20 inch full suspension street build (now with twin motors)

Great work!! The full suspension 20" is one of my pending proyects :D
 
Great build Matt. Amazing craftsmanship, your work never ceases to amaze me.
Me and I guess a whole bunch of others are rooting for a dual drive for this project. Just to take it to the max :D
 
macribs said:
Me and I guess a whole bunch of others are rooting for a dual drive for this project. Just to take it to the max :D
Hmm, maybe a completely new style twin motor drive is warranted for this bike? Thing is, twin 3220s is so freaking over the top on a bike of this size it is not even funny.......

I decided to name this bike "Holeshot"

Seems fitting........

Matt
 
Hmm, maybe a completely new style twin motor drive is warranted for this bike? Thing is, twin 3220s is so freaking over the top on a bike of this size it is not even funny.......

I decided to name this bike "Holeshot"

By this bike do you mean the one you just built or the new build with twin motors?

BTW I had an ah ha moment when I saw the 4 stem clamps holding the end plate on the battery box. Perfect solution.
 
100volts+ said:
Hmm, maybe a completely new style twin motor drive is warranted for this bike? Thing is, twin 3220s is so freaking over the top on a bike of this size it is not even funny.......

I decided to name this bike "Holeshot"

By this bike do you mean the one you just built or the new build with twin motors?

BTW I had an ah ha moment when I saw the 4 stem clamps holding the end plate on the battery box. Perfect solution.

I meant this bike pictured on page 4.
 
Recompence, With the 4 stems on the steerer tube solution, were you thinking " with this setup I won't have to worry about steerer tube warp during welding" or was it solely to keep front fork angle in the jig? Or both?
 
100volts+ said:
Recompence, With the 4 stems on the steerer tube solution, were you thinking " with this setup I won't have to worry about steerer tube warp during welding" or was it solely to keep front fork angle in the jig? Or both?
It was done for a number of reasons.

First, it allows me to change head tube diameters, angle (with machined shims or new clamps), height, and length.
Second, it eliminates warp issues from welding.

I guess you can say I wanted to leave my options open and this removable head tube does that.

Matt
 
recumpence said:
They are Havoc 1.5 inch steerer tube handlebar stems.

The bike went to the powder-coater today. It should be done Friday.

Matt


Matt, where did you get the steerer tube? Or is that just a standard (outside diameter and inside diameter) tube that you cut to length.
 
StinkyGoalieGuy said:
recumpence said:
They are Havoc 1.5 inch steerer tube handlebar stems.

The bike went to the powder-coater today. It should be done Friday.

Matt


Matt, where did you get the steerer tube? Or is that just a standard (outside diameter and inside diameter) tube that you cut to length.

It is 1.5 inch OD, 1.375 in ID if I remember correctly.

Matt
 
OK, by popular demand, I decided to go with twin motors. I was torn between posting these pictures in this thread or starting a completely new thread......

My standard twin motor drive would put both motors in line. This would put the forward motor in extremely close proximity to the front wheel. It would also look weird on this frame. Besides, I was out of stock on the long twin motor plates. :wink: So, to that end, I decided to go with an entirely new drive unit layout. I have wanted to build a V-Twin drive for some time now, but never had the excuse to do it, until now! When I laid out the twin drive on this frame, the lower motor was too close to the front wheel. So, I decided to make the drive more compact to bring the motor away from the wheel. This looked odd for a couple reasons. Finally I came up with this asymmetrical twin. It better fills the void behind the front wheel, yet has more than enough room for various pulley diameters, idler wheels, and other things I may add later.

You can see I sacrificed two of my new style heavy duty drive unit motor plates to make one siamese V-Twin motor plate. I cut the plate to fit the contour of the primary motor plate and V ground the edges of each part to get good weld penetration. I made two passes on each side of the plate with the TIG welder at 150 amps to accomplish the joining process. This is the first time I have ever TIG welded such thick aluminum. It turned out well, I must say! I clamped the pieces to some scrap material to hold them straight during the welding. I am happy to say it is perfectly square in every dimension! I am proud of that. I was very concerned about warping.

One thing you may notice.... The lower motor pulley does not have as much belt wrap as the upper motor. There is enough room to add another idler to increase belt wrap around that motor pulley if I find the belt tends to skip. I want to try it this way first, however, because fewer idlers is more efficient.

Funny thing, this drive uses a very weird length belt. I just so happened to have that belt length in stock. I make it a point to stock many sizes of screws, bearings, pulleys, belts, etc, "Just in case". :D

These are 5 turn Delta 3220s. They peak at a touch over 14,000 watts each for very short bursts (a couple seconds at a time). So, this drive has the [very short burst] potential of 28,000 watts. That is purely academic, however, because I highly doubt the drive will ever pull more than 18,000 to 20,000 watts and that only if I lay on the bars under hard acceleration. Odds are it will see tiny 1 second wheelie snaps at 15,000 watts and sustained power of 10,000 watts for high speed running.

The bike will initially be geared for 50mph. I hope to add steering damper for stability. I will try it up to 60mph if the bike proves to be stable at speed. The Hooligan was plenty stable at 45mph. So, 60mph should be fine with this longer wheelbase bike with the added weight it has. We shall see.

