LightningRods mid drive kit

[waynebergman]

Hope I am not getting too off track here on the subject of the lag time in mid drives but I feel it is worth mentioning here.

For the version 3 CA on my Giant DH I have no feeling of lag what so ever with my mac 10t in the wheel.

EDIT: Actually there is some lag if no watts are going to the hub just before you hit the throttle, but if a small amount of current is going to the hub motor just before you hit the throttle it responds almost instantly and I think it is because of the mac clutch system. So if you feed the motor a tiny bit of current just before you need the power to come on you can get the feeling of no lag.

With the mac 10t in a different bike as a mid drive it is a different story because of the mechanical lag built into the mid drive system itself ( this is my opinion anyway ). I feel this is perceived because of all the free wheel stuff not being under load when hitting the throttle. If you are going up a hill for instance under load with a mid drive system and hit the throttle you don't feel the lag time like you do when coasting and then hitting the throttle.

Am I missing something here or are we talking about two different things? I see the lag time in mid drives as a bit of a bummer and not too much talked about when it comes to slow speed trials type riding. You are constantly fighting the jerky ness of it all during slow speed start up unless you are under load before hitting the throttle. I know on my poorly tuned gas dirt bikes the hesitation was overcome by revving up the motor and dumping the clutch which we can not do on our electric rigs.With my mid drive bike on the trails I have found myself going down hills with the brakes on and also the throttle on just enough to put some power to the wheel so the system is loaded, so then if I need to dump some controlled power into the system for short wheel stands climbing over obstacles etc I can do it with no feeling of lag. This is a bit of a pain but seems to be the only way to get rid of the lag time in MY mid drive system.

I have often wondered if a spare clutch in the mac hub motors could be used for the free wheel solution housing drive sprockets as there engagement is instant and also silent. Not sure what kind of power these clutches can handle but I feel a mid drive needs an instant engagement of any freewheels used in the drive train for a happy feel at the throttle. .........just my opinion.

 

[Wishes]

Hope I am not getting too off track here on the subject of the lag time in mid drives but I feel it is worth mentioning here.

For the version 3 CA on my Giant DH I have no feeling of lag what so ever with my mac 10t in the wheel. With the mac 10t in a different bike as a mid drive it is a different story because of the mechanical lag built into the mid drive system itself ( this is my opinion anyway ). I feel this is perceived because of all the free wheel stuff not being under load when hitting the throttle. If you are going up a hill for instance under load with a mid drive system and hit the throttle you don't feel the lag time like you do when coasting and then hitting the throttle.

Am I missing something here or are we talking about two different things? I see the lag time in mid drives as a bit of a bummer and not too much talked about when it comes to slow speed trials type riding. You are constantly fighting the jerky ness of it all during slow speed start up unless you are under load before hitting the throttle. I know on my poorly tuned gas dirt bikes the hesitation was overcome by revving up the motor and dumping the clutch which we can not do on our electric rigs.With my mid drive bike on the trails I have found myself going down hills with the brakes on and also the throttle on just enough to put some power to the wheel so the system is loaded, so then if I need to dump some controlled power into the system for short wheel stands climbing over obstacles etc I can do it with now feeling of lag time. This is a bit of a pain but seems to be the only way to get rid of the lag time in MY mid drive system.

I have often wondered if a spare clutch in the mac hub motors could be used for the free wheel solution housing drive sprockets as there engagement is instant and also silent. Not sure what kind of power these clutches can handle but I feel a mid drive needs an instant engagement of any freewheels used in the drive train for a happy feel at the throttle. .........just my opinion.

2 different things.

What we are referring to is the standard throttle from your CA 3, from any current CA or infineon controller and almost all other controller short of the ones mentioned in a previous post, controls the amount of volts sent to the motor. What we were discussing is the ability to throttle the AMPs to the motor instead of the volts. In theory it would provide a completely different feeling to it. Something closer to how the throttle on a gas motor feels. The CA version 3 supports such a function, but it has a delay before it reacts, so your throttle feels like it is working with a delayed reaction. You don't get an immediate response when applying the throttle. And from what I've read, it oscillates while trying to even out the amps. Much like the CA does when you hit your max amp setting and it applies its limiting function. There is a delay before it does, that usually causes your max amps to overshoot your max setting by a few.

