Evolution of Skill....

Hello all.

After becoming completely obsessed with e-bikes several years ago, it appears as though I have finally come to the conclusion,once again, that there is nothing quite like a light,fast electric bicycle.

It has been quite some time since I have been active on the sphere with any frequency - upon the completion of my last real high speed bike, I was ready to do something more... I quit my job, attended school for EME, and even tried retailing ebike components.... In the mean time, as garage projects continued to pop up, it became apparent to me that with all of my projects, the main limiting factor in the execution of design ideas was my inability to weld. I bought a welder. I welded,I learned. I went to classes. Time passed.

Much has changed since I have left - here on the Sphere, (and in my personal life), but one thing has remained. I am meant to spend my free time working out the designs of stronger, more efficient ebike designs based on the easy-to-build- around hub motor so many folks look to install on their own bikes....

Non - Frock? My machining tools include a drill, a file, a cut off wheel, band saw. I regularly get Optibike updates.. 12k for a new 850R? 6k for a used bike? Yeah. One can by lots of energy density (batteries) with that kind of fundage.

So having spent some time away, I have been pouring through posts-seeing what is new, looking at my old fast bike
http://endless-sphere.com/forums/viewtopic.php?f=6&t=2389&hilit=formal+introduction, and looking at chassis/swingarm platforms members have designed here for inspiration..

I cant believe that thing has held up for 4300+ miles at the speeds I was traveling....

Enough story telling - next post gets into it....

So I have spent the last several years learning how to weld adequately. Been building ICE motorcycles - bobbers...

My biggest personal quandry when figuring out where to start is
1. Do I build the X5 around a bicycle platform?
2. Do I build the X5 around a motorcycle platform ?

Bicycle frames are not designed and engineered with the consideration of running with a 20-25 pound hubmotor/wheel. Period. As always, this has implications when mounting the X5 on a bicycle frame of any kind. The other big issue is trying to mount batteries in a bicycle frame not originally intended to do so.

I need a STRONG swingarm. I need a frame that is STRONG, and designed to carry batteries, controllers, etc, within it.

So I have concluded that given the hub motor rear wheel weight, I need a motorcycle - strength swingarm. I am going to start with this and modify it to work with the frame. Honda CR80 rear swingarm....
View attachment 2



I have also concluded that a moncoque frame is the best solution for an integrated system that serves as a chassis design and battery compartment. Nothing new here, already been done. Just want something that works well as a designed system...


This bike will be heavy. More of a moped than bicycle, but certainly lighter than a moped....

My intentions are to incorporate a level of strength and rigidity into this design that just cannot be recognized using a bicycle frame as a starting point. It will be juiced at 74v/20ah. I need to have a range of 30 miles. My current 74v/10ah set up @ 20mph gives me right around 22 miles (with a few WOT's). Should be able to reach my goal easily. Year round travel, completely weatherproof, discs, etc.

I thought at length about perhaps purchasing Markcycle's new 6 series motorcycle-class hub motor, but my end conclusion was that it would require just too much energy to propel it at the speeds and distances I am aiming for.

The sweet spot is what I am after......

Len

Sounds like you are doing what I've been fantasizing. A "bike" frame with a motorcycle swing arm could handle hubmotors even more powerfull than x5. 8)

Goes without saying also, rims and tires from a motorcycle too.

dogman said:

...... rims and tires from a motorcycle too.

Click to expand...

Dunno yet - there will be some heavy duty downhill bicycle parts on the bike. I have to re-lace the motor to a rim of some sort, but I really don't want the additionl rotational weight of mc tires and rims at the outer edge of the wheel.

My first inclination is to use 36 hole downhill rims - 26". There are a few urban assault tires (panaracer Uff'da, maxxis hookworm) that could hold up,potentially...

Added to the list - weight comparison of heavy duty bicylce rim/tire set up vs light duty mc rim/tire setup...

again, the key is gonna be findidng the level of build-out that fills the gap between down hill bike and moped/small mc...

