E-S Stealth Electric Bike Owners

[Kepler]

OK something a little different.

I have been nagging John to build a light weight version of a Fighter using a geared hub for quite some time now. He wasn't that keen but my persistence finally payed off with him finally giving in to the concept.

The main frame was kept close to stock however, extensive modifications to the rear swing arm were required to suit the 135mm motor spacing. The rest was up to me. To be clear, the reasons why John agreed to this build was basically to gauge the feasibility of using a geared motor in Fighter. So its lucky me. I get to build the Fighter I always wanted.

Specs:

Stock Fighter main Frame.
Modified swing arm
Bafang code 10 geared hub motor.
Custom 6 FET Mini monster controller setup for 2000W max output. Mounted internally.
18S 75V LiPo. 8Ahr
MT2 Magura brake set

Target weight: 28kG
Target range: 25km to 40km depending on riding style.
Target top speed: 60kph

Assembly is going well and should be ready to go in week or two. The second picture shows the controller in position. The frame becomes the heatsink for the controller.

[kiqnkf]

It's a slender, fine looking bike, may I suggest the "Stealth Bolt" as in "Crossbow Bolt"??? Probably look ok with the lightning bolt shaped "S" they use too...

That seat pole looks about 50cm too short for you Kepler....

So, anyway, Cruising down the road in the Prius, HV battery warning comes on. Off to the factory, pull the battery out - start the reconditioning process...
Using the Commodore, short of it, 3rd gear starts to slip.... Off to my trans guy.
Monaro still sitting in the factory, haven't quite finished the window reg thing... maybe in a couple of weeks.
No more cars to drive, so go to rent a bomb, hire a junker.

Get home, my kids decided we should go for a ride to the skate park, and tear it up.

Get the Bomber out of the house, start pedalling, click.....click...click..click.clickclick.clickclick.... Crap. V-boxx buggered.... Thought I could rely on the bike at least!!! NO!!! Wont be attending the ride this weekend.... Worst part about it.

Not my week.....

Does anyone have a golden egg-laying goose I can rent for a week or so?

[Hyena]

Cool pic Mr Lowbank, only to be trumped shortly after by Kepler!

Nice work mate, 8ah is quite a small capacity. Have you enlarged the opening that the side covers usually go over ? Looks like it, but maybe I just haven't had a close look at them before with both covers off. Would I be correct in assuming with that small battery capacity and big internal space you'll be mounting a clear window in the side covers to try and maintain a hollow triangle ? That's what I'd do! and it's what I'm trying to achieve with the custom frame I'm planning - still good performance but more literally more stealth. Since riding my fighter in public alot lately I've never had so many people say "is that electric?!"
John should provide a jacket with the bike that has "YES, IT'S ELECTRIC" written across the back

[Kepler]

It's a slender, fine looking bike, may I suggest the "Stealth Bolt" as in "Crossbow Bolt"??? Probably look ok with the lightning bolt shaped "S" they use too...

That seat pole looks about 50cm too short for you Kepler....

So, anyway, Cruising down the road in the Prius, HV battery warning comes on. Off to the factory, pull the battery out - start the reconditioning process...
Using the Commodore, short of it, 3rd gear starts to slip.... Off to my trans guy.
Monaro still sitting in the factory, haven't quite finished the window reg thing... maybe in a couple of weeks.
No more cars to drive, so go to rent a bomb, hire a junker.

Get home, my kids decided we should go for a ride to the skate park, and tear it up.

Get the Bomber out of the house, start pedalling, click.....click...click..click.clickclick.clickclick.... Crap. V-boxx buggered.... Thought I could rely on the bike at least!!! NO!!! Wont be attending the ride this weekend.... Worst part about it.

Not my week.....

Does anyone have a golden egg-laying goose I can rent for a week or so?

Seat post is just for the bike stand to grip. I will be using a gravity dropper seat post to accommodate my freakily long legs.

Bad luck on all the failures. Perhaps you should look at Dilogic's V-boxx clinic thread.

[Kepler]

Cool pic Mr Lowbank, only to be trumped shortly after by Kepler!