As for your point I agree, you can't just hit the throttle and let spin up and jerk into load. Especially at higher power levels, you will wreck your bicycle drive train in no time. What i've learned after riding this for a year, it is somewhat of an art form to ease the throttle up until the load hits before dumping the power to it. And doing it quickly. You can't ride it like at WOT on and off like you do with a motorcross. Well you can, but many parts won't last.

There is a reason motorcross motors need a rebuild every season or so.

Wishes




Wishes

 

[panurge]

That's really sanitary! And you managed to keep the disc brake. You're using the same mounting holes on the hub for both sprocket and rotor with spacers in between? I know that regular old center pull brakes are probably adequate for a rear brake but I much prefer a disc brake if possible.

The hub drive/fat bike setup that sounded kind of cool to me was a dual hub that gives you all wheel drive. That sort of suits the fat bike go anywhere utility.

Yes, that's quiet normal on LH drives that use the Miles/Recumpence/FFR trikes spider adapter design, with the old spider version you need a narrow caliper (12-15mm wheel side max) while the new ones have an offset that allows for a better caliper matching, with these olod Magura GustavM you don't nees spacers in between the rotor and the adapter.....you could see more pictures at the last pages of my old build thread or if you search a bit on the Sphere about those Adapters

About Current control....:
I have a CA-LRC and a CA-V3, and also the RC throttle interface (Volt based) with a Magura pot.

The V based throttle is my preferred in terms of performance and feelings, although is a bit hard to be handled....
The AMp based throttle used with the CA-LRC is working soooooo coool, guys....IT makes everyting smooth and Controller friendly.....I have no lag with It if a bit of throttle residual is applied....some surges/lag happens only at repeated open/close throttles or with deep open throttles from 0....but there's a clutch for these situations on Matt's drives.

I've never achieved the same result with the CA-V3 but I've not spent a lot of time with it since the beta LRC version works so good.

 

[MitchJi]

Hi,

Fantastic post, wishes. I am designing my build now and just making the decision to go with a left side power drive exactly for the experience you state. I want a RELIABLE and DURABLE bike, not one wearing out and breaking down. Plug and go as they say. Also want to upgrade power when I figure out more power is more fun! After a LOT of research and diving into the long time and lots of experience in the gas motor bike world, it is clear driving the bike on its own drive line is the only way to go if you are going to power it up.

Need to consider that you need a lot more power to make up for not having use of the gears. Gary Goodrum ran at least 5000 watts through a Nexus three speed without any problems, he felt the three speed gave him the equivalent of twice the power. It may not have been that much, but you could see the bike jump each time he shifted gears on the video.

 

[panurge]

Hi,

Fantastic post, wishes. I am designing my build now and just making the decision to go with a left side power drive exactly for the experience you state. I want a RELIABLE and DURABLE bike, not one wearing out and breaking down. Plug and go as they say. Also want to upgrade power when I figure out more power is more fun! After a LOT of research and diving into the long time and lots of experience in the gas motor bike world, it is clear driving the bike on its own drive line is the only way to go if you are going to power it up.

Need to consider that you need a lot more power to make up for not having use of the gears. Gary Goodrum ran at least 5000 watts through a Nexus three speed without any problems, he felt the three speed gave him the equivalent of twice the power. It may not have been that much, but you could see the bike jump each time he shifted gears on the video.

I think an IGH and a standard derailleur have to be considered in different categories....
With the IGH the limit is only a mechanical rating of the internal gears, and is not "chain related" with a derailleur you have problems mostly while shifting, and for bad chainlines at the cluster's extremes...
The Only one I remember on ES, that pushed true Kwatts thru a derailleur is MotoMoto with his crankdriven astro 3220, and, I think, an XTR.
Would like to have more feedback from people with say more than 3Kw thru a derailleur....though

 

[LightningRods]

Need to consider that you need a lot more power to make up for not having use of the gears. Gary Goodrum ran at least 5000 watts through a Nexus three speed without any problems, he felt the three speed gave him the equivalent of twice the power. It may not have been that much, but you could see the bike jump each time he shifted gears on the video.

