1982 MB-5 HubmonsterHE build (98% done and running)

[Spacey]

Edited previous reply...both

http://upload.wikimedia.org/wikipedia/commons/0/09/Honda_MT50.JPG

[hillzofvalp]

Was it the wife that sold the ar80? Or what? What were you thinking...

[grindz145]

Hahah I was harsh on LiFePO4 (and admitted it in the thread) mostly because some of those moped chumps were pissing me off.
But seriously, if you're going to make a build of a small motorbike like this, why bother with something that has pathetic volumetric energy density. Cycle life is a beautiful thing, but unless you just want to pack the thing full of cells, which would look ugly, LiPo is a better option.

[hillzofvalp]

I'm getting my cells for super cheap.. that's the only reason why, really, except that with BLDC I like to have consistent top speed. the curve of lipo seems too steep for my interest, for a sub-100V 4110 bike that is already barely getting 48mph in this configuration. I'm using cylindrical cells so they will take better form than lipo with such small space, but certainly vastly more difficult to package and prepare.

[grindz145]

Don't get me wrong those A123 pouch cells are awesome. I've even considered them for the Magnum build. It's just not succinct with my vision for this build. I have no distain for any particular chemistry blindly. It's just that it's hard to have an intelligent conversation over there at the mopedarmy:)

[hillzofvalp]

I got it. Start a thread on your build. we need more of these going on this forum.. tomorrow I'll pick up the frame and post pictures and mockups. I hope the frame is perfectly sized to fit cells side by side inside (13-14cm wide)

[grindz145]

I will once I actually start something. This will be a fall project. Too many other things going on right now. Nobody wants to look at a thread with a pile of parts for 2 months

[hillzofvalp]

this makes me so happy: (125cc tuned variant of the mb-5 or mb-8 platform)

at :33 he starts. Pretty peppy! but not as peppy as cromotor!

[Haste]

I just grabbed a full rigid pinto frame(very rare)



I was thinking...it will be around 500 to fully build it up....

how much will a cromotor set me back? And where are you getting those batteries so cheap? I would build a brace where the motor normally mounts up and keep it compact..i believe it could be pulled off very easily.

[hillzofvalp]

That thing is pure chick magnet. No place to put the lady though!

my source is out of batteries, otherwise I'd tell you. Cromotor is ~$600. I sort of wish I had the higher KV version for this application.. cause 28S A123 is manageable with two hyperions... but only enough to get about 50mph in a 21.5" wheel. we will see how light I can get this thing.... some day if I'm not happy with 50mph I might just throw on a bigger controller

I'll post pictures of the frame tomorrow. I'm pretty excited to explore the possibilities with it..

Even considering putting the batteries deep in the frame and leaing the front lower area for stealthy stowage for groceries!

[hillzofvalp]

The "dropouts" are 12.5mm.. but it is made of 4-6ply steel that has been pressed together (about 1/4" thick). Also, the end is not open.. very similar on motorcycles... so I would have to probably cut the tips off or install one side of the axle first. I would definitely be welding the torque plates on the inside if I was to use the cromotor... we will see. I might have to just get a scooter hub with the correct axle.

rear spacing is 180mm! The cromotor is a little on the wide side when spaced.. around I think 145mm. can't remember. so we're looking at .68" pinching torque plates on each side.. Or bending the swing arm first and using some smaller torque plates.

update: just figured out that if I leave it as is and add torque plates .68" each on the inside of swing arm, the axle will protrude enough on each side enough to fully thread each nut on.. but not very much passed the nut. I would have to probably leave out unnecessary washers. Would the pinching torque plate be enough to not require lock washers? would it be okay if I only engaged nut about 75% with the largest diameter nord locks installed?

feel free to chime in if you know anything.. johnrobholmes would:
-would you recommend any pre built front motorcycle wheels (16-19")? (i might run the original, but I rather the front and rear match) (disc brake compatibility? no idea)
-scooter/moto cycle hubs that are disc capable?
-recumpence rims a good idea? build will probably be 140-180lbs. I'm 200 lbs.

[hillzofvalp]

To break 60, I'm really going to need at least 32S m1. I'm going to have to get a new controller. Stick with 24 or 36fet Infineon? What about kelley kbl? I'm thinking future proof for 20kW.

