The Harley Davidson Electraglide Build

[ebike_rocket]

Hi folks,

Well, after messing around with electric bicycles for a while, I actually got a paid commission from a friend of mine to build him a high end Electric bicycle based on a limited edition Harley Davidson produced Veloglide. Apparently, these things are collectors items! This thread is to document my build from the ground up, and also to ask questions.

Currently, here's the bill of materials.

1 Harley Davidson Limited Edition Veloglide
1 Crystalite 3625E Phoenix 2 36 volt 900 watt hub motor, controller, wiring kit, etc
1 Battery space 37 volt 16 Amp-hour lithium MnNi battery

Here are the before pictures.

And a picture of my buddy at the bike shop making a final adjustment on the hub motor that we mounted onto the new suspension fork.

The biggie is making an attractive battery box. I at first floated the idea of using an old ammo container and repainting it chrome. But the more I thought about it, the more I didn't like it. So the next idea I had was to use my backyard foundry and sand casting setup to make an aluminum box. But then weight issues made that a problem. Then I thought about using fiberglass. The only problem is I didn't include fiberglass construction in the budget. Then I thought about using wood AND fiberglass as a composite, which would simplify construction, make a lightweight, strong, and fireproof container. I was at first going to paint this with a chrome metal, but now I'm thinking I'll paint it with a color that matches the peanut tank.
Anyway, stay tuned to this thread. I'll be updating it as I go along.

 

[StudEbiker]

That front fork looks to be alloy. I hope you are taking appropriate safety precautions with that application or this could lead to very bad things.

 

[ebike_rocket]

That front fork looks to be alloy. I hope you are taking appropriate safety precautions with that application or this could lead to very bad things.

Well, it has a torque arm installed.

Unless you're referring to something else. I haven't seen more than a torque arm installed in most electric bikes with front suspension.

 

[StudEbiker]

Well, personally, if it wasn't my personal bike, I would never consider putting a front hub on an alloy fork, period. I actually want to restate that, even if it were my own bike I wouldn't do it, but for different reasons. Conventional wisdom these days is that it can be done, but it must be done correctly. Much like using LiPo for me, the risk doesn't justify the reward. There are lots of threads on ES regarding alloy forks and front hub motors. Here are a couple good places to start:

http://endless-sphere.com/forums/viewtopic.php?f=3&t=6811

http://endless-sphere.com/forums/viewtopic.php?f=2&t=14195

 

[liveforphysics]

Hubmotor on the front really really sucks.

Hubmotor on the front with an alloy fork really really sucks, and breaks and hurts you badly.


Lithium MnNH battery?

 

[ebike_rocket]

Hubmotor on the front really really sucks.

Hubmotor on the front with an alloy fork really really sucks, and breaks and hurts you badly.


Lithium MnNH battery?

Unfortunately he doesn't want to replace the back internal gear. He wants as little physical modification to the bike as possible to keep it in "Harley" esque mode. I already have a torque arm installed, and am picking up two stainless steel c-washers for the drops outs. Unfortunately, we went through my buddy's bike shop catalog for the strongest fork at my friend's price point, and what he got was the fork which does have cromoly uppers, but cast aluminum lowers. I'm guessing one more torque arm for the other side of the fork probably wouldn't hurt. The motor goes maximum 25 amps, so the C-washers are rated for that maximum.

 

[neptronix]

Hmmmmm.. yeah that's definitely not the strongest fork i can think of
Solid cro-mo/steel chopper forks exist and i think they would be quite suitable here.

Aluminum lowers are what will break on ya.

Seriously consider changing those out for something else.

 

[ebike_rocket]

Hmmmmm.. yeah that's definitely not the strongest fork i can think of
Solid cro-mo/steel chopper forks exist and i think they would be quite suitable here.

Aluminum lowers are what will break on ya.

Seriously consider changing those out for something else.

Well, like I said, we scoured the bike catalog, and he got what he could afford for his budget. Unfortunately, finding a steel suspension fork is practically non existant, and the chopper forks aren't in his taste. He wants to keep the bike as close to original build as possible.

Which is why I'm running dual torque arms and C clamps. Seems they no longer make steel suspension forks.

Anyone have any experience using dual torque arms in combination with C-washers on alloy forks?

 

[full-throttle]

He wants to keep the bike as close to original build as possible.

The forks on two pictures above are different. I'm confused.

+1 re: front motor + suspension fork = bad idea

Not a bad looking frame. I like the look of the fenders. No belt drive? Would have expected a bit more from Harley though, maybe they should just stick to motorbikes.

 

[Jamzz]

First off, I have zero experience with front hub motors.

If I had to use a front hub motor, I would try to epoxy something like DoctorBass' Torque arms. I had one that he sent me handy. It looked it would work on the forks I have.

 

[ebike_rocket]

This is the torque arm I have on the right side of the hub motor.



The idea I have is to add another one on the left and include C-washers. I'd think many many other folks have run into this problem, considering the vast, if not 99% of all suspension forks are alloy out there. I figure with dual torque arms, the C-washers, which are rated for 25 Amps, should work well, after reading the threads about torque arms and hub motors. A good number of those threads where members did tests pointed out that even steel chromoly forks aren't less susceptible than alloy to ripping out the dropouts. They just don't shatter catastrophically. Which, considering that I'm using dual torque arms, those arms should mitigate that significantly.

 

[StudEbiker]

Your build, your choice. However, have you informed the buyer of the risks, and the safeguards you have taken, of a front hub on alloy forks?