Len

i dont think it has to be heavy.a aluminum swing arm doesnt add much.and you can use angle aluminum plate to build battery compartment.looks like an exciting build .

Hub motor is out of the 26" hoop.
She' will soon be heading west along with a new front disc hub to be built by one JRH....

Have the fork in my hands, but still need the wheelset before real frame mock up begins. Still kinda sketching design for the trellis frame idea I have floating around in my brain... Also need to fab up a frame jig. And retro fit this old 5303 to disc. And....and....and....

Ebike building gnomes are starting to poke their heads around the corners in the house here again.....

Len

Man I gotta say congratulations to those fabricators out there that have built e-bike specific frames from scratch. This takes alot of planning. And trial n error, and expense, and etc.

In the long run, I know it is cheapest just to pay for a frame built by more qualified individuals that have gone before me with commercial success with their designs.

That said, I have metal tubing ordered and en route to the house. Let the games begin....if I crap the bed on this project, I will appreciate purchasing someone else's hard earned end results that much more.....

I am going to be using mild steel, not chromoly. Using a mig welder at the house here, some of my buddies suggested I use mild rather than cromo if I am not going to TIG. Gonna be a heavy, robust frame.....

Main tubes - 3/4"X 3/4" X 1/8" erw square tube
Head Tube - 1 1/2" OD X 1.334" ID DOM round tube.
Tubes ordered from: http://www.speedymetals.com/c-8242-round-tube.aspx?pagenum=4

the DOM round tube I am using looks like it will work for head tube stock; the ID should allow me to use a standard 1-1/8" external head set (maybe a little extra grunting with the headset press).. At this point, it appears as though the only bicycle - specific tubing i will need will be a BB shell...As far as gearing, by my calculations, no matter how many volts I throw at a 20" wheel, I am not going to see much more than 35 mph. With a 50t front/16t rear big ring set up on my last bike, I was out of effective pedal input at about 22mph. I think this time around I am planning on a 44t front with and 11/28 5 speed rear freewheel. That way I can bag the single rear/double front two speed setup I was running on the stealth bike...

Going to go with a trellis frame design, and create a cradle system inside trellis for batteries. Initially I am going to be running my current power supply, 74volts/10.5 AH of LiCo. I am going to be sure to design the frame with ample space to increase the amount of energy/pack size as needed/wanted...

Rear 5303 hub has been laced by JRH to one of his 16" moped rims. Since this is an old version of the motor, I need to dig up any old threads relating to converting to disc. I read a few a while back, but if anyone has a better memory than me, feel free to post up links... Tire selection - 2.4 chunky bmx trials tires to start . I chose these rims due to 1.) their strength over bicycle rims and 2.)versatility with running either bicycle(bmx) tires or moto/moped tires are high speed or demanding applications. I was not too keen on running such a small diameter wheel to begin with, but I think I can set up this suspension to be super plush....Batteries/tires/controller decisions will be changed as the amount of pack energy changes are made, WAY down the road from right now...

Was kind of bored sketching frame plans tonight, so I mocked up my bits and pieces. Cardboard cutout of the main triangle is the exact size of the front triangle on my old fast ebike FS frame, but just as a reference point. The overall wheel base is going to be longer than my last ebike, and I want the bike to be somewhat lower to the ground while maintaining adequate BB/crankset clearance on 20" tires.....Appears as though determining the COG is pretty important for the front and rear suspension to work well with each other...Some pics:

Lenk42602 said:

Was kind of bored sketching frame plans tonight, so I mocked up my bits and pieces. Cardboard cutout of the main triangle is the exact size of the front triangle on my old fast ebike FS frame, but just as a reference point. The overall wheel base is going to be longer than my last ebike, and I want the bike to be somewhat lower to the ground

Click to expand...

I realize nothing is carved in stone yet, but do you have any idea what your wheelbase & chainstay length (BB to rear axle) will be?

