Lightning Rods Big Block Mid Drive - 2017 Configuration

Motor

The bike is built around the Big Block mid drive, made famous by Michael Backus (www.lightningrodev.com).  I purchased one of the earlier production Big Block motors back in 2015 so it was a little finicky and required a fair amount of back and forth with Mike to get it on the bike.  In the end (i.e. 2017) it just made more sense to send the whole frame to Mike and have him install it for me. This provided the added benefit that since 2015 he has continued to evolve his kit and sending the original back to him provided the opportunity to swap in all the various upgrades. 

At Mike's suggestion some of these upgrades included moving the 18t Drive Pulley out and replacing it with a 25t.  The intent here was to make things a little quieter and less prone to slippage.  The trade off is that, according to LR, I'm limited to a terrifying 60mph when in off-road mode (72V and 40A).  Note that when on public roads I always adhere to 182.1 of the BC Motor Vehicle Act.

Additionally, and as per Mike's repeated comments on the forums, he bolted a piece of aluminum between the frame and the motor casing to keep the twisting forces to a minimum. 

Frame

I had a couple of legit choices for the donor frame.  

Initially I had thought that I would use a an extra-large 2007 Giant Anthem 0 that I picked up off of Craigslist here in Vancouver for about $800.  This would allow for a ridiculous amount of triangle space and it was a good fit for my lanky 6'2" body type.  

As chance would have it I had also come across a large 2004 2004 Giant DH Comp on E-S which was available for $500.  I purchased the DH Comp with the intent of switching direction and mounting the Big Block on it instead

In the end, after lengthy discussions with Mike and flip flopping back and forth several times, I settled on using the DH Comp.  Despite the frame being a touch small (the spec from Giant's Japanese language web page reads that the the max 'suitable/appropriate' rider height for a large DH Comp is 185cm), Mike's repeatedly stated view was the the '04 DH Comp is nearly the perfect frame to use as a platform for his big block. Who am I to ignore.

Drive Train

The decision making around the drive train was convoluted, to say the least. I initially planned on using a Rohloff Speedhub because of its reputation for durability.

The Rohloff evolved into a single speed after a long conversation with Mike.  His argument, essentially, was that when a big block motor is driven by 72 volts (nominal) and 40 amps it dramatically reduces the need for multiple gears.  More specifically, the thinking is that if you don't have to climb lot of hills, and don't care about pedaling along, the use of a 72 volt battery to some extent takes the place of additional gears. This was the operating theory throughout much of the build process.  

In the end, however, I made a last minute / arbitrary decision to switch to an eight speed cassette with an 11-40T spread. This decision was driven by a combination of wanting to be able to pedal up a hill if absolutely necessary and advice around chain growth on FS ebikes that I got from my LBS and that was confirmed by Mike. 

Battery

LiGo batteries from Grin (www.ebikes.ca) are completely modular and come in 10S1P units (36V/10A/2.7Ah).  This is the battery style I've been waiting for.  8 packs, configured as "2S4P", yields 72V/40A/10.8Ah.  By following Justin's advice and charging to 80% and  discharging to 20% I'm hoping to stretch the LiGo's life out to 600 charge/discharge cycles over a 3 year period.  I have a pair of 72V Satiator's that I use to charge on each side of my commute (at the office and at home). 

Controller

The controller is an 18 Fet Lyen and will comfortably run up to 65A continuous (www.lyen.com) which allows for additional LiGo’s to be added in the future if/when I feel the need for more power. I asked the Ed to install an on/off switch right on the controller itself in order to reduce the likely hood of issues further down the road and to further comply with the applicable section of BC MVA 182.1.  

Battery Bag

Since I couldn't really fit enough battery in the triangle to make the round trip from home to my office I opted to just throw the battery into my existing commuter backpack.

      

E-bike specific items

Other e-bike specific items include a Cycle Analyst, a GPS enabled analogger and a Cycle Lumenator (www.ebikes.ca).  