Nice work mate, 8ah is quite a small capacity. Have you enlarged the opening that the side covers usually go over ? Looks like it, but maybe I just haven't had a close look at them before with both covers off. Would I be correct in assuming with that small battery capacity and big internal space you'll be mounting a clear window in the side covers to try and maintain a hollow triangle ? That's what I'd do! and it's what I'm trying to achieve with the custom frame I'm planning - still good performance but more literally more stealth. Since riding my fighter in public alot lately I've never had so many people say "is that electric?!"
John should provide a jacket with the bike that has "YES, IT'S ELECTRIC" written across the back

True, small battery capacity. Plan is to install the batteries in the upper half of the battery cavity to optimize front to back weight distribution. The frame opening is stock Fighter and will be fully covered to stay true to the Fighter's standard look. It will look slimmer though without the controller mounted underneath. I will also use a 5ah Aux pack in a seat bag for extended range when required.

I may use the lower section of the battery cavity for a permanent mounted 240V charger but haven't made a solid decision on this yet.

[kiqnkf]

Kepler, you legend....

I looked at it, got to the part that said "2 year warranty" and sent FullThrottle a PM.....

[voicecoils]

True, small battery capacity. Plan is to install the batteries in the upper half of the battery cavity to optimize front to back weight distribution. The frame opening is stock Fighter and will be fully covered to stay true to the Fighter's standard look. It will look slimmer though without the controller mounted underneath. I will also use a 5ah Aux pack in a seat bag for extended range when required.

I may use the lower section of the battery cavity for a permanent mounted 240V charger but haven't made a solid decision on this yet.

Super nice new project, now I know of at least 3 people who own a Bomber AND Fighter. Lucky owners!

If you could run a fan-cooled controller and charger both internally, that would be sweet.
[edit: reread your post, you already planned to mount the controller internally, nice.]

Have you had a look at the zippy compact range? You could do 18S, 11.6Ah with just 4 of these packs:
http://www.hobbyking.com/hobbyking/store/__21386__ZIPPY_Compact_5800mAh_9S_25C_Lipo_Pack.html
4.5 kg for 772 Wh

[remf]

Yes you have to look closely at that pic to spot the controller mounted up there. Super sleek & very impressive John. Looks like it'll climb mountains.

[Justtoby]

I like the "lighter fighter" I think it should sell as a fighter rs like the Porsches.

I would want more range I think but I suggested to john a while back for a light weight 72v fighter.

Can't wait to see it in action, I assume you will add dérailleur?

[Kepler]

True, small battery capacity. Plan is to install the batteries in the upper half of the battery cavity to optimize front to back weight distribution. The frame opening is stock Fighter and will be fully covered to stay true to the Fighter's standard look. It will look slimmer though without the controller mounted underneath. I will also use a 5ah Aux pack in a seat bag for extended range when required.

I may use the lower section of the battery cavity for a permanent mounted 240V charger but haven't made a solid decision on this yet.

Super nice new project, now I know of at least 3 people who own a Bomber AND Fighter. Lucky owners!

If you could run a fan-cooled controller and charger both internally, that would be sweet.
[edit: reread your post, you already planned to mount the controller internally, nice.]

Have you had a look at the zippy compact range? You could do 18S, 11.6Ah with just 4 of these packs:
http://www.hobbyking.com/hobbyking/store/__21386__ZIPPY_Compact_5800mAh_9S_25C_Lipo_Pack.html
4.5 kg for 772 Wh

Interesting option on the packs. I hadn't seen those yet. Might look at that at a later date. For now I have plenty of LiPo's though so I will stick with plan A for now

[Kepler]

I like the "lighter fighter" I think it should sell as a fighter rs like the Porsches.

I would want more range I think but I suggested to john a while back for a light weight 72v fighter.

Can't wait to see it in action, I assume you will add dérailleur?

Fighter RS. I like it. I was thinking "Urban Fighter" ie biased towards on road and path use more then hardcore off-road duties.

In relation to the battery capacity, this is always such a compromise between weight and range. I have been running the same combo in my commuter for quite some time now and with the efficiency of the geared hub, the 8ah pack has been adequate for most of the riding I do. I want to keep this bike light enough for me to lift over my head.

All setup for a derailleur. Got a nice Shimano XLT deraillier and 8 speed twist grip shifter ready to go. Will start off with just a fixed ratio and Schlumpf for starters though.

