was available at Walmart, and no one will ship bikes into Maui, to be even slightly rational they need to come in a container load.

It was a lot simpler to build the Mongoose than the Trek I just finished. I couldn't get the big sprocket on the BaFang to line up in the middle of the gear cluster of the Trek. It was easy on the Mongoose, but the trek bottom bracket attaches to the rear frame with sharply bent tubing, which lmits sprocket placement. I'm going to try getting a smaller sprocket from Lunacycle (better anyway) but if that won't let me center the drive I'll have to swap in an Alfine internally geared hub I have sitting around. That means lacing up a wheel and a few weeks of delay.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

1tuberider

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Re: Cheap Electric fatbike
« Reply #66 on: August 28, 2016, 07:22:45 AM »
Thanks Pono
I did not realize the mart bike was ok. I know you get rid of the crank, but there is more to it than the crank
assembly. The frame build is a major concern when adding power. The other components are easy to change.

The issue with weight for me, is that I lift the bike to a bike rack on the back of the truck. Its pretty high as I
have a tall 3/4 ton truck. Power overcomes the weight for rolling and lifting. I am doing the lifting, not some
gorilla.

I am using the 31 tooth luna sprocket. Great power at the low end. Top end I am not to worried about as I get
tire bounce and there is no suspension. Yet!

I have been roofing my house. 4 weeks of all my time to remove shake, clean surface, repair damage and then
reroof. 4000 sq ft has had me busy. Should be done this week and then back to the beach. Things you do to save
money. This savings is over 8k. Not to bad for a month of time out.  I may have to build another e bike with all this savings. I do have the 3k watt cyclone motor kit.

GOTWAVZ

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Re: Cheap Electric fatbike
« Reply #67 on: September 01, 2016, 06:47:43 PM »
Luna Cycle has some specials going on a bad ass frame for $499, if  you want to build a beast;


http://lunacycle.com/electric-enduro/

They also have a 3000W motor, which I guess you have Tube rider....crazy, must be so fast!
Where are these things going to be in a year from now, they are advancing so quickly along with the battery technology.

From Luna......

We have the mini-cyclone in stock which offers the same power the 3000w offers when using  a 48v or 52v battery in a smaller size and weight.  This is a very nice motor

Check it out here its an awesome motor:

 http://lunacycle.com/mini-cyclone-kit/
HB, CA, Oahu, HI
JK 7'-8' x 28"x 4" = 99L
JK 7'-10" x 41/4" = 106 L
Joe Blair Gun 8-10" x 28 x 4 1/4
198 lbs - 5'-9"

PonoBill

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Re: Cheap Electric fatbike
« Reply #68 on: September 01, 2016, 07:27:27 PM »
Pretty slick stuff. I'm a decent TIG welder, so I don't mind reinforcing a frame if I think it needs it. So far I haven't felt the need, though if I were going to 3KW or more I'd consider it. Might even build a custom frame. That's four horsepower. there are lots of ways to finesse that amount of power. I'd be as worried about the stock freewheels and axles as anything else. I blow spokes out of my three wheeler with just a 1200 watt mid-drive, but they last long enough, the last wheel I laced up I got some pretty heavy duty stuff and it's holding up well.

There are lightweight water-cooled outrunner motors available up to 55KW (75 horsepower) that are intended for UAVs. There's no practical limit to how far you can go, just a matter of, umm, why.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

Beasho

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Re: Cheap Electric fatbike
« Reply #69 on: September 03, 2016, 10:10:17 AM »
Is there any reason NOT to go with this motor? 

2000 Watts, small, apparently light and $419.  I am about to pull the trigger and think this would be pretty fantastic.
http://lunacycle.com/mini-cyclone-kit/

Also:  The Mongoose comes in the Dolomite (Blue) and the Malus (Silver).  Any particular differences?  I am leaning towards the Silver Malus.

stoneaxe

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« Last Edit: September 03, 2016, 12:22:54 PM by stoneaxe »
Bob

8-4 Vec, 9-0 SouthCounty, 9-8 Starboard, 10-4 Foote Triton, 10-6 C4, 12-6 Starboard, 14-0 Vec (babysitting the 18-0 Speedboard) Ke Nalu Molokai, Ke Nalu Maliko, Ke Nalu Wiki Ke Nalu Konihi

Beasho

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Re: Cheap Electric fatbike
« Reply #71 on: September 04, 2016, 03:22:36 PM »
Good overview of the Hub vs. Bottom Bracket motor. 

Similar to what Pono stated.  He added the observation about the increased Current required with a hub motor, which is essentially single geared system.  4X more power on a hill, for example, means 4X the current which is squared in the form of heat, e.g. 16X, and gets inefficient pretty quickly.

This all vs. leveraging the bicycles natives gears which have evolved to near perfection over the past 150 years, lowering unsprung weight . . . .

https://www.youtube.com/watch?v=KL7tTUZCFDs&list=PLaVr3cF6sYhtq_VDNU9CYxRhxpGpsTrXc&index=3
« Last Edit: September 04, 2016, 03:26:24 PM by Beasho »

PonoBill

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Re: Cheap Electric fatbike
« Reply #72 on: September 04, 2016, 08:13:21 PM »
Beacho, 'm not sure what comes with that kit. Looks like just a motor, mounting system and drive sprocket. You'll need a controller, wiring, throttle, cadence sensor, probably a freewheel on the crank sprocket. You should call Lunacycle and see what you're getting into. You jump right into the deep end, don't you.

Bob, I don't know anything about the boys bike. If it has disk brakes, and multi-speed rear derailleur it will probably work fine. You need to fid out what the bottom bracket width and inside diameter is. Basically, you can fit a wide Bafang drive to anything, but you might need some simple adapters. I turn mine out of tubing, but any machine shop can make you a sleeve for not much money, you can cobble something together like I do. A snug fit and good spacing makes for a happy bike.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

southwesterly

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Re: Cheap Electric fatbike
« Reply #73 on: September 05, 2016, 01:47:19 PM »

Beasho

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Re: Cheap Electric fatbike
« Reply #74 on: September 05, 2016, 05:33:30 PM »
I am leaning back towards the Bafang.  The primary reason is the enclosed gearing.  I didn't like the look of the exposed 2nd chain the cyclone kits. 

My primary interest in this bike would be to replace my current Surf-Mobile.  This would involve some beach riding in hard to soft pack.  I am getting comfortable that the 1,000 Watt BBSHD Bafang should deliver the goods in a more hermetically sealed package.

Also:  Considering the upgrade from "Cheap" to the Gravity Bullseye Monster PRO: $999 with Front Suspension.  No longer in the Cheap category, but should last for a few years and be able to run stairs and perform like on off-road beast:

http://www.bikesdirect.com/products/gravity/fat-bikes/fatbikes-monster-pro-bluto.htm#specs
« Last Edit: September 05, 2016, 05:37:52 PM by Beasho »

 


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