Dave's 80:1 RC mid drive kit build log
- Thread starter tangentdave
- Start date
tangentdave
1 kW
The Pinion gearbox isn't setup for mid-drives, their website says specifically running the E-motor through a transmission isn't the best way to power the bike. I disagree. The Tangent unit run through the Shimano Alfine gearbox is dreamy.
tangentdave
1 kW
Not thru the Shimano Alfine 8 extensively yet, but through a Rohloff 14spd yes. It handles the power fine. I need new mounting brackets for the Zerode to really test the Alfine. After everybody's kits are in mail this round I might have some time to work on my own stuff...
-dave
-dave
MitchJi
10 MW
Hi Dave,
Notes:
Don't use a very small sprocket. After you go past #15t, chordal motion and its associated noise is roughly eliminated. Maybe using #219 chain will help.
I already have a 7T 3220, kv 97. It sounds like your system is flexible enough to accommodate the relatively low kv (compared to most of the systems you sell) and work well, with about a 50 volt battery?
Please let us know when you have definitive results with the Alfine 8.tangentdave said:
Is the 20:1 unit quieter? If it is you maybe you should consider eliminating the 40:1 drive, and replacing it with the 20:1, and getting the same overall ratio with the 20:1 reduction by doubling the chain reduction.tangentdave said:
Notes:
Don't use a very small sprocket. After you go past #15t, chordal motion and its associated noise is roughly eliminated. Maybe using #219 chain will help.
How hard would it be to accommodate slotted mounting bolts?tangentdave said:
I already have a 7T 3220, kv 97. It sounds like your system is flexible enough to accommodate the relatively low kv (compared to most of the systems you sell) and work well, with about a 50 volt battery?
tangentdave
1 kW
I'm trying to avoid using slots and a pivot in the mounts to tension the chain, bolted interfaces flex and rock and don't account for eccentricities. Using double the chain secondary with the 20:1 is possible, we'd need a 48t receiving sprocket to get back to 60:1 overall, that's a pretty big chainring. Shorter pitch chain is also possible. I'm trying to keep as much bicycle compatibility as I can, fewer tools, fewer parts that are easier to get a hold of. The 40:1 isn't loud- this system doesn't need to be run at high RPM for efficiency. It's actually the most efficient when run slower, in the 3k motor RPM range, a comfortable pedal cadence.
Along this line, the 20:1 gearbox with a standard 11-36t rear cassette and 32t front chainring is simply sublime on the trails. Run at 60A with the 3210, the cassette's range gives climbing ability like the larger ratio gearbox but also a top end Bruno will love (50kph on flats is about 1200W on knobbies and only halfway up the cassette). Each gear runs twice as long and turns every trail into a flow trail that's as fast as you dare. Throttle only since the crankset is spinning twice as fast; you can still pedal with an assist if you pick a tall gear and only use a tiny bit of throttle so the motor doesn't overpower you. But on the trails....sublime. This also means we have half the chain pull and ride in the larger cogs most of the time, reducing the stresses overall.
I'm beginning to send out 20:1 kits to people who plan on trail riding and want a moto/throttle feel. This is what I'm after, a mini-moto with pedals. It's no problem to lift the front all the way down the straight now. This will also ride beautifully as a single speed geared for ~30mph. The slower gearset works well for commuting/PAS setups. The two ratios are easily interchangeable by swapping the cycloid gears and camshaft, a 30min job.
97kV at 50V is about 5000RPM. I've run this gearbox at 14kRPM so no problems. The motors ride better when operated at their intended voltage, the motor will feel sluggish and respond slower when run at half voltage (compared to rated voltage). It will work though, we'd pair it with a 20:1 unit to yield 125RPM at the crankset (40:1 overall motor->crankset). That wind makes lots of torque...
-dave
Along this line, the 20:1 gearbox with a standard 11-36t rear cassette and 32t front chainring is simply sublime on the trails. Run at 60A with the 3210, the cassette's range gives climbing ability like the larger ratio gearbox but also a top end Bruno will love (50kph on flats is about 1200W on knobbies and only halfway up the cassette). Each gear runs twice as long and turns every trail into a flow trail that's as fast as you dare. Throttle only since the crankset is spinning twice as fast; you can still pedal with an assist if you pick a tall gear and only use a tiny bit of throttle so the motor doesn't overpower you. But on the trails....sublime. This also means we have half the chain pull and ride in the larger cogs most of the time, reducing the stresses overall.