Twice the power is what I have read in the literature of most EV conversion companies. I think this is more true when moving from a stop or negotiating hills. Once you are rolling fast enough to be in the range of high gear in a multiple gear setup, the more powerful direct drive rig will have an advantage. Just don't slow down. That's why you'll see a lot of direct drives in racing.

It stands to reason that a three speed hub would be stronger than an 8 speed. Three gears is plenty for e-bike use. Was he using a hub that's still in production? I'm hesitant to recommend IGHs because I hear so many stories of them fragging.

 

[Wishes]

Hi,

Fantastic post, wishes. I am designing my build now and just making the decision to go with a left side power drive exactly for the experience you state. I want a RELIABLE and DURABLE bike, not one wearing out and breaking down. Plug and go as they say. Also want to upgrade power when I figure out more power is more fun! After a LOT of research and diving into the long time and lots of experience in the gas motor bike world, it is clear driving the bike on its own drive line is the only way to go if you are going to power it up.

Need to consider that you need a lot more power to make up for not having use of the gears. Gary Goodrum ran at least 5000 watts through a Nexus three speed without any problems, he felt the three speed gave him the equivalent of twice the power. It may not have been that much, but you could see the bike jump each time he shifted gears on the video.

Not just more power but you need lots of volts to give you a wide range of rpm. Without a good rpm range, you will be hard pressed to find a good reduction ratio on that left side that works well for low torque and high speed applications. With the gng I wouldn't consider left side mounting without 100v minimum.

Wishes

 

[crossbreak]

It stands to reason that a three speed hub would be stronger than an 8 speed. Three gears is plenty for e-bike use.

i agree, 3 speeds are enough.. but 3-speed IGHs have only ~186% spread. A two steep with 200% would do even better! Miles is working on something like this

@ Mitch: Totally agree

He used a Rohloff for that system [...]he hadn't had any problems with it.

rohloff is rated for double the power, that does not amaze me

What really concerns me is that you guys still talk of "power"... 5000W and so on. All drives we use are not AT ALL at the end of it's power. They all break because of too much torque/chain force. A derailleur can take several KW if the chain is fast enough. I use still use 3kW with my first chain on the BMC.. since <1000km.. BUT: I use a virtual 70T chainwheel and a cassete with 14-36T, that's what makes the difference.. i dont use much more torque/force than a normal 250W Bosch puts on the chain.

That's why I always advertise the use of the crossbreak style drive.. it speeds up the chain a lot.

 

[LightningRods]

What really concerns me is that you guys still talk of "power"... 5000W and so on. All drives we use are not AT ALL at the end of it's power. They all break because of too much torque/chain force. A derailleur can take several KW if the chain is fast enough. I use still use 3kW with my first chain on the BMC.. since <1000km.. BUT: I use a virtual 70T chainwheel and a cassete with 14-36T, that's what makes the difference.. i dont use much more torque/force than a normal 250W Bosch puts on the chain.

That's why I always advertise the use of the crossbreak style drive.. it speeds up the chain a lot.

I'm trying to really understand this. I get the advantages of more teeth of engagement. The load is spread out over more sprocket teeth and chain rollers. I also understand that in a two stage reduction the primary side is high speed and low torque. If the primary side has a 5:1 reduction the secondary side has 1/5 the speed and 5x the torque. The thing that is somewhat confusing to me is that on the final drive the reduction is the same whether we use large sprockets or small. So reduction is not the issue.