Looks good. Thanks for all the details you provide, as this is going to be interesting watching you build from the ground-up, Ooops, wheels-up. :lol:

Kool build. 8)

wheelbase looks ~ 48"

Swing arm (chainstay) ~ 20"-22", maybe a little longer.

depends on exactly where the optimum swingarm pivot point is...

Len

Couple of updates:

My 16" wheel arrived from John yesterday. What you see here is a 5303 (old style) laced to a steel 16" moped rim, 1 cross. He did a great job. Thanks John! Tires are BMX, 20" X 2.4", these: model IA-2021 - http://www.innovatires.com/menu.php?xCPId=B06
......for now....

View attachment 5



3 years later, I am finally taking Ypedal's advice and getting this 5 series into a smaller diameter rim!

Other goodness that showed up today.......

METAL!

Square tube stock:


Round tube stock:


Was worried I might have an issue with the ID of the tube and the OD of the headset cup, but we are good to go...BTW, that line is one of Jake's dog hairs, not a crack....



FSA DH PRO headset. All steel construction - cups, races, sealed bearings. Heavy as snot...So heavy in fact, it altered the magenetic field around the camera causing blurriness.....



Later

oh, just in case,

this is jake. my assistant.



later

awwwwww what cute Jack Russel...is he a yappa or a well behaved pup?
You sure jake is the asssitant and not the supervisor? My Pit Bull and Bull Terriers
seemed to think they were Supervisors whenever i was doing something,
couldnt do it without tripping over them. hahaha...

Best of luck with the build... *subscribed

KiM

It may be merely optical, but, that square tube looks to be VERY thick wall (heavy). What wall thickness is it?

Matt

....I am going to be using mild steel, not chromoly. Using a mig welder at the house here, some of my buddies suggested I use mild rather than cromo if I am not going to TIG. Gonna be a heavy, robust frame.....

Main tubes - 3/4"X 3/4" X 1/8" erw square tube
Head Tube - 1 1/2" OD X 1.334" ID DOM round tube.

Click to expand...

Frame building is as much "art" as science or engineering.
It takes a lot of experience to get the proportions and tube sections optimised for strength, weight and of course ...looks :lol:

Looks good. I'm interested to see how this turns out because I'm planning something a slight step up from that. Something still inbetween an ebike and a motorcycle, strong and stable enough to withstand sustained highway speeds, but light enough (custom chromoly tube frame) that at least the frame will be lighter than a motorcycle. As long as I can get it past MD motorcycle inspection it's good to go. Then no limits on where I can ride it or how big a motor I can put in it.

Wow, 1/8 inch wall is VERY heavy tube. I would recommend going with slightly larger diameter tubing with far thicker wall. I prefer 14 guage wall tube.

I like the looks of the bike, however!

Matt

Ah, yes, sorry. I meant to say "Thinner" tubing.

Your tube will work fine. It is just that you will add alot of weight to gain strength rather than being lighter for the same strength with larger diameter, thinner wall.

I am not trying to be a Know-It-All. I just figured you are going to do much labor on this bike and if something can be improved, you may as well do it now rather than later.

I am a big fan of 3/4 inch square tube, 14 guage wall. 1 inch is good too, but may be overkill depending on the application.

Matt

Matt,

This is going to be my first foray into building a frame, so all of your suggestions are welcome.

Since the material is already here, I will give it a go. I plan on using gussets, so perhaps a thinner wall would be optimum.

All the tubes will be precut and fitted prior to welding, so if the design proves strong enough to use lighter tubes, I can just order additional thinner tubing and recut all the pieces. We will see how much of a pig this thing ends up weighing and then go from there... I figure I could lose 2-3 pounds of weight by just using a thinner wall tube considering my estimated linear feet needed...

keep the input coming!

Len

Manged to cut to length, ream and then face the head tube at work today. The ID of the head tube stock required a little bit of hand milling with our reamer/facer. I pressed in the cups to check that they would install correctly and then knocked them back out until the welding phase is over...