I'm beginning to send out 20:1 kits to people who plan on trail riding and want a moto/throttle feel. This is what I'm after, a mini-moto with pedals. It's no problem to lift the front all the way down the straight now. This will also ride beautifully as a single speed geared for ~30mph. The slower gearset works well for commuting/PAS setups. The two ratios are easily interchangeable by swapping the cycloid gears and camshaft, a 30min job.
97kV at 50V is about 5000RPM. I've run this gearbox at 14kRPM so no problems. The motors ride better when operated at their intended voltage, the motor will feel sluggish and respond slower when run at half voltage (compared to rated voltage). It will work though, we'd pair it with a 20:1 unit to yield 125RPM at the crankset (40:1 overall motor->crankset). That wind makes lots of torque...
-dave
tangentdave
1 kW
It seems there are two approaches to ebikes. The industry seems to be trying to keep the feel and function of bicycles while adding an electric motor and trying to appeal to bicyclists. I think a second approach is to use these amazing handling bike frames and add a motor to create a hybrid of sorts, between a motorcycle and bicycle. Riding fast on the trail with a Tangent requires proficiency in both MTB and moto worlds; smooth flow is rewarded but there's enough power to charge over obstacles and make up for mistakes, more lines are possible, more trails are fun. It really does allow moto guys to ride more places the way we want while keeping the handling and riding characteristics of the MTB (not to mention way less maintenance than a moto).
To each their own, both approaches are great. More ebikes, less combustion. A Tangent bike doesn't damage the trail or annoy neighbors but it should be ridden on trails that expect speed, not so much ridden at your crowded local bike park.
-dave
To each their own, both approaches are great. More ebikes, less combustion. A Tangent bike doesn't damage the trail or annoy neighbors but it should be ridden on trails that expect speed, not so much ridden at your crowded local bike park.
-dave
lightrush
100 W
- Joined
- Jan 18, 2016
- Messages
- 104
I finally have some better shots of the my torque-PAS commuter. I've done some 300km so far on it. It's amazing. All pictures in high-res can be found here: https://cloud.ndoytchev.com/s/rlPf75Ve00m5QCp. And here are some low-res samples:
izeman
1 GW
Did you ride in salt water? A little wd40 and a brush would help. The bearings inside may look the same like the freewheel outside!
nutnspecial
10 MW
Yeah baby
HamsterPower
10 mW
Lightrush,
Thanks for the updates! I too am going to do a Tangent PAS.
I've a few questions for you:
I've been looking at the 136mm spindle Thun and have been unsure if that'd work even though it's longer on one side. Which Thun did you use?
Is that gear sensor doing anything for you?
I need a 130mm BCD chaninring mount size and yours seems small. What is the size of yours and if it's not 130mm BCD, was one available?
Were the longer motor mounts (to allow the controller to be mounted instead of zip tied) not an option?
Thanks for the updates! I too am going to do a Tangent PAS.
I've a few questions for you:
I've been looking at the 136mm spindle Thun and have been unsure if that'd work even though it's longer on one side. Which Thun did you use?
Is that gear sensor doing anything for you?
I need a 130mm BCD chaninring mount size and yours seems small. What is the size of yours and if it's not 130mm BCD, was one available?
Were the longer motor mounts (to allow the controller to be mounted instead of zip tied) not an option?
