E-S Stealth Electric Bike Owners

[Tench]

RE Whizzkids crash; If there is no video,,,, it didnt happen,

if it did happen i hope hes ok!

[QMS]

Here is a few pics of my bomber side covers before i get them powder coated, i will post more pics once they are painted

QMS, I like it. Nice work. Looking forward to seeing how it looks once powder coated. How does the Stealth logo look on the lefthand side of the bike? I presume the "S" will be backwards. I imagine it will look more like an "electric shock" then an "S" on that side.

I like the smoother look with the controller covered. Also I think the controller will still get plenty of cooling with the way you have it vented.

Cheers Kepller!!! Yes the "s" is backwards on the other side and i wasn't sure if it was going to look right but the factory "old style" vinyl decals were reversed (chopped along the top though) so i thought it would be consistent with that. With the outline of the "s" only, and not a solid shape it does look like a "VOLT/ELECTRIC SHOCK" symbol

[Deutch420]

QMS,

How did you get those 888 lowers black?

Couldn't you just get lowers from the 888 RCV or the 888 CR?


http://www.marzocchi.com/Template/listP ... &idIU=2463

[Phoebus]

Marz wants 200 or 300 for the different lowers. Half the price of the fork, just about!

[Justtoby]

Took a ride out today that ended with a 35mph Fighter going through a fence, it really was a full speed accident. Bike held up really well but Whizzkid looks very second hand at the moment, lots of blood and then fingers pointing in the wrong direction until popped back in!

Ouch..Just how old is Whizzkid? The point is well made though that the bikes have the potential to carry you a hell of a lot faster than a MTB, along with an associated risk profile, as whizz kid has just discovered. ATGATT applies here - All The Gear, All The Time. I'd be inclining more towards dirt bike style PPE than MTB if you're going to be riding WOT, just to cope with the speeds at which you're going to find yourself falling off at. Hope there's no permanent damage, lesson learnt applies to all of us.

Thanks..and to Tench. I had a text from him to say he is f@/) sore. I think he was supposed to be working in the operating theatre today so expect that he has had to find another to work for him? He is similar age to me so close to 40. He was wearing mx trousers but only a hoodie on top plus a full crash helmet and gloves. I had full body armour.

Agree, all the gear, all the time.

[whizzkid]

WhizzKid had a "momentary lapse of reason", spurred on by some guys asking Justtoby & me for a full demonstration of "what speed it really can do". Never again. The omitted PPE has now been purchased, and I shall have gorgeous a scar to remind me forever. Fingers like sausages and a lovely colour.
Clearly not fourteen, but its anagram. Should know better, and especially in my line of work!
Thankfully no video, just flashbacks.

[Rix]

Justtoby,

Crashing sucks. I have an artificial radial head and several titanium screws holding my left elbow together. I ride Dirt Bikes and MTN bikes. The worst injury I ever ahd was on my MTN Bike hence the elbow injury. I thinks its because I wear so much more PPE when riding my dirt bike. Get well quick.

Rix

[Justtoby]

Justtoby,

Crashing sucks. I have an artificial radial head and several titanium screws holding my left elbow together. I ride Dirt Bikes and MTN bikes. The worst injury I ever ahd was on my MTN Bike hence the elbow injury. I thinks its because I wear so much more PPE when riding my dirt bike. Get well quick.

Rix

Justin (whizz kid) is round my house now and he has very puffy and purple hands...3 broken or dislocated fingers and the biggest gravel rash up his arm I have ever seen. His fingers are not very straight.

[Rix]

