My first eBike

[fordsnake]

The LBS where I volunteer, recently obtained several discarded Stromer E-Bikes...yes, these were dumped at the local refuge center! These are $4,000 bikes ea.; tossed among the garbage, buried under piles of trash (how they wound up there is another story). Many of the aluminum frames were crushed or destroyed, but the shop managed to rescue twelve nice orphaned frames, eight motors and a sundry of miscellaneous parts.



The owner of the shop had no interest in fixing up the bikes (because almost every part is proprietary and could be an expensive proposition) Instead he asked the volunteers to stripped them all down for their components. Everything was pulled, every wire cut from the frames at the digression of the volunteers.

As the months passed, the bikes sat derelict in the backyard of the shop...I thought I would at least try to get one back on the road…little did I know what I was getting myself into? There are so many nuances and so much to understand, i.e., different motors; front, rear, or middrive – some with controllers, some without! Different displays with different cable ends...torque sensors for PAS or POD! It was a bit daunting and challenging for a novice like myself, but I did managed to assemble two of the bikes with the assistance of the guys at my LBS.

 

[Rat Rod]

How did they ride?

 

[The Renaissance Man]

How did they ride?

Yes, and enigma too. Still waiting on that ride video! Glad to see that your health has improved.

Cool looking ebikes.

 

[kingfish254]

I remember you telling me about these over beers in Berkeley. Glad to see them. Are you having fun with them yet?

 

[fordsnake]

How did they ride?

They ride incredibly nice! I love the PAS (Pedal Assist System) mode vs the POD (Pedal On Demand) throttle. Traipsing up the hilly areas where I live is a piece of cake. I would love to get more milage range from the battery though (average range is around 20-25 miles before I need to charge it) I'm thinking about bumping up to 48V-20AH battery? But i would need to add a huge controller somewhere, plus and a bulky battery on the rear mount?

I remember you telling me about these over beers in Berkeley. Glad to see them. Are you having fun with them yet?

Yes...I'm loving them. So much I've decided to build a Stromer FAT BIKE!
Here are a few pics of its progress:



One of the problems building a Fat Bike is aligning the chainrings, derailleurs and rear sprockets! The bottom bracket shell had to extend out far enough to accept the Stromer's 170mm motor hub and a 100mm rear rim! First thing I did was modified the frame and made a new rear end!



A little tube bending for the new aluminum rear fork





It's hard to believe, but no one makes an aluminum 100mm bottom bracket shell!!! So I cut a 68mm aluminum BB in half and sandwiched it in. This also allowed for lacing the spokes on the wider rim with a smaller offset. Most Fat Bikes only have one or two front chainrings, plus many are now deleting the front derailleur. I'm using three chainrings up front!



I've also dimpled and sliced the chain stays so that the crank arms can clear with each pedal stroke. All the electrical wiring will be hidden internally inside the aluminum tubing.



So that's where I'm at so far...I'm trying to get it ready to ride it in my backyard. For all you Klunker and MTB aficionados my backyard is Repack.

 

[fordsnake]

Yes, and enigma too. Still waiting on that ride video! Glad to see that your health has improved.

Cool looking ebikes.

RM, thanks for your concern regarding my health...I feel much better now. Maybe when I'm done with the Fat Bike, I'll pull Engima off the garage wall and do a ride video just for you

 

[fordsnake]

I've spent the past week building the rear wheel (twice)! First time, I didn't account for the rear sprocket cluster and dishing the rim on the drive side...initially, I had built it symmetrically and was off a half inch. (pic) The vertical white line down the hub is the real center with the mounted freewheel



One of the nice thing about volunteering at my LBS...access to the tools – this is a spoke cutter and threader




I had to offset the spoke holes 17mm. Drilled new holes in the rim's center.


Ta-da...the laced rear wheel

 

[Rat Rod]

Backyard is Repack.....not fair!

 

[LukeTheJoker]

This is a cool build! That rear triangle is super beefy!

Luke.

 

[fordsnake]

Thanks Brian, Luke and Steve! I thought this build was going to be rather easy at first...repurposing all donated and found parts


...but every corner I would turn, new problems seemed to pop up, i.e., altering the geometry of the bike and offsetting everything for an ideal chain line. I honestly believe this is why most fat bike's run 1or 2 chainrings up front, to avoid new designs and engineering?

"Surly" is one of the few bike companies that has taken on the task of designing FAT bike frames around a 100mm rim; their Surly Moonlander is weird looking; the right side of its front and rear fork are distorted to accommodate disc brakes and an ideal chain line.
...also the lacing of many of their early rims were extremely offset...laced to one side of the rim!


I'm certain it would have been easier if I had purchased everything off the shelf or in a kit...but hey, how ya gonna lurn anything if ya don't get ya hands durdy?

 

[fordsnake]

Today, I managed to take the bike out for several test rides...handles incredibly well!


Added a cavity to both sides of the beefy chain stays, for the crank arms to clear when pedaling.


The hydraulic brakes with 200mm rotors really stops the beast on the dime!

The 5 - 38T sprocket freehub is a old Sungino...check out that rear rotor, its the same size as the motor.


With it's 4" cushy tires and a "Thudbuster' seat post...this ride has an incredible suspension.

This pic gives you an idea how far I had to shove the front derailleur out and away from the seat post.


A few extra batteries being charged for juice. Now its time to finesse and to enjoy.

 

[Rat Rod]

We need video.

 

[LukeTheJoker]

Oh yeah! Very awesome!

Luke.

 

[fordsnake]

We need video.

Here's a quick video of this morning's ride...

 

[LukeTheJoker]

Cool vid!

Luke.

 

[fordsnake]

Cool vid!

Luke.

Thanks Luke, sorry for the shakiness (iPhone), but you get the idea? I was riding at an easy pace with one hand holding the camera and climbing the hills between 12-13 mph.

On the flats I can crank it around 33 mph!

 

[MIGZ]

I've spent the past week building the rear wheel (twice)! First time, I didn't account for the rear sprocket cluster and dishing the rim on the drive side...initially, I had built it symmetrically and was off a half inch. (pic) The vertical white line down the hub is the real center with the mounted freewheel



One of the nice thing about volunteering at my LBS...access to the tools – this is a spoke cutter and threader




I had to offset the spoke holes 17mm. Drilled new holes in the rim's center.


Ta-da...the laced rear wheel

Nice, I really like the spoke machine

 

[Rat Rod]

So without electric assist you'd have been going how fast up the hill?

 

[fordsnake]

The bike weighs a whopping 72 lbs...so pedaling up a hill without PAS...is no easy task! However, I do have another 4" tire & a 100mm rear rim (sans an e-motor) Without the e-motor and the battery, the bike easily converts to a "conventional" FatBike! With the weight lost and the low gearing I'm able to spin up the same hill at around 8-9 mph...but I can only manage to go so far before I'm physically exhausted.

 

[gigmata]

I am always impressed with your builds. I appreciated how inventive you are. I would like build build an electric Felt cruiser using the old style tank frame.


- by Gigmata