lightrush
100 W
- Joined
- Jan 18, 2016
- Messages
- 104
I don't remember. Dave bought it for me and I only looked at the label on the bag several months ago, which is long gone.HamsterPower said:
Dave may have some record from my order. Dave?It's great for PAS. The PAS takes a second or two after you stop pedaling to roll off. If it weren't for it, I would have to wait for it to roll off before any shifting. Or I would have to tap my brake. Or rotate cranks backwards to stop the PAS before shifting. With the Gearsensor I shift as normal. On top of that, at high assist levels, where I apply little force to the pedals, I could even shift without reducing the force as I'd normally do on a normal bike. That's because I'm already pushing the pedals "lightly". I just pedal and shift. It is not that useful for shifting while using the throttle. If the throttle is pressed hard, I still hear horrible noises from the back. It could be possible to make it work for shifting under throttle as well by fiddling more with the CA's ramps and what not. Haven't given up on it yet, but it's not crucial. Reducing the throttle while shifting and pressing it again afterwards works fine.HamsterPower said:
Mine is 110BCD. My original crankset used 130mm. However it seems that 110BCD "cyclocross" chainrings are readily available for 110BCD from RaceFace and WolfTooth among others. WolfTooth goes to 50t on that spider. In fact I have a 50t WolfTooth I planned to use but couldn't fit it because it impacted the chain tensioner pulley. It's why I installed a 40t. Some of those days I will shorten the motor chain which should allow for the tensioner to move further away from the BB and maybe I could squeeze the 50t in. Longer motor mount would most certainly alleviate this issue, but my motor is very close to the front tire already so I didn't want to go for that.HamsterPower said:
I don't think that would have helped. The controller already sits far enough from the BB so that it intersects with the "further away" part of the crank arm. Still the crank arm was rubbing it. The problem could be solved in a number of ways. You could file just the bit that was rubbing from the crank arm. Or you could install washers on the inside of the mounting bolts of the controller, which would bring it closer to the frame, depending on how many washers you use. (I don't know why I didn't do that) You could flip it and mount it on the inside if you have enough spacing between the downtube and the motor mounting plate. (I didn't)HamsterPower said:
alaskaoneday
1 µW
- Joined
- Mar 28, 2016
- Messages
- 2
Here is a quick pic of my Tangent Ascent build. This is my first ebike.
Bullitt Cargo bike
Rohloff drivetrain
Tangent Ascent 40:1 Astro 3210
Lunacycle 52v 25r 20ah triangle pack
I use this bike as my main mode of transportation and taking my grandson to school. On our first ride to school, the first thing out of his mouth was, "YES!" and the second was, "I need to put one of these on my bike!". He is only five but the seed has been planted.
Dave has been great to work with and the install was quite easy.
Bullitt Cargo bike
Rohloff drivetrain
Tangent Ascent 40:1 Astro 3210
Lunacycle 52v 25r 20ah triangle pack
I use this bike as my main mode of transportation and taking my grandson to school. On our first ride to school, the first thing out of his mouth was, "YES!" and the second was, "I need to put one of these on my bike!". He is only five but the seed has been planted.
Dave has been great to work with and the install was quite easy.
tangentdave
1 kW
Lightrush is using the 128mm THUN BB from Grin: http://www.ebikes.ca/shop/ebike-parts/torque-sensors/thun-128l.html
The freewheel on the crankset sticks past the end of the crank 6-8mm so we need a BB with a little bit of stickout on the drive side. The 128mm Truvativ GigaPipe BB's are perfect for 68/73mm frames but Grin's THUN BB isn't offset the same. I can mill a few mm's off the left crank to include this BB to be used in a PAS kit.
-dave
The freewheel on the crankset sticks past the end of the crank 6-8mm so we need a BB with a little bit of stickout on the drive side. The 128mm Truvativ GigaPipe BB's are perfect for 68/73mm frames but Grin's THUN BB isn't offset the same. I can mill a few mm's off the left crank to include this BB to be used in a PAS kit.
-dave
adriftatsea
100 W
alaskaoneday said:
That is awesome.
Greetings,
Now that I have over 300 miles and counting on my Tangent build and I'd like to share the little I know about this awesome kit.
In 2015 I built a Motoped, but found it was too loud for urban use and sold it prior to moving to Hawaii. As an avid motorcycle commuter in both Japan and San Diego, I knew I would not be happy sitting in Oahu traffic/heat (wearing military required gear) on my motorcycle and started to look into alternatives.
Shortly after arriving on island, I started shopping with the intent on building an ebike suited to Oahu. My commute is only 3 miles but over 600 ft elevation, roads are rough and narrow, traffic is bad. I wanted a lot of suspension to ride out hitting a pothole, washout or being pushed into a ditch or curb. In October, I picked up a well built and well used Intense 951 FRO off craigslist. Amazing bike and I am incapable and unwilling to ride it to its full potential. I found endless-sphere and this thread and placed order #7 in October for the Tangent kit. I couldn't be more pleased. The assembly is simple for those who perform their own bicycle maintenance, instructions clear and sufficient and Dave's support is outstanding.
