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PWD's Rocky Mountain Element - 2WD

Posted: Jan 18 2019 11:50am
by pwd
I figured it was time to start a build log for my science project on wheels. :bolt: Here is my current configuration:

2008 Rocky Mountain Element 10
Front: Magic Pie 4 with stock controller running at 25 amps peak
Rear: Leafbike 205 35 "1500W" with a West Coast Electric Cycles 18 MOSFET AOT290L Controller running at 80 amps peak

Two eme3v batteries in parallel:
14S5P Samsung 30Q
14S6P Samsung 25R

Here is my list of things to do:
  • clean up wiring
  • paint touch ups on extra parts
  • shunt mod to rear controller for stronger regen
  • add 12V step down
  • LED strip + bar end turn signals
  • LED strip brake light
  • new headlamp switches
  • temperature meter for rear motor
  • Statorade for rear motor
  • Hubsinks (depends if I actually need them)
  • rear fender

With old controller:
IMG_20180802_110059 (1).jpg
flir_20180705T125853.jpg (381.32 KiB) Viewed 5181 times
flir_20180705T125904.jpg (396.1 KiB) Viewed 5181 times
I moved the bike inside where it is warm so that I can putter with it to my hearts desire over the winter. I've started stripping it down to clean it up and see what needs attention:

Re: PWD's Rocky Mountain Element - refresh

Posted: Jan 20 2019 8:32pm
by pwd
I finally managed to open up my XM-L T6 lights with the blown driver:
I didn't realize the back would thread off like the front; so I get it with a hammer and a screwdriver. I then noticed the back began to spin. Note: this light was only designed to work with a 2S battery pack.

For comparison I opened up my working 4-84V version of this light to see what the number on the board was:
Does anyone know where I can find a replacement high voltage driver like the one above? I'd like to convert the first light to work on my pack voltage but I can't find any similar driver boards. The only thing that came up when I punched in the board number was this guy also looking for a replacement driver:

I was quite happy I manged to get the damn thing open; but without a replacement driver; I'm not much further ahead.

Re: PWD's Rocky Mountain Element - refresh

Posted: Jan 23 2019 8:22pm
by pwd
I received some more gadgets from China over the last week:

12V Temp display that runs off of an NTC 10k thermistor. I'm loving the green. I also have a blue one on the way...:
The switch arrieved damaged but I'm working out a refund of sorts from the seller. Luckily for me; the switch components can be found on ebay so I don't have to buy a whole new unit.
IMG_20190122_172955 (1).jpg

Re: PWD's Rocky Mountain Element - refresh

Posted: Feb 03 2019 6:33pm
by pwd
I've striped the bike back even more now since I'm basically redoing all of my hasty wiring jobs. My goal is to clean up the cables and reduce clutter by trimming out extra lengths of cable that I don't need. On my 2wd setup; that are a lot of cables. Here is one example:

My Magic Pie harness can be chopped up to remove that junction box and the excess length since I only use the front brake and throttle inputs
I received my new Chinese handlebar stem so that I can fit my BMX bars back on the bike. I like having the brace since it allows for my clamping points. This will be especially handy to center my Cycle Analyst and run two headlamps. I've also drilled a hole in the bars to run some bar end turn signals; I feel better about doing it on these reinforced steel bars than the aluminum ones I was using before.

Re: PWD's Rocky Mountain Element - refresh

Posted: Feb 03 2019 8:32pm
by motomech
Wow, that thing must weight a ton. Over the course of the 8 years I've been riding my Rocky Mountain Edge, I kept adding stuff until it was over 75 lb.s! That is w/ a mini frt geared motor, an Ezee geared rear and 25 Ah's of LiPoly. I trimmed the batt. packs back to a total of 14 Ah's and now it feels like a bicycle again.
The bike itself has been awesome, the only non-drivetrain maintenance items have been the Fox shock and the linkage pivot points. The shock received a seal kit once and at that time I added a Fox tuning kit to better deal w/ the extra weight of the Edrive related stuff and rider :roll: and inspected the linkage bearings once. As I don't ride in the wet, they were fine. Every couple of years, I would start to get some squeaks, at which point I simply lay the bike on it's side(s) and let some penetrating oil work it's way in overnite. I also add a few CC's of shock oil every year or so.
Speaking of the shock, are you not concerned about having the shock mounted backwards? I think what little oil that's in there rests where the seals are and w/ the way you have it mounted now, the oil would sit at the opposite end of the chamber. Maybe it's NBD.

