E-S Stealth Electric Bike Owners

[Alan B]

Well the little BPM is officially toast.

At least I found the limit of the motor. I rode the bike as hard as I could which meant it spent the majority of its time on this ride at over 2000W.

One thing I love about these motors are that its so easy to remove the motor assembly out of the hub. No need to re lace the wheel, just slot in a new motor assembly. $200 and about an hours work in total and the bike is up and running again. I think I will leave the current limit where it is for now and just be a little kinder to the motor in future. Might look at adding a temp sensor too.

I thought the little 6FET controller would be the first thing to pop under these conditions but I am finding its hardly getting warm even under off road conditions. Having the frame as a huge heat sink is no doubt helping.

Not sure how the BPM compares to the BMC but Ilia of ebikessf who sells a lot of BMC indicates 1500W is about the max for good reliability on the BMC. If the BPM is smaller it might handle even less. The real problem is that at low speeds the efficiency drops and the power handling is even less, so it is easy to toast them under the right conditions.

Temperature sensor is a great idea.

To make much temperature difference will require more than a 10% reduction in power. With a temperature gauge you could figure it out before making toast.

[cruzxia]

Rix

I tried wave washers, was not successful, I would avoid welding the axle, You would be better off welding the adjuster plates and then file fitting them.

Cruzxia

[Rix]

Cruzxia,

My wave washer nylock nut combo lasted two 25 mile rides. Between the regen breaking and accleration, I believe the axel is rocking back and forth in the swing arm dropouts. Each time it does this, the nuts are rotating a little which is causing them to loosen up. I can actually feel the play and its obvious which is how I know when to pull over and tighten while riding. I thought for sure between the waver washers, red locktite, and the larger nylon locking nuts, my problem would be solved, but its not. You are right, it would be much better to shim the axel adjuster blocks than the axel. Might even be able to force some very thin and small 4 mm washers between the blocks and the swingarm instead of welding and grinding. If the axel is tempered, I could screw up the temper by laying a bead on the flat portion of the axel and then grinding to fit tight. The only real solid fix I see though is your flange nuts and the torque arm. Thats what Stealth needs to do. Does anybody else out there with a newer bomber experiencing this problem?

To all bomber owners,

I contated Martin, (Dlogic) he clarified the maintance needed for the Vboxx tranny. With his permission, I cut and pasted his response to my questions below. Thank you again Dlogic for taking the time to answer my questions.

Sent: Tue Jul 10, 2012 3:33 am
by Dlogic

Hi Rix,

The cable setup is not complicated but hard to explain just using words. I'll take the time these days to figure out an adjustment without the need to disassemble the vboxx. When it comes to lubrication please don't fill er' up with oil. Although equiped with gaskets, the shifter shaft and hexagonal crankshaft are not sealed in a professional way. The great thing about oil is that it creates a mist while the gears rotate thus lubricating everything perfectly. But since you'll end up with a dripping oily mess grease is the only alternative. I used 40 ml of the chain cleaning liquid sold in any good bike store. Just remove one of the 4 bolts where the grease will be pressed in and fill the box with that liquid. To really make sure it washes of all the old grease go for a short ride and switch through all the gears at least once. After that place a bucket under to bottom bolt on the vboxx and remove. Now your liquid should have changed in colour from transparent to black. Put the bolt back in and regrease via the 4 upper bolts. Suntour recommends 20 ml in every hole. I used a Teflon based grease that is also used for bicycle chains. Please make sure that it's not to sticky or else your gears won't shift smoothly. I have heard of people that have never changed the grease ever. But I don't just ride my bomber via the motor. No, I always pedal. My vboxx has done about 17400 Km. I change the grease every 3700 Km.

With kind regards,

Martin

[Kepler]

Hmm, this is obviously an issue that needs to be resolved. I would suggest not to use the regen until a solution has been found. Cruzxia's solution looks good but not a simple solution since its a machined part. Also I am wondering if the design reduces your chain adjustment.

With the stock torque arm, if you could squeeze a 4mm washer on its side in the gap, then its sounds to me the gap is too big. My torque arms are nice slop free fit and can only presume this is the reason why I am not having the same issue.

Rix, try slotting a spacer in there like a 4mm washer and see how that goes. It sounds like you can handle a welder. Perhaps also consider building up the hole in the torque arm with some weld and filing back for a perfect fit over the axle.

[Rix]

Hmm, this is obviously an issue that needs to be resolved. I would suggest not to use the regen until a solution has been found. Cruzxia's solution looks good but not a simple solution since its a machined part. Also I am wondering if the design reduces your chain adjustment.

