Descendence Astro 3220 mid drive build

[madm3chanic]

The last one seemed a bit too high to me. It was fine and plenty fun to ride, but was very hard to manual (controlled). In general if felt quite well balanced but I recon moving it down that little bit will improve the handling. It's nearly as far back toward the rear wheel as I could work out how to do, but it put the COG almost exactly central to the wheelbase center line so happy days.

You'll notice I didn't put the batteries all the way down the bottom and put the motor above them-i did that purposely to put the weight a bit higher, at about shin height. It's all just a experiment tho, at least I'll have a really good basis for comparison now.

The seat is a bit lower on this one too, so I'm gonna use a dropper seat post which will be nice on the climbs.

 

[motomoto]

It looks like you are a frame builder from your website. What do you think about about aluminum vs steel as a frame
for ebikes?

 

[madm3chanic]

It looks like you are a frame builder from your website. What do you think about about aluminum vs steel as a frame
for ebikes?

I havn't really formed am opinion yet to be honest. I could say I think the same as per all dual-suss frames I guess- I prefer steel front triangles and Ali swing arms...

Ali is difficult to use for one off builds tho because you need to heat treat it, and there is no one in Perth that does heat treating for small parts. Not that I've managed to find anyway.

 

[madm3chanic]

some progress pics managed to get a fair bit done in the last three days

this is my downtube before attachement to the bellypan-


jigged up


all welded up


some other bits i've finished



all in all, going well and i think its progressing nicely! ill work on the top tubes and upper attachments tomorrow evening after work, should get them finished off.

 

[motomoto]

Where do you get tubing like your downtube?

 

[spinningmagnets]

Looks awesome. Make sure to continue taking lots of pics of the process...

 

[madm3chanic]

Where do you get tubing like your downtube?

I made it from .9mm cromolly sheet so anywhere you can get sheet I suppose

 

[madm3chanic]

i would forgive any of you if you thought i'd bailed on this project...alas i just got really distracted building a prototype electric assist off-road handbike for a company here in Perth. its an awesome project, but took all of my fabrication time for a good 5 months.

anyhoo...







frame is complete apart from the floating brake mechanism and mount. the last pic is the battery box for my lipo bricks, and the mount thing that holds the box in place. the astro will go on eccentric plate mounts on those three stub threaded things, and the controller will hide away against the inside of a belly pan thing that goes between the parallel downtube square tubes. i have to mount a big on/off switch on there somewhere, and the 150amp fuse. not sure where its all gonna fit...it all got a bit more squashed up that in my original CAD.

 

[Wheazel]

Now this is a build that makes sense.
Nice fabrication.

 

[recumpence]

I am speachless, Dude.

Phenomenal. Just phenomenal. Much respect.

Matt

 

[liveforphysics]

Beautiful work!

 

[Lurkin]

Sooooo.... I'm really hoping this is progressing

 

[madin88]

looks impressive^^

 

[madm3chanic]

ohhhhh yes my friends, it has certainly progressed!





she's a goer! and fark me does she go. i vaguely recall someone saying that they thought the single astro 3220 would be a bit underwhelming...it shoots immediately to top speed as fast as i can get rear wheel traction.

ill post some vids up sometime soon, once i get the wiring all neat and sort out some aesthetic stuff in her.

but big grins

 

[litespeed]

Looks good!

Tom

 

[recumpence]

Yup, Astros are worth the effort......

 

[tangentdave]

Steel, giant single pivot rear...gimme gimme gimme, I want, amazing build. Seriously, I do want one.

-dave

 

[motomoto]

What a great build !!!

You thought it out well and executed the construction marvelously. Well Done !!

I want to do something similar. I like the high shock with the battery and motor low.

 

[ScooterMan101]

Great job. When I see builds like this ( and a few others of you down under ) I sure wish I had the talent and access to machine shop/tools as well.

There are a couple of options I am looking at right now, I do want good amount of power, and a heavy rear hub is not the direction I want to go next.

I have been considering a Cyclone for the last few months but have been put off by the heavy weight of the cyclone motor, and having to use the heavy square taper Bottom Bracket and crankset they have .

What kind of BB are you using ?

Where did your source your BB ?

The crankset I am guessing , has a freewheel ?
2 piece crankset or 3 piece ?

