E-S Stealth Electric Bike Owners

[Rix]

Now this is what I am talking about, listenting to Kepler and Hyena talk tech, is like grass hopper learning something from the mighty Shaolin priest. Good stuff.

 

[Kepler]

Continued with the oil cooling mod today.

So baseline approx 100ml of oil. No leaks and a reduction of noise of maybe 50% at full throttle. Hard to judge temp but the motor seemed be getting as warm was it normally did for similar style of riding.

Went 150ml. Maybe slightly quieter. Again temp felt similar. Close inspection revealed a bit of oil weeping from side of the motor at the shaft. Not good but possibly acceptable.

Next was 200ml. Motor noise and temp the same as 150ml. However this time I noticed my back brake was no longer working too well. Looked down and sure enough, there was oil all over the place. Bugger, just what I was trying to avoid.





Spent the next 2 hours stripping down the motor, draining and cleaning up the mess. I stink of ATF.

So this is where this experiment finishes for me. Perhaps I would have seen better results by sealing the axles and adding a vent hole but I am not interested in risking anymore mess. I will leave the motor oil lubed by adding 50ml back into the motor but I doubt if this will be enough to aid in cooling.

My personal opinion is that its not worth the mess.

 

[Hyena]

So this is where this experiment finishes for me. ...

My personal opinion is that its not worth the mess.

Bummer mate, and this is exactly why I haven't bothered pursuing it. Having to clean up and deal that that mess even once is too much for me :lol:
And as you found, the liklihood of losing your back brakes with a leak is high which to me is a no go, especially on a geared motor where you have no regen to fall back on. And for a commuter where reliability is all this is bad.

I will leave the motor oil lubed by adding 50ml back into the motor but I doubt if this will be enough to aid in cooling

It sounds like 100ml was the sweet spot in terms of oil leaks and noise reduction. Any reason you've only gone with 50ml ?
I guess it'd be nice to get some long term data from a leak and noise point of view, though I use that term loosely - even a few weeks of leak free commuting would be good enough IMO. Then maybe sneak it up to 100ml and see if the noise benefits are worth it?
If you are enthused in following it further and trying to do away with leaks around the axle one idea that I had (which I suggested to GCinDC when he was playing with ATF) is to make up a cone like shield fixed to the side cover around the edge of the bearing. It wouldn't totally keep the bearing free of the ATF but it'd keep alot of the splash and drips away when you stop and it all sloshes down from the top and runs straight down the side covers. I dunno, it may not be of any benefit but in theory it should help. I'm happy to be an armchair spectator on this one though, just pulling down and degreasing my schlumpf was enough oily/greasey mess to last me for the next year

 

[Rix]

Crap Kepler, I was hoping this would have been better. On another note, I have had great luck with venting the hub on the Bomber. Like I posted a while back, i live in real dusty condtions and when I opened up the hub after almost 400 miles of riding, there was only a tiny bit of dust around the vent hole openings (trailing edge of rotation) and almost no dirt on the stator. I thought I would have had a lot of dust build up, but not the case. Of course, I don't ride with people and there for I am not eating dust from somone in front of me. Maybe under those circumstances I would have some dust build up on the stator, just don't know though. Hyena has also had excellent results with venting his over volted hubs which I am sure you are aware of, maybe worth trying on the bafang. Even though I am a dumbshit compared to your guys with electrics, I have developed my own theory why my bomber hub temp is cooler, I think a portion of the cooling comes from ventalation when the motor is in motion. But after five minutes of stationary he quench, my hub shell never get as hot like it used to before venting which leads me to believe that a larger percentage of cooling comes from the venting allowing heat build up to escape when stopped. Before venting, I would ride it hard and couldn't touch the shell for more than a second or I would risk getting burned. Now, even before the weather turned cold, I can ride and climb as hard as I want and the the shell will get quite warm, but I haven't seen it get hot enough to come close to burning me such as it would before venting. Of course my peak watts is just over 5KW and thats really not alot of current for the mighty 54xx series. Anyway, right or wrong, your guys thoughts about my theory would be appreciated.

Rick

 

[Hyena]

Hyena has also had excellent results with venting his over volted hubs which I am sure you are aware of, maybe worth trying on the bafang.

I think Keplers main gripe was with the noise, in which case air cooling will just make it worse. But yeah, from a performance point of view I've had good results.
I actually just pulled down my old commuter bike last week after 2 years in service. I say commuter but for a long time it was my primary bike that was used for offroad thrashing too. It saw plenty of rain, mud and dust and when I opened it I was quite impressed with how well it has held up. I can't remember exactly when I drilled this motor but it was over 2 years ago. This was before I was painting/insulating the stators so this is a straight, raw motor with drilled covers. There is some light rust but all in all pretty good. Based on pics I've seen from others running sealed motors the amount of rusting is the same or even less than sealed ones.

