Mongoose dolomite fatbike? 7spd, disk brakes, INEXPENSIVE

Joined
Dec 4, 2013
Messages
252
Location
Hudson, New Hampshire USA
Mongoose Dolomite- $249 with free shipping from Walmart
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bike is steel framed
7spd freewheel which i believe is shimano
front and rear disk brakes
4 in wide tires

from what ive read on some mtb forums- this bike is actually pretty good for the price...

I know some of the guys on here have converted the mongoose beast which is very similar, except that they are single speed and lack disk brakes. one guy actually ran a cellman em3ev bag in the frame on his beast....so im hoping mine will fit in the frame of this dolomite.


Id ultimately like to build it for snow/winter. Ive gotten so used to riding to work that I cant see myself pumping gas this winter....

Im thinking-

crystalyte hs3540 or some equivalent (i run this on my eboardtracker- sensorless, because one of the halls burnt up and it seems more reliable this way)
lyen or infineon 40 amp controller (run the infineon on my eboardtracker, but might buy an additional one to have a spare)
cycle analyst-dps

and the battery would be my 76v 21s7p 20R samsung triangle pack from paul at em3ev, which does fit in the em3ev bag....(and hopefully in the frame of the dolomite :wink: )
 
It was just a matter of time, aye? This would be an easy platform for adding a single speed mid-drive to the inboard of the rear sprocket. Even if you used this as a 'disposable', it would be inexpensive to just bolt your electric gear to the next one.
 
I know very little about mid drives. my battery will most likely end up in the frame triangle, so I dont think Ill choose that route. I would like to build a mid drive setup someday, with gearing for rediculous speed and acceleration...with a fat top tube to house a lot of juice.
 
So where do you get the hubmotor with a fat rim? $125 to get your rim laced to a E-bikekit motor, so that's one option. The rear motor axles are long enough. Then some fiddling about with spacers to make the disk line up. You also need a spacer to move the freewheel outboard some. http://www.ebikekit.com/kit-components/wheel-parts/freewheel-spacer-for-1-speed/

Does EM3ev offer a fat rim version of his 12t mac? That would be a great choice, but are the axles long enough? I really don't know.

Mid drive, the bafang won't fit the wide bottom bracket. And I bet a GNG kit would not line up right either, so mods to the mount would be needed.
 
How wide are the dropouts? They MUST be more than the typical 100mm front and 135mm rear! :?:
 
There is a thread on here about one of these bikes with a rear (135mm) clyt laced into the front wheel, the forks didn't last long though!

I think the rear dropout is about right for a Cro!! :shock:

Here it is;
http://endless-sphere.com/forums/viewtopic.php?f=6&t=61757
 
http://endless-sphere.com/forums/viewtopic.php?f=6&t=44696

^^^^^this guy ran an hs3540 on the rear of his surly. he mentioned that it was 170mm dropout i believe. the motor was not modified or anything
----not sure if hes running a 7spd. ill have to read through it

my friend will re-lace the rear wheel to my motor of choice for around 100. he uses really high quality spokes and can cut them to length because he works at a local bike shop. hes done a set for me in the past
 
I need to get on this. I have a work commute through dirt that's 2.5 miles (mostly hard pack but there is some gravel and big gravel near train tracks that normal mountain bikes hate).

By car it's almost twenty minutes (and 6 miles).

In other words, if I can comfortably go by E-Fat-Bike across the dirt I can do it in half the time and twice the enjoyment.

I have a front hub motor (9c direct drive). Is there any hope to use that motor built into either the rear or front?
 
I just took a spin on the single-speed with back-pedal brake. I can see the appeal, and in spite of the drawbacks of it being a cheap Wal-bike...the low price allows you to spend your limited budget on other upgrades. $250 is still a good price, and the 7-speed system with disc brakes is a huge improvement.

The 2-speed Xiongda thread said that it can run well on 48V X 15A =720W, and here is a blurb: "If you want to use one of these hubs (or two of them?) on a fat bike, order the hub with a drum brake, which has 166mm wide shoulders on the axles to fit the 170mm drop-outs on fat bikes"

I'm told that at 44V, the 2-speed hub will do 14-MPH and 22-MPH.
 
No chance for the rear. It might fit in the front, but I don't know the width of the forks.I was going to buy one of these the other day but can't find them in stock for $250 anywhere. My rear motor (225mm axle) will fit easily in 170mm dropouts, but I will probably drop a 3-5kw motor in it if I get it. Plenty of room for it even with a 7 speed freewheel.
 
I considered putting a cheap motorcycle cromotor in one of these.
And then i saw the weld quality of the bike.

Looks like what they allow the new hires to practice on, to be frank.

Give it a look before you buy. Check out the weld quality. Maybe it's hit and miss.... but for high power, i would not go for anything other than proper..
 
bought the bike. ill have it next week and report back. im going to get a hub motor to fit the back of this this bike one way or another.
 
Seems like a front hub motor would be much smarter (and easier to install, obviously). With the weight of those bikes and grip/size of the tire, I really can't see any advantage of putting a hub motor on the rear. Just my thought (although it's a guess).