Where did you get all the parts of the drive system from ?

The Chain or Chains are 8 speed ? / 9 speed ?

On the Lipo pack, what S ( volts ) and P , or what kind of packs and how are they arranged in a S and P configuration ?

 

[recumpence]

Great job. When I see builds like this ( and a few others of you down under ) I sure wish I had the talent and access to machine shop/tools as well.

There are a couple of options I am looking at right now, I do want good amount of power, and a heavy rear hub is not the direction I want to go next.

I have been considering a Cyclone for the last few months but have been put off by the heavy weight of the cyclone motor, and having to use the heavy square taper Bottom Bracket and crankset they have .

What kind of BB are you using ?

Where did your source your BB ?

The crankset I am guessing , has a freewheel ?
2 piece crankset or 3 piece ?

Where did you get all the parts of the drive system from ?

The Chain or Chains are 8 speed ? / 9 speed ?

On the Lipo pack, what S ( volts ) and P , or what kind of packs and how are they arranged in a S and P configuration ?

Most of your questions are answered in the very first post of this thread.

 

[ScooterMan101]

Only the total Volts and Amp hours of the pack was answered, but I am wondering about what kinds of packs did he wind up using to get that .
7 cell packs ?
As most Lipo Chargers only go up to 6 cell batteries, few over 6 cell chargers, and very hard to find 8 and 9 wire/pin JST-XH connectors and extensions.
So I will elaborate questions a little more specific here,
Charging each pack separately or using a parallel board ?


He said he is using a 100 mm oversize BB, but that is just the outer shell,
what BB model is being used and how wide ?
about the crank set , Where did he source that ? , Freewheel Which brand / model ? Brand of crank, Type of Bottom Bracket ? ,
which are What chains are being used ? ( said he modified the rear derailleur but did not elaborate ) as I have heard that high power mid-drives are hard on chains.

Most of your questions are answered in the very first post of this thread.

 

[madm3chanic]

yaah my bad- i was gonna use 7s packs cause they were cheap, but i ended up using four 6s/16aH packs.

the bottom bracket IS a 100mm bottom bracket, you cant use an anything else ISIS bottom bracket in a 100mm shell, obviously. the other stuff, google it yourself.

 

[Mongo1]

Wow!! Great work!

 

[macribs]

So how does she ride? Got any videos made? What you think about this compared to your other build?

 

[madm3chanic]

sorry about the massssssive delay in updates on this thread, i did some stuff like have a son which kinda took up most of my time for a while there.

View attachment 2





i had it going a few times before this incarnation but i had a few issues with the gearbox. but alas Dave @ Tangent is quite awesome and extraordinarily supportive of his product, thus we came up with some lovely high-powered/high geared solutions and she seems to be going great guns now.

i've got it three speed at the moment- i have a gear for 40, 60 and 80km/hr (ish), it shifts quite nicely as long as its not under full load. i can always pedal it to shift the gears if need be, but usually i do it with the throttle.

i had to make a weird franken-chain device to stop my pant being sucked into the chainring (if im not riding in my moto boots) which was harder than it sounds given the odd chainline from the dual-ring thingy on the cranks. if the device-bits stick out too much the crank hits it (as the chain is much closer to the crank arm than on normal cranks) so it was quite tricky to do.

i also designed and had machined for me the top crown for the 2007 fox 40's to accept a boxxer bolt pattern direct mount stem. dont ask why i needed the boxxer stem, i just had one so i did. as far as im aware there is nothing available for the old fox 40's to accept DM stems so i just made one. also this is a seriously beefy bit of kit at 32mm thick- i wanted to be able to have the option of mounting the CaV3 on it so wanted it to be really wide.

i also had to do extensive work on both the front and rear shocks (re-valving both, hardest spring available for the 40's) to make them handle ok at this speed/with the weight of the bike. the concentric pivot doesnt really make for a great intrinsically performing suspension platform also so that took a lot of tweaking on the rear shock to get feeling ok. it still squats a bit under power which slackens the head angle and takes traction from the front wheel, but i've mostly tuned it out now and the rest is kind of weighting the front wheel as you turn. its hard to explain.

i've really only been riding it seriously for three or four days, so havent had a chance to make any film of it going yet. that is coming soon tho, seeing as it seems to be reliable now!