I have developed my own theory why my bomber hub temp is cooler

Your own theory is well established and documented :lol:
There's been a heap of discussion about air cooling and what works or doesn't.
The above motor is a 9C running 5kw peaks daily and you can tell from the windings that this motor hasn't been stressed by that. I've seen bigger, beefier crystalytes (sealed) totally smoked with 3kw so it's certainly effective (though knowing how to use high power in moderation no doubt has alot to do with it)
I've always put holes on one side close to the rim over the windings and close to the centre on the other side to encourage centrifugal action. Others whack dirty big holes in the covers large enough to suck in small rodents. While I personally think this approach leaves the windings more prone to damage it does atleast vent the hub and allow heat to radiate directly from the windings to atleast some free air even when stopped. Some will tell you that your hole placement is wrong but I'm of the opinion that any holes are better than none. Think of the hub like an oven, even a small leak is going to prevent it maintaining it's temperature or slow the rise in temp (in an oven a leak is a bad thing, in a hub we're trying to achieve the opposite)

And yeah it's well documented the heat builds up when you stop. A hub, sealed or otherwise realises on shedding heat primarily through the side covers and when you're still it can only radiate heat from the surface. When there's airflow over it it's going to shed that heat quicker, like blowing on a hot cup of coffee.

 

[Kepler]

I went with 50ml because the stator was still saturated so its more like 100ml now added in total.

Been for a few rides since and it is definitely quieter so it certainly wasn't a waist of time. No further leaks either which is good. Back brakes still haven't recovered fully though. Used a heap of brake cleaner which has helped and putting the brakes through a few heat cycles is slowly improving braking power also. I will give it a few more rides and see how it goes.

On a DD hub I will definitely go down the air cooling path based on you guys good success.

So now my attention has turned to the Bomber. After 6500 km and 12 kW peaks plus some very noisy wheel bearings, I think it's time to pull the motor down for some TLC. The plan is to do a bit of a tutorial on Bomber motor bearing replacement for the general knowledge base.

 

[Rix]

Hyena, your analogy makes it easy to understand by the less than savy wannabees such as myself. Thank you for that. I agree and don't think the size of the holes is the key, just the fact that heat can escape. BTW, my venting was done with a 12.5mm drill bit or 1/2 inch. I wouldn't go bigger than that and when I get my 5404 back, I will vent it too and place the outer vent holes slightly closer to the center than I did with the 5403 so the stator wont be directly exposed at all.

Kepler, Dlogic suggested to me that replacing the stock chinese bearings with SKF units would be the best way to go. I can remember the sizes but I do remeber the disk side bearing was slightly smaller than the cog side. If you are interested in going the SKF route and need the sizes, let me know and I will get that info for you. Cant wait to see your video on the tutorial.

Rick

 

[cruzxia]

FYI - Bomber bearing sizes are:

Disk size Bearing = 6005
Chain side Bearing = 6004

 

[cruzxia]

Kepler

With oil cooling the heat from the stater should be transferred via the oil to the outer casing more rapidly.
So your motor should heat up faster from cold than it did with no oil. I would the expect it to run cooler internally, but the outer case should run hotter than it when it was just air.

8)

 

[Kepler]

And that is exactly what is happening, even with only around 100ml of oil. Bit disconcerting at the moment as I use to the motor staying cool for quite a while before it starts to heat soak. Hopefully it will be running cooler internally.

 

[Kepler]

Finally got around to changing out the bearings on the Bomber motor yesterday. So nice to have smooth quite bike again. Should have done it ages ago. The bearings were absolutely stuffed and although they hadn't collapsed, they were certainly on the verge.

As promised, I have put together a short video on replacing bearings in a 5405 Bomber motor. Hopefully it will be help out someone wanting to have a go at this.

[youtube]eQHz3eAh9SE[/youtube]

 

[Rix]

Great Vid Kepler. Thank you for taking the time to make it.

Rick

 

[full-throttle]

I have put together a short video on replacing bearings

Nice video
The freewheel must've been loosened before @0:48 :lol:
When the motor is opened up for the first time @1:58 the bearing's seal is rubber not metal. Is that how they come?

My BPM needs new bearings soon..

 

[Hyena]

The freewheel must've been loosened before @0:48 :lol:

Heh I was thinking the same, I pulled my fighter down 2 days ago and needed a 2 foot breaker bar on the spanner to crack the freewheel loose!