With the stock torque arm, if you could squeeze a 4mm washer on its side in the gap, then its sounds to me the gap is too big. My torque arms are nice slop free fit and can only presume this is the reason why I am not having the same issue.

Rix, try slotting a spacer in there like a 4mm washer and see how that goes. It sounds like you can handle a welder. Perhaps also consider building up the hole in the torque arm with some weld and filing back for a perfect fit over the axle.

Kepler,

I am heading to the parts store to grab some washers and attempt to shim tonight. I also need to take a close look at the torque arm and see where the slop is coming from, axel or mount, or both. As it stands, I average between 1-3% on regen per ride typical and I can live without that additional range if I have to. I will let you know what I come up with.

Rix

[Rix]

Kepler,

I just emailed Stealth this morning about the issue and they already got back to me. (Wow that was fast) The US rep Darrin said he needed to speak with an engineer at Stealth tonight local time and said whatever resolution they needed to come up with will be covered by warranty. I am really impressed with Stealth's customer service/feedback. So for now, I wont be doing in welding or reingineering myself in leau of warranty coverage.

Rix

[Hyena]

I've had regen issues too but then I'm using an aftermarket motor with more power so it's not something I can really call stealth out on. Though Kepler is running higher power too and has had no issues so who knows.

Don't go welding to the axle though, modding the torque arm is definately a safer bet. This sounds like more of a QC issue with the TA (bad machining / laser cutting ? for a less than tight fit) and it's good that stealth are sorting it. Though knowing crystalytes varying degrees of QC I wouldn't be surpised if it was the axle itself that wasn't properly machined. An ideal solution would be a clamping torque arm insert to replace your existing one. Basically a longer version of what's supplied but with an open slot and a pinch bolt on the end. You'd lose the tensioner adjustment but how necessary are they on an ebike anyway? I don't bother with them and tighten up my axle nuts first and then nip the tensioners up afterwards just so they're not rattling around

[cruzxia]

The pinch bolt is a good solution to clamp the axle using a thicker redesigned chain adjuster.
The problem is that as you clamp the axle the adjuster moves away from the swing arm, because you are making it narrower by clamping the axle. It would be better than the current setup, but not perfect, as the adjuster plate could rotate.

It would prevent the nut undoing, as if the axle rotates, the adjuster plate and nut would rotate with it.

I considered this idea, before designing my torque arm.

Cruzxia

[Rix]

Kepler, Hyena and Cruz,

Dont I feel stupid. I don't have a torque arm. I should have noticed this when I removed the rear wheel and installed the Tuffy Tire liner between the tube and tire. Unless the axel blocks are also considered the torque arms. Here is a close up pick of both sides of the hub axel and swingarm dropouts. It looks like Stealth eliminated the need for a torque arm by the way the cut the swingarm dropouts and axel adjuster blocks. The dropouts are cut so that the hub motor axel can only be installled by sliding into the dropouts sideways with flat ground portion of the axel facing up and down. Same with the axel blocks. I guess this design would eliminates the need for a torque arm. I don't know what the Stealth Engineers will do to fix this, but I can tell you what ever the process involves, it will have keep the hub motor axel from having any rotational play when installed in the dropouts on the swingarm. I loosend the axel nuts all the way and rotated the wheel forward and backward. There is just a tiny bit of play that I can feel. Apparently thats enough though. Its either coming from the axel blocks and swingarm dropouts, or tolerance of the axel itself in the swingarm dropouts and axel blocks. For the mean time, im going to do what Kepler suggested and try shimming the blocks with 4mm washer. No voided warranty concerns with this. Cruzxia, you having of the flange nuts and custom torque arms for sale? I found some M14 1.5 pitch grade 5 titanium flange nuts on the net for 23 bucks a piece. I would rather stick with steel though. I will let you guys know what stealth says.

Rix

[Kepler]

Its our general terminology that has confused you. We are considering the blocks used to adjust the wheel position and chain tension to be the bike's torque arms. So as with all Stealth bikes, you do have torque arms. Go with plan "A" for now and see if you can shim the "torque arms" with the washers. I think the introduction of regen has been the main cause so if they still come loose, definitely stop using the regen until the factory gets back to you. I will be interested to see what they come up with.

[Hyena]

Yep as Kelper said what were describing ARE torque arms, it's just hte shape of the frame holds them in place rather than needing to be bolted in like many others.