Lipo Questions. I have been told with a standard 3.7 volts that max voltage charge can never exceed 4.3 volts and never discharge below 2.7 volts. So if I multiply 4.3 V by 18 I get 77.4 Volts and if I multiply 2.7 volts by 18 I get 50.4 volts. With this information, if I build me a lipo pack using 6 Desire Power 6sp 22.2 Volts 8300 mAH wired in series of 3 by 2 for median voltage 66.6 Volts x 16600 mAH, does this mean my operating ranges would be from 77.4 volts peak charge to 50.4 maximum discharge? If this is the case for the extremes would be safe to set the CA not to drop below say 53 draw volts and my balence charger not to exceed 76 volts for safety margins? I have only used Lipos in RC cars and my ESC shuts off when the current gets to low. I use a balence smart charger that handles the peak charge. Also, If I quick charge my rc batteries at 4c and higher, they don't last nearly as long as charging at 1c. I am talking both performance and cycle life of the lipos. I have never kept track, but I would be willing to bet that I'm getting 3 times the cycle life or more out of my RC batteries charging at 1c for 60-70 minutes over quick charging at 4-5c for 10 to 15 minutes. So am I correct with the peak charge and disharge numbers? What about maximum watt discharge? If I multiply the 77.4 volts by 16600 mAH I get about 1,285 watts or 1.285 KW. Using the 10-20% dischaging rule of thumb, I should not drop below 200 watts approx 17-18% of total capicity. Or should I base the total watts on 66.6 volts for 1,105 watt or 1,105 KW and not drop below 180 watts? Or, am I totally way off?

Rix

[sn0wchyld]

Lipo Questions. I have been told with a standard 3.7 volts that max voltage charge can never exceed 4.3 volts and never discharge below 2.7 volts. So if I multiply 4.3 V by 18 I get 77.4 Volts and if I multiply 2.7 volts by 18 I get 50.4 volts. With this information, if I build me a lipo pack using 6 Desire Power 6sp 22.2 Volts 8300 mAH wired in series of 3 by 2 for median voltage 66.6 Volts x 16600 mAH, does this mean my operating ranges would be from 77.4 volts peak charge to 50.4 maximum discharge? If this is the case for the extremes would be safe to set the CA not to drop below say 53 draw volts and my balence charger not to exceed 76 volts for safety margins? I have only used Lipos in RC cars and my ESC shuts off when the current gets to low. I use a balence smart charger that handles the peak charge. Also, If I quick charge my rc batteries at 4c and higher, they don't last nearly as long as charging at 1c. I am talking both performance and cycle life of the lipos. I have never kept track, but I would be willing to bet that I'm getting 3 times the cycle life or more out of my RC batteries charging at 1c for 60-70 minutes over quick charging at 4-5c for 10 to 15 minutes. So am I correct with the peak charge and disharge numbers? What about maximum watt discharge? If I multiply the 77.4 volts by 16600 mAH I get about 1,285 watts or 1.285 KW. Using the 10-20% dischaging rule of thumb, I should not drop below 200 watts approx 17-18% of total capicity. Or should I base the total watts on 66.6 volts for 1,105 watt or 1,105 KW and not drop below 180 watts? Or, am I totally way off?

Rix

To be honest mate this probably isn't the thread for noob lipo questions... there's allot to learn about lipo, my best advice is to use the search function. Dont take it the wrong way, but you've shown you're not really up to speed yet on lipo for ebikes. it took me like 3-4 months before I felt good enough to buy some, and even now I treat 'em like little bombs.

pretty much all your other questions have been answered in other threads dozens of times.... So hit up the search function and if you're still having issues start a new thread and people'll either answer them specifically or point you in the right direction. theres a couple of points ill address though as it seems you've gotten some info from a less than ideal source already...

I'm mildly surprised you haven't had problems already given the way you charge your lipo (particularly if you're cells arnt rated for 4+c charging). most cells are only rated at around 2c unless you get high -end ones, and unless you have to its best to charge at 1c or less. and the general rule of thumb is never above 4.2, never below 3.6v, some will even say 4.15 - 3.65. 4.3 volts is usually reserved for the extreme guys chasing that little bit extra for a drag race, and there's a notably increased risk of fire when doing it, not to mention it knocks 10's of cycles off your bats compared to ~4.15V charging, for the gain of just 3% more power and 10% capacity if your lucky.

max discharge is easier to base on ah rather than wh, so for a 10ah pack you try to keep it under 8ah, however many wh that may be. I think you got this part a bit mixed up with discharge watts... discharge watts is how much power you can get out of the pack as a rate, not a capacity, ie 1kw rather than 1kwh.