The moment when I started to understand gearing was when I thought of a gear as a lever. With a small gear a short movement produces a lot of rotation but there is not much leverage (torque). With a large gear the same movement does not produce much rotation but the lever is longer and so the torque is greater. It seems the way to understand your point is to think backwards on this. With larger sprockets a small amount of rotation produces greater chain speed and also allows greater reverse leverage for the chain to absorb torque loads. So larger sprockets provide both more teeth of engagement to distribute the strain on each tooth and a longer lever to reduce the torque loads on the chain.

 

[ten.ring]

lightningrods;

you built a furnace to take the temper out of the motor shafts. I know for your purpose you are going to work on a lot of them, but if I only need to machine one, after I grind down the 24mm dia. to .500, do you think a carbide cutter would cut the keyway? or will it be too hard? I can grind the key way but that's a lot more work.

I would prefer to get a big block from you but it looks like it will be some time before you have any to sell. will you post the link to the site that you think I could get a big block from, I have found several in searches but if you have one that is proven or even suspected as reliable that would be a great help.

thanks mark

 

[LightningRods]

lightningrods;

you built a furnace to take the temper out of the motor shafts. I know for your purpose you are going to work on a lot of them, but if I only need to machine one, after I grind down the 24mm dia. to .500, do you think a carbide cutter would cut the keyway? or will it be too hard? I can grind the key way but that's a lot more work.

I would prefer to get a big block from you but it looks like it will be some time before you have any to sell. will you post the link to the site that you think I could get a big block from, I have found several in searches but if you have one that is proven or even suspected as reliable that would be a great help.

thanks mark

The GNG motor shaft is soft as butter and easy to cut/grind. As you might expect they make that one themselves. The factory motor spindles are a different deal. I broke a carbide cutting tip trying to cut one without annealing. You can probably find someone locally to press the motor spindle out and anneal it.

I don't have a good source for the big block motors yet. The only vendor I've tracked down sent one Forum member a used motor and sent me three in the same box with almost no packing. Two of three were badly damaged. I don't recommend him but you might get lucky and get a new motor properly packed. I wish I had someone better but I don't. http://item.taobao.com/item.htm?id=16360173272

I don't think I'll ever do a volume buy on the big motors because the small block is plenty of motor for most people. But I do plan to make a big block kit and I will try to keep at least a few big motors around for the power freaks.

 

[ten.ring]

lightningrods;
thanks for the info.
I can anneal it and temper it. I was hopping to be more lazy than that.

the small block would likely have ample power if I go to 72v I have decided I do not want a multi speed hub. so i'll need the extra rpm from the 72v over the 60v I was planning on.

pm me and I will paypal you the $ for a small block with a .500 keyed output shaft, you can ship it when ever you get them done. sounds like some others are interested in .500 too. I will be using gates gt2 5mm pulley on the motor. I will bore it and cut the key way in my shop.
I know it will be some time before they are ready, I promise not to bug you about it. I do not have a Microsoft email so I can not email you from you website.

mark

 

[LightningRods]

lightningrods;
thanks for the info.
I can anneal it and temper it. I was hopping to be more lazy than that.

the small block would likely have ample power if I go to 72v I have decided I do not want a multi speed hub. so i'll need the extra rpm from the 72v over the 60v I was planning on.

pm me and I will paypal you the $ for a small block with a .500 keyed output shaft, you can ship it when ever you get them done. sounds like some others are interested in .500 too. I will be using gates gt2 5mm pulley on the motor. I will bore it and cut the key way in my shop.
I know it will be some time before they are ready, I promise not to bug you about it. I do not have a Microsoft email so I can not email you from you website.

mark

The deal with the big block is just lots and lots of batteries. The BB itself is a hulk at 11 lbs and you're going to need a bunch of cells to make use of all of that copper and magnet. When you consider that you have to go above 35 amps to get much benefit from the BB it kind of sobers you up. Yes it would look awesome hanging on your bike. But it's going to exact a price in weight. It amazes me how similar this conversation is to the small block/big block discussion in the car world.

I'll PM you about the details on your order. Motors are in middle of next week and we are down to business as soon as they get here. The shop press and furnace will be busy.