Cruzxia, I agree having a pinch type insert would deform slightly when tightened but it'd be minor. One solution would be for stealth to weld in the "torque arm" so the last rear inch of the bike became essentially a thick drop out. Then you could pinch bolt it tight and have no worries. It wouldn't be replacable like the current one but it wouldn't need to be as it'd be super strong and the axle would be going no where.
On mine where there has been a slight bit of play the axle has slightly deformed the TAs, chewing slightly threaded grooves into the edge of the 10mm flat (but as stated previously this is with higher power so not really stealths issue)

Also on an unrelated note, any stealth owners that have missed the not so subtle notice in my signature - there's a ebike group ride in Sydney this weekend. It's looking like we'll have 2 fighters there but I know there's more stealth owners in Sydney so it'd be great if more came along. Click on the link in my sig for details

[remf]

I'd like to be there but I'm not in Sydney at the moment. Not only that but my Fighter is in pieces waiting for new bits. Next best thing...some of your usual HD goodness.

[Hyena]

No worries, hopefully we can get some more ride happening down the track.
My fighter is in pieces too, gotta lace up a new rear wheel before Sunday!

[Rix]

Kepler, Hyena, and Cruzxia,

Found the solution!!! Last night I squeezed two 4mm flat washer between the axel block and the swingarm drop out lip and went for a 13 mile ride using the crap out of my Regen. It stayed tight. I contaced Darrin (US Rep) and suggested that the Stealth "parts guy" go through the axel block (Torque Arm) bins and mic the the thickness of them top to bottom. If he can find two that are slightly thicker (.020) or thicker difference, send them to me. Kepler, sorry about the terminology confusion, in the gasser world those are referefed to as "adjustable axel blocks" and I am using gasser terminology to describe Ebike stuff which I am like a whitebelt cooley compared to you guys who are like 5th degree blackbelts. But I am learning slowly. Anyway back to the torque arms, your suggestion with the 4mm washers proved to be the solution. Thank you. I will be riding Lake Tahoe tomorrow and will post some pics. You guys have a good weekend.

Rix

[Rix]

Kepler,

Went home at lunch and snapped some pics of the washer shim mod. Its ghetto, but its working so far.

Rix

[cruzxia]

Rix

Great that that is working. All you need to do now is put a spot of weld on the adjuster plate where you placed the washer, and then file it down to a perfect zero clearance fit.
As suggested, I would like to be able to offer the flange nuts and torque arm that I made, but they take to long to make by hand, If they were CNC machined, they would be low cost to produce. I did send photos to John, I think that I will mail him the 2 spare flange nuts to try.

Cruzxia

[Kepler]

Interesting. That's not what I was expecting. I was thinking the shim needed to go between the motor axle and torque arm, not the torque arm and the and the swing arm dropouts.

I would have thought by having the axle adjusting bolts tight, you couldn't have any movement there. When I tighten my motor up, I nip up the main motor bolts then adjust the chain tension and wheel alignment with axle adjusting bolts. I then tighten up the motor axle bolts nice tight and finish off with then tightening up the axle adjusting bolts nice and firmly. This way I am making sure the torque arm doesn't rock.

It may well be that the tolerances need to be looked at though.

I went and visited John at the factory yesterday and discussed this issue with him. He is looking at a few options at the moment to remedy the problem.

[Hyena]

Here's a few pics of my fighter which is nearing completion - until I change my mind and reconfigure it all over again

I've drilled the larger 40mm motor which while probably unnecessary will let me run even more power The windings were pristine after a few months of 7kw peaks but it'll run even cooler now, letting my ride harder for longer. I've fitted an internal 100 degree thermostat inline with the hall voltage line which will essentially kill power to the motor in the event it gets too hot. 100 degrees is pretty conservative too but I'd rather be on the safe side. With my health being the way it is I couldn't push the bike home with a melted winding or even pedal it very far unpowered - but I CAN sit on a log for 10 minutes until the thermostat resets and then ride home a bit easier

My lipo charging solution is nearly finished. Balancing and isolated cell charging will happen though the centronics plug in the original CA location. This allows charging of individual cells at 8 amps which makes very short work of balancing. I could charge the battery only this way but charging at 8 amps is for suckers I'll use it just for balancing occasionally, which will only take minutes with this set up. Main charging will be done with a home made 2400w super fast charger - the most powerful one I can run on a standard house mains AC outlet This will charge the 18S 18ah pack at 32 amps - just under 2C fror a 90% recharge in around 30 minutes. I've also replaced the standard key with a motorbike one which has a second click for accessories. First click turns on the bike, second click turns on the internal DC-DC converter which powers the lights (not yet fitted)

8 amp balance charging

fighter3-ES.jpg (155.31 KiB) Viewed 414 times

I've also removed the 3" halo knobby (and what a task that was!) and replaced it with a DMR motoRT which is more suited to the sort of riding I do. Not as slick as the crazy bob but still rolls fast on the road and hard trails. It's quite similar to the berm master actually.

