LightningRods mid drive kit

spinningmagnets

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Electricbike.com review published December 2014 https://www.electricbike.com/lightning-rods-mid-drive-kit/

The "for sale, new products" thread can be found here: http://endless-sphere.com/forums/viewtopic.php?f=31&t=65229
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I'll be getting a LightningRods mid drive kit as soon as they are available, and I'm starting this thread as a place for discussing this kit.

For those who are new, back in August 2012, electricbike.com found the new GNG mid drive kit during a Google search to compile a list of "top ten" available kits. It had some configuration features that made it note-worthy, and after posting about it, several ES members bought a kit to try out. The crankset was very weak, the bracketry was flexy, the 12T feewheel was junk, and there was not enough reduction in the two-stage drive to take full advantage of this configurations potential capabilities. The original thread can be found here: http://endless-sphere.com/forums/viewtopic.php?f=28&t=42785

However, this motor has far exceeded everyones hopes. The low pole-count meant that it could run up to 72V without eddy-current losses, and the amount of copper mass that it has will run up to 30A without saturation (you could use more power, but that would cause some waste-heat), 40A is the max recommended, while keeping an eye on the motor heat... The performance was exceptional enough that the ES community sought remedies for the design flaws. This drive provides 72V X 30A = 2200W / 3-HP, and since its configuration allows the motor to use the bikes gears, it also provides exceptional hill-climbing without overheating, while keeping the motors weight centralized (UN-like a powerful, but heavy one-speed rear hub).

The Cyclone 148mm-wide ISIS Bottom Bracket crankset was determined to be the best bang-for-your-buck replacement for the stock unit. ES member LightningRods began discussing his take on possible re-design options to improve the performance. Several members replaced the narrow and weak 15mm-wide primary belt with a chain, and this allowed builders to verify the motors potential at 72V and also 100V (instead of the stock 48V).

Interestingly, after this was published...the GNG website also made an optional 8mm chain-primary kit available (although they didn't improve the other weaknesses of the kit). However, the added performance of the high-RPM chain-primary came at the price of a dramatic increase in the noise. Primary chain thread found here: http://endless-sphere.com/forums/viewtopic.php?f=28&t=46738

Mike (LightningRods), began making the upgraded parts to fix the problems one-by-one (including widening the quieter primary belt to 25mm so it could survive 72V), but this put ES members in the position of needing to buy the entire GNG kit, just to throw away everything but the motor, and then...also needing to order the Cyclone crankset as an individual part from China.

One major design change was when Mike moved the reduction freewheel from the chain secondary to the belted primary reduction. This reduced the load on the freewheel (which should allow it to live much longer), but most importantly, that single change allows much more reduction from the same size of a drive unit. (GNG: 21:1, LR kit: 33:1)

A second major change is that the primary reduction belt was widenend to 25mm vs 15mm, and also this mounting bracket is adjustable for tension, so the original design belt tensioner can be eliminated. Although that stock idler used up 100W, the main issue is that the idler "backbended" the belt to tension it (which was necessary on such a small drive pulley since it would reduce the belt from "skipping/ratcheting"), since the original drive pulley was very small and had very few teeth holding the belt. When you backbend a toothed belt that was not designed to do that, it will accelerate the breakdown of the fibers inside the belt, and reduce it's life.

Mike found the original motor factory, and can now buy them direct in bulk, and he has also secured direct supply contracts for the 148mm wide ISIS crankset, so now...the entire upgraded kit can be purchased from one supplier in North America. I'll be posting pics and details as soon as possible. The pic below is skyungjae's full suspension bike. He started with the GNG kit, and has added every LightningRods upgrade, so his bike should perform exactly like the production kit.

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Reduction

The original GNG provided a 21.0:1 reduction between the motor and the BB.

The Lightning Rods primary has a 90T:18T belt = 5.0:1.

The #219 chained secondary has a 80T:12T = 6.6:1, so the total reduction is (5.0 X 6.6 =) 33:1

edit: for a "speed" set-up, the secondary stock sprockets can be swapped out for an 18T/64T set, for a 3.55:1 ratio, so (5.0 X 3.55 =) 17.7:1 reduction.
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Crankset Chainrings

This kit uses common chainrings that are easy to swap-out, which is needed for a tooth-count change, or to replace a worn chainring. The stock system uses two chainrings with tooth-counts of 32T and 48T, the interface is a common 104mm-BCD.
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LightningRods1.jpg

His upgraded parts web-site can be found here: http://www.lightningrodev.com/

His Facebook page can be found here, for those who wish to stay up to date on the latest developments:
https://www.facebook.com/pages/Lightning-Rods/613804531978401

His "Big Block" kit
http://endless-sphere.com/forums/viewtopic.php?f=28&t=57483&start=125#p916680
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Hall-sensor Wiring to Lyens Infineon / Xie-Chang controllers
Thanks to ES member jdevo2004 for publishing this
http://endless-sphere.com/forums/viewtopic.php?f=28&t=57720&start=2000#p960389

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Konakids spec sheet with all possible sprocket size gear reductions
http://endless-sphere.com/forums/viewtopic.php?f=28&t=57720&start=2350#p986838
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First pics of the finished kit, page 23:

http://endless-sphere.com/forums/viewtopic.php?f=28&t=57720&start=550#p901245

Kit1-2.jpg
 
Great idea creating this thread.