A Cycle Analyst V3 ties everything together.

Non e-bike specific items

Other non e-bike specific items include 203mm discs.

Not 88mph but definetly 40

I'll try and keep this brief.

The Context

My wife, son and I live about 20km from my office in beautiful Vancouver BC.  Truth be told we live just outside of Vancouver in a small town called New Westminster because, despite two professional incomes, we can't afford the price tag of a house closer to work - it's stupid really (http://www.crackshackormansion.com).

If I use public transit to get to the office it takes me over an hour each way.  Driving is almost as bad and can be WAY worse, plus I have to shell out $23/day for parking.

Searching for an alternative I discovered e-bikes.  This discovery quickly led me to endless-sphere.com and the realization that one of the top guy's on the planet (if not the top guy) lives about a 10 minute pedal from my office.  Clearly this is awesome. 

The Evolution

My first build (August 2013) was a 48V/25A/eZee combo from Justin which I bolted onto a Raleigh  Misceo 2.0 donor bike.  It worked well for about 6 months, and then the bug hit me.

My first e-bike - a converted 29er running 48V/18Ah on a front eZee hub

Somehow I got it in my head that I would be safer if I could keep up with the flow of traffic.  That meant 50-55kph.  But let's be honest and admit that 50-55kph is really 55kph. 

A little reading led me to the conclusion (rightly or wrongly) that a maximum speed of 55kph wasn't optimal, and that I really needed a little more as "contingency".  Somehow I arrived in the head space that I might as well make it 60kph.

Then I realized that 64kph would put me in the 40mph club.

So, all of a sudden, I needed 65kph.

 

The Planning

Obviously 13S wasn't getting me to 65kph, so the research began.  3 months later, obsessively reading e-s and a crap ton of visits in to Grin, I had arrived at several conclusions.

1) In a wide variety of posts Dogman, and others, make it abundantly clear that if you plan on joining the 40mph club then a full suspension bike is pretty much a necessity.  Finding the right frame turned out to be an iterative process as I juggled the variables of range / speed /  chemistry / cost associated with the big ass battery I knew I'd need. 

In the end, after considerable searching, I settled on a bare "Mental Manno" frame because it: a) is fully suspended, b) has a massive "triangle" for the battery, and c) is chromo all around. 

Mental Manno frame as received from Neptronix

2) The wisdom of the sphere, and Justin's simulator, both suggest that to hit 65kph you need 72V nominal.  Since I ride my bike to the gym (free plug for Loki; http://www.maelstromcore.com) which is 17km away, I would need a big enough battery to ride 35km round trip without charging.  Given that my round trip work-commute is 42km, the decision to size the battery for 42km and not have to charge at work was an easy one.  To meet this goal the simulator suggested that I would need 23Ah.

Add in the 25% contingency that Dogman is so fond of and you arrive at a 28.75Ah sized battery.

With this information I turned my attention to finding a vendor. On that point all of my research pointed to one inescapable "fact".   If I wasn't going to be using RC LiPO then I should be using Cellman.  And, to be honest, reading the stories of RC LiPO scared the hell out of me.  So I contacted Paul.

A lengthy back and forth revealed that, taking the C rating of 29E's into account, 21S10P of 29E should do the trick as long as I kept the amps down.

This is what 21S10P looks like if you buy from from Cellman

3) Since the triangle on my frame wasn't really a triangle I had to find someone that could turn out a custom bag.  After much searching I decided that a small Calgary based shop called  PorcelainRocket.com could build me a product that I would be happy with.  I traced the "triangle" as per directions the owner Scott sent me and mailed it off to him.  After some thought I figured that I might get a better product if Scott new exactly how the battery would sit in the "triangle" bag.  So I mocked up a 1:1 scale 3D cardboard replica and gave it to him to work with (I'm fortunate that my work takes me to Calgary on a regular basis).  The final product ended up far better than I could have imagined.   I can't speak highly enough of PorcelainRocket.com and Scott's level of service.