Re: PWD's Rocky Mountain Element - refresh

Posted: Feb 04 2019 11:32am
by pwd
Yep, the bike is heavy; I'm guessing its around 85-90lbs fully loaded. I'm adding even more stuff to the bike as you can see in my to-do list; but I'm trying to do it with some better planned cable management. This Element has been great so far. It's been handling my short but aggressive commute well.

I purposely reversed the rear shock so that I could fit the battery with ease. I did not realize/consider that the oil would be at the opposite end now; I will have to look into that. Thanks for noting that.

Re: PWD's Rocky Mountain Element - refresh

Posted: Feb 05 2019 2:13pm
by pwd
I've been playing with some schematics for my lighting plans while I wait for the Chinese new year to be over... This is all in theory and not tested yet:
Screenshot_20190205_141042.png (35.13 KiB) Viewed 4952 times

Re: PWD's Rocky Mountain Element - refresh

Posted: Feb 12 2019 9:59am
by pwd
I managed to get some soldering done with my new Weller 25W iron. I broke my other one by snapping the tip off in the heating module...

I added some jst-xm connectors to the cables and turn signals
bar end signals
the flasher relay I bought was bigger than I expected but fortunately I was able to remove the outer case and solder some pigtails directly to the board
flasher relay
testing out my LED strip for rear turn signals ( I hope they will be bright enough)
led strip
I also added a connector to the cycle analyst so that I can disconnect it from my main power cables if necessary. I was also able to chop the excess cable that I had coiled up an zip tied to the frame. I re-used an 8 pin connector from my old Magic Pie 2; and it worked out nicely.
cycle analyst
Check out all of the cables I managed to trim out of my setup, it should help with the look of the bike
chopped wires

Re: PWD's Rocky Mountain Element - refresh

Posted: Feb 15 2019 10:38am
by pwd
I have been working on my rear seat-post rack lately. My plan is to add LED strips around it for a brake light and turn signals. The rack was cracked in a couple spots and bent from a couple wipe outs and other mishaps. I've had it repaired and added an extra solid rod of aluminum to it for strength and to have more surface area for the LED strips:

Re: PWD's Rocky Mountain Element - refresh

Posted: Mar 03 2019 1:33pm
by pwd
I spent a few hours working on the bike this weekend:
Preview from the front to see how the new panel looks
Front preview
new sub-dash panel for temperature gauge and future switches. I am thinking of adding multiple temperature probes and a switch to toggle the display between probes to display motor/controller temp.
rear rack is complete with working LEd strips for turn signals and brake light
I did the shunt mod on my controller because I wanted more regen strength. This controller was only doing about 7 amps of regen at full strength and my old one could hit 10 and felt much stronger. I've also turned down the battery current to compensate for the shunt mod; although I will have to dial it in when it is working on the bike.

Re: PWD's Rocky Mountain Element - refresh

Posted: Apr 06 2019 5:34pm
by pwd
I got the temperature sensor swapped out for a 10K NTC so that it works with the eBay temperature meter. I have a problem though, the meter doesn't display the temperature, I just get an "hhh" on the meter. I tested the thermistor with a multimeter and it is showing the correct resistance (around 12K ohms for 21 celcius).

The thermistor shares the ground wire from the motor's hall sensor ground and also has a white wire. If I power the temperature meter from a 9V battery, it displays the temperature no problem. When I power the meter from a dc to dc converter using the main battery pack; the meter shows "hhh". If I unplug the controller's power; the meter displays correctly.