 

[LightningRods]

There is a lot of meat available to machine to pretty much whatever you want. Part of my strategy here is to have a solid, reasonably priced motor that can fit a variety of builds. I will set you up with 12mm, 1/2", whatever you want as long as it fits in the red box. You can have an output shaft up to 16mm diameter by 50mm length (.63" x 1.97"). That should do it for most people.

 

[turbo1889]

Okay, as said earlier I have a spreadsheet simulator that could provide some graphs for those that want them.

First Disclaimer: These Are Theoretical graphs only and I don't quite trust them especially with this motor because its showing a "weird" power curve that seems to be shifted way to the top end. Usually max power is at or a little over 50% of the no-load RPM. I've seen a few motor power curves and am currently running one in one of my builds that can push that peak power point up to about 70% of the no-load RPM (mainly RC airplane out-runner motors built for spinning propellers at high RPM) but never anything like this motor is showing up when I enter its specs. into the motor parameters. I realize that this motor does behave like it wants to run at nearly top RPM all the time and that where it does seem most powerful but still curve looks wrong to me so I might have to dig into the background formulas used in the spreadsheet and see if I can discover an error or something not taken into account.

Second Disclaimer: I like to run controllers which keep the bottom end torque of the motor from too much multiplication so that shows up in the few example graph runs I ran and made post-able images of.

Third Disclaimer: On the range calculations used in the spreadsheet there is a 1/4 throttle cheat factor that keeps the results from showing unreasonably long range capabilities at very low throttle settings. Hardly anyone has the self control to maintain less then 1/4 throttle over extended distance and even if they did you still wouldn't be able to obtain the really long theoretical ranges possible at low speeds and very low throttle settings because big motors tend to run very inefficiently at very low power and low speed settings in real life despite what theory may say to the contrary. So you will see the low speed range capabilities show very low numbers because if you bog the motor down like that you waste a lot of power not going anywhere hardly fast at all. Probably not as bad as the resulting bar graphs show but it ain't good.


Okay here is the motor graph that my spreadsheet simulator shows for the motor itself with the stock 22-Amp battery side only 48v GNG controller which allows a full bottom end torque multiplication effect, I think you can see what I'm saying about the peak power point being way to high up on the RPM band to be "normal". Think its at least partially an error in the spreadsheet program but it may be quite possible that this motor does have a curve that is shifted a lot more to the upper RPM band at least that is how the one GNG I have feels when I'm riding it:

------------------------------------------------------------------------------------

Realizing that all the following are based on that possibly flawed base graph:

This is the current GNG drive system that I personally am running. Its an original belt drive model with my own freewheeling crank with double 48t chain-wheels (one for the motor chain and one for the wheel drive chain) with a 13-14-15-16-19-23-28-34 rear derailer spool. Paid a nice low price for a slightly used unit off someone else after he got sick of tearing up belts and then broke the GNG freewheeling crank assembly. Sold me what was left and I found running it at on a 38.4v lower voltage 12s LiFePO4 battery on a reduced 15A current level allowed the stock GNG drive belt, brackets, freewheel, etc . . . to actually hold up and last reasonably well and it makes a good commuter for someone who doesn't mind the lower power and likes to pedal along with the motor (click on to open BIG full size):




I can confirm that the range calculations for flat ground at speed are very close to correct as are the speed at which it can climb hills with the extra cargo loads indicated being hauled or towed when gearing down. So at least at this lower power level I can confirm that the results do appear to be at least close to accurate.