(click for bigger pics)

[cruzxia]

Axle clamping
I would guess that by pushing the adjuster plate down with the shim, it is clamping the axle on the top with the adjuster plate, and the underside of the axle is pressing on the swing arm. So it is acting like an axle clamp.

Hyena, Great looking fighter you have there, I bet it flys at 7kw. I like your balance connector idea 1 plug is the way to go. That is a rapid charging plan you have. Is your charger adjustable (current wise), Charging a a lower rate when you are not in a rush, will prolong cell life.

[Kepler]

Here's a few pics of my fighter which is nearing completion - until I change my mind and reconfigure it all over again

Nice work Hyena.

I think this bike is arguably the number 1 hub powered ebike on the forum (in my opinion ). Although there are lots of great bikes here, I dont think any of them can match the combination of reliable hi power, reasonable weight and big battery capacity, all wrapped up in one of the best ebike frames around.

Great work and cudos for doing it your way

[Rix]

Hyena,

WOW!! Your fighter is Awsome! That thing looks wicked with the vented hub and the zock forks. 7KW with 18s. I am guessing between 90 and 100 amps. Got Torque?

Cruzxia,
I may end up tac welding the washer and form fitting. So far its working great. Did a 30 miler yesterday and no problems.

Kepler,
I appreciate you inquiring at the factory about the problem I was having. I have a temp fix with the washer but I think I know why my axel nuts keep coming loose. The post on one of my torque blocks was bent pretty good. I have straightend it a little but its still bent slightly. Anyway when I snug up the post face place against the end of the swingarm dropout after I tighten the axel nuts, the post plate isn't seating properly into the grove on the drop out. If you look at picture with the washer, you can see the plate isn't seated properly. Here is a pic of the post after I straightend it a little. I need to heat it with a torch to straighten the rest of the way. Still doen't seat evenlty but fits better than before.

Rix

Rix

[Kepler]

I think you could straighten that completely cold without a problem but if you have a torch, probably a better method. Will be interesting if once this is straight and is torqued up squarely on the back the dropout whether the problem continues to occur. With my discussions with John, he fully acknowledged the issue was there but was saying that he couldn't get it to occur at all with the factory testing.

Would be great if you could just fully straighten the adjustment stem and install using the method I described and see how it goes. Then if still moves, email John and get the OK off him to weld in the shim so as to protect your warranty.

[Hyena]

Hyena, Great looking fighter you have there, I bet it flys at 7kw. I like your balance connector idea 1 plug is the way to go. That is a rapid charging plan you have. Is your charger adjustable (current wise), Charging a a lower rate when you are not in a rush, will prolong cell life.

Yeah she goes OK Previously when out chasing dirt bikes and crawling over steep, rough terrain and thick mud (ie the worst thing you can do for any hub motor, let alone a higher speed wind) it got quite hot, not enough to burn my hand instantly but enough I couldn't keep it on the cover. After some hard riding yesterday it was barely warm so the air cooling has really helped. I don't really need any more top speed but I might up the voltage to 24S with a small external booster pack. I like round numbers and 10kw has a nice ring to it 6S 18ah will sit nicely in the low dip on the top of the frame and I can easily wire my charge port with a series link that can be removed to plugged in the extra booster voltage.
And yeah I have multiple chargers - the isolated balance charger (which could do the whole pack if I wanted) Also a 4 amp 18S bulk charger for slow, usually over night charging or when I'm not in a hurry. This charges to 75v (~4.16v/cell) and then if I'm going on a big ride like yesterday I'll balance charge it up to 4.19v. Incidently I used 16.5ah of the 18ah pack yesterday (doing 42km) and the cells were all well balanced at 3.5v at the end.
I also have a 20 amp 6S bulk charger (for parallel charging each sub pack @ 6.5a) and a 32 amp 6S bulk charger (for parallel charging each sub pack @ just over 10a) both of which are well under 1C so will be gentle on the packs. The big 2400w charger is just for the occasional fast recharge or as a charging station for doing multiple bikes at once. Like yesterday on the Sydney group ride, all the the bikes built by me run on 18S so I could have recharged all 3 of our bikes while stopped for lunch.