A couple of things make this build unique: I used this mount from Amazon to move the CA3 below the bars to protect it when I loop the bike: K-EDGE Universal Camera Pro Handlebar Mount, 31.8mm. Lights are Grintech ELight_12F headlight and LED8RB taillight. I use a 1-to-3 12v 5.5mm 12VDC splitter to power the lights and a Grintech DC-USB_Dual adapter to charge my phone. 3" of Velcro holds the phone to the hydro-formed toptube securely and protected from a crash but visible for GPS routing.
After initially using a MOLLE Sustainment pouch ziptied to the downtube to hold the Luna Cycle 25r 20Ah pack, it is now mounted in a hand-fitted .060 Kydex 'holster' laced to the downtube with 550 cord. Since the frame is angular rather than round there is no side-to-side movement and has only needed to be tightened a bit to keep 1/4" clearance from the drive. The motor has so much torque that it wants to wheelie off the line even with the 12lb battery pack strapped to the front.
After snapping the 26t cog of the original SRAM 970 12-26 cassette in half, (yes, this kit has that much torque!) I upgraded to a PG-950 11-34. Having a strong wide ratio cassette is advised. I average 2miles per amp hour and have rode up to 40 miles with 800ft climb on one charge with plenty of power remaining. GrinTech Satiator and Luna Cycles packs are top notch.
Updated pics are posted to the Tangent site: http://tangentmotors.com/media/
Thanks Dave!
-Ren
Now that I have over 300 miles and counting on my Tangent build and I'd like to share the little I know about this awesome kit.
In 2015 I built a Motoped, but found it was too loud for urban use and sold it prior to moving to Hawaii. As an avid motorcycle commuter in both Japan and San Diego, I knew I would not be happy sitting in Oahu traffic/heat (wearing military required gear) on my motorcycle and started to look into alternatives.
Shortly after arriving on island, I started shopping with the intent on building an ebike suited to Oahu. My commute is only 3 miles but over 600 ft elevation, roads are rough and narrow, traffic is bad. I wanted a lot of suspension to ride out hitting a pothole, washout or being pushed into a ditch or curb. In October, I picked up a well built and well used Intense 951 FRO off craigslist. Amazing bike and I am incapable and unwilling to ride it to its full potential. I found endless-sphere and this thread and placed order #7 in October for the Tangent kit. I couldn't be more pleased. The assembly is simple for those who perform their own bicycle maintenance, instructions clear and sufficient and Dave's support is outstanding.
A couple of things make this build unique: I used this mount from Amazon to move the CA3 below the bars to protect it when I loop the bike: K-EDGE Universal Camera Pro Handlebar Mount, 31.8mm. Lights are Grintech ELight_12F headlight and LED8RB taillight. I use a 1-to-3 12v 5.5mm 12VDC splitter to power the lights and a Grintech DC-USB_Dual adapter to charge my phone. 3" of Velcro holds the phone to the hydro-formed toptube securely and protected from a crash but visible for GPS routing.
After initially using a MOLLE Sustainment pouch ziptied to the downtube to hold the Luna Cycle 25r 20Ah pack, it is now mounted in a hand-fitted .060 Kydex 'holster' laced to the downtube with 550 cord. Since the frame is angular rather than round there is no side-to-side movement and has only needed to be tightened a bit to keep 1/4" clearance from the drive. The motor has so much torque that it wants to wheelie off the line even with the 12lb battery pack strapped to the front.
After snapping the 26t cog of the original SRAM 970 12-26 cassette in half, (yes, this kit has that much torque!) I upgraded to a PG-950 11-34. Having a strong wide ratio cassette is advised. I average 2miles per amp hour and have rode up to 40 miles with 800ft climb on one charge with plenty of power remaining. GrinTech Satiator and Luna Cycles packs are top notch.
Updated pics are posted to the Tangent site: http://tangentmotors.com/media/
Thanks Dave!
-Ren
Dave,
I'm working in my first e-bike. Mid-drive with a cycle analist, Castle edge 80 and a Astro 3205. The problem that I have is when I move the throttle half way the red LED on the controller goes off and the motor stops. For what I read sounds like a throttle out issue but don't really understand what all this means. This is what I have in my CA.
