Dave's 80:1 RC mid drive kit build log

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
User avatar
tangentdave
1 kW
1 kW
Posts: 301
Joined: Jun 06, 2015 11:40 am
Location: Seattle, WA
Contact:

Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Jun 26, 2017 5:48 pm

I am, same Zerode, same drive unit as in the kit (well, the 20:1 version because of the arrangement of the IGH-- the kits use 40:1 unless you have a setup that doesn't drive the crankset) plus an additional cooling fin piece I want to test in the desert. Waiting on a new fork crown race to arrive in a couple days to mount a new pair of forks. And I need to ride as much as possible before July 8 or I'm gonna end up killing myself I'm so out of practice.

Image
Zerode G2/Tangent 6kW
Intense Tracer 29er/Tangent 3kW PAS

dtx1
10 mW
10 mW
Posts: 22
Joined: Oct 04, 2015 5:04 pm

Re: Dave's 80:1 RC mid drive kit build log

Post by dtx1 » Jun 27, 2017 7:30 am

Hey Dave,

about those seals: without knowing what this might all entail, but maybe you can adapt seals from IGHs for this purpose? The Rohloff or the Kindernay both are sealed and oilfilled and very roughly the same size as the tangent so maybe you can use those (somehow...)

User avatar
m4k3r
1 W
1 W
Posts: 59
Joined: May 31, 2016 3:50 pm

Re: Dave's 80:1 RC mid drive kit build log

Post by m4k3r » Jun 27, 2017 1:28 pm

tangentdave wrote:I am, same Zerode, same drive unit as in the kit (well, the 20:1 version because of the arrangement of the IGH-- the kits use 40:1 unless you have a setup that doesn't drive the crankset) plus an additional cooling fin piece I want to test in the desert. Waiting on a new fork crown race to arrive in a couple days to mount a new pair of forks. And I need to ride as much as possible before July 8 or I'm gonna end up killing myself I'm so out of practice.
Fack!!! The race is already in a couple weeks...totally wanted to go this year too. Where do i go to find out when/where it's happening ahead of time so i can plan accordingly?

Edit: guess i should have looked at the flyer closer, ecobikeadv.com :::face palm:::
Last edited by m4k3r on Jun 27, 2017 4:00 pm, edited 1 time in total.
“We will never know world peace, until three people can simultaneously look each other straight in the eye.”

devo1223
10 W
10 W
Posts: 72
Joined: Nov 06, 2012 4:32 pm
Location: Lake Tahoe,CA

Re: Dave's 80:1 RC mid drive kit build log

Post by devo1223 » Jun 27, 2017 4:00 pm

I PM'd Electric43 a month ago to find out the date of the race. Definitely worth the trip if you can make it.
Rocky Mtn switch/Lyen 18 fet/18s5p tesla cells
Mxus 3k turbo 3t in 17in moto rim
50mph

User avatar
m4k3r
1 W
1 W
Posts: 59
Joined: May 31, 2016 3:50 pm

Re: Dave's 80:1 RC mid drive kit build log

Post by m4k3r » Jun 27, 2017 10:53 pm

Short video of the new design, much quieter IMO. There is still sound of course, but as you can hear in the video the clicking from the crank is louder than the drive (up to a certain RPM, I'm guessing 5000-7000ish).

https://drive.google.com/file/d/0B1xYL6 ... sp=sharing

Edit: after letting the loctite set from the fresh install i took her out for a spin with my buddy and his BBSHD. he confirmed it's WAY quieter (we ride together all the time so he knows what the old one sounded like). absolutely silent when i was behind him and barely heard when i was in front. the nobs on my tires are just as loud at speed. much improvement in the vibration department too...new powder coating looks great as well!
“We will never know world peace, until three people can simultaneously look each other straight in the eye.”

Ham
100 W
100 W
Posts: 212
Joined: Feb 18, 2016 3:08 am

Re: Dave's 80:1 RC mid drive kit build log

Post by Ham » Jul 14, 2017 10:40 am

m4k3r wrote:Short video of the new design, much quieter IMO. There is still sound of course, but as you can hear in the video the clicking from the crank is louder than the drive (up to a certain RPM, I'm guessing 5000-7000ish).

https://drive.google.com/file/d/0B1xYL6 ... sp=sharing

Edit: after letting the loctite set from the fresh install i took her out for a spin with my buddy and his BBSHD. he confirmed it's WAY quieter (we ride together all the time so he knows what the old one sounded like). absolutely silent when i was behind him and barely heard when i was in front. the nobs on my tires are just as loud at speed. much improvement in the vibration department too...new powder coating looks great as well!
Damn that is quieter, by a margin too. Good work Dave...
http://www.HamsFitness.com Strength, Conditioning & Diet