I see this has something to do with the meter having a shared wire between power ground and one of the sensor wires but I don't know how I can get around that. Any ideas? :?:

Re: PWD's Rocky Mountain Element - refresh

Posted: Apr 08 2019 3:18pm
by pwd
Here are some updates on my build with photos:

I trimmed a bit of weight (300 grams) from the rear rack by replacing 90% of the square tube with aluminum. I Made a kind of receiver to fit the seatpost clamp (steel) into the aluminum square tube. I then put a bolt and some jb weld on it and called it a day.
bike rack weld
rear view
I attempted to recycle a rear fender from a 700c cruiser bike that was left for trash. I relocated a couple of the mounting holes, acquired some rubberized clamps (surprisingly hard to find around here) and it seems to fit OK. With my frame having piviot pints; my mounting points are limited but I was able to mount it across the same section of frame. It is still waiting on a road test to see if it will survive the vibrations and potholes....
fender side
fender back
My order of Statorade arrived last week and I finally removed the rear wheel and cracked open the motor side cover. I also replaced the motor's temp sensor with a more standard 10K NTC thermistor so it works with cheap ebay temp meters which I have already blown (see above post).
open hub motor
sealed hub motor
while I was at it; I headed to my LBS to purchase some headset spacers. I also cleaned and regreased the headset bearings etc.. I noticed that my bike was missing the lower bearing dust cover and was allowing all sorts of sand and grit to enter. My quick and easy solution was to wrap it with some silicone tape to keep the weather out of there. It actually turned out great; and it almost looks factory.
headset service

I am close to getting this thing wrapped up. I am just waiting on some final bits:

new bar end turn signals (already broke them before riding) - a note: I had ordered ones with plastic threads but they broke from tightening; I found identical ones but with aluminum or steel threads so I hope they survive longer

on-off-on switch for turn indicators

new led temp meter for rear motor

Re: PWD's Rocky Mountain Element - refresh

Posted: Apr 28 2019 2:47pm
by Raketemensch
I love these stealth builds :shock:

Seriously though, nice work. I'm currently trying to sort out a good temp gauge situation of my own, that looks pretty cool. What'd you use for sealant when you put the hub cover back on?

Are the headlights aimed downward?

Re: PWD's Rocky Mountain Element - refresh

Posted: Apr 29 2019 8:08am
by pwd
Thanks for the comments. I used some old RTV sealant I had. I believe it was this kind: ... B0002UEN1U

I've been running it for a couple of weeks now and no leaks have appeared. Also, if you are going to do the eBay temp gauge thing; I find the blue LCD works the best. I found the green one was not visible at all in the daylight.

The headlamps are aimed slightly downward. I ride during the day on "medium" brightness so I'm not too worried about blinding oncoming traffic.

Good luck!

Re: PWD's Rocky Mountain Element - refresh

Posted: May 09 2019 9:39am
by pwd
The bike has been running pretty well and I'm happy with the modifications I've completed over the winter. The temp gauge is pretty handy. With warmer weather around the corner, I plan on ordering some hub-sinks to help shed the heat from my rear motor a bit better. So far the max temp temp I saw the motor reach was 90 Celsius but the ambient temperature hasn't been over 18 Celcius.

I was reading this thread on Field Weakening to try and understand it a bit better and I stumbled on this nice piece of info:
billvon wrote:
Aug 09 2018 5:51pm
One interesting thing I notice with phase advance/field weakening is that when you get to the motor's base speed and keep accelerating you don't notice any difference. But when you get off the throttle (i.e. motor current goes to zero) you get very strong braking as the inverter's diodes rectify the motor's voltage (now higher than the battery's voltage) and feeds it back to the battery. Once you go under base speed it stops regen'ing.
Ah ha! That explains the behavior I am having with my setup. I would still like to know what the following parameters do in XPD for my controller:

Flux weakening level
Flux weakening finetune
Flux weakening position
Flux weakening utrnpoint

does anyone have and ideas?

Re: PWD's Rocky Mountain Element - refresh

Posted: Jun 04 2019 3:08pm
by pwd
Note to future self: ... 8511182266
cell layout.png
I *might actually* be able to fit 14S7P of 21700 cells in my frame using a "bulged" version of the em3ev 6P pack layout.

Re: PWD's Rocky Mountain Element - refresh

Posted: Jun 04 2019 6:47pm
by ZeroEm
Do you have another build thread before the refresh?
Did you get the brake lights working?

I am putting together AWD and was wondering what you think about AWD do you like them?

Re: PWD's Rocky Mountain Element - refresh

Posted: Jun 07 2019 8:47pm
by pwd
ZeroEm wrote:
Jun 04 2019 6:47pm
Do you have another build thread before the refresh?
Did you get the brake lights working?

