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.
litespeed   100 kW

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

Post by litespeed » Jul 02 2018 6:24pm

That bike looks just crazy excellent!

I need to do one of your drives one of these days......

Tom
I'm married so you know I'm no stranger to pain!

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

Post by 12-C » Jul 03 2018 9:30pm

tangentdave wrote:
Jul 02 2018 2:15pm

This drive is easily removed from the frame in only a few minutes, turning the bike into a 34lb enduro beast. A custom mounting bracket matches the lines of the frame and shows no flex under a full 8kW load. The freewheel crankset can remain in place or is quickly swapped with a standard crank arm for another 1lb of weight savings. The CA remains tucked behind the handlebars, the Domino is exchanged for a normal lock-on grip.


20180628_165924.jpg20180628_165936.jpg


Why a removable motor unit? So I can race Cascadia enduro events one weekend, plug the motor in, race Lost Sierra the next, pull the motor and ride the Downieville DH course same day. This bike is capable of competing in absolutely punishing Enduro World Series events and hang with the motos in OHV areas. One bike, any trail.
This is exactly what I had in mind!

Are you going to sell these by any chance?

Is it two pieces in that picture? looks like the cross member "X" is retained by two bolts either side?

On a separate question, you mentioned that you did away with the soft mounts either side of the motor. What was the reason for that? How thick of a shim would I need to replace those at each bolt hole? Would it be better if it was a single piece similar to the shape of the motor flange or would thin washers at each bolt be adequate?

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

Post by Mugenski » Jul 08 2018 6:06pm

Few thoughts on the new G1.5 kit I've been breaking in the last few days.

Temps are noticeably better managed by the waterjacket for those of us who have astros and not the G2 kit with bonded stator. I am loving the change to the spider and that standard chainrings can be used now. More teeth and chain means less wear. 6kw motor is better protected and cooled by the extended housing. Drive does take a bit of time in break in and can sound a little rough - As previously mentioned. 12C you are right with the isolation TPU being gone from the kit. I'm having a hard time telling if there is a difference compared to the G1 considering the change of the gearbox itself. I did keep the TPU bumper for the downtube brace with a slight trim to fit. Raw silver finish looks fantastic, like it more than the black powdercoat.

The refinement and ease of installation has improved. The new frame brace is now a hollow tube with a bolt going all the way through instead of a threaded tube and two screws, much improved. New downtube straps can be cut to a length that suits your frame. Design change to help pull freewheels and gear assembly from the housing. I could go on but the point here is that a good amount of thought went into improving on the G1.

My only change may be moving back to a full 9speed cassette. The chainline is improved and there isn't a need to shift the more commonly used gears outboard.

Thumbs up from me all around!
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Re: Dave's 80:1 RC mid drive kit build log

Post by 12-C » Jul 08 2018 7:22pm

Cool review, thanks. What are you using for coolant?


Dave,
I can't recall if I've asked, would the new chain ring set up work with the previous Gen even though the motor drive is slightly different? If so, how would it change the chain line from motor to crank set?

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

Post by Animalector » Jul 08 2018 9:18pm

slightly off topic. Do you know about TQ motors that are in the new Haibike Flyon? do you think they use a similar gear reduction to yours? I watched a vid, and it sounds 'similar'..

EDIT - Apparently it does... similar...
https://www.tq-e-mobility.com/en

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

Post by andrebandre » Jul 08 2018 10:44pm

The TQ motor probably not the same but reminds of the M1 Spitzing

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

Post by cr0m08 » Jul 09 2018 12:13am

Hey Mugenski,
I'm also curious about coolant. Just water or did you mix some glycol too? And what total volume did you use? Did you fill it all way up or just partial fill? I didn't find heat an issue on 3220 V1, but I think the jacket will help the 3210 in the V1.5 kit as the V1 version got hotter quicker. My 3210 was early V1 and is a 7 turn rather than the 6 turn motor, my 3220 is after this, so its a 3 turn instead of 4 turn. I think the lower turn counts run cooler perhaps?
I'm still assembling my two V1.5 kits 3210 and 3220. I purchased with 3210 V1 first, but power is a funny thing, you have some, you want more. So I got the 3220 V1. Looking back, I should have bought straight into the 3220. Oh well, live and learn. So now I'm updating both to V1.5
2015 Nukeproof Pulse, 3220/HV160 @12S V1.5, 26x2.8" Nextie 50mm wheel set
2006 KeeWee Cromo Eight, 3210/HV80 @12S V1.5, 24x3" wheel set.
1998 Marin B17, Mac 10T @18S in 19" Kris Holme Trials rims, 19x2.5" wheel set (still to finish)
part build Basman 346, QS205 hub motor @12S in 24x3" wheel set. (still to finish)

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

Post by Mugenski » Jul 09 2018 2:15pm

cr0m08 wrote:
Jul 09 2018 12:13am
Hey Mugenski,
Interesting question. Dave stated it should take about 10ml. Initially I filled until I couldn't get any more water in with the bike sitting level. Probably around 10-12 ml. I then flipped the bike upside down for some work and when I placed it back down I checked the water level and found it could take an additional few ml. Maybe 5ml more. So far I haven't ridden the bike hard enough to get the water to boiling temperature, only peaked at 55C. I am thinking though that I will probably add glycol to it at some point so it doesn't freeze if I leave the bike in the garage over the winter.

