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

[Ham]

Braingv99 I'd be interested to hear what gearing you're using and what range you get with that set up?

Ham

 

[SlowCo]

+1
Brian if you can post a photo from the chain side that would be great.

 

[guyavitov]

After using other kits on DH bike's, Dave's is the easiest and reliable of them all!

I have the 3220 installed on a Giant glory with 11-34T rear cassette, 38T Front chainring.
With 12S24Ah Lipo battery and CC Talon 120HV ESC.
The bike goes super fast up to 60Km\h, no heating issues what so ever for both ESC or Motor.
And It just working, besides making a custom chain guide so the chain wont fall during gear shift.
Im very pleased with the kit, Photos soon.

 

[briangv99]

Braingv99 I'd be interested to hear what gearing you're using and what range you get with that set up?

Ham

Hey Ham, gearing is 20:1 Tangent with 20t ACS Crossfire to a 32t on the input side and 32t Race Face narrow wide on the output side to 20t Wolftooth 20t single cog. Bike is a 26er. My thinking is I can still pedal the bike up to 25kph when needed and let the motor do the rest. I love the seamless power delivery of a hub motor from zero to top speed, so figured why not do the same here, with 200Nm of torque and 6kW power (in) on tap, I can just twist the throttle and ride with out worrying about mashing the drive train from a bad shift.

Range is about 30km with the on board pack, with a mix of climbs, single track and some gentle cruising between the trails, so about 23wh/km. The pack can be quickly swapped out on the trail for the 4kg spare pack(s) in my backpack to double the range.

+1
Brian if you can post a photo from the chain side that would be great.

g'day SlowCo, here's a pic from the same ride on Saturday. I can post a closer pic if you'd like. BTW chain tensioner is a SRAM X01 DH Type 2.1.

 

[briangv99]

PS - forgot to say motor is a 3t wye 3220

 

[SlowCo]

Thanks!

 

[Ham]

Brian, what's the kv of of the 3220 3t in wye?

Just working numbers to see how you get 40mph with that set up.

How do you find no pedal dead stops on steep hills?

 

[briangv99]

Brian, what's the kv of of the 3220 3t in wye?

Just working numbers to see how you get 40mph with that set up.

How do you find no pedal dead stops on steep hills?

Astroflight list the Kv for the 3t wye 3220 at 226rpm/volt http://www.astroflight.com/3220.

The start up torque the Castle is strong, no problem getting moving from a dead stop on a steep hill, the power delivery is just a bit more abrupt than a big hubbie, so a gentle twist of the throttle is all that's needed to get rolling. We'll see how it holds up, but so far no failures or drivetrain problems so far.

 

[Ham]

That's a nice set up. I still run mine through the 11-36 cassette but am intrigued by single speed set ups and am still waiting on an ebay purchase of a Alfine to play with.. I killed my hv160 and am now using the talon 120. What max amps are you running?

Have you actually hit 40mph in testing or just calculated numbers? Impressive if you have! My HK batteries sag too much to hit full speed but they'll do for now

 

[briangv99]

Dave sent me the CA setup with max amps at 140a and I've stuck with that. It seems to top out at 126a, I'm sure i could hit 140 or more if I slam the throttle a bit harder at low speed, but just taking it easy to see if it holds up to the tracks around here.

Hot off the charger the bike pulls 65kph and over 60 for most of the discharge, so yes can confirm the real word figures line up well with the calcs. Don't know how long it would go flat out, I just tend to open up every so often and cruise the rest of the time not to draw any attention.

I suspect the Alfine may not hold up too well (I had one on another low torque mid drive several years ago) while I didn't break it, it had a habit of slipping out of gear under load.

 

[Ham]

Interesting. When I was running the 160 controller I saw a peak of about 130 amps once but when i was hill climbing at in a high gear. I rarely see more than 90 to 100 now with the right gear selection.

i'm looking forward to trying the Alfine if it ever arrives...10 days and counting. Damn ebay.

Any reason you went with the 3 turn motor instead of the standard 4 the kit usually ships with?

 

[panurge]

yep....3t is 226kv
on my separated left drive, @12s, and 26x2.5 tires a 3220-4t geared 15:1 (so pretty the same wheel speed of a 3t geared 20:1) hits 70kph from a full fresh charge that's pretty close to the 40mph reported by briangv99, but in my bike i feel that gearing (for a 4t at least) too tall for serious climbs under 20-25kph. I use that bike most of the time with 19:1 and a 24x2.5 tire topping out @51 kph full fresh charge, this way I can climb almost anything, have crazy acceleration and stay on a relatively safe top speed for the bike components and brakes, I have 11500Km made with the same 3220 motor in 4 years, and the same old Castle ICE1 HV160. The 3220 astro motor rocks!!
Interesting to see a single speed ascent, but, having the derailleur there, why don't you just put a 3 speed DH cog-set into an 11 speed cassette driver with a slightly more esc-friendly 22t central cog @60kph for 90% all day use and say 26t and 18t on the sides for serious climbs and a 75kph top speed?....Perhaps developing a slightly floating 3 speed cog-set over the cassette driver shouldn't be a bad Idea? sure a challenge but might be feasible....maybe isn't even needed though seeing at the race bike....
Using an 11 speed chain has the benefit of a narrower chainline offset between the cogs, I don't expect 11 speed chain to be less strong than 9-10 although thinner, but the cogs and chainring wear may increase a bit.

