20 inch full suspension twin 3220 build begins!

recumpence

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For those who are reading this thread for the first time, this bike has now (9-22-12) been sold. It is being built up with two 3220s. The following text is about the original plan for me to build this bike with one 3220 for myself. However, the bike is now sold and I am building it for a high-end client. If you would like to begin with the new layout twin 3220 build, that part begins on page three. :)

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Hey Guys!

This started way back when I built the PK Ripper BMX bike. That bike was far more fun than any other bike I have built. However, it was too short (wheelbase) and had no suspension. I have had many requests for another 20 inch build and I began moving in that direction when I built the Cannondale Hooligan (Crimson) late last year. That bike looked to be a perfect candidate for an electric conversion. However, the lack of rear suspension was an issue as was the seat to rear wheel relationship. That bike is VERY wheelie prone. That is fine for pedalling, but not for high powered E-bike work. On top of all that, I had this Diamondback X6 frame sitting around (built by Intense Racing back in 99). This frame was bought for its perfect frame setup. There is room in the triangle for lipo and a high, round downtube for drive unit mounting. It also has a great swingarm for left side chain clearance.

That brings us to last week. My work has slowed down and I have been looking at various projects. However, money is tight. So, I did not want to buy anything new. So, I began doing some calculating and figured out that my X6 frame would work if I used a longer shock (I had one lying around) and flipped the shock linkage upside-down. This would drop the swingarm to the correct level for a 20 inch wheel (to have the proper crank height). So, I took my beat up X6 frame to the powder-coater for some gloss black and promptly disassembled my Crimson red Hooligan. Then I built up this bike with those parts and we have what you see here.

When I reconfigured the frame for 20 inch wheel use a couple cool things happened. First, the rear end is plenty long. This is great for a forward CG. It also rotated the frame forward, thus steepening the head tube angle. This sets up the geometry for proper road riding. I think the head tube angle looks a bit too steep. But, the bike handles phenominally like this. The wheelbase is also longer than my Hooligan (way longer than a BMX bike). This makes the bike far more stable while retaining sharp steering with the steep head tube angle. The forks are White Brother's Groove 180s shortened to 4 inch travel for me by White. The brakes are Hope 2 piston units. I may to to a 4 piston up front. We shall see. The wheels are Industry Nine custom items using my 47mm wide rear rim. I have another set of wheels like this that use standard spokes and hubes. I may use those and save these to put back on the red Hooligan as a peadl only bike. I have to see how things go with these wheels.

You can see the HUGE amount of room under the down tube for the drive unit and plenty of room for lipo. Four 6S packs will reside inside the frame triangle while I am considering a bunch of 3S packs (configured in 12S layout) on each side of the frame with side covers to protect them. That will keep the overall width reasonable and give me plenty of range.

The drive will be a 4 turn 3220. This is the most powerful motor I have run that is absolutely 100% reliable. I could go higher power like a 6 turn Delta. But, that would be a bit too much power and would be a bit hard on the controller at partial throttle. This setup will be good for a reliable 9,000 watts without any reliability concerns. I honestly think I will need to dial out the wheelie tendency with the slipper clutch as it is.

Anyway, I will be working on this bike a little at a time over the next few weeks. I am guessing about 2 months to get it running.

Matt
 

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As a small wheel converting wacko,
I love the look of the bike already. :D
Cant wait to see it adorned with all the sexy parts that you produce.
:mrgreen:

*edit*
Love the all black, red spoke, color theme.
 
Hi Matt

That was a beautiful bike....actually even better..... :D

Sincerely, yes, It looks too step to me.....but is really hard (at least for me) to judge the geometry of such a strange machine without ride it, and I've not that big experience in riding 20" wheel bikes other than BMX.

As you point out more than one time, a dedicated 20" FS frame should be the best way to realize such kind of machine....My thought is that an adjustable platform with some slope adjust, a BB high adjust and slide Dropouts should makes life easy for this bike concept, the only hard choice to do concerns the SA pivoting style and the prevalence between the pedaling side and the motor side....I think there's not a true solution there, It's easy to figure out that a dual input bike is forced to sacrifice efficiency (in an extended meaning) to one side as the other is improved.