I've been looking for something that Can protect to -40C as well as 160C+ boiling point for the tangent. Evans coolant claims it is good from -40C to 190C. I am suspecting it will be a little hard to find however. Nevermind I found it locally for me in Canada, means anyone stateside should be able to find it too. Euro friends let us know what you find.

The other option with typical antifreeze would be probably best mixed somewhere between 85-95% EG depending on how much freeze protection you want. If your only concern is boiling then just go 100% EG and you'll start burning the astro before the coolant boils. Boiling point Freezing point
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Re: Dave's 80:1 RC mid drive kit build log

Post by E1Allen » Jul 09 2018 9:23pm

I ran Evans waterless coolant in my dirt bike. Race bikes with no fans get hot in Hawaii. Never boiled over again with Evans.

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

Post by ltu » Jul 10 2018 10:50am

hello dave

do you have any news about your peregrine dh bike?

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

Post by tangentdave » Jul 11 2018 11:01am

The chainline is 'adjustable'...what I mean is the motor chain position is fixed but we can move the spider to either side of the FW flange, use BB spacers between crank and FW, and also slide the BB spindle left/right within the bearings.

There are many variations of cycloidal gearing. The M1 Spitthing (uses the TQ motor) is interesting that it uses like 150 fixed pins as the gear teeth and the eccentric gear does not use a cycloidal profile at all. Makes for a large diameter though.

The Peregrine frame rode great with the high pivot. I rode it at Dry Hill, a proper DH course in Port Angeles, WA. The frame seems intended for single speed use, the chain idler at the rear pivot is very far outboard. The frame held the power without noticeable flex, but wheel chain drops were vicious; the chain routing needs some love.
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Re: Dave's 80:1 RC mid drive kit build log

Post by thepronghorn » Jul 12 2018 6:35pm

tangentdave wrote:
Jul 02 2018 2:15pm

Drive unit weight: 7.5lbs
Dimensions: 100mm diameter, 120mm length
Engine: Neutronics 3215, 225kV
Controller: Castle Talon 120, custom mount/heatsink, QS-8 main battery connect
Performance (calculated w/ 120A phase):
135ft-lbs crankset torque
400RPM crankset
48t cog: 216ft-lbs wheel torque, 21mph
42t cog: 189ft-lbs wheel torque, 24mph
32t cog: 144ft-lbs wheel torque, 31mph (straight chainline)
24t cog: 108ft-lbs wheel torque, 41mph
18t cog: 81ft-lbs wheel torque, 56mph
The math above doesn't quite seem to add up.

225Kv = 0.042 Nm/A, so at 120A phase, you are getting 5Nm at the motor which is 3.7 ft-lbs.
To get 135 ft-lbs at the crankset, you need 135/3.7=36.6x reduction.
This means your motor is spinning at 400*36.6=14600 rpm
For a Kv of 225, this would be 14600/225=65V which is the full charge voltage of a 15.5S pack or the nominal voltage of a 17.6S pack.

I suspect that the torque figure is a little off because I think the drive is 20:1 and it looks like you have 30:20 from the crank to the drive unit which adds up to 30:1. 30x reduction means 400*30=12000 rpm which is a much more realistic 12000/225=53.3V which is pretty close to the nominal voltage of a 14S pack. Or maybe you calculated with a little more than 120A phase current?

Either way, sorry to nitpick, the tangent drive sets the bar for high performance and is an inspiration to us all who are trying to push electric technology forward!

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

Post by tangentdave » Jul 12 2018 7:23pm

Nitpick away, you look to be correct. Hardware does what it supposed to or it doesn't, no way to cheat it. The CA monitors battery power, not phase current, and I can occasionally get the 240A warning out of the Talon...the thing that really matters is how the bike rides, these numbers are a secondary description.

Astro updated their website, specs are missing...the 3turn should make 6in-oz/amp (correct me if wrong), so 120 of them is 720in-oz (3.75ft-lbs). Internal reduction is 20:1, secondary is 20:30= 1.5:1; so that makes 30:1 motor->crank. 3.75*30 is 112.5ft-lbs. My previous math works with 144A phase, which is closer to 8kW than 6kW (112ft-lbs makes sense, there is a very noticeable difference between 120A and 150A max battery). Rest of previous math correct if assume 144A phase, good catch. Can quickly increase torque with smaller motor freewheel if needed, but that's why there is a cassette, right? The Astro can peak higher, but with 120A max battery current, we can ride hard hard for a 20Ah pack without thinking about overheating and get excellent wheel torque/speed. 150A is eye opening and borderline unnecessary on such a short wheel base, but....yes.