[Rix]

Snowchyld,
I took this from Desire Power web site. I have never charged my RC car lipos at 10c, but Desire Power says its possible depending on time constraints. I never had any thermal breakdown on my lipos charging at 4+C. I have stopped a charging cycle before because they were really warm to the touch. Looks like I am off on the useful voltage range though. However, I got that info from another forum on this site: they quoted "lipo rules, never above 4.3 and never below 2.7". Apparently that info is incorrect which is why I asked here. As you pointed out, there are a many other forums to go to for my inquiry, however the information can be wrong there. Kepler and Hyena have both done lipoly conversions with great success which is why I posted my querry here. I believe this forum will point me in the right direction with sound advice. I can do the math and come up with a more accurate voltage range as long as the info provided is correct. BTW, Watts can be measured in current draw output and also in capacity of a storage devise. Stealth Bikes lists the capacity of their batteries in watts on their website. Bomber's battery capacity is 1.5 KW (probably 72+ volts 20 Ah) and the fighters battery capacity is 1.1 KW (probably 55 peak volts at 20 Ah) not to be confused with the bomber's output up to 4.5 KW (probably 60-65 Ah @ 72+ volts) and the fighter up to 3 KW (probably 50 Ah @ 55 volts). I think your max discharge rate example for a 10 Ah battery being discharged at 8Ah max tells me that you are referring to a battery rated for 1c continues discharge. The lipos I am looking at rate anywhere from 35c continues up 65c with short burst that doubles these numbers. Having said all of this, I am not very knowlegible about Lipos, I use them in my RC car and my RC Helicopter with out any problems. They are 11.1 volts and 7.4 volts respectively. For me it is litteraly plug and play and my smart chargers balence and charge the batteries. Anyways thankyou for taking the time to answer my questions and for providing the information about voltage ranges for lipo cells.

[Mr Lowbank]

I am thinking a sprung shock rather then an air shock. Something like this. http://www.dnmshock.com/bicycle-wheelchair-shocks/burner-rcp.html. I will do a bit more searching. Hyena has a different shock then standard on his fighter. Not sure what it is.

Speaking of rear shocks I would like to find a lighter spring to replace the the Bomber spring as I do 95% street riding. If any one knows what is stock and where to find lighter please let me know.

I got the orange bomber been riding and too knackered to do much else Haven't done a photos shoot yet, hope to get to that before I scratch it up to much. I also am wondering about the rear shock spring. The compression dampening was wound right out when I got it but still seems to hit hard in the ass end. I am wondering if a lighter spring with a bit more compression dampening might be the way to go. Also the back tire hits the shock reservoir pretty hard when landing with the razorbacks. has anybody noticed this? I put some white tape on the reservoir before gong for ride. And the tape has been marked.

The chain is stretching every ride so when the wheel gets back a bit it may miss? I would like to see the action with no spring.

The work stand


he weight of back wheel 17kg

[Kepler]

Rix, I presume you have looked at the conversion I did.http://endless-sphere.com/forums/viewtopic.php?f=6&t=23996&hilit=desire+power&start=894 Follow this, and you wont go too far wrong.

I have been around LiPo's since they first started being used in RC modelling and now run nothing but LiPo in ebikes.

The rules are simple.

:> Inspect the packs very carefully when you first receive them and make sure the pack is well balanced even before you do the first charge.

:> Be extremely cautious with the first first few charges. If there is a manufacturing defect hopefully it will show up during this break-in phase.

:> If using an RC charger, balance charge where ever possible. An RC charger will take the pack to 4.2V per cell. From 4.1V onwards is when you tend to see the packs loose a bit of their balance hence the recommendation to balance charge where ever possible.

:> If bulk charging, take the pack to 4.1V per cell. There are 2 reasons for this.
1) The pack holds balance really well to this voltage.
2) Should one cell be faulty and stop accepting charge, an 18S pack effectively becomes a 17S pack. This 17S pack still is charged to same total cut off voltage and as such each cell will now be charged to 4.34V. The pack should still be safe at this voltage and hopefully you will pick up the anomaly.

:> Discharge should be no lower then 3.5V per cell. 3.6V is safer but personally I use 3.55V as the safe cutoff. On an 18S setup the CA should be setup to an LVC of 64V. My packs show 10% remaining at this cut out point but I only take it down to this if I really need to stretch the range.

:> When using LiPo's, always keep an eye on your voltage via the CA. Get to understand you pack's discharge characteristics and investigate immediately if something seems to have changed.

The 64V low limit is with the pack under load, not at rest. The battery may read 65.5V when not loaded and still be considered fully discharged.

Follow these simple rules and you will get great life out and safe operation out of the packs for many hundreds of cycles.