Here it is in the 20-inch version (four-inch tires). Boys mountain bike.

shopping


Also, check this out. Three-inch tires (not the same, I know), but it's a beach cruiser and looks pretty fun for under 300

http://www.rakuten.com/prod/fito-modena-gt-alloy-1-speed-man-26-inch-beach-cruisers-bikes-matte/263998194.html
 
id much rather have a rear motor. Steering and propelling on one axle is counter productive in my opinion. I posted a link to someone who has a clyte hs3540 on the back of his fat bike. He said the motor had no modifications to fit...

I have a beach cruiser ebike with 3" wide tires and rims and Ive seen that fito modena converted before. Mine isnt a fatbike though. the mongoose should be a good winter/semi offroad rig. interested to see how those tires will be on the street at 30 mph....without snow on the ground. but we will see.
 
I don't get why you'd want the fat tires for street. Well, cushion I guess, at $250, suspension will not be great as an alternative.

But I have thousands of miles of bottomless sand dry washes in my area. A fat bike would be great for that.
 
danjpendleton said:
id much rather have a rear motor. Steering and propelling on one axle is counter productive in my opinion. I posted a link to someone who has a clyte hs3540 on the back of his fat bike. He said the motor had no modifications to fit...

I have a beach cruiser ebike with 3" wide tires and rims and Ive seen that fito modena converted before. Mine isnt a fatbike though. the mongoose should be a good winter/semi offroad rig. interested to see how those tires will be on the street at 30 mph....without snow on the ground. but we will see.

That's assuming you could build a system that could move it that fast. It would take an awful lot of muscle to move it to 30mph, and it would eat up a lot of power in a short time.

Better for offroad use or slow on-road use (around the neighborhood, around town, etc.).
 
i have the beach cruiser/boardtracker for most days but when it snows or the road conditions arent so great i think this fat bike will do the trick quite nicely. plus they are a relatively new style of bike and i think overall it will be a lot of fun. I can always run a different set of tires if need be, but ill see how the original tires hold up at first.

Hell, if it doesnt work out ill sell it.
 
MikeFairbanks said:
Seems like a front hub motor would be much smarter...

I'd say exactly the opposite. Those forks look suspect even before adding a motor that will put significant stresses outside of the design criteria. I can't think of a failure worse than a front fork failure. Due to the wide tire the common issue of a rear motor, running out of space, goes away.
 
John in CR said:
MikeFairbanks said:
Seems like a front hub motor would be much smarter...

I'd say exactly the opposite. Those forks look suspect even before adding a motor that will put significant stresses outside of the design criteria. I can't think of a failure worse than a front fork failure. Due to the wide tire the common issue of a rear motor, running out of space, goes away.


^^^i second that
 
Aargh.

I bought one. Should see it next week.

I just couldn't justify the price of a decent one given the seat time it competes with against the rest of the pedal bikes my stable. There is about two months here in Pittsburgh where there is actually snow on the ground. I think I can use this sucker along a railroad track in bad weather and not have to deal with cars sliding into me when its sloppy out.

there are a bunch of crappy parts on the bike, to be sure. The high ten frame is not particularly strong or lightweight.

Its 50 pounds outta the box. Steel seat post/clamp, lousy crankset with pinned chainring, spindle bb with caged bearings, solid axles. cheap stem, bars and brakes..... Dumping the craptastic parts, and focusing on dropping some weight on those wheels, I should be able to get it down around the low 30's....

For me personally, I have a BUNCH of spare bicycle parts that are a direct swap, and cost zero additional bucks to transfer over to.. Between that, and some modifications to the wheel that cost just my time, the thing is an easy cheap entry into a fat bike.

Word on the street is that my LR kit is shipping tomorrow; I built a chassis based on a 26" steel full suspension frame for it. If for some reason that kit doesn't seem to work well on the frame I have, I may try that mid drive on the dolomite.

I will post the bicycle - part upgrades and wheel hacks when I get it....

len
 
danjpendleton said:
John in CR said:
MikeFairbanks said:
Seems like a front hub motor would be much smarter...

I'd say exactly the opposite. Those forks look suspect even before adding a motor that will put significant stresses outside of the design criteria. I can't think of a failure worse than a front fork failure. Due to the wide tire the common issue of a rear motor, running out of space, goes away.


^^^i second that

^ Third. And it seems Plebe, who had built one and used a front motor, agrees. He retired his build after concerns about the front fork. viewtopic.php?f=6&t=61757 These might be fun if built right, but it's still walmart quality.
 
Ill have mine wednesday. if i wasnt going to convert it, i would have purchased something a little more upscale, because ive ridden the fatboy and they are a blast. I agree with lenk42602- a lot of the parts are lower quality because it is a walmart bike, but from what ive read in the mtb forums it isnt half bad. may need to swap some parts out and upgrade things as i go. i commute pretty early in the morning so im not too worried about other cars.

my way home ill probably take an alternate route
 
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