Nice work Hyena.

I think this bike is arguably the number 1 hub powered ebike on the forum (in my opinion )

Thanks mate, that's quite a compliment from someone with 2 very sweet custom stealths himself
And thanks Rix and Cruzxia for the compliments too.

WOW!! Your fighter is Awsome! That thing looks wicked with the vented hub and the zock forks. 7KW with 18s. I am guessing between 90 and 100 amps. Got Torque?

Yep running around 100 amp limit. Being a fairly high speed wind it doesn't have a mountain of torque off the line, which is kind of good in a way as you don't have to worry about it flipping you off the back if you lean on the throttle too hard. But if you want to wheelie it a sharp jab of full throttle will do it. The triple clamp forks actually make for quite a heavy front end. I built a bike for a bloke recently with a giant reign xo and it was stupidly light - I could literally lift it with 2 fingers. It had a fox shock and carbon rims and spokes and just steering the bike around my workshop by the bars made it pull up in the air a few times. Crazy. Whacking a big H40 motor and 15ah of 18S lipo on there cured it's anorexia but I can only imagine what it'd be like with a light weight RC drive set up.

[Rix]

Hyena,

Here is a pick of me going 56MPH (92.7 KMH) on the bomber. Slight downhill 2%, but if I factor in my coworker's radar cosign effect of the 2% grade, I am actually going 58MPH (96.3 KMH). This is an old ashphalt road. It was so rough in places that my vision was blurred from bouncing all over the place. YAH!!!! My max draw was 5.1 KW and pedaling my ass off. Not bad for a stock bomber @ 84 Volts with the CA set at 66 AH.

Kepler,

I straightend the post out almost completely and followed your suggestion of snugging the axel nuts and the post nuts in stages finishing with torquing the nuts to 50NM. I think there is a tiny stress crack in the weld from straightening, but its structually sound and I will reweld when I go up north to see my dad. Anyway I tested the bike's accel and regen (low speed and high speed) on this shitty bumpy road that I took the speed run picture on. The nuts did not move or loosen at all. If you look at this pic and compare it the pic I posted a couple of days ago, you can see that the axel post plate even fits better into the grooves now. BTW, I added a jam nut to the axel post. I believe between straightening the post and snugging the nuts in stages like you suggested solved my axel nut problems. Thank you for the advise. Next on the agenda will be venting the hub. I ride smart, but I noticed that when the hub is hot to the touch and I am accelerating, my CA indicates that my current doesn't drop like it does when its cool which I believe I'm loosing some power to heat. Is this correct?

Rix

[QMS]

Hyena,

Here is a pick of me going 56MPH (92.7 KMH) on the bomber. Slight downhill 2%, but if I factor in my coworker's radar cosign effect of the 2% grade, I am actually going 58MPH (96.3 KMH). This is an old ashphalt road. It was so rough in places that my vision was blurred from bouncing all over the place. YAH!!!! My max draw was 5.1 KW and pedaling my ass off. Not bad for a stock bomber @ 84 Volts with the CA set at 66 AH.

Kepler,

I straightend the post out almost completely and followed your suggestion of snugging the axel nuts and the post nuts in stages finishing with torquing the nuts to 50NM. I think there is a tiny stress crack in the weld from straightening, but its structually sound and I will reweld when I go up north to see my dad. Anyway I tested the bike's accel and regen (low speed and high speed) on this shitty bumpy road that I took the speed run picture on. The nuts did not move or loosen at all. If you look at this pic and compare it the pic I posted a couple of days ago, you can see that the axel post plate even fits better into the grooves now. BTW, I added a jam nut to the axel post. I believe between straightening the post and snugging the nuts in stages like you suggested solved my axel nut problems. Thank you for the advise. Next on the agenda will be venting the hub. I ride smart, but I noticed that when the hub is hot to the touch and I am accelerating, my CA indicates that my current doesn't drop like it does when its cool which I believe I'm loosing some power to heat. Is this correct?

Rix

Hey Rix that speed is pretty damn inpressive I recken you have a bit of a freak bike there! Can you confirm those volts and AH figures they dont sound quite right



Hyena. SWEEEEEET Fighter MAAAN. Awsome job mate Had a chat with a Bomber owner over here today is a customer of yours from about 12 months ago, goin to catch up with him for a blast soon