[Kepler]

I am thinking a sprung shock rather then an air shock. Something like this. http://www.dnmshock.com/bicycle-wheelchair-shocks/burner-rcp.html. I will do a bit more searching. Hyena has a different shock then standard on his fighter. Not sure what it is.

Speaking of rear shocks I would like to find a lighter spring to replace the the Bomber spring as I do 95% street riding. If any one knows what is stock and where to find lighter please let me know.

I got the orange bomber been riding and too knackered to do much else Haven't done a photos shoot yet, hope to get to that before I scratch it up to much. I also am wondering about the rear shock spring. The compression dampening was wound right out when I got it but still seems to hit hard in the ass end. I am wondering if a lighter spring with a bit more compression dampening might be the way to go. Also the back tire hits the shock reservoir pretty hard when landing with the razorbacks. has anybody noticed this? I put some white tape on the reservoir before gong for ride. And the tape has been marked The chain is stretching every ride so when the wheel get back a bit it may miss? I would like to see the action with no spring.

The work stand
http://www.box.com/s/37b2cae280c3b5314513



he weight of back wheel 17kg

I havent seen a tire come in contact with the shock before but moving the wheel back should help. Not sure how much adjustment is left but perhaps it even needs an extra link installed.

[Kepler]

Now that your pictures are coming up, I can see you have the shock spring fully wound off. I run my spring at full tension. Ride is still quite plush.

[sn0wchyld]

Snowchyld,
I took this from Desire Power web site. I have never charged my RC car lipos at 10c, but Desire Power says its possible depending on time constraints. I never had any thermal breakdown on my lipos charging at 4+C. I have stopped a charging cycle before because they were really warm to the touch. Looks like I am off on the useful voltage range though. However, I got that info from another forum on this site: they quoted "lipo rules, never above 4.3 and never below 2.7". Apparently that info is incorrect which is why I asked here. As you pointed out, there are a many other forums to go to for my inquiry, however the information can be wrong there. Kepler and Hyena have both done lipoly conversions with great success which is why I posted my querry here. I believe this forum will point me in the right direction with sound advice. I can do the math and come up with a more accurate voltage range as long as the info provided is correct. BTW, Watts can be measured in current draw output and also in capacity of a storage devise. Stealth Bikes lists the capacity of their batteries in watts on their website. Bomber's battery capacity is 1.5 KW (probably 72+ volts 20 Ah) and the fighters battery capacity is 1.1 KW (probably 55 peak volts at 20 Ah) not to be confused with the bomber's output up to 4.5 KW (probably 60-65 Ah @ 72+ volts) and the fighter up to 3 KW (probably 50 Ah @ 55 volts). I think your max discharge rate example for a 10 Ah battery being discharged at 8Ah max tells me that you are referring to a battery rated for 1c continues discharge. The lipos I am looking at rate anywhere from 35c continues up 65c with short burst that doubles these numbers. Having said all of this, I am not very knowlegible about Lipos, I use them in my RC car and my RC Helicopter with out any problems. They are 11.1 volts and 7.4 volts respectively. For me it is litteraly plug and play and my smart chargers balence and charge the batteries. Anyways thankyou for taking the time to answer my questions and for providing the information about voltage ranges for lipo cells.

if they're rated for 10c then 4c shouldnt be a problem... though the drastically shortened life suggests that they're not ideally suited to those charge levels. they're obviosly not as concerned with cycle life, and they're not charging up huge packs, so if 1 small pack goes pop its usually not a big danger (relatively), if 10 or 20 of those packs go up at once, thats a different matter, hence the conservative 4.2/4.15 to 3.6 in the ebike world.


and just a small point on terms... you've got the Ah/A and Wh/W's mixed up... Watts is a measure of power, or work done per unit time, Watt Hours is a measure of capacity or storage. Ie when you refer to battery capacity, such as the fighter, its in Kwh (kilo-what hour) ie it can draw 1.1kw for an hour. its calculated from multiplying the nominal volts (ie about 3.7-3.8V for lipo, about 2.9V or something for life, dont quote me on life though) by your cell count, and then by your usable capacity in Ah.

When determining the power output of a battery, you take the net voltage at that time, and multiply it by the amp (A) draw. this will give you the power output, ie 3Kw for the fighter.