Nice video Kelper, that's probably worthy of it's own thread in the vids section as it is the same procedure for pretty much all hub motors

 

[Kepler]

Come on guys no picking on my handy work. That motor came apart 3 times to get all the shots I needed :lol: I can tell you right now, nothing came apart easily after 12kW and 6,500 km.

 

[full-throttle]

Clamp the tool in a vice and spin the wheel to release stubborn freewheels

 

[Rix]

Hey guys, quit insulting Kepler That free wheel was really tight, it just looked like it came off easy because Kep is strong. You guys smell that stink? Thats Kepler because he is the shit. Real world, thanks again John for making the video and for the follow up with John K. I learned another way to remove the stator, I always use my Harbor Freight Special 3 prong puller when removing the stator, all I needed was a 2x4, its faster and easier.

Cruzxia, did you ever get around to revalving the DNM? If you did, let me know what you got

Rick

 

[Dlogic]

Replaced my bearings a week after i got my Bomber. Not because they had failed but yes, the OEM ones are ZZ types. They come with metal seals. These have a tiny gap between the inner and outer ring, as scraping metal would not be something desired. Rubber could touch though and will prevent dirt from entering. That´s why please always get the 6004 and 6005 ones with 2RS after the number. This guarantees a rubber seal. Another positive side effect is also that the grease won´t be thrown out by the centrifugal forces that occur when the bearing spins. I did use a puller though to disassemble the motor. It takes more time but prevents damage to the magnet ring. Oh and please but some grease in between the lips of the 2 rubber seals inside the plates. If not these will wear out fast or cause squeaking on the plastic piece where the wires enter.

[youtube]7y87_3CQKhw[/youtube]

 

[Rix]

Awsome Video Martin, that will come in handy down the road. Thank you for taking the time to make it. Also, thanks for the work you are doing on the 5404. Can't wait to get it on the Bomber and going. Went for a ride Thursday, it was 54F. Set a new personal speed record on the Bomber, slight down hillgrade, WOT, pedaling my ass off in 9th. Hit 58.8 MPH or 94.6KPH. My CA @ 35MPH, was calibrated with my friend's Police radar unit. Running the current' 24.9" OD motor cycle tire on my rear, CA setting for the wheel is at 1987mm when you take 24.9x3.142x25.4. Mine is set at 1990mm. @35MPH indicated on my CA, radar confirmed 34-35 flickering. What that means is I am actually going between 34-35 MPH. Radar reading was taken at head on angle so cosign effect was completely eliminated. This run could be closer to 58MPH instead of almost 59MPH due to the very slight margin of error. As you can tell from my CA, I peaked at just over 71Ah with 79 volts,which comes out to just over 5.6KW. YAH!! Not fast like Hyena's Fighter or Keplers Bomber for acceleration, but pretty good.

Rick

 

[Kepler]

Replaced my bearings a week after i got my Bomber. Not because they had failed but yes, the OEM ones are ZZ types. They come with metal seals. These have a tiny gap between the inner and outer ring, as scraping metal would not be something desired. Rubber could touch though and will prevent dirt from entering. That´s why please always get the 6004 and 6005 ones with 2RS after the number. This guarantees a rubber seal. Another positive side effect is also that the grease won´t be thrown out by the centrifugal forces that occur when the bearing spins. I did use a puller though to disassemble the motor. It takes more time but prevents damage to the magnet ring. Oh and please but some grease in between the lips of the 2 rubber seals inside the plates. If not these will wear out fast or cause squeaking on the plastic piece where the wires enter.

Excellent instructional video Martin. Some great tips there especially with improving the the wiring path along the motor shaft.

Perhaps a link to where you got that very nice hall cable connector from would be handy also.

I also extended my motor cabling very early on and have it set up so all the connectors are now plugged in inside the frame. A bit less convenient in relation to removing the wheel but ensures no moisture gets to the plugs.

Also good tip on lubricating the seals in the motor casings. I forgot to mention that in my video but it's always something I do as the motor will end up with annoying squeak especially at low speed if you don't.

You have an excellent workshop there. Thanks for posting a "best practice" instctional video for those with access to all the right equipment.

 

[Kepler]

Set a new personal speed record on the Bomber, slight down hillgrade, WOT, pedaling my ass off in 9th. Hit 58.8 MPH or 94.6KPH.