God bless park tools...

Next few days off - picking this up over the week-end so I can get started:


later

Spent all day yesterday cleaning out the basement so I can have a place to work that isn't in sub freezing temps like the garage...

Funny, but you never seem to calculate all the peripheral work associated with building something, like gathering 12 bags of garbage and empty boxes just to create some space to work .....had to be done sooner or later I guess...

Got the saw set up, uncovered an old dining table that will be my jig table. Since our forum was down these last few days I was forced to look elsewhere for my fix. I went over to rat rod bikes looking for frame jig ideas - low and behold I find our very own AJ build thread... Brilliant idea, he used a weight machine frame for the basis of his jig....
http://www.ratrodbikes.com/forum/viewtopic.php?f=48&t=31200

Take a guess what else was laying in my basement?

Close to finalizing the main frame triangle dimensions/configuration:


Considering I am going to use what I currently have for batteries, the dimensions for Lipo packs, dewalt cells, PSI cells, etc., I am trying to create enough interior battery space to be able to upgrade to any of my choosing, while not exceeding 115 mm at the frame's widest point....I am easily at 15 pounds with the length of tubing required to build the frame as it sits .... :lol:

so now that the workspace is clear,

- jig set up,
- swingarm modification,
- then I begin cutting tube sections to length...

Hopefully I wont be posting any pics of cardboard!

Lenk42602 said:

I am easily at 15 pounds with the length of tubing required to build the frame as it sits .... :lol:

Click to expand...

So I actually added all the 1/8" wall tubing lengths up tonight for the frame and came up with 19.5 pounds! This is without the swingarm, monoshock, gussetts, etc .

Decided to follow the sage advice of Matt (recumpence) and ordered enough 3/4" " 14 gauge tube for the job. This should keep the weight around 15 pounds for the same design, maybe a little less if I can trim the at a bit.

Len

that radrodbike thread is actually aussiejester here in ES!!!!

nice build so far!!

been playing around with this software - you can download the demo version for free, but the actual software allows you to pinpoint exactly where your pivot points should be on your suspension set up based on the simulator...

http://www.bikechecker.com/home.phtml

pretty neat. gets me closer to the summit. thinner wall tubing showed up today, and I have made a few passes on the saw to get it set up and running correctly. I am so glad I have that thing....was actually considering a hacksaw for all this tubing...





So the lower swingarm pivot will be above the bottom bracket shell, and I am incorporating 3 separate pivot locations along the pivot arc in 1" increments. On the upper shock mount, I am also incorporating two different mounting locations ~ 1" apart (three if I have room) in order to allow me some latitude for factoring sag, spring rate, impact on head tube angle, bb height, stroke travel optimization, etc...


Gotta get the back wheel converted to a disc set up soon. Swingarm gets built around the final conversion....


later

Len

So I laid out the entire main frame dimensions. All tubing sections lengths/angles are measured and ready to be cut on the saw.

Saw is working pretty well - used some of the heavier gauge square tubing for set up and to practice mitering angles. Plan on cutting the actual .083 wall tubing for the main frame this friday. Seems like the real benefit over any hand held saw is consistency... and no sweating involved...

While working on the crankset width dimensions, I was looking at different bicycle tubing frame suppliers for a BB shell. However, after some thought, I realized that the due to the ID, the round tube stock I am using for the head tube could just be cut to length on my new saw, and then faced and threaded at the shop. Voila, heavy gauge bottom bracket!

Cut the round stock on the band saw to ~ 72 mm here at the house:



Then I headed off to work today.... Used the Park bottom bracket thread cutter tool on the section of tube. Afterward, I faced the outer edge so that the BB lip has a good purchase with the outer edge of the BB shell. The old 68mm bb laying in the photo in the background threaded right in just like butta...Can't believe it! Looks like its gonna work!




later