------------------------------------------------------------------------------------

Now here are some potential theoretical possibilities for mid-drives using LightningRods Improved Mid-Drive (click on to open BIG full size):


16s LiFePO4 51.2v 35Amp 3-Speed 37% Step IGH Drive:
----- largest reduction 93t #219 secondary reduction crank sprocket
----- 52t bicycle chain wheel
----- 14t driver on IGH hub







------------------------------------------------------------------------------------


12s Li-Poly 44.4v 20Amp 9-Speed Derailer Drive:
----- 84t #219 secondary reduction crank sprocket
----- 48t bicycle chain wheel
----- 12-13-14-15-16-19-23-28-34 nine speed spool derailer drive wheel







------------------------------------------------------------------------------------

And here are a couple potential theoretical possibilities for left-side drives using the motors supplied by LightningRod and some of the chain drive parts he stocks (click on to open BIG full size):


13s Li-Poly 48.1v 30Amp #219 Chain Left-Drive:
----- 93t #219 sprocket, his 5-bolt mount adapter for same, on a Staton-Inc dual drive hub with five bolt south-paw big sprocket mount sprag clutch freewheel
----- 12t #219 sprocket on motor shaft
----- This one is geared lower then it needs to be for excess torque on the whole band for good hill climb even though its only one gear ratio.







------------------------------------------------------------------------------------


20s Li-Poly 74v 40Amp #219 Chain Left-Drive:
----- 80t #219 sprocket, his 5-bolt mount adapter for same, on a Staton-Inc dual drive hub with five bolt south-paw big sprocket mount sprag clutch freewheel
----- 12t #219 sprocket on motor shaft
----- This one is geared for speed with constant torque no amps multiplication bottom end. Around town flat land speedster with tamed out bottom end so it don't throw you on take off slamming the throttle to full right away. 20" rear wheel instead of 26" because of the high voltage high RPM system.

 

[ten.ring]

wow thanks!

 

[ten.ring]

lightning rods
I agree the big block, would not be a efficient choice for me, just as the big block in my olds 442 was such a gas hog, went like a bat out of hell but so did the fuel. great at the drag strip but not a good choice for commuting.

my desire for the big block must have something to with nostalgia. the good old days of mussel cars.

 

[LightningRods]

It's a beautiful sunny Sunday here and I have parts to make but I want to make some comments that Turbo 1889's data sheets brought to mind. It may be apparent to you by looking at his data or it may not.

- 36V is adequate for commuters. Battery packs are smaller for the same amp hours and range will be better. Wire for ah rather than volts if you want long range. Also the low voltage and accompanying low motor rpm make reduction simpler. The stock GNG reduction is adequate at 36V. (67 kv x 36v = 2,412 rpm divided by 20.9 overall reduction = 115 beats per minute). Still too fast but far better than the 150 beats of the stock 48V kit. I recommend 36V for commuter customers, whether Gen 1 or Gen 2.

- If you get your motor reduction in sync with your pedaling cadence through the BB top speed will be limited to that of the stock bike. Most bikes are geared for around 25 mph since that's about all average human power can sustain on level ground. It's also around the top speed allowed for bicycles by law. In order to have a higher top speed you need to either raise the final drive gear ratio or allow the motor to spin faster than you can pedal. I intentionally chose a Specialized 'Niner' 29 inch wheeled bike for a potentially higher final drive. The bike comes with a 41T large front chainwheel which I am going to replace with a 48T. Between the large diameter tires and higher final drive it will be able to motor as fast as I personally want to go. If I get the sudden urge to go for a land speed record I can always add more voltage for more rpm and a higher top speed. Above 35 I won't want to be pedaling anyway.

- If you're coming from a background in infernal combustion engines, like I am, there are some things about electric motors that take some getting used to. Unlike a gas engine that typically makes very little power at low rpm, an electric motor makes max torque from zero revs. Even stranger for us gas heads is that torque actually falls off as rpm increases. You'll often hear EV users talk about "upshifting for more torque." This would make it seem like there is no advantage to higher volts and higher rpm but it's not really true. Despite the theoretical inefficiencies of high voltage and high amps the people who do it will tell you that there is a lot more performance to be had even if it is at the price of efficiency. If you're worried about efficiency you're probably a commuter, not an overvolter.

Thanks for taking the time to work up all of this data Turbo 1889!

 

[LightningRods]

lightning rods
I agree the big block, would not be a efficient choice for me, just as the big block in my olds 442 was such a gas hog, went like a bat out of hell but so did the fuel. great at the drag strip but not a good choice for commuting.

my desire for the big block must have something to with nostalgia. the good old days of mussel cars.