I would like to work on a design for this, With your hooligan and this Intense builds you changed a bit my point of view, typically I'm not in love with small wheels bikes, I love 29ers and these 27.5ers that should be pushed-up by the Majors soon.....(they have millions new frames to be welded and try to invent stuff for a saturated market... :) )

Jules
 
The bike actually rides wonderfully. I think part of that is the rigidity of the frame, forks and wheels allowing the steep head tube angle to work. The wheelbase is also longer than a typical 20 inch bike and the forks are a touch heavy. This slows the steering down a touch. I have ridden it fast no-handed without a problem. My mountainbikes can get the headshake wobbles when I do that, but not this bike. I just think it looks odd. Call me crazy but I like my bikes (and any other projects I build) to look correct.

Like I said, it rides wonderfully! The steep head tube angle sharpens the handling that would normally feel sluggish. Whenever I build a bike with wide tires and heavy forks it steers heavy. Not this bike!

I am getting used to looking at it like this. I wish it was one degree shallower just for the look.

Remember, small wheels put far less twisting load on the frame and fork. They also flex less by their very nature. Beyond that, disc brakes are far more effective with smaller wheels. Also, small wheels allow much more room in the frame for electric components. This makes small wheels and ideal choice for a dedicated electric bike, or at least a dedicated electric agressive streetbike.

Anyway, yes, I would love to see a 20 inch electric frame made with the artwork you apply to all of your bikes.

Jules, your frames are absolutely beautiful. If I could have my wish, it would be an Ogre frame (or another frame that looks extremely technical) height corrected for 20 inch wheels, with these forks, and my new drive/motor setup.

Oh, Man, now I will have a hard time focussing on this bike since I have an image of a 20 inch Ogre in my head! :wink:

Matt
 
I could be wrong here, I am not an engineer. :wink:
I dont think the geometry of the bike has changed.
Steerer angle should remain unchanged, with 20" wheels.
Only ground clearance & overall length should be affected.

I think it looks fabulous. Unique compared to every other eBike/pedal bike.
bzhwindtalker said:
best streeT supermoto in the making? I like this frame, seems like designed to hold lipos :!:
+1

recumpence said:
...
Like I said, it rides wonderfully! ... :wink:
Matt
Thats #1.

#2 is appearance, and I think you have that nail'd as well.



recumpence said:
...
Remember, small wheels put far less twisting load on the frame and fork. They also flex less by their very nature. Beyond that, disc brakes are far more effective with smaller wheels. Also, small wheels allow much more room in the frame for electric components. This makes small wheels and ideal choice for a dedicated electric bike, or at least a dedicated electric agressive streetbike.
...Matt

Yup :wink:

I cant wait for more.
:mrgreen:
 
The rear was raised three inches and the front was dropped six inches. That rotates the frame forward. That being said, the head tube angle was far too relaxed for a streetbike before.

Matt
 
recumpence said:
The rear was raised three inches and the front was dropped six inches. That rotates the frame forward. That being said, the head tube angle was far too relaxed for a streetbike before.

Matt

Apologies Matt, :oops: I am paying attention, just confused two threads there for a minute.

recumpence said:
Hey Guys,

...

That brings us to last week. My work has slowed down and I have been looking at various projects. However, money is tight. So, I did not want to buy anything new. So, I began doing some calculating and figured out that my X6 frame would work if I used a longer shock (I had one lying around) and flipped the shock linkage upside-down. This would drop the swingarm to the correct level for a 20 inch wheel (to have the proper crank height). So, I took my beat up X6 frame to the powder-coater for some gloss black and promptly disassembled my Crimson red Hooligan. Then I built up this bike with those parts and we have what you see here.

When I reconfigured the frame for 20 inch wheel use a couple cool things happened. First, the rear end is plenty long. This is great for a forward CG. It also rotated the frame forward, thus steepening the head tube angle. This sets up the geometry for proper road riding. I think the head tube angle looks a bit too steep. But, the bike handles phenominally like this. The wheelbase is also longer than my Hooligan (way longer than a BMX bike). This makes the bike far more stable while retaining sharp steering with the steep head tube angle. The forks are White Brother's Groove 180s shortened to 4 inch travel for me by White. The brakes are Hope 2 piston units. I may to to a 4 piston up front. We shall see. The wheels are Industry Nine custom items using my 47mm wide rear rim. I have another set of wheels like this that use standard spokes and hubes. I may use those and save these to put back on the red Hooligan as a peadl only bike. I have to see how things go with these wheels.