Having been through the trials and tribulations of the original kit from GNG I would certainly have gone for this kit had it been around at the time. I'll be recommending this to all of my friends - although it does appear I will be doing the actual install for them as well :)
 
Thank you once again Spinningmagnets, for distilling an otherwise time-consuming effort to learn about the evolution of the GNG kit. I just wished that we could vote threads up and down which would seed the threads based on popularity. That way, clean and succinct posts like these will be seen more often. You always link back to the original topics so if someone were really wanting to, they could find the old parts.



On topic:

I've been mulling around the idea of using a GNG kit as well, but one project at a time :D . I'm going to target to finish by MAC mid drive soon and then I'll copy you on this one too :mrgreen:

subscribed!
 
Hi Spinningmagnets, I echo Cal3thousand's sentiments; thanks for the foundation information on this new system.

Watching Lightningrods kit with interest, the more photos the better and I'd love to see this fitted on a lightweight 29er to provide
performance to rival mopeds.

Also interested in how this compares to a stock BBS01 Bafang 350w in terms of efficiency.
 
I have been waiting all winter for this kit to become available. Mike at LightingRods is progressively raising the bar of what can be accomplished in aftermarket Mid-Drive kits. I'll be building up a Specialized Demo 8 later this spring. It will require custom sheets for the pure downhill specific 83mm BB.

Cheers from Canada
 
I'll be watching this thread. The GNG thread is just a headache to figure out what is available.
 
I believe that 72V X 35A = 2500W is very close to the max you can run through a derailleur with bicycle chain. Using more power is clearly possible, but wearing out the bicycle-grade chain and sprockets very fast, and sometimes breaking things is not a good system design. Nothing else on the market is close to what this kit will provide. The freewheeling bottom-bracket crankset is also another link in the power-limit. Since this motor can provide 2,500W all day without melting down, looking for a bigger motor is not needed for 2,500W.

Lukes Deathbike ran a single-speed left-side drive that used a #428 chain (and a large motor), that is the next step up. The GNG "Big Block" motor's stator has twice the width (and twice the copper mass) compared to the standard GNG motor, so I feel safe in suggesting that the Big Block should handle 60A well. That is not bicycle chain territory, and derailleurs are just not up to surviving that. The LightningRods jackshaft sprocket/pulley parts are reconfigurable for a variety of projects.

A Lyen 18-FET at 72V flowing 60A being fed to a Big Block should be a fairly easy to "plug and play" beast (72V X 60A = 4,300W)...for those times when a standard 2,500W kit just isn't quite enough...

There are definitely bigger motors out there, but you might find they are more expensive, larger, heavier, and harder to mount in a frame...I guess we'll see soon.
 
His upgraded parts web-site can be found here (be aware it may be April 2014 before the website is fully updated): http://www.lightningrodev.com/

Because of the delay in website updates, I'm assuming that LightningRods or Spinningmagnets will post on here when the kit is available?

I was all set to buy a BBS02 over the GNG. Then I saw this, and all the things I disliked about the GNG looks like they will be fixed (exposed gearing, shoddy quality, and noise).

As long as the price doesn't get jacked up substatially, LightningRods will have a best-seller. Price should be comparable to the BBS02 (<$600 delivered).
 
+1 on Cal3thousand's comments.
New to this area of activity, but have been reading a lot around Endless Sphere and learning what I can.

The amount and quality of information available on ES is amazing: thanks to all for sharing their expertise, experiences, successes and failures for the benefit of those of us less experienced.

I built an electric minibike for my 3 year old grandson for Christmas, and it was so successful that I definitely want to build something for myself...
Looks like the GNG and / or "big block" are the most promising motors out there, and Lightning Rod's engineering is worthy of respect, so I am also waiting on his pricing with interest.
Considering three different projects:
1) Putting a complete mid drive kit on my Iron Horse Chrome Moly hardtail mountain bike, as a "learner project";
2) Building from scratch a slightly bigger, gruntier version of the Oset 20 (no pedals trials bike) for teenagers to learn / have fun on, but just big and strong enough for adults as well; and
3) Building a lengthened swingarm to pivot on the bottom bracket of a Kona Stinky or similar downhill bike, and mounting a big block GNG (or the lower kV alternative just surfacing on the forums) on the swingarm, directly driving the back wheel, like the Oset bikes do. (Obviously, no pedals).