I totally get it. The last car I built was an early '70s Mustang with a built 460 Ford in it. The car came with a smogged out 302 2 bbl and was no fun to drive. Once I made the swap the car had 50% more displacement and 300% the power. Driving it was what I described as "surfing a tidal wave of torque'. It was a blast in a straight line. BUT the handling was heavier, more nose heavy, and the car was less well balanced. Just like the muscle cars were back in the day.

I hope we're able to do some side by side testing of direct drive big blocks and small blocks running through the gears. I think this would make a great article for electricbike.com. I'll build it if they'll test it.

 

[turbo1889]

Just one note I would add to LightningRods comments. If you have a "normal" electric motor controller that only limits Amps on the battery side of the circuit then what he says is absolutely correct about the maximum torque being at dead stall and the torque decreasing steadily as RPMs increase all the way up to the motors free spinning, no load RPM where the motor has only enough torque to overcome the resistance of its own bearings and no more.

However, if you use a more advanced electric motor controller that also limits Amps on the motor phase side of the circuit then that changes things and "tames" the low end torque down so there is a long section of the lower band that has all the same torque from dead stall up to a certain RPM where torque does start to drop off often very near the top end of the band. Such a set-up is inherently more efficient and easier on components and feels more like an IC powered vehicle in throttle response, but it is also less powerful all other things being constant.

Long story short if your a commuter worried about efficiency and longer component life get one of those more advanced electric motor controllers especially if you are running the motors power through a multi-speed bicycle gearing system. If your power crazy especially if your not running the motor through the bicycle gears but rather with its own left side chain then go for one of the "normal" electric motor controllers that only limit Amps on the battery side and allow the motor phase amps to multiply exponentially at lower RPMs.

Every graph I posted except for the first motor graph assumes the use of a more advanced electric motor controller that has the ability to set seperate limits for both sides of the circuit.

Here is two sets of three graphs that illustrate, this. The three left side graphs are from a 200Kv RC 6354 outrunner motor designed and wound to run only only 4s cells (12.8v low voltage system) that I built a full DIY mid-drive around and the three right side graphs are the GNG motor on 48v. Top two graphs are the motor curves when using a "normal" electric motor controller that only limits battery side Amps and allows unlimited amps multiplication at lower RPMs on the motor side. Middle two graphs are with a more advanced electric motor controller that limits everything on the motor phase side of circuit so the whole range of the motors power until it reaches the peak and drops off is constant amps and constant stable torque with no lower end torque multiplication. It tames the bottom end of the motor and improves efficiency at lower speeds. The bottom two graphs are where a more advanced electric motor controller that has seperate limits for both sides of the circuit is used with a slightly higher setting for the motor side of the circuit to allow some amp multiplication to occur which produces a hybrid between the two.

Same two motors, but how the controller limits the current and at which (or both) ends of the circuit it does so produces noticeable differences. If your interested in reducing wasted energy pay special attention to the thin orange line in the graphs which represents how much of the input power is being wasted in the form of heat losses (both copper and iron losses) and is the motor just trying to melt itself down acting as an electric heater. For the power crazy guys notice the green power output line and how you loose so much of it at the lower RPMs if you use a more advanced controller that limits the amps on the motor phase end of the circuit instead of the battery end like a "normal" controller. Power or efficiency take your pick, or use a controller that allows you to adjust both ends and achieve a halfway balance between the two:

 

[turbo1889]

Also, you guys need graphs for anything specific, say so, its not that hard for me to put in different variables. No guarantees though either on the accuracy or whether I will have time to cover all requests. Just remember its all theoretical computer math crunching, I can confirm the results are close enough to be reasonably accurate and useful for the personal GNG set-up I'm running but can't guarantee it all works out right for anything different.

