Mongoose FatTire Build Pics

[plebe]

Just thought I'd post pics of a Fat Tire e-bike I made a while ago. It started as a Mongoose WalMart bike (sad to say I bought from them. :*( ), and added disc brakes and fairing. Motor is rear (135mm drop out) to fit wide-front forks. I had to cross the spokes when lacing to dish it enough to work. Tricky, but was super-strong! It's got a Sturmey Archer 3-speed with an old-school chopper shift-lever mounted on top-tube. It was generally fun, but sadly, it was pretty terrible handling (Almost broke a tooth it was so bumpy!) due to the geometry, and the power in the front (40a/53V) fatigued the forks quite a bit, so I quit before it failed on me catastrophically. Sure was fun while it lasted and got a lot of attention. Maybe I'll resurrect it with shocks someday.


View attachment 18

View attachment 16


View attachment 13




View attachment 8

 

[plebe]

 

[litespeed]

Looks pretty cool but I always wonder why you ( and most!) went with a front motor in stead of a rear one?

Nice work and good looking welds.

Tom

 

[plebe]

Hi Tom,

The reason I used a rear motor is that the drop out width is for 135mm, which is what the front dropout width is on a fat tire bike. The rear is even wider (180mm?). So therefore a rear motor works in the front as a drop-in replacement without modifying the forks. However, it's dished, so I had to cross the spokes to make it work. That was a tricky one.

 

[tahustvedt]

Nice mods.

What tires are those? I haven't seen 26" fatbike tires like that before.

 

[Drunkskunk]

Very cool build. Since you can weld, have you considered improving the geometry a bit?

Also, what tires are those? I need some for the Monster.

 

[plebe]

Nice mods.

What tires are those? I haven't seen 26" fatbike tires like that before.

They are actually 24" rims but the tires take the circumference up to 26", so it's like rolling on 26" wheels. I looked all over the internet for a pair, which I typically bought from cycles.us ( http://www.choppersus.com/store/ ), but he seems out of stock quite often. So I found a German site which seems to carry a lot of cool custom stuff. It took a long time to get the tire, but was the exact type I was looking for to match the rear. Classic Cycles in Germany ( http://classic-cycle.de )

 

[plebe]

Very cool build. Since you can weld, have you considered improving the geometry a bit?

Also, what tires are those? I need some for the Monster.

Ha! Yes, actually I thought about reviving it and changing the front forks to shocks with a beefy stem to take the torque loads (2000W is a lot of torque!). And cutting the rear, adding a pivot, and a rear shock behind the seat stays. This would make a much better ride for sure. I just may do that!

 

[danjpendleton]

so it looks like the em3ev bag fits in the frame triangle just barely. Im thinking about picking up the new mongoose fatbike that comes standard with a 7 speed and disk brakes, but wasnt sure if my battery would fit in the frame. I have a 76v battery from paul, but it does fit in the bag he sells, so my fingers are crossed

 

[plebe]

so it looks like the em3ev bag fits in the frame triangle just barely. Im thinking about picking up the new mongoose fatbike that comes standard with a 7 speed and disk brakes, but wasnt sure if my battery would fit in the frame. I have a 76v battery from paul, but it does fit in the bag he sells, so my fingers are crossed

Yes, it was a bit of a tight fit. Also, to lessen shock, I packed it all the way around with the foam packing it came wrapped in. Seemed like a good firm foam. I ran a few layers along the bottom/back and top, and couple along the sides. My pack never gets hot, but I did leave a space around the BMS in back. You will probably get it to fit, though mine was a 54V (58V full charge) pack so might be a little smaller.

Good luck!

 

[danjpendleton]

thanks for the quick response! and nice bike!

they just released the mongoose dolomite- standard with a 7spd cassette and disk brakes for $249 shipped!

I think im going to buy it regardless of whether the electric conversion works out. Still seems like a pretty cool bike for the trails. (but Im sure I can get it epowered :wink: )

 

[ambroseliao]

Hey Plebe,

Do you have any photos of the completed bike with the front fairing? I'd love to see it.

 

[plebe]

Hey Plebe,

Do you have any photos of the completed bike with the front fairing? I'd love to see it.

Yeah, but I don't have them. I'll see if I can dig them up with a request to my brother. Hang tight!

 

[motomech]

Nice build.
I'm wondering if spending some more for a bike up-grade would make sense for a conversion like this?
Like this bike;
http://www.bikesdirect.com/products/gravity/fat-bikes/fat-bikes-bullseye-monster.htm
It has a crome moly fork and while it's 2 to 3 times the price of the Wallyfats, it's still cheap compared to a Surley.

 

[plebe]

Nice build.
I'm wondering if spending some more for a bike up-grade would make sense for a conversion like this?
Like this bike;
http://www.bikesdirect.com/products/gravity/fat-bikes/fat-bikes-bullseye-monster.htm
It has a crome moly fork and while it's 2 to 3 times the price of the Wallyfats, it's still cheap compared to a Surley.

Yeah I don't see why it wouldn't be a good fit for a conversion. Go for it! I did another commuter bike that I typically use day-to-day to get to work, which I bought from bikes direct. Brakes not the best, so I'm working on switching to the Avid BB calipers.

 

[plebe]

Hey Plebe,

Do you have any photos of the completed bike with the front fairing? I'd love to see it.

Yeah, but I don't have them. I'll see if I can dig them up with a request to my brother. Hang tight!

Here's some pics I dredged up of some friends riding the bike. Not the best pics but gives a sense for what it looked like on the road. As I say, not on the road anymore!