Mugenski
10 mW
10 mW
Posts: 25
Joined: Aug 02, 2015 9:03 pm
Location: Toronto

Re: Dave's 80:1 RC mid drive kit build log

Post by Mugenski » Jul 14, 2017 2:46 pm

Newer version is with the 7075 gears as well yeah? Anyone put significant miles on them to compare to the louder cromo gears?
Giant Glory Tangent 6kw @ 44v - Soon to be 52v

lightrush
1 W
1 W
Posts: 59
Joined: Jan 18, 2016 7:31 pm

Re: Dave's 80:1 RC mid drive kit build log

Post by lightrush » Jul 14, 2017 4:12 pm

Incredible. Put some load by pressing the rear brake while under throttle so we can hear the under-load sound. My steel gearbox gets louder when under load.

morati
1 kW
1 kW
Posts: 325
Joined: Mar 07, 2012 7:24 pm
Location: Ontario, CANADA

Re: Dave's 80:1 RC mid drive kit build log

Post by morati » Jul 14, 2017 4:53 pm

Thank you Dave.
Attachments
Santa Cruz 2.jpg
Santa Cruz 2.jpg (147.19 KiB) Viewed 1937 times

ideate
1 mW
1 mW
Posts: 11
Joined: May 15, 2017 10:47 pm

Re: Dave's 80:1 RC mid drive kit build log

Post by ideate » Jul 14, 2017 7:06 pm

That Knolly looks very interesting.. I might try and find a frame to play around with. They're good bikes too start with.

I just put a BBSHD on a Banshee Spitfire (I call it the Spit-e). The only complaint I have is with the cranks and bottom bracket axle. I ride my bike properly and have since wrecked those after market Lekkie crank arms. I'm now always wondering about some setup where I could use better cranks and a stronger bb axle with a mid drive.. It looks like I've found the solution!

ImageImageImage

User avatar
tangentdave
1 kW
1 kW
Posts: 301
Joined: Jun 06, 2015 11:40 am
Location: Seattle, WA
Contact:

Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Jul 15, 2017 4:03 pm

Image

Stunning countryside and fast racing. First place went to Enleau and his 15kW q205 drag race beast with 3kWh of LiPo in a Chinese ebike frame. The course really favored big power with deep, sandy uphills and relatively smooth trail for drag racing corner to corner. I calculate I was about 30seconds behind on my Zerode with 6kW Tangent (traffic on the course, see split times in the video). I puffed a cell on my good 14s pack the day prior and was running 12s 20Ah LiPo for the race (prob didn't slow me down, but it's def not as fun and snappy). Enleau's hub was almost smoked by end of the event, my Tangent equilibrated between 120-130deg C for the event, even dipping below 100C occasionally (mind you, it's in the California desert, midday, 92deg F). The difference between a 15kW hub and 6kW DH Tangent is down to rider ability...I make up time through corners, over rough and jumps while the big, heavy hubs saw 50mph on some straights. The hub used 1200Wh for 13 miles (17Ah@72V consumed), I used 760Wh (16Ah@48V consumed).

Tangent takes 1st in the PAS class, 2nd and 3rd in the open throttle class. Kyle's Banshee Phantom 29er is set up with a 3kW Tangent PAS kit that he raced in both classes (unplugged throttle for PAS event), he absolutely smoked the pedal assist class with power limited to 35A (~1500W). My times between the PAS and throttle class show the difference in speed, 9min faster lap times onboard my Zerode vs a class I pedelec (borrowed Fantic full suspension from EcoBikeAdventures). Nick turned in a great time of 24min onboard his hardtail with BBSHD+phaserunner, but Kyle's fitness and FS 29er+Tangent is the combo to beat.

The Tangent gearbox used on the Zerode frames is special order lower reduction ratio, not the normal customer gearbox due to the placement of the IGH inside the Zerode frame, so pardon the cool sounds. Besides, 8HP ain't no ebike...it's a motorbike, as the difference in my lap times show. It's my dirtbike replacement.

Light and nimble vs heavy and fast. I choose light and nimble, but with prodigious torque :)

Bring out your setup and prove how fast you are...I could've pushed harder and next race I will...