I am putting together AWD and was wondering what you think about AWD do you like them?
I don't have another thread for this bike but I do have an older picture (before the refresh):
Magic Pie 2 on rear
Infineon 12 3077 fet controller from em3ev
a single 14S5P battery (barely cutting the mustard)
old build
IMG_20170602_160954-1.jpg (220.99 KiB) Viewed 4175 times

I did get the brake lights working! The key component was this particular relay:

Unfortunately the LEDs I chose were not very bright though. I have a new LED strip tail light on the way that will hopefully be brighter: ... 2749.l2649

As for the AWD setup, I love it but it does come with a few quirks that need addressing. The leafmotor 1500W is about the largest motor I would want to fit on a bike frame at the moment. Having another motor on the front gives me an extra 1400W or so that would otherwise be mostly heat if I tried pushing that extra power through the rear motor. Although I don't offroad much, the extra traction of a front hub does come in handy.

In other news, I installed a set of Hubsinks today on my rear motor. I did't evenly distribute the thermal grease so I didn't have enough for the last hubsink. Fortunately, I had some (really old) thermal paste for computer components that I used for the last one. I think it works fine. As per the hubsink instructions, I gave the motor a hard workout to get it hot (107 Celsius to be exact). The real test for me will be the final motor temp on my next commute to work:

Re: PWD's Rocky Mountain Element - refresh

Posted: Jul 07 2019 10:53am
by pwd
The bike has been performing well. I recently got to rip along some short hard packed trails that were an absolute blast around 40-50 km/h. There were many ups and downs and even a bit of air. The clearance between my rear fender and racks is not enough so it kept smashing after hard hits. The bike and new battery bag handled pretty well.
trail shot
Before that, I had topped up both packs and manage to hit a new record for battery draw:
cycle analyst
The motor was pretty toasty though.

Re: PWD's Rocky Mountain Element - refresh

Posted: Jul 15 2019 11:45am
by thundercamel
That's a nice beastly build! This thread was fun to read :)

Re: PWD's Rocky Mountain Element - refresh

Posted: Jul 22 2019 8:48am
by pwd
Thanks for the comments thundercamel!

Here is my next change for the bike:
new motor
IMG_20190721_105437.jpg (508.8 KiB) Viewed 3807 times
This is another leafbike 1500W motor for the rear but this time I'm going with the 4T version instead if the 5T which I'm currently running. The new motor is laced into a 24" rim. It will be getting the Statorade (7mL this time) and Hubsink treatment as well. Here is the difference I'm expecting between the two motors: ... kv_b=13.16

I am looking forward to a higher top speed without flux weakening. The motor gets warmer than I expected during my commute so I am hoping I can get away without using flux weakening for my commute and cut back on the heat generated when riding near top RPM. I expect I will still use flux weakening for fun. The smaller wheel diameter should also help keep efficiency even with my current setup. I plan on increasing the phase current by 30 amps to make up for the different motor winding. I have some 8AWG cable on the way too.

Re: PWD's Rocky Mountain Element - refresh

Posted: Jul 22 2019 10:38am
by neptronix
Looks like a monster of a bike. You must be going fast if your motors are getting hot. What's a typical cruising speed for you?

Re: PWD's Rocky Mountain Element - refresh

Posted: Jul 22 2019 10:47am
by thundercamel
Wow, that looks just like my ebikeling 1500w motor, seen here. I recently got 50mL of statorade, and just just going to dump 10mL in. Why are you choosing 7mL? I didn't see a number you used last time.

Re: PWD's Rocky Mountain Element - refresh

Posted: Jul 22 2019 10:56am
by pwd
Thanks Nep. My cruising speed is anywhere from 50 to 60 kmph depending the flow of traffic. There is one particular stretch with a slight uphill where I'm usually cruising around 55 kmph to 58kmph. That puts me just outside the max rpm of the 5T motor (running 14S) and is where I use the most flux weakening. I also tend accelerate hard from stops etc... but the motor does seem to heat up the most when using flux weakening for more rpm.

Re: PWD's Rocky Mountain Element - refresh

Posted: Jul 22 2019 11:35am
by neptronix
I see. Maybe you're 1 cooling mod away from being able to just use the 4T leaf in a 24". When mine was drilled, i could maintain a bit ore than 60kmh perpetually.

..then again, i was always in the tucked position, and i had some of the lowest friction tires one could buy. But you have the advantage of a smaller wheel. Could pan out in your favor.