If you want to calc the max power output of the batteries you need to know they're discharge C rating. lets say the packs in fighters are rated at 20C. you take this figure, multiply it by the Ah of the pack, and then by its voltage. You can also multiply the capacity of the pack in Kwh by this number to get the same result. in this case, 22Kw.

so a fighter has a peak output of 3kw, (lets say a 60V battery being discharged at 50A). it has a capacity of 1.1kwh (60V multiplied by its capacity in Ah, about 18Ah).

when I stated the 8 ah that is to help calculate the 'safe' usable capacity for lipo if you want it to last... Ie the rated capacity of my 24s 10ah lipo pack is 24 x 3.8 x 10, about 910 Wh, or 0.910 Kwh. If I want it to last, I need to multiply this figure by 0.8, the reason I said multiply your Ah by .8 is it gives you a clear number for Ah used on heads up displays like the cycle analyst. It also removes the inaccuracy that comes from people's varying opinion of 'nominal voltage', which is arguably between 3.6 and 3.8 volts. for me I use 3.8 since about 50% of my capacity comes above that figure. This is where the 8Ah number comes from. It has nothing to do with the rated discharge rate of my packs (which is 20C, or 200A for a 10Ah pack). Personally I usually multiply the 'rated' C rate by 0.5 to get a more realistic value. Which still means my pack should output 100A without breaking a sweat.

Hope that all makes sence/clears things up for you. either that or I've confused you further....

nothing wrong with asking questions mate, I'm meerly pointing out that there's answeres to be found (i'd suggest searching ES via google ie 'lipo questions endless sphere') on ES, as you can imagine lots of people have lots of questions, but rather than people answering each person's individual q's each time, its often easyer/quicker to search up on the basics. personally if you're looking at a stealth, I'd be keeping the stock battery. it doesnt have quite the same wh/weight as lipo, but for the sake of worry free plug and play, I'd keep it stock, atleast until they pack started fading/was out of warranty.

edit
just to be clear, im not suggesting you should shy away from a lipo conversion, meerly pointing out that the simplicity of a stock stealth is quite desireable, and is what I'd choose initially if I could afford one!

[Mr Lowbank]

Now that your pictures are coming up, I can see you have the shock spring fully wound off. I run my spring at full tension. Ride is still quite plush.

Yea this forum business in new to me just working out how the photo attachemts work, using Google Picasa now.
Are our spring Identical? mine is 750 LBS/IN
Photo of chain adjusted Quite tight

[Kepler]

Doesn't look like you have a link in it with the adjustment.

Not sure what my spring rating is. Its stock so I presume the same. John at Stealth runs his spring fully wound up in his bike. See how it feels. maybe half way will be a better compromize.

[remf]

just to be clear, im not suggesting you should shy away from a lipo conversion, meerly pointing out that the simplicity of a stock stealth is quite desireable, and is what I'd choose initially if I could afford one!

Definitely right. LiPo's are great for shedding kilograms, with a lot of care, they should perform very well for many hundreds of cycles. The stock LFP battery is so easy to charge, can take 30A regen abuse better and considerably longer cycle life than LiPo. I know some experts have gone back to stock packs for these reasons.

[Hyena]

"lipo rules, never above 4.3 and never below 2.7". Apparently that info is incorrect which is why I asked here.

That's worst case scenario. In normal usage your limits should be 4.2v max charge and 3.0v LVC.
As stated if they get a little out of balance at up to 4.22-4.25 with bulk charging it's not the end of the world but I wouldn't be routinely taking them the other way.
What Kepler says is a good and fairly conservative way to go and should maximise your pack life. The difference between 3.2v and 2.7v when a pack is flat can be mere seconds under high load so it makes little difference to the range you can wring out of a battery.
My controller LVC is set at 57v (~3.2v/cell) with the CA set at 63v (3.5v/cell average) If all cells in the pack were perfect you could probably safely take it a bit lower than this but I leave it set at 63v knowing that in an emergency I could drop the LVC in the CA down to 60v if I needed to.
Ideally if you know what you're doing your Ah consumption shouldn't really sneak up on you and leave you flat and stranded (gasp, having to pedal!) and if it does drop suddenly because of a weak cell then you shouldn't be pushing it any further anyway.