[Kepler]

Yes you have to look closely at that pic to spot the controller mounted up there. Super sleek & very impressive John. Looks like it'll climb mountains.

Cheers Sam. Yes the geared hubs have great low down pulling power. Power tends to drop off with speed though. At 2000W, I think the bike will come close to keeping up with a 3000W stock Fighter. I will be doing som acceleration comparisons with my mate's Fighter with him at 3000W 75V. Should be interesting.

[remf]

2,000W sounds ideal. Who would have thought the BPM could handle that much. Are you using the stock nylon gears or metal replacements? I imagine the metal gears would be noisier and filings in the stator could be an issue.

[knoxie]

Very nice Kepler I only noticed those new BPM Bafang motors the other day, they look pretty sturdy looking dont they, the gears are far more substantial looking than the MAC and the BMC motors, not seen any reviews on them or know much about them so I will be interested to see how this runs for you, it seems a lot of folks are using geared motors off road, I still think its a tough call for those gears off road but time will tell, we toasted Deecanios geared motor in about 30mins jumping it over at jozzers.

[Kepler]

Thanks knoxie. This will be my second Bafang. The first one in my commuter hasn't missed a beat in 2000 km. I haven't tried a Mac or a BMC so I can't compare but it's worth noting that the importer here in Aust has spare gears in stock but is yet to sell a set.

I agree its still a tough call under serious off road duties. This bike will spend most of its time on bike paths rather then off road but it will still be worked hard with plenty of high speed stuff.

Just quietly though, John an Al are belting the crap out of one of these motors as part of factory testing. No doubt they will find the limits of this motor

[DALBYNATOR]

...it's worth noting that the importer here in Aust has spare gears in stock but is yet to sell a set.

Hi Kepler, I'm down here in Adelaide and just wondering who your supplier for the BPM motors are? And whether I could get one shipped down here?

Cheers, Tom.

[Paul_G]

I use to carry a 2nd battery for long rides and when one dropped dead I would swap it but after draining them down to dead over many cycles I found they held less and less till both only held 1050 WH's. John replaced them both at no charge.

To prevent that from happening in the future I wired them in parallel to prevent ever drawing one that low and I never have to bother swapping them again.

2nd battery just plugs into the same type connector on the seat post rack when needed.

There is also no sag.

Just got home from a 50 mile ride at 30-40 MPH and used 2000 WH's so each draw down was 1000 WH's......if you carry a 2nd this is the way to go......Win Win

[full-throttle]

Get the Bomber out of the house, start pedalling, click.....click...click..click.clickclick.clickclick.... Crap. V-boxx buggered.... Thought I could rely on the bike at least!!! NO!!! Wont be attending the ride this weekend.... Worst part about it.

John from Stealth Electric kindly agreed to take a look at the problem with the gearbox and replace it under warranty if necessary. How that for a customer service!

Don't feel to bad about missing out on the groupride this weekend - it's meant to be wet anyway. I'm sure we could re-visit it another day. SamD is having some issues with his bike and my spokes only arrived today. But they did arrive! And the length is right

[full-throttle]

Nice bike Kepler!

[Kurt]

Thanks knoxie. This will be my second Bafang. The first one in my commuter hasn't missed a beat in 2000 km. I haven't tried a Mac or a BMC so I can't compare but it's worth noting that the importer here in Aust has spare gears in stock but is yet to sell a set.

I agree its still a tough call under serious off road duties. This bike will spend most of its time on bike paths rather then off road but it will still be worked hard with plenty of high speed stuff.

Just quietly though, John an Al are belting the crap out of one of these motors as part of factory testing. No doubt they will find the limits of this motor

It's good to see the BPM motors getting a beating and I am keen to see how the build turns out. I have been using the same motor in my recumbent trike for just under a year now. 45A at 60v ...2700w In a 20 inch wheel its got some nice torque. I now live on a unsealed dirt road with some very steep climbs and have been giving it a beating along this road (no suspension on the trike) and it hasn't missed a beat. I even tow a trailer around with it . For burst of high power and snap off the line they have some balls for a small motor(comparing it to my older 5304 and 80/100 Rc motor on same voltage/amps. They are very efficient to due to freewheeling. I think freewheeling is a HUGE plus for a nice bike like the fighter if you want to peddle and have that bike feel rather than motorbike feeling.