I have just scored a Kona Stinky frame for $21 because it has a damaged swingarm pivot on the frame, and a bombproof 24" back wheel, so project 3 is looking tempting right now..
 
I have forgot the all details on the GNG kit and it is a long thread so I also will be looking forward to your review on this kit with the upgrades from Lightningrods. A question for you and a request.

1. What are your plans for the battery?

2.Can you let us know how the slow speed control and smoothness is on this kit when its up and running compared to say a hub motor? It would be nice to know if there is a smooth throttle control option for this kit.

Wayne
 
waynebergman said:
2.Can you let us know how the slow speed control and smoothness is on this kit when its up and running compared to say a hub motor? It would be nice to know if there is a smooth throttle control option for this kit.

I replaced the stock controller with a lyen controller + CA and connected the throttle through the CA and it seemed a lot better than the stock controller. I can modulate the speed quite well with this so happy with this setup.

The stock GNG ( with Lightening rods LR brackets ) is fairly quiet under 1KW, I'd say road noise etc drowns out the motor imho.
 
got in a university and just moved to a new city, thinking about building a e-bike for easy travelling.. is this the best option around for now (when its available)?
i also dont know anything about mounting the systems, alot of research ahead.. any advices?
 
The stock GNG ( with Lightening rods LR brackets ) is fairly quiet under 1KW

What is noisy over 1kw ? the motor or belt/chains ?

Also how durable will the primary belt be in dirty and muddy offroad terrain? i think chain drive kits has the advantage that its self cleaning with dirt and mud, or even if sticks gets in to it, it will be pushed through the chain. Belt drive does not have the dirt removing ability or a stick could even bounce in-between pulley/belt and dislodge or lockup and snap the belt ?

I know on bike rear belt drive systems they use a different type of pulley and belt that has holes in it to remove dirt.
 
What is noisy over 1kw ? the motor or belt/chains ?

Not sure, according to the CA, peaked at 1 KW ( on takeoff ) but hover around 200-600w when cruising at 30-40 kmh. The hub riders have commented on how quiet it is, we were all expecting it to be noisier.

Also how durable will the primary belt be in dirty and muddy offroad terrain? i think chain drive kits has the advantage that its self cleaning with dirt and mud, or even if sticks gets in to it, it will be pushed through the chain. Belt drive does not have the dirt removing ability or a stick could even bounce in-between pulley/belt and dislodge or lockup and snap the belt ?

I haven't really used it off-road much, mostly clear fire-trails and parks. It gets muddy but I just gently hose it off. Mine is primarily a commuting bike rather than a down-hill monster.
 
Gab said:
Also how durable will the primary belt be in dirty and muddy offroad terrain? i think chain drive kits has the advantage that its self cleaning with dirt and mud, or even if sticks gets in to it, it will be pushed through the chain. Belt drive does not have the dirt removing ability or a stick could even bounce in-between pulley/belt and dislodge or lockup and snap the belt ?

I know on bike rear belt drive systems they use a different type of pulley and belt that has holes in it to remove dirt.
I've been taking my bike through the mud and dirt and haven't had any functional issues. The extreme cold, ice and slush has been more damaging to my belt drive than the dirt...4 belts this winter...the gates belts snapped very quickly in the cold. The bestorq belts I'm using now have lasted way longer (just blew my first bestorq after 800km. The gates lasted only around 200-400km)

I think Mike is also working on a cover to enclose the belt side of the drive.

Oh..FYI, I'm still on the stock belt drive, not Mike's upgraded belt yet.
 
The website is up.
It shows price and a choice of a battery-less and controler-less kit. Or parts.
$800.00 plus shipping. NO controller. No battery.
 
Mixed feelings of awe and fear.

How many watts can a rear cassette take, I wonder. With my 750W Bafang, my heart skips every time I shift gears under high load.

Next step would be to figure out the best/most durable power transfer mechanism from the crank to the rear wheel.

Carry one or more space chains and a chain breaker.
 
teslanv said:
Mixed feelings of awe and fear.

How many watts can a rear cassette take, I wonder. With my 750W Bafang, my heart skips every time I shift gears under high load.

Next step would be to figure out the best/most durable power transfer mechanism from the crank to the rear wheel.

Carry one or more space chains and a chain breaker.

Above 1000 watts, never shift under load.

I read somewhere a bicycle drive train can handle around 2000 watts. Above that, your stressing it. I run my gng at about 3.5kw, and it eats through chains, bends chain rings and wears out your rear cassette pretty fast.

Wishes
 
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