Now, more on topic for this thread, how have you guys found your CF stickers hold up to washing ? I gave my bike a wipe over with a wet rag which cleaned the frame up nicely but the CF stickers seem quite mud stained. I didn't want to scrub too hard as I can feel it's textured and didn't want to scuff it up. I guess warm soapy water is the next logical thing to try but I'm interested to hear what others have found.

Also riding the bike this morning I noticed if I pedalled hard it made quite a racket. Looking down it seemed the side cover bolts were just clipping the inside of the brake caliper but if I tapped the rear brake the noise stopped. I thought the caliper must have come loose but when I got to work I found the axle nuts had come totally loose and I was able to easily slide the wheel back and forth in the drop out with only the tension on the chain keeping it from sliding straight off the back of the bike Thank god for a strong chain and stealths integrated torque arms!

[QMS]

"lipo rules, never above 4.3 and never below 2.7". Apparently that info is incorrect which is why I asked here.

Also riding the bike this morning I noticed if I pedalled hard it made quite a racket. Looking down it seemed the side cover bolts were just clipping the inside of the brake caliper but if I tapped the rear brake the noise stopped. I thought the caliper must have come loose but when I got to work I found the axle nuts had come totally loose and I was able to easily slide the wheel back and forth in the drop out with only the tension on the chain keeping it from sliding straight off the back of the bike Thank god for a strong chain and stealths integrated torque arms!

Hey Hyena. Same thing happened to me "re loose rear wheel" in a most inconveniant situation, no spanner or 10mm. I put spring washers on the axle and haven't had an issue since

[Cowardlyduck]

Also riding the bike this morning I noticed if I pedalled hard it made quite a racket. Looking down it seemed the side cover bolts were just clipping the inside of the brake caliper but if I tapped the rear brake the noise stopped. I thought the caliper must have come loose but when I got to work I found the axle nuts had come totally loose and I was able to easily slide the wheel back and forth in the drop out with only the tension on the chain keeping it from sliding straight off the back of the bike Thank god for a strong chain and stealths integrated torque arms!

Hey Hyena. Same thing happened to me "re loose rear wheel" in a most inconveniant situation, no spanner or 10mm. I put spring washers on the axle and haven't had an issue since

I had this same issue. John sent me some tighter tolerance torque plates, which I think come standard now from the looks of the photo's, but I still had a little movement even with the nuts as tight as I could possibly manage. I now carry a spanner large enough for the axle nut, wrapped in a rag sitting on top of the battery in the recess where the seat connects to the frame above the battery. So far I haven't needed it though.
I did the same as QMS and put some spring washers on with the smaller nuts, and I added a few extra nuts all around.
The pictures should speak for themselves. (Sorry about the shocking quality.)




Cheers

[Hyena]

I'm sure it's the regen, after tighening mine up I didnt feel the usual slight clunk I feel when engaging regen but a few minutes later it was back. I didnt check the nuts again when I got home but I'll bet they're loose again. Because I'm running a non-standard motor I have a nut on both the inside and the outside of the drop out - one tightening out, one tightening in. I'm not sure if that's better or worse...
It's good for adjusting alignment though!

[Paul_G]

Now that your pictures are coming up, I can see you have the shock spring fully wound off. I run my spring at full tension. Ride is still quite plush.

I also have my spring wound out like that and the ride is still harsh compared to the old style shock that went bad and was replaced with the new style. Thats why I was looking for a lighter spring.

But I agree if your bottoming out tighten that spring down an inch and you wont bottom and or turn up the shock dampening and maybe speed up the rebound to get the wheel back down quicker as it could be packing.

[QMS]

I'm sure it's the regen, after tighening mine up I didnt feel the usual slight clunk I feel when engaging regen but a few minutes later it was back. I didnt check the nuts again when I got home but I'll bet they're loose again. Because I'm running a non-standard motor I have a nut on both the inside and the outside of the drop out - one tightening out, one tightening in. I'm not sure if that's better or worse...
It's good for adjusting alignment though!

The opposing forces from drive to re-gen will naturally work the nuts loose after a while no matter how tight you do them up! The first time it happened i thought the bearings were shot, when i engaged the re-gen it went CLUNK!!! Renewing the Nylock nut regularly helps too as the nylon wears out with repeated removal and ends up like a normal nut after a while. If you tighten both nuts at the same time you will evenly centre the axle in the torque plates and reduce excessive play