...
Matt


I think most important is that it feels stable & handles well,"fun".
Sounds like you have that.
Maybe hit some big hills see how it "feels" @ speed.

Sorry for geometry confusion.
 
Very much looking forward to seeing this one completed. I loved your PK Ripper build, but this is going to be even better!
 
Forks looked a little steep to me Matt, but i put a book under one end of the laptop and its sorted, carry on! :D
 
Being serious though, it does look a little steep but i am a fan of quick steering, if it feels stable enough and right on the road go with it.

Simon
 
I think the head angle looks aesthetically fine Matt. The fact that its got sharp steering but stable at high speed certainly suggests a good mechanical compromise has been met. Perhaps a 24" front might work too if you just want to lift head angle a bit.
 
Kepler said:
I think the head angle looks aesthetically fine Matt. The fact that its got sharp steering but stable at high speed certainly suggests a good mechanical compromise has been met. Perhaps a 24" front might work too if you just want to lift head angle a bit.
Good call.

I may go to 24 inch wheels front and back and rotate the frame rearward a touch. But, I really want to stay with the 20s if at all possible.

I need to do some 30+mph testing. It rides awesome at 20mph. It corners like a freakin 125cc sportbike.

I am getting used to the look. But, again, it is a touch steep.

I will keep you posted. If nothing else, this will be a wonderful test bed for some cool stuff I cannot tell you about just yet. :wink:

Matt
 
MadRhino posted in a thread awhile back about adjustable angle headsets. Might get you 1-2 degrees improvement in angle, if all the parts fit. I can't find the post, but a quick Google search finds results from FSA and Cane Creek. From his post it seemed he has experience with adjustable angle headsets, maybe PM him for more info?
 
MattyCiii said:
MadRhino posted in a thread awhile back about adjustable angle headsets. Might get you 1-2 degrees improvement in angle, if all the parts fit. I can't find the post, but a quick Google search finds results from FSA and Cane Creek. From his post it seemed he has experience with adjustable angle headsets, maybe PM him for more info?
You mean this one....
http://www.canecreek.com/component-headsets?browse=Complete&name=AngleSet
 
morati said:
MattyCiii said:
MadRhino posted in a thread awhile back about adjustable angle headsets. Might get you 1-2 degrees improvement in angle, if all the parts fit. I can't find the post, but a quick Google search finds results from FSA and Cane Creek. From his post it seemed he has experience with adjustable angle headsets, maybe PM him for more info?
You mean this one....
http://www.canecreek.com/component-headsets?browse=Complete&name=AngleSet

Sweet! I am a Cane Creek dealer. I will contact them tomorrow.

Thanks for the tip!

Matt
 
It looks great to me Matt. Cant wait to see it rippin!
 
Nice to see another one of your builds starting, Matt.

Are you going to run it through the gears, or use a single ratio setup?
 
Good question.

I will probably do a single ratio to start with. It will be 9,000+ watts. With a short, light bike, single ratio will be fine.

I did some measuring and the headtube angle is identical to my titanium hardtail mountainbike. So, it is not crazy steep. I do plan on getting the adjustable headset, however.

Money is tight right now. So, the build may take a few weeks to really get underway. But, It will happen for sure. This will be my summer bike. Acutally, I plan on making it an ultra light motorcycle with pedals. The bike is so freaking stout, that I cannot help but move it in that direction. I want to see how motorcycle-like I can make it while remaining under 70 pounds. If I have to, I will go up to 80 pounds. But, that would be pack size dependant. I will start with 1kwh of battery and see if that is enough for my riding. If not, the weight will go up to add range. But, I am committed to making this a true light streetbike/motorcycle. I want the chassis, wheels, brakes, electric system, etc to all have headroom I.E. I want to make sure nothing is overstressed. I want to know I can beat on this bike, hit rough pavement or small potholes, do some trail riding, aggressive street riding, and have the bike survive.

This is my new flagship build. It will be for sale as well, but not until I have learned what I want to learn from this build.

Matt
 
recumpence said:
......This is my new flagship build.....
Matt

Ah cool, like the enterprise..... Will you be incorporating any transparent aluminum into your design.... :D
 
Hobbit said:
recumpence said:
......This is my new flagship build.....
Matt

Ah cool, like the enterprise..... Will you be incorporating any transparent aluminum into your design.... :D


Ahh, spoken like a true Treky!

Matt
 
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