-dave




Image
Image
Zerode G2/Tangent 6kW
Intense Tracer 29er/Tangent 3kW PAS

morati
1 kW
1 kW
Posts: 325
Joined: Mar 07, 2012 7:24 pm
Location: Ontario, CANADA

Re: Dave's 80:1 RC mid drive kit build log

Post by morati » Jul 15, 2017 5:48 pm

Nice race Dave! You got screwed by the guy on the ATV!
Gotta say....Had some initial problems with my Tangent kit that kept me from enjoying it for the first couple of weeks of ownership. I was a royal PITA to Dave during this time but he kept his cool and came through for me to correct all of my issues. Had my first trail ride today with all issues corrected and the Tangent 3kw PAS kit is a joy to ride. I've never gone this fast on my local trails before! Dave D. is not just a genius for designing this system but also an honest business man. Very much appreciated Sir! One of these days I will buy myself a GoPro or similar and show you guys for myself.

User avatar
tangentdave
1 kW
1 kW
Posts: 301
Joined: Jun 06, 2015 11:40 am
Location: Seattle, WA
Contact:

Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Jul 16, 2017 5:18 pm

The new beta CA firmware plus a THUN...some tuning still remains. Several people are riding and tuning, putting the gear through it's paces. My personal settings don't seem to be how most riders want their PAS to respond. I like the motor engaging only when I put out effort (50-75 watts of human before motor engages), this way the bike is normal when riding slow technical sections; sprinting brings on the motor cause that's when I wanna go fast. We're finding most people prefer to engage the motor almost immediately, at a low cadence (16RPM engagement). The THUN isn't as responsive as a Brose or Yamaha motor, but if you think about the bike a little differently, the THUN can be great on the trail. Instead of wishing that the motor should be seamless, think of it more like a throttle device that you control with your pedaling. We only get torque from the left side crank so rest with the right foot forward and start pedaling from this. When approaching obstacles, give yourself 3 pedal strokes (right-left-right) before the attack; this will take the slack out of the driveline and preload the suspension with motor input. Once the motor is engaged, the torque response is fairly quick.
20170714_182650.jpg
20170714_182650.jpg (219.97 KiB) Viewed 1828 times
20170714_182713.jpg
20170714_182713.jpg (227 KiB) Viewed 1828 times
Customer wants the lightest drive unit possible for a titanium framed 120mm fatbike. This unit uses a 3205+HV80. Had to modify the housing since the 3205 is so tiny and create an additional spacer to extend the mounting plates out to 120mm. 2.8kg = 6.2lbs.

-dave
Zerode G2/Tangent 6kW
Intense Tracer 29er/Tangent 3kW PAS

Alex07
100 W
100 W
Posts: 123
Joined: Jun 27, 2016 4:00 am

Re: Dave's 80:1 RC mid drive kit build log

Post by Alex07 » Jul 21, 2017 7:20 pm

by lightrush » Sat Jul 15, 2017 7:42 am

Incredible. Put some load by pressing the rear brake while under throttle so we can hear the under-load sound. My steel gearbox gets louder when under load.
Comes without saying all gearboxes are significantly louder under load ! so that's when you want to compare noise improvements not with the wheel off the ground when its quiet naturally lol.

User avatar
m4k3r
1 W
1 W
Posts: 59
Joined: May 31, 2016 3:50 pm

Re: Dave's 80:1 RC mid drive kit build log

Post by m4k3r » Jul 26, 2017 3:07 pm

Alex07 wrote:
by lightrush » Sat Jul 15, 2017 7:42 am

Incredible. Put some load by pressing the rear brake while under throttle so we can hear the under-load sound. My steel gearbox gets louder when under load.
Comes without saying all gearboxes are significantly louder under load ! so that's when you want to compare noise improvements not with the wheel off the ground when its quiet naturally lol.
I agree, but the noise level is significantly less compared to my previous version with the same exact test (wheel off ground and on stand). I guess i should have made that video to post for comparison...also can't exclude that different microphones will record sound differently and different speakers will produce sound differently (lower the volume and the drive becomes silent lol :P ) Lots of variables...

I've got about 100 miles on the new gearbox so far, so i'll try to get another video up with the drive under load. I'll also try to get a GoPro video up from a ride...
“We will never know world peace, until three people can simultaneously look each other straight in the eye.”

User avatar
beast775
100 kW
100 kW
Posts: 1258
Joined: Jul 05, 2007 11:55 am
Location: victoria british columbia

Re: Dave's 80:1 RC mid drive kit build log

Post by beast775 » Jul 30, 2017 4:16 pm

Thnx for the race vid :)
2 FINGER SALUTE TO ESSO.no buying gasoline for 7 years now.
I spent all my money on bicycles women and beer the rest i just wasted.