BTW, see what I did practicing for Lost Sierra? A little too much material removed apparently, the output of the gearbox twisted completely off. This GG bike needs to move the output sprocket 1/4" outboard for chainline, possibly caused too much twist/pull/bend (and this piece could be steel, for a 100g weight penalty). Normal kits have the FW right against the gearbox (can see the 1/4" stickout in the pic)

-dave
Attachments
20180706_200454.jpg
20180706_200454.jpg (186.4 KiB) Viewed 731 times
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Re: Dave's 80:1 RC mid drive kit build log

Post by aCeMadMod » Jul 12 2018 7:59pm

hi Dave You love me I tell you one word


" Titanium "


your friend

tell me the cost of a new rev gearbox I buy 2 thank you 8)

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

Post by morati » Jul 13 2018 5:04am

Race results Dave?

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

Post by tangentdave » Jul 14 2018 11:08am

Kyle has the list of official times. We ran almost the same course as last year, so silty double track with tough to read corners. Bikes were designated class 1 pedelec, open pedelec, open throttle (plus kids). Pedelecs did 1 lap (6miles), throttle bikes need 2 consecutive laps to count as finished. Not sure who won the class 1 pedelec race.

HPC had a couple fast riders, took the open pedelec class with their Revolution hub bike (1500W I think). Their big, modified Typhoon had a rear tire issue and had to get picked up off the course by the side-by-side (rear tire came off and wrapped around the disc/axle). Their souped up BBSHD bike blew the nylon gear Friday.

Tangent sheared a piece off the gearbox in Friday practice, but ES user CamMan was kind enough to let me pilfer the gearset from his Tangent unit for the race Saturday, but in my haste I didn't seat the snap ring properly...About 1/2 mile into the race it popped out of the groove which let the gearset shift and bind inside the housing...welp. Had to take it back to the shop to remove it properly. My thanks to Campbell for letting me try (took his whole unit back to the shop, reinstalled gearset with fresh grease and it's on the way back to him).

Bjorn from Kranked took first in the throttle class by a decent margin (he's fast). He brought one bike, raced then rode the rest of the weekend without an issue, even pushed me up the Mills Peak climb at 15mph with no pedaling the entire way. Chris's fleet of cyclone mini's performed well but they're no match to what Bjorn has been building.

For the next event, Bjorn and I are thinking of a more difficult and technical singletrack course, for those who deem themselves a 'pro'. Steep climbs, steep descents, drops, tech, flow- the works. Kranked is up here in the PNW with me, so maybe we organize a fun event up here somewhere.
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Re: Dave's 80:1 RC mid drive kit build log

Post by morati » Jul 14 2018 12:36pm

Thanks for the report Dave. Mr. Enga is certainly FAST! Sorry to hear you had some mechanical issues but there's always next year. Did you happen to talk shop with Bjorn about his Raceface cinch crankset design?

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

Post by E1Allen » Jul 19 2018 5:49am

Just got this bike from Pinkbike. 2015 GT Fury World Cup.
8B2F4C0E-5474-47E8-BF29-E2F46D48527C.jpeg
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2ADE8BDC-E23D-461F-8CAC-20091192F6A0.jpeg (234.8 KiB) Viewed 503 times
Ordered Dave's drive last night. Looking forward to some fun real soon.

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

Post by tangentdave » Jul 19 2018 11:57am

Oh yeaaah. Ordering next round of engines today, 4ish weeks.

I want you to fit a wider range cassette on the back. The intent of the gearing is to have a straight chain on the cog we use the most, which will be the 32t cog (32t chainring to 32t cog yields almost 400rpm, ~30mph). A straight bike chain can use full power without problem and 6kW gives good wheel torque when geared to about 30mph. If you have a 42-11t cassette, you'll have a couple slower gears for mega hill climbing and a couple faster gears for going faster without bending the chain much. And you can still pedal the bike.