Hey Dave! That open throttle race was amazing, would be a dream having something similar in my country!!! Well done with the bike...that was a serious session!

 

[briangv99]

Any reason you went with the 3 turn motor instead of the standard 4 the kit usually ships with?

3t just seems to be the best fit for what I built. The 50v limit for the HV160 means to take the 3220's to its max 10,000rpm (could probably go higher, but that's what Astro list the maximum as) the Kv needs to be somewhere over 200. Since basically power out is torque by RPM, gearing down and getting the RPM up is the way to get the most out of the 3220. The performance seems to back up the theory.

Interesting to see a single speed ascent, but, having the derailleur there, why don't you just put a 3 speed DH cog-set into an 11 speed cassette driver with a slightly more esc-friendly 22t central cog @60kph for 90% all day use and say 26t and 18t on the sides for serious climbs and a 75kph top speed?....Perhaps developing a slightly floating 3 speed cog-set over the cassette driver shouldn't be a bad Idea? sure a challenge but might be feasible....maybe isn't even needed though seeing at the race bike....
Using an 11 speed chain has the benefit of a narrower chainline offset between the cogs, I don't expect 11 speed chain to be less strong than 9-10 although thinner, but the cogs and chainring wear may increase a bit.

If the hills around here were steeper (ie +40%) I'm sure a second or third gear would be a useful addition. I'll see how much abuse the ESC can take, I'm sure the phase amps getting up there in some of the slow technical going, but at the moment I just like the twist and go of the single gear setup.

 

[Ham]

I see...a little higher KV on yours sees a higher crank speed...I guess I could achieve that with a play around with the gearing. I am not going for more speed until I have a better battery and frame

 

[briangv99]

Yep an adequate current limit and not too saggy battery is a must. As for speed, just play with the gearing to suit your needs, once you're over 3kW pedalling becomes slightly redundant, but it is nice still to have a gear you can pedal the bike with occasionally

 

[panurge]

If the hills around here were steeper (ie +40%) I'm sure a second or third gear would be a useful addition. I'll see how much abuse the ESC can take, I'm sure the phase amps getting up there in some of the slow technical going, but at the moment I just like the twist and go of the single gear setup.

Yep If you don't have steep climbs or really techy trails you likely don't need any gear there. And I totally agree, even for me the twist and go is the best feel for those bikes. I admit however, that I have never ridden a Tangent drive and it really tease me. A 3 speed with only occasional use of the side cogs is not substantially different from a single speed thru the derailleur, and for my area would be my choice, owning one of these drives....
But probably the first I will get will be for a guy here, that own a 36" wheel bike and plans to electrify his baby

the tangent could be a perfect fit here keeping everything clean. those big wheels would allow to use a standard 26" setup, using bigger cogs to reach the same speed, increasing overall reliability....With this kind of bike, a Tangent, could be useful even for a separated left (or right) drive with the 20:1 unit and a rear sprocket in a better suited 30t size. I like unconventional builds and I'm really trying to push him to order one!!!!

 

[Ham]

That's crazy big wheels!

Panurge...just a heads up...check your profile links...last I clicked...one of them for Recumpance links was a bit....ahem....

 

[panurge]

thanks Ham for the advice! the link is now updated....

 

[waynebergman]

Hey Jules do you have a build thread or any more photos of the large wheel project shown in the post above. I love the look of those front forks ...........wayne
Edit....no worry Jules I found it here...... http://www.truebikes.eu/ crazy I love this bike!

 

[panurge]

there is a whole small world of 36er lovers and builders (and even racers).
Personally i like more conventional wheel size on bicycles but, speaking about big wheels, without true snow or sand trails to do, but mostly wishing for a big wow-looking bike, faster and comfortable in fact of bumps and small obstacles, a 36er is way more elegant lighter and suitable than a monster 4"-5"tire fat-bike IMHO....

 

[Ecyclist]

Hi guys, can you post source for the high quality left handed freewheel? The only one I can find is ACS Southpaw. Is this any good?
https://www.amazon.com/ACS-Southpaw-Freewheel-Drive-Metal/dp/B00X057BPY

 

[Ham]

That's what i have on my tangent kit fwiw

 

[tangentdave]

http://www.staton-inc.com/store/index.php?p=catalog&mode=search&search_in=all&search_str=southpaw

If you get the style that looks like the 14t on the staton-inc.com website, you'll have to epoxy the bearing cup to the center bore, otherwise it will come loose during use and fall apart. The other style of ACS southpaw with the removal splines on the outside are what I use in the kit, from the staton-inc.com website. These FW's are durable and tough.

-dave

 

[briangv99]

Testing out the climbing with single speed (20:1), no shortage of torque on this 45% (25 degree hill) 300m climb.

Haven't got a temp sensor wired, so exercised some caution, let the motor an controller cool off before continuing. The 3220 does get hot, but not too hot to touch.

Very happy with Dave's fantastic creation.

View attachment 1

 

[12-C]

Beauty of a build!

Dare I ask if there is anyone with a dual astro setup of this reduction?

Sorry had to...

Is there any way to do that?