 

[SamTexas]

..., considering the vast, if not 99% of all suspension forks are alloy out there.

Not sure exactly what sort of alloy you're talking about, but I see more lower end suspension fork stanchions made with steel (magnet test). I have 2 in my garage, Suntour and RST, both of them are of steel, stanchions and sliders.

I have never installed a hub motor on a suspension fork before, but I intend to do one soon. It'll be a 350W geared hub. Max power when accelerating will be around 700W. I think it has to do with the power level. Anything above 750W (1hp) would be a no-no for me.

 

[mrzed]

I've got a 9C front hub running 1100w peak on an RST suspension fork with either aluminium or magnesium lowers. I also run an ebikes.ca torque arm and c washers. I've had accidental regen at 30kph heading down a short but steep hill on the same setup but on a cheap steel rigid fork. My old torque arm - also from ebikes.ca fully deformed but likely saved my face doing it. The new torque arm is much thicker, and fits like a glove on my axle. I'm quite confident in this setup, but I wouldn't trust anything less with a mid-power front hub setup.

That pic of the torque arm looks slightly inferior to my old torque arm from ebikes.ca. I'd opt for something much beefier.

Front hub may suck for a fun bike, but for commuting on pavement, it is very practical. Use any gears, changing flats far less of a pain, 2WD if you actually pedal. I'd love a 3KW+ RWD bike, but my front hub has replaced 1000's of Km driving, and my 4 year old thinks riding a bike is the normal way to get around, all for less than 300Wh, or less than $.05/day in electricity.

 

[neptronix]

My RST fork cracked on half on me, almost sending me over a car while hitting the car at 3mph.
So hell no would i ever run a front motor on an aluminum fork... that thing flexed like crazy too.

Torque arms being rated for xxxx amps = a useless metric to go by. What you need to look at is watts, but most importantly you need to look at how much torque the electric motor is kicking out at startup....

I would not run a more powerful motor on the front at all ( such is the case with the crystalyte HS ), unless you want to run at stock speeds on 36 volts... then fine, i say go for it.

 

[liveforphysics]

You don't look at watts or amps to determine when the fork will break, it's simply about the torque on the axle. Justin did a really really nice write up on this exact subject, and broke a dozen or more forks in testing to find out at which points they snap. It's pretty scary low. lol

 

[vin791]

if i was the OP i'd try to hit up sam texas for a steel suspension fork. if not, do the build how you're gonna do it, but i completely agree with a high strength epoxy and some of doc's torque arms. heck even if you get the steel fork, why not?

 

[gogo]

Springer steel forks are cheap and very "Harley".

 

[dogman dan]

you realllllllllllly need the c washers and double torque arms on any alloy fork install.

http://endless-sphere.com/forums/viewtopic.php?f=4&t=15163

http://endless-sphere.com/forums/viewtopic.php?f=4&t=15167&p=225311#p225311

Ufortunately the pix got lost from the threads. The big deal is that the shoulder of the axle on the inside of the dropout must be big enough, if not, then you have to cut new shoulders that allow putting a spacer washer into there, then the c washers into the cup, then the torque arms. The idea is to bear all the force on the dropout, with no force bearing on washers that span the cup.

Washers that span the cup WILL deform, and when they do the space created lowers the pressure from the nut. Then you go over the bars when the wheel falls off the bike, and spit teeth on the street.

Done exactly right, it can be fine. Done wrong, and you have the motor wreck the forks while you can still see your driveway.

 

[Ykick]

Springer steel forks are cheap and very "Harley".

+1...

My #2 bike is a steel suspension fork DD hub motor with 2 torque arms under 2kW. I don't normally fear monger but this is one area I'd be very careful proceeding with Alloy suspension fork. Especially, doing the work for somebody else to use/operate - either under hire or as a favor.

 

[DAND214]

Here is a cheap steel sus fork http://www.ebay.com/itm/310352287205?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Dan

 

[ebike_rocket]

Well,

Talked to my buddy at the bike shop, and we're hunting down a steel fork. "Fingers crossed"

I still don't think that's that much extra insurance against a break out.

 

[gogo]

The springer forks will keep the wheel captive even if the axle spins. The wires might rip or short out, but you won't lose the front wheel. There is a forked member and a full surround member on each side of the axle.

http://www.choppersus.com/store/product/1221/Fork-Classic-Springer-Black/

 

[ebike_rocket]

Well,

While I wait on the bike shop to let me know when the steel fork comes in, which unfortunately, they don't have any steel suspension forks that ALSO fit the steering tube diameter, which was the biggest issue, so we're stuck with a rigid fork, I've went ahead to mock up a cardboard prototype of the electonics bay.



View attachment 5







View attachment 1



I also have to mock up a front hole for the on/off switch for the controller, which will be mounted inside on the top, a side hole attached to the removable door for the key switch, and I'm thinking of leaving the side vents open to all cool air flow through to cool off the controller and the battery. The actual box build will be made of 1/4 inch plywood sandwiched into a composite of fiberglass and resin. I'm thinking polyester, since that's what's available at Home Depot, but I've noticed some other folks were using Epoxy? What's the benefits/tradeoffs, and can you get Epoxy resin at Home Depot or Lowes?

 

[SamTexas]

Building the battery/controller boxes is always the hardest, most time-consuming task for me. And the two I made are for regular bikes with "true" triangle. Despite the significant effort, I still don't like the way they look. Just too "add-on" for me.

For you I think the job will be much much harder due to the rounded shape of the bike. BTW, are you planning to make use of the empty space in the "gas tank"?