Honestly, this thing kind of scares me. This is the most powerful upright bike I have ever built. I will probably find it necessary to tone it down to make it more ridable. I will add a few little tricks to make the bike "Settable" for general riding, or for hard core insanity. Otherwise I would not be able to let anyone ride this beast. I am being totally honest here, this much power on a bike of this size and weight takes a huge amount of concentration to ride properly. Hopefully I will not hurt myself with this thing.....

Anyway, enjoy the pictures!

Matt
 

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With that much torque on hand, even with the slipper clutches how the hell do you keep from throwing yourself off the damn 12KW bike?

Beautiful creation, INSANE... but beautiful!

-Mike
 
The plan of attack for taming this bike is multifaceted.

First of all (as Mike mentioned) I am using a torque limiter. However, that is not something that can be adjusted on the fly. It is adjusted for driveline protection mainly.
Second, I plan on using Delta/Wye switching. On the single motor Hooligan, I used a removable plug to switch from Delta to Wye. On this bike, I hope to install either blade switches or relays to accomplish the same thing.
Third, I have an adjustable throttle end point knob. This is a simple potentiometer mounted in-line on the blue throttle wire. It limits throttle end point and the controllers limit current accordingly.
Fourth, I have the controllers programmed for soft throttle response. This dampens the throttle by adding some ramp to it. This does not limit power. But, it does reduce the top fueler insane hit of the throttle and makes it come on more controllably.

Of course, many people will tell me to run a CA. However, this system would require using the 500 amp shunt. I have experience with this and the CA does not run properly with that shunt. I cannot get full power with it and I have to do a bunch of weird programming work arounds to get it functioning properly.

So, the above four items are my plan for this bike.

Matt
 
Just as a curiosity, would there be an advantage to using 2 smaller motors to get the peak power a little lower? I have noticed your go to motor seems to be the 3220 but as you keep saying the full use of that power would be hard to get to for any sustained period of acceleration due to wheelie physics. Would there be any weight savings or controller load advantage to using 2 3215s or 3210s to get the useable peak power somewhere closer to the full duty cycle of the motors?

It would be interesting to see if going sensored would provide the throttle control to output more power without killing yourself.

I also wonder if the suspension will make it harder to control the wheelies since the balance point of no return where you loop out is now dynamic. Hope you have some good leathers and a helmet! Thanks for testing these limits for us in an open forum! Can't wait for the videos.
 
Yes, that is correct. In fact, I have already spoken with astro flight about obtaining two 16,000 rpm 3215s instead of these 13,200 rpm 3220s. If geared the same, the controllers would have less load, I would save weight, and the torque would drop a touch. It would also cost less. However, they do not offer the 3215 with a vented can for fan cooling or the larger bearings for the 1/2 inch shaft. So, the 3215 would be compromised in this application.

I have not ruled out making my own fan cooled 3215 cans though.

The wheelie tendency on the twin 3220 20 inch wheeled bike I build last summer for a customer was very progressive with suspension. I think it actually helps soften the front end snap up a little.

Matt
 
izeman said:
twin motors looks very cool, and i like it. i know it's your bike, and you added all that bling on purpose. but just to show you what it would look all black i did photoshop it a bit :)


The build gets better and better :shock: incredible work the bimotor looks great :!:

I am with izeman :mrgreen: love full black bikes :wink:
 
chucho said:
izeman said:
i know it's your bike, and you added all that bling on purpose. but just to show you what it would look all black i did photoshop it a bit :)
I am with izeman :mrgreen: love full black bikes :wink:

I have a perspective that comes from decades of working on other people's bikes, many each day. To me, completely blacked-out bikes look one of two ways:

1) cheap, like a no-name eBay fixie, or

2) stolen and hastily repainted.

In this case I'd say swiping out the machined highlights makes it look cheaper and more homemade.
 
Chalo said:
chucho said:
izeman said:
i know it's your bike, and you added all that bling on purpose. but just to show you what it would look all black i did photoshop it a bit :)
I am with izeman :mrgreen: love full black bikes :wink:

I have a perspective that comes from decades of working on other people's bikes, many each day. To me, completely blacked-out bikes look one of two ways:

1) cheap, like a no-name eBay fixie, or

2) stolen and hastily repainted.

In this case I'd say swiping out the machined highlights makes it look cheaper and more homemade.

I like the more blacked out look but taste is subjective. What this and most other bikes of this type need is some contouring of the side panels to add some depth and interest. It is the large expanse of flat side panels with hard edges that makes these types of bikes look homemade. Stamped or moulded side panels and even some graphics would help this.
 
+ 1 to the above post :mrgreen:
 
I am looking into a few options for this bike. It is funny, even using tiny RC components, I am having a hard time finding room to mount everything. The tiny Edge controllers are even tough to mount.

I believe I have maxed out the power density on this build.

Matt
 
I know what I like and don't like, style wise. But when it comes to high-end low-production hot-rod E-bikes...I don't think anyone has as much "hands on" experience with top shelf customers as Matt...I am certain of it.

When it comes to the finishing touches, I am going to trust whatever Matt decides concerning the style. This is definitely an assault rifle, and not a plinker. Matt will be the first builder to have three custom E-bike features in electricbike.com...

https://www.electricbike.com/50mph-monster-electric-trike/

https://www.electricbike.com/matts-astro-hooligan/
 
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