Jumping the bike under throttle could be a different story though. If you let off the throttle of jumps and let it free wheel when you hit the ground it would help make it last longer.

I took a little video of the same motor at 2700w on dirt road...spins the wheel no prob.

[kiqnkf]

Yep, John at Stealth is terrific.

Called the shop, left a message re: gearbox. Little while later, he called back, suggested I tighten up the crank arms, PERFECT!!!

So I'm back on the road. Vic cruise Saturday 21st April (this weekend), which I will now be attending.

[Rix]

Hey Lowbank,

Your are correct about the axels on MX bikes. Both of my KTM's with an aluminum axel nut spin over a revolution before the axel nut starts turning freely. Maybe four complete turns before I can drop the socket wrench and spin with my fingers. And that with greasing the threads of the aluminum axel nuts. But still, I don't think a jam nut would hurt on your axel block post. Even little 3 hp 50cc childrens motorcycles have some type of jam nut on the axel block. But the torque from the a non hubmotor cycle isnt an issue like as with hub motor cycles. Last thing anybody wants is the hub motor spinning backwards at the axel. BTW, that is one cool bomber you got. Orange just makes it look faster. I just go a call from Darrin, the Stealth dealer here in the states. He spoke with John earlier and both of them recomended that I switch my order from the fighter to the bomber because of my body weight (around 118KG). So now I got an army green bomber on the way. Hooyah!!! Can't wait. Hopefull the ETA is the same.

Kepler, sweet fighter, cant wait to see the finished product. Please post some vids.

Rix

[Justtoby]

Rix, glad you went for the Bomber as I think you will benefit from the extra power and gears.

Glad the vboxx was an easy fix, we should all check the crank arms for tightness it would seem.

[Kepler]

It's good to see the BPM motors getting a beating and I am keen to see how the build turns out. I have been using the same motor in my recumbent trike for just under a year now. 45A at 60v ...2700w In a 20 inch wheel its got some nice torque. I now live on a unsealed dirt road with some very steep climbs and have been giving it a beating along this road (no suspension on the trike) and it hasn't missed a beat. I even tow a trailer around with it . For burst of high power and snap off the line they have some balls for a small motor(comparing it to my older 5304 and 80/100 Rc motor on same voltage/amps. They are very efficient to due to freewheeling. I think freewheeling is a HUGE plus for a nice bike like the fighter if you want to peddle and have that bike feel rather than motorbike feeling.

Jumping the bike under throttle could be a different story though. If you let off the throttle of jumps and let it free wheel when you hit the ground it would help make it last longer.

That video really highlights that these motors are a serious package worthy of duty in a bike like a Fighter. Gives me even more confidence in this combo

Jumping the bike under throttle wont be a big problem for me (my wheels stay firmly on the ground most of the time ) but this is certainly one of the things getting tested hard by John and Al.

[Kepler]

Hey Lowbank,

Your are correct about the axels on MX bikes. Both of my KTM's with an aluminum axel nut spin over a revolution before the axel nut starts turning freely. Maybe four complete turns before I can drop the socket wrench and spin with my fingers. And that with greasing the threads of the aluminum axel nuts. But still, I don't think a jam nut would hurt on your axel block post. Even little 3 hp 50cc childrens motorcycles have some type of jam nut on the axel block. But the torque from the a non hubmotor cycle isnt an issue like as with hub motor cycles. Last thing anybody wants is the hub motor spinning backwards at the axel. BTW, that is one cool bomber you got. Orange just makes it look faster. I just go a call from Darrin, the Stealth dealer here in the states. He spoke with John earlier and both of them recomended that I switch my order from the fighter to the bomber because of my body weight (around 118KG). So now I got an army green bomber on the way. Hooyah!!! Can't wait. Hopefull the ETA is the same.

Kepler, sweet fighter, cant wait to see the finished product. Please post some vids.

Rix

Thats great news with Stealth contacting you and steered you towards the Bomber. This is definitely a better fit bike for you. Yet another example of how Stealth take care of their customers