Electricbike.com review published December 2014 https://www.electricbike.com/lightning- ... drive-kit/
The "for sale, new products" thread can be found here: http://endless-sphere.com/forums/viewto ... 31&t=65229
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/viewto ... 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/viewto ... 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.
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.
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.
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/Lightnin ... 4531978401
His "Big Block" kit
http://endless-sphere.com/forums/viewto ... 25#p916680
Hall-sensor Wiring to Lyens Infineon / Xie-Chang controllers
Thanks to ES member jdevo2004 for publishing this
http://endless-sphere.com/forums/viewto ... 00#p960389
Konakids spec sheet with all possible sprocket size gear reductions
http://endless-sphere.com/forums/viewto ... 50#p986838
First pics of the finished kit, page 23:
http://endless-sphere.com/forums/viewto ... 50#p901245