The "triangle" bag from Scott at Porcelain Rocket

4) Next up was the motor.  For all the talk on the sphere about motors I thought that this would be where most of my efforts were focused.  The solution was really quite simple and I arrived at it quite quickly.  Although, going into this, I really wanted a Cromotor, my proximity to Grin coupled with the 135mm dropouts on the Mental Manno meant that the Crystalyte TC-80 from Justin was the best bet for me.

25lbs of copper that Crystalite calls The Crown-80

5) With the frame, battery and motor all dealt with I turned my attention to the controller.  Post after post on the Sphere all seemed to suggest that you shouldn't over spec your controller.  Specifically, if a 12 fet controller will do, don't jump to an 18 fet. I'm not sure if I understand this properly.

With that said, since one of my goals was to maximize battery life and my pack was 28Ah using 29E cells that it would be prudent to limit the max current to 35A.  As an FYI this was  based on separate discussions that I'd had with both Justin and Paul regarding different, but  related, topics where they had each said that 2C was really about as high you want to take a 29E pack.  Since 2C would be approximately 56A I applied an (overly?) healthy contingency and arrived at 35A which would result in 1.25C at 28Ah.  For anyone else out their contemplating a similar build - when Justin, Paul and the sphere all say the same thing you're best to heed your betters.

What this meant for me, was that I ended up settling on the 72V40A Grinfineon Controller for a number of reasons: a) I didn't need something that would handle more than 40A, b) it was plug and play with the TC-80 from Grin, c) it does proportional regenerative breaking, and d) it would keep things in a tidy package if I need to get the guys at Grin to help trouble shoot something (remember I'm blessed by geographical determinism).

It's shocking how smart these dudes are

6) The Cycle Analyst V3 came from Grin.  Being able to just plug everything in is very compelling and I saw little reason to not stick with Grin for this critical piece of the build.

[NTD: hold for photo of CAV3]

7) The list of bits and pieces is long and distinguished (please insert favourite Topgun joke here) and  came mainly from my original build.  Wuxing ebrake (new), Grin Illuminator,  Grin Analogger with GPS, Garmin Virb Elite and Grin USB power cable.  As an added note I usually ride with a Garmin 910XT plus heart rate monitor so that I can get a sense of what kind of calories I'm burning.

Additionally, I've installed Grin Version 4 torque arms on each side and pre-loaded them in opposing directions to account for the torque from the regen braking. Wherever practical I installed Nord-Lock washers as a prudent safety measure.

[NTD: hold for photo of goodies]

8) The bike components are a little all over the map and probably represent the least amount of thought.  The fork is a cheapo Rock Shox XC-32; Neptronix suggested it and I have faith in his rationale but am open to suggestions.  The front brake is a 203mm and rear is a 180mm.  The Chainring is a 52T roadie and the Freewheel is a 16T from Grin which results in "limted contribution" while pedaling at speeds greater than 32kph.  FWIW the rear wheel/tire combo is the stock Clyte 26"  with the 2.0" 2014 variant of the Marathon Plus (the fancy "ebike rated" one). 

9) The in-progress pieces include fenders, a schlumpf high speed drive and a fancy rear LED from Grin (maybe  2)  These pieces are still under consideration but I am leaning towards fendors from Planet Bike (http://ecom1.planetbike.com/7016.html) as suggested by mvly and the hsd from iliya at ebikessf.com (who has been very patient with me). I recognize that the 52T chain ring will need to come off and be replaced by the 37T for the HSD, but by my calculation the 93T equivalent should be good for pedaling up to about 60-65kph at 80-90rpm.  Also I'd like to get a better front wheel/tire comboso it matches the back. 

If anyone has comments please let me know.

The Riding

I don't have much to say yet, other than the first 3 months have been great.  The bike seems to be holding up well.  The big test will be how it does through the Vancouver rainy season.

Chain ring side

Brake  side