Fastest1
10 W
10 W
Posts: 65
Joined: Jan 03, 2014 2:22 am

Re: Dave's 80:1 RC mid drive kit build log

Post by Fastest1 » Aug 10, 2017 6:36 pm

Dave
If I were to desire a better chainline for my application (A 2004ish Giant DH Team 100mm bb). How complicated would it be for me to move the motor driven chain to the outside ring of the bottom bracket sprockets?

User avatar
tangentdave
1 kW
1 kW
Posts: 301
Joined: Jun 06, 2015 11:40 am
Location: Seattle, WA
Contact:

Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Aug 10, 2017 7:40 pm

I'd just make a new output piece that would hold the motor freewheel outboard a few mm's. I'm gonna mess around with moving the motor chain to the outboard position, all these different BB arrangements are a pain!

-dave
Zerode G2/Tangent 6kW
Intense Tracer 29er/Tangent 3kW PAS

User avatar
m4k3r
1 W
1 W
Posts: 59
Joined: May 31, 2016 3:50 pm

Re: Dave's 80:1 RC mid drive kit build log

Post by m4k3r » Aug 11, 2017 1:25 pm

For those that run your battery in a backpack, I ordered a USWE backpack which features their "No Dancing Monkeys" technology. So far I like it a lot, just takes some getting used to as we are all familiar with the standard straps for backpacks. The built in suspension technology really helps with the weight of bigger batteries. The pack does bounce a bit up and down when hitting jumps but so did my last pack. At least with this one, the suspension helps distribute the weight and makes for a really ergonomic ride. Can't wait to take it out for a real shred sesh this weekend... (i don't work for nor affiliated with this company in any way, just trying to help my fellow tangent riders!)

http://www.uswe-sports.com/products/hyd ... kprotector
Patriot15_ChiliRed_05_WEB.gif
Patriot15_Black_01_WEB.gif
“We will never know world peace, until three people can simultaneously look each other straight in the eye.”

morati
1 kW
1 kW
Posts: 325
Joined: Mar 07, 2012 7:24 pm
Location: Ontario, CANADA

Re: Dave's 80:1 RC mid drive kit build log

Post by morati » Aug 13, 2017 3:43 pm

Anybody using a Domino throttle with the pedal assist? Not a fan of the thumb throttle.

knurf
10 mW
10 mW
Posts: 24
Joined: Aug 29, 2016 12:15 am

Re: Dave's 80:1 RC mid drive kit build log

Post by knurf » Aug 30, 2017 4:50 am

Found this, sounds very interesting (from the zerode build thread):
Sadly, I won't be producing these Tangent units any longer. A lighter, stronger, larger engine version is in the works if you can hold out through the winter. If not, mount a cyclone or LR's big block motor above the shock, or like others have said, a geared hub motor. There's 130mm between the steel triangle plates in the frame and 4.5" diameter clearance at the frame centerline, about 3" diameter clearance 50mm from centerline.
Exciting! Any more details? Time for a new build log? Hope you'll still be available to whip up the occasional spares for us Tangent owners.

User avatar
tangentdave
1 kW
1 kW
Posts: 301
Joined: Jun 06, 2015 11:40 am
Location: Seattle, WA
Contact:

Re: Dave's 80:1 RC mid drive kit build log

Post by tangentdave » Aug 30, 2017 2:21 pm

Spares and support for sure. Anybody who's purchased a Tangent from me or bought it used will be taken care of.

This has been a big success, there's 80+ kits out there tearing it up, on-road and off-road. I've sold out of all the parts I pre-made and am incorporating lessons learned into the next design.

First year findings:

We've lost 4 ESC's (and one I plugged 100V into by accident), 2 were very early and probably the weak ones of the bunch, 1 succumbed to heavily salted roads in Scandanavia and the last had a few hundred miles on it (unexplained electronic death). In general, the THUN is not meeting expectations- it's not responsive enough for trail riding. For a street commuter it's ok, but the delicate wires, small bearings and square taper interface don't last as long as it should off-road. Not to mention the CA is barely capable of providing enough accessory current at 48V/52V (DC-DC converter issue inside the CA) to drive the THUN; any additional accessories and it's only a matter of time before the CA dies. Nobody wants the CA on their handlebars and half the customers won't deal with the interface.

The JST connections used on the CA aren't tough enough. The bundle of unused connections hanging out the back are fugly.

The gearboxes are holding up well. None of the larger eccentric gear bearings have failed and none of the steel gearboxes have failed. 7075 aluminum is not strong enough for more than 1500W but does make the unit ~300g lighter and a little bit quieter. The lack of grease seals is a minor inconvenience no one seems to care about, same with the 150-200mile grease interval.