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

Post by cr0m08 » Jul 19 2018 9:15pm

Whilst on gearing, I did an excel calc for gearing with the tangent kits I have (screenshot and excel attached). The formulas can easily be changed to suit others if wanted (description of formula at top). I know its not much, but thought some of the newer guys may like it. Of course its only calculated and doesn't consider loading or drag. The motor revs or RPM calculation is based on 12S LiPo at 50% charge, either a 3turn 3220 or 7turn 3210 so just change the figures in the formula to suit others. Hope it helps someone.
That GT Fury is one nice looking rig and should be a hoot with a Tangent! Post updates :D
Attachments
tangent gearing exel calc.jpg
Tangent Gearing Calc.xlsx
(52.54 KiB) Downloaded 25 times
2015 Nukeproof Pulse, 3220/HV160 @12S V1.5, 26x2.8" Nextie 50mm wheel set
2006 KeeWee Cromo Eight, 3210/HV80 @12S V1.5, 24x3" wheel set.
1998 Marin B17, Mac 10T @18S in 19" Kris Holme Trials rims, 19x2.5" wheel set (still to finish)
part build Basman 346, QS205 hub motor @12S in 24x3" wheel set. (still to finish)

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

Post by E1Allen » Jul 20 2018 10:17am

cr0m08 wrote:
Jul 19 2018 9:15pm
Whilst on gearing, I did an excel calc for gearing with the tangent kits I have (screenshot and excel attached). The formulas can easily be changed to suit others if wanted (description of formula at top). I know its not much, but thought some of the newer guys may like it. Of course its only calculated and doesn't consider loading or drag. The motor revs or RPM calculation is based on 12S LiPo at 50% charge, either a 3turn 3220 or 7turn 3210 so just change the figures in the formula to suit others. Hope it helps someone.
That GT Fury is one nice looking rig and should be a hoot with a Tangent! Post updates :D
Thanks, I'm hoping it makes a nice ebike since I don't have much actual downhill in El Paso. I fiddled with the graph, added MPH for myself. I'd like for someone to take some actual numbers to see what percent difference losses in motor efficiency take place. We have already seen the drive capable of high speeds. In the future I would like to add some output wattage at X speed. Only good for estimation since anything other than level ground will change those numbers.

Also, Column G which is chainring, you can adjust. It affects the speed in the last column however at a pedal cadence of over 300 I wasn't sure if it had a place since we cant pedal that fast anyways.

Has anyone bothered changing their Chainring to something that supports a straighter chainline by swapping the rings to ones used? I saw this picture over on electricbike forum. Only using three or four gears under electric power and putting them close to center.
rear cassette.jpg
rear cassette.jpg (196.18 KiB) Viewed 409 times

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

Post by cr0m08 » Jul 20 2018 11:04am

E1Allen, I just used spacers to move my cluster around. On my 3220 kit I'm only using the 17-34, which is 6 sprockets on a single spider (this also stops the much higher torque load from damaging my freewheel like the thin single sprockets do, though it is now HopePro4 and now steel not aluminium). That gives me a 200% gear range, heaps for the torque of the 3220. On the Gen 1 version of the 3220 the output chainring from the crank to rear was using the chainring on the outside. Didn't give a friendly chain line at all for the larger end of the cluster. So I dumped the 1st 3 gears off, used spacers behind the solid set of six. Then changed the screw in the deraillier that moves the top guide wheel lower away from the cluster, as my 1st gear was now 17T instead of 11T. I also had to use a double length screw to stop the deraillier from going too far inboard, so stopping at 6 gears instead of 9. Works a treat and as you say, better chainlink. So spacers can also be used and just remove the unwanted gears.
Attachments
0604.jpg
2015 Nukeproof Pulse, 3220/HV160 @12S V1.5, 26x2.8" Nextie 50mm wheel set
2006 KeeWee Cromo Eight, 3210/HV80 @12S V1.5, 24x3" wheel set.
1998 Marin B17, Mac 10T @18S in 19" Kris Holme Trials rims, 19x2.5" wheel set (still to finish)
part build Basman 346, QS205 hub motor @12S in 24x3" wheel set. (still to finish)

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

Post by tangentdave » Jul 20 2018 12:02pm

pedal cadence of over 300 I wasn't sure if it had a place since we cant pedal that fast anyways
The drive actually runs up to a cadence of almost 400 (with 20t motor FW, 32t at crank). Pedaling has little effect with any throttle amount over about 10%. A higher motor cadence keeps the driveline stresses tolerable, and besides, you don't need to use the full RPM but it's nice to have it when you're motorbiking. When you wanna ebike, just restrain the throttle input or create a custom profile in the CA.

The derailleur chainring up front is now 12mm outboard of the face of the BB and should line up with the middle of cassette on most frames.
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Re: Dave's 80:1 RC mid drive kit build log

Post by DolphLundgren » Jul 22 2018 8:07am

Came across these freewheel Cranks and I was wondering if they work with a tangent:
http://hxr-components.com/en/products/4 ... kit-3.html

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

Post by aCeMadMod » Jul 22 2018 8:45am

Hi I been use the. Easy Shift Crankset by HxR Components

they work well


for over 1 year


I am only one that input power from my legs hehe with my ebike at full speed


care take all 8)

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