[hillzofvalp]

Maybe Ishould just buy a custom front wheel pre made.... and order matching spokes and rim for the cromotor:

http://www.radmfg.com/RAD-Front-WHEEL-K ... 85100f.htm

[hillzofvalp]

Mb-5 pron (especially the unoccupied bike):



In other news, I have contacted all cell for PCM material for battery modules. I figure it will make life much easier during tab welding and waterproofing.. .just as we did on our go kart and my friend's motorcycle.

Building one of these bikes from the ground up isn't all that difficult.. because hub motor leaves the rest of the frame for 50 lb battery pack... and front ends and headsets are readily available. This bike may actually cost less than my 29er from a rolling chassis standpoint, but still outperform it..

I will raise the rear end a bit so I can carry a 110lb woman on the back.

[hillzofvalp]

Little update:

Cells are on the way.
Driving to Chicago to pickup some raw PCM blocks which I will mill into probably 7 5.75x9.5" 12p4s modules.
Formex on the way.

I modeled the pack with drywall because it w a cheap option. The home depot guy helped me for a half hour cutting out thinner variety which stacks to be about 2.6" which is perfect for 65mm modeling. It's looking good. Pack should attach too original motor mount. Should be around 60lbs when it's said and done... Kinda worried I may not be able to make this a lighter machine than the original. We will see after I gut the gas tank and have everything assembled.

Is anyone against not heat treating the Spingarm after having torque plates welded to it? It's a weird layered steel.

How will a vented cromotor behave in 23" wheel at 50mph with continuous output of 5.5kW?

Do you think the cromotor is up to the task? Should I consider reinforcing the axle somehow to protect against breakage or at least ad a safety mechanism so i can keep the bike under control? A new axle is something I'll consider. Wish I had a drawing of the original one,

[hillzofvalp]

One more module (7 total) will go in front of the rear tire. drywall stacked this way came out to 66mm, which is a good approximation for 26650 modules with nickel and garolite sandwiched in between. It's easier to work with than you would think, and a good, rigid alternative to cardboard. it cost me $5. I think I already said that.

The frame is painted and taped weird because I was trying to stich it well to make a 3d model with 123D catch from autodesk. Turns out that software doesn't really like structures like this, unless you get the lighting perfect.

[Drunkskunk]

I'm really curious how this will turn out! I'm an MB5 fan. I had mine up to 60mph this weekend with the new pipe. If you can beat that, I may convert mine to Electric

If I can make a sugestion on the rear swing arm, the rear wheel sits far forward. it makes for some strange handling quirks at high speeds and makes the nose feel light unless you ride in a tuck at full speed. Not a big deal, but I can feel the diffrence between the axle al the way forward and aall the way back in the adjuster.
I'm planning to extend my swing arm 2 inches, and you may find that adding some material to yours makes it easiet to also modify it for the spacing you need.

I'm watching with intrest to see wht you find for a front wheel. I suspect a CR80 17" from the mid 90s should fit backwards, with the disk, but I haven't found one to measure yet.

[hillzofvalp]

Awesome! Keep the tips coming! I'd be thrilled to hear more about your experience with it.

Do you think it would be worth just making a new swing arm out of a block of aluminum (free block)? Probably takes too long. Have you welded it before? What kind of Steel is easiest to weld on it? I have to add two .675" thick torque plates to the inside. In order to get to cromotor spacing. I want to use doctorbass plates but they're only .375" thick. This is where a custom swing arm might make sense.. And maybe even make it a unishock


With a 23" wheel it might do 50-52mph. With field weakening on, I may get it up to 55. I am limited right now by the controller (18FET 4110 to start).. So now is the time to convince me to buildit into a higher voltage pack. Also, balancing with hyperions is easiest at 28s...

But I have some linear bms boards that will allow up to 36S.

Edit: I can always go up to a higher kv hub I guess...

[Drunkskunk]

Milling down a block of Aluminum would be awesome, but expensive and hard, and heavy in the end.


However, the CR80 from the late 80s (big wheel) is a little longer swing arm, and monoshock. you would just need to weld a mount to the center spine on the frame. Lots of pics on google of it done to MB5s.




Actualy, thats the bike from the bike pron pic you posted, the unoccupied one

[hillzofvalp]

Love that bike. Actually, right now with the batteries the way they fit, I'm not sure a mono shock would work.. I would have To make a smaller pack. Do you know how far the mono shock goes? See my above pic. While looking at it, also please tell me what the different threaded holes are For on the top tube. I was given a bare frame. Also where does the gas Tank bolt on? How hard is it going to be to gut out and still retain all mounting locations?

I have free aluminum and I work on CNC machines for a school job... A great time to knock someting out with my