 

[ten.ring]

lightningrods asked about hubs in an earlier post, I've been searching around for a real strong hub too! I found the hubs that straton sells they are buried pretty deep in their website. I would have posted a picture but don't know if it would be ok with straton.
http://www.staton-inc.com/store/products/Rear_36_Hole_14_gage_Hub_Left_and_right_hand_threads-885-0.html.
it looks like it's about 110mm wide and the 135mm is the dimension between the nuts. the first nut goes on backward then the outside nut clamps it in place. so it would need to be laced up like a cassette hub to keep the wheel centered in the chainstay, i think?

turbo1889
thanks for that last post, it put a lot of things together that were floating around in my head about these motors and controllers we're using.

 

[LightningRods]

Great data, great info. Thanks for your time!

 

[AussieJester]

Regarding the mechanical lag, I use the rear brake to load the wheel while introducing throttle, the freewheel is the loaded when I want instant power without the lag...try it out

KiM

 

[turbo1889]

I can confirm that the Staton-Inc. hubs are an excellent way to go if your doing a left drive build.

I have used them myself. He does sell more then one model. Spoke drilling options are (these are all hot links just click on them) 48@14ga., 36@12ga., 36@14ga., 32@14ga., & 28@14ga. (I personally would suggest the use of either the 48@14ga. or 36&12ga. wheel spoke option if at all possible for a good strong wheel). Each of which is available in either a 110mm or 135mm dropout spacing with 10mm nutted axle. 110mm is centered (or darn close) and no dishing of the wheel is required but takes only a single speed freewheel on the right side (you can squeeze in a white industries double double rear freewheel that fits in the same space), where as the 135mm which unfortunately does require dishing of the wheel can be used with a 5,6,7, or 8 speed freewheel or even one of the 9 or 10 speed freewheels that are made to fit hub motor conversions (I personally would strongly suggest the use of a good Shimano 7-speed freewheel).

The hubs are excellent and have four cartridge bearings and are nearly or just as strong and with their sealed cartridge bearings require less maintenance and last longer as the lower priced non-cartridge bearing free-hubs (think Shimano basic line and clones/copies/imitations). The axle is also extra strong since only the threaded ends are 10mm which immediatly steps up thicker to 12mm for the bearings seats and then even thicker then that in the middle. I've run cargo loads on mind that would bend the axle of a quick release skewer freehub without issues.

He will build them into wheels and send a whole finished wheel to you if you so desire, here is a link to his built wheel selection options (with links to most of the built wheels he currently offers listed but still run a search using the terms "staton custom left right hub wheel" because sometimes new offerings and short runs doesn't get added to that list, right now there is one wheel that isn't in that list but shows up in the search and also the 32 hole drilling for his hubs is new as well since the last time I was on his sight): http://www.staton-inc.com/store/products/List_of_Pre_Made_Wheels-1138-14.html

Be warned though that the quality of his wheel builds is not quite as good as I personally would like, better then machine built wheels and as good as some hand builders even those in bike shops but not quite as good as top of the line hand built. Expect to have to replace a spoke and nipple or two after a year of service or so. Still at his prices for building the wheel for you it is more then worth it to at least start with one of his built wheels unless you have the skill to lace the wheel yourself. Cheaper then any hand wheel builder I know of.

As to how to attach your motor drive sprocket to the left side of his hubs. This is what your looking for: http://www.staton-inc.com/store/pro...HAND_thread_freewheel_sprag_clutch-967-0.html

Standard 5-bolt pattern we are used to using for freewheeling crank chain-rings. Will work with such as well as some sprockets he has on his site for #35 chain and maybe some other chain sizes as well as will fit the adapter LighteningRod makes to make the large #219 chain kart drive sprockets fit as well.



The main "down sides" to using his hubs in this kind of set-up for a left-drive build are:
----- Have to use old style screw on freewheels not modern cassettes for the pedal drive
----- No rear disk brake possibility, have to use rim brake on rear (I suggest good Shimano V-brakes with good cartridge pads)
----- No re-gen. braking capability.

If you can't handle those downsides then your probably going to want to instead build using a disk brake compatible freehub use a big sprocket that hard mounts to the disk brake mount on the left side.