Can you tell me what values should I change.
ThrO Outpt Mode R/c Pulse
ThrO Min Out 0.85 mSec
ThrO Max Out 4.65 mSec
ThrO Brake Out 0.59 mSec
ThrO Up Rate 2.00 mS/sec
ThrO Down Rate 4.00 mS/sec
ThrO Fast Rate 4.00 mS/sec
ThrO Fast Thrsh 3.00 Amps
Thanks
I'm working in my first e-bike. Mid-drive with a cycle analist, Castle edge 80 and a Astro 3205. The problem that I have is when I move the throttle half way the red LED on the controller goes off and the motor stops. For what I read sounds like a throttle out issue but don't really understand what all this means. This is what I have in my CA.
Can you tell me what values should I change.
ThrO Outpt Mode R/c Pulse
ThrO Min Out 0.85 mSec
ThrO Max Out 4.65 mSec
ThrO Brake Out 0.59 mSec
ThrO Up Rate 2.00 mS/sec
ThrO Down Rate 4.00 mS/sec
ThrO Fast Rate 4.00 mS/sec
ThrO Fast Thrsh 3.00 Amps
Thanks
tangentdave
1 kW
It's the Thr0 Max Out setting. The CC ESC's expect a pulse signal between 1.0-2.0msec to indicate 0%-100% throttle. Try these:
Thr0 Min Out: 0.98msec
Thr0 Max Out: 2.02msec
The idea here is the 1-2msec range is contained within the range actually output to the ESC. You always want to be able to get to 0% throttle with a mechanical device (the twist or thumb throttle) so a little padding on the top and bottom of the range is a good idea.
If you're using a freewheel on the output of the motor, try reducing the Thr0 Fast Rate to 0.1msec/sec to engage the freewheel more gently (since the Astro motor accelerates almost instantly).
-dave
Thr0 Min Out: 0.98msec
Thr0 Max Out: 2.02msec
The idea here is the 1-2msec range is contained within the range actually output to the ESC. You always want to be able to get to 0% throttle with a mechanical device (the twist or thumb throttle) so a little padding on the top and bottom of the range is a good idea.
If you're using a freewheel on the output of the motor, try reducing the Thr0 Fast Rate to 0.1msec/sec to engage the freewheel more gently (since the Astro motor accelerates almost instantly).
-dave
Are these empirical values?
I tried Thr0 Max Out: 2.02msec but the LED on the controller goes red when the throttle is half way. With a value of 1.84msec I can go WOT and seems to work OK.
With Thr0 Min Out: 0.98msec the motor starts spinning as soon as I power the system. The value of .90msec works but the LED blinks once in a while
https://www.youtube.com/watch?v=IdCrDbKVmSo
Goes away as soon as I touch the throttle and the motor works. Is something I should be concern about it? I went down to ThrO Min: .45 but can't get rid of the blinking.
I tried Thr0 Max Out: 2.02msec but the LED on the controller goes red when the throttle is half way. With a value of 1.84msec I can go WOT and seems to work OK.
With Thr0 Min Out: 0.98msec the motor starts spinning as soon as I power the system. The value of .90msec works but the LED blinks once in a while
https://www.youtube.com/watch?v=IdCrDbKVmSo
Goes away as soon as I touch the throttle and the motor works. Is something I should be concern about it? I went down to ThrO Min: .45 but can't get rid of the blinking.
tangentdave
1 kW
What are your Throttle In values? These need to be set just under what the CA reads at 0% physical throttle and 100% physical throttle. Don't remember what the values are off the top of my head for Grin's hall throttles, but for the Domino 5k twist with a 470ohm resistor on the black signal line, the CA is set to 0.02V as 0% throttle and 4.94V as 100% throttle.
Go to the Throt In main top menu, it'll show you what the CA reads from the physical throttle. Set the 0% and 100% voltage based on these values, set it just under. For example, the Domino 5k twist reads 0.00V at 0% throttle and 4.97V at 100% throttle.
-dave
Go to the Throt In main top menu, it'll show you what the CA reads from the physical throttle. Set the 0% and 100% voltage based on these values, set it just under. For example, the Domino 5k twist reads 0.00V at 0% throttle and 4.97V at 100% throttle.
-dave
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