As you can tell from my CA, I peaked at just over 71Ah with 79 volts,which comes out to just over 5.6KW. YAH!! Not fast like Hyena's Fighter or Keplers Bomber for acceleration, but pretty good.
Rick

That's a seriously fast Bomber you have there Rix. Also some serious stock power at 5.6kW. Looks like you got one out of the box with this bike 8)

 

[Rix]

Set a new personal speed record on the Bomber, slight down hillgrade, WOT, pedaling my ass off in 9th. Hit 58.8 MPH or 94.6KPH.

As you can tell from my CA, I peaked at just over 71Ah with 79 volts,which comes out to just over 5.6KW. YAH!! Not fast like Hyena's Fighter or Keplers Bomber for acceleration, but pretty good.
Rick

That's a seriously fast Bomber you have there Rix. Also some serious stock power at 5.6kW. Looks like you got one out of the box with this bike 8)

I was thinking the same thing Kep. When I orginally pulled off the controller cover to solder the shunt, I noticed some stuff inside of the controller that I haven't seen on my quest for knowlege search. Besides the shunt with the huge looking resistor type bar on it, the controller traces on the board appeared to have been beef up as well. My dad (who knows a hell of alot about electric powered 1/4 scale RC planes thought the same. I am talking really thick and wide oscilation solder paterns on the traces that I haven't seen anywhere else. A while back before winter hit, I turned my CA up to 75 AH and I pulled just over 5900 watts out of it from dead stop but then the wattage dropped quickly. Taking my CA up to 80 AH didn't draw anymore current than at 75 AH. I don't know if that was from the load decreasing really quick as I was acceleration, or if there was a software setting that limited the current deliberately. You and I talked about this quite awhile back and my number were differnt because the battery was still breaking in then. Anyway I also contacted John K and he told me that Stealth was experimenting with some software settings when my bomber was made. John K also specifically remembered me and the fact that I was a much larger than average person bodyweight wise which may be why I have the setup I do. Just the fact that John K rememberd me out of the hundreds of customers that Stealth has sold units to says alot for the company. Darin Brin in the US has been awesome with customer service. I orderd an extra shock, crank arms, and break pads all on seperate occasions. All shipped from Stealth in Australia. The most I waited was 2 weeks to get the parts. That is awesome after the sale customer support. Enough about my "how great Stealth is tangent" I will have the 5404 up and running probably within the next few weeks, I am thinking with the speeds I have had with the 5403, Its not unrealistic to expect 45-47MPH and more torque out of the 5404 that Dlogic is pimping out for me. Will post my results when I get that going.

Rick

 

[Rix]

Went for a ride yesterday at about 30 minutes before sunset. It was fuqn cold! I started out the ride at about -1F. On a full charge after 6 miles, my battery was hitting the LVC like a fat kid eating a cup cake. @ just over 7 miles, it was flat on its ass dead. So, I got to pedal the last 4-5 miles (8-9KM) home. Now I knew it was cold because the sweat that came off my head had frozen to my ski mask. So I got in my vehicle and drove my ride route. Temps ranged from -9F to -11F or -21C to -24C. Here is what I learned: The bombers battery doesn't work worth a shit when its this cold and what ever your range is when its above freezing, cut that by 66%. At least I'm riding. Anyway here are some pics at the turn around point right before my battery went completely dead and some pics at the temps.

Rick

 

[Archer]

Rix,

I have seen the weather out your way is way below normal,you guys out West must be suffering this cold snap! Although I know didly about the electric bikes I follow along with interest.

Hey just a thought,your in Nevada correct? Lots of sun. I was thinking to myself I wonder if there is such a thing as a solar heater for the batteries? Maybe something portable like for those occasional cold snaps.

Probably something wrong with this idea huh.

Rix,love your post as well as others here.So interesting.

Take care Tim.

 

[Rix]

Archer,
I'm in norther Nevada and funny you mentioned a solar heater, I was looking at a super thin solar survival blanket to wrap the battery in but with it being this cold, I wouldnt have rode much farther if I had full charge. In fact, I wouldn't have ridden any farther than I did, I just would have had power getting home quicker. I read somwhere on the forum about batteries subjected to cold not working as a well. I didn't know it would reduce output by as much as it did though. When I left the house fully charged, I took it easy because the streets were/are covered with ice. But after a couple of miles, I came across the some clear patches of paved and dirt roads and opened up the throttle. I couldn't draw any more than 2600 watts of power. Way lower than the 5600+ watts my machine is capable of when temp is warmer. I should have stopped and turned around then. But I didn't. Oh well, as stated above, you know what happend and how my ride finished. Your are right about lots of sun shine, we have about 295-310 days of sun light a year here, but it can get cold as you can see from the pics. Glad you enjoyed reading the posts and comments. Take it easy if you can and take it twice 8)

Rick