I started with too high of a reduction ratio and have been reducing the overall ratio since. The gearbox is still either 40:1 (3210) or 20:1 (3220) internal ratio, but I'm finding the bikes ride/perform better when reduced to about 200RPM (3210) and 300-350RPM (3220) at the crankset. The trade off for the reduced ratio is higher demands on the battery due to the higher powers the motor is able to pull. The 6turn 3210 and 3turn 3220 (225kV winds) provide a flatter torque curve in our application and keep the heat lower than the 7turn 3210 and 4turn 3220 (170kV winds) originally spec'd. The 3turn 3220 can be run especially hard with the 120A Talon ESC, but moreover, it can be run hard for an entire 20Ah pack. It'll handle an HV160 no problem, but there's really not a whole lot of need and I only want to carry at most 10lbs of battery on my back. Perhaps with plenty of battery in the frame, like a Qulbix, an HV160 could be fun (plus the Talon is half the size and fits on the kit better).

The drive unit's diameter is the most important dimension in order to fit more frames and be able to put the weight in more advantageous positions. Outrunners are cool but too large. Lower kV motors of the same power are too large.

There aren't any commercially available battery packs that will support 52V and 120A burst, which is a bummer (sure, some ES users will build packs to order).

I greatly prefer the motor chain to use the inner chain position. It's visually cleaner, I can put a tiny 24t sprocket on the inside position which fits all frames, less lateral force. Downside is the derailleur chainring is about 1/4" farther outboard but straight chain is still in the middle of the cassette. The ISIS BB is needlessly heavy; a custom crankset might save a pound of weight. Four of the ACS freewheels on the motor have broken (one poor guy broke two in a row with less than 50 miles). No issues with the crankset freewheel.

The gearbox parts needs to be of high precision. This style of gearbox is less forgiving to positional errors between the ring and eccentric gear than a more traditional involute pinion/spur arrangement. It's difficult for me to hold the tolerance needed on my equipment, which is the real reason for the pause in sales- it takes me frocking forever to produce a gearbox. I'll be prototyping and making spares in house, outsourcing the production parts to production shops with expensive machines. Still here in the US of course, but these parts should be made on a CNC lathe with live tooling, and most preferably, all parts come out of the same machine. So it makes sense to redesign the drive unit at the same time then work with a shop or two to produce the parts more exact and 10x faster than I can now. The initial design is already finished, the internals are nearly identical; most of the changes will be to the housing to accommodate manufacturing, remove unnecessary material and increase versatility. I still have to make and use several to verify the design before pulling the trigger on manufacture.


Suggestions and criticism welcome. Updates of design and testing to follow.


-dave
Zerode G2/Tangent 6kW
Intense Tracer 29er/Tangent 3kW PAS

User avatar
Adamlivi
1 mW
1 mW
Posts: 10
Joined: Nov 26, 2016 2:52 pm
Location: Norcross, Georgia

Re: Dave's 80:1 RC mid drive kit build log

Post by Adamlivi » Aug 30, 2017 3:32 pm

You remain my ebike hero Dave!
Last edited by Adamlivi on Aug 30, 2017 4:06 pm, edited 1 time in total.

Ham
100 W
100 W
Posts: 212
Joined: Feb 18, 2016 3:08 am

Re: Dave's 80:1 RC mid drive kit build log

Post by Ham » Aug 30, 2017 4:04 pm

Always exciting to see and hear about your updates and changes Dave.

I believe my 3220 kit was the first in Europe and had a few teething issues in the first 100 miles that you kindly helped me get fixed (blown gears and then a fried ESC) since the new gears and ESC all has been well and I think I am coming up to 1000 miles now.

One day I'll get it transferred to a better frame that can hold the batteries.

Keen to see more on what you have planned....
http://www.HamsFitness.com Strength, Conditioning & Diet

ScooterMan101
100 kW
100 kW
Posts: 1255
Joined: Oct 06, 2012 4:45 pm
Location: South of San Jose, California.

Re: Dave's 80:1 RC mid drive kit build log

Post by ScooterMan101 » Aug 31, 2017 3:07 am

Are you now using Direct Mount Cranksets now ? with a freewheel ?

If so , which Direct Mount Crankset, Sram ? , Race Face ? FSA ? or E*thirteen ?

Down hill / Free Ride Riders are using Short Crank Arms ( 160mm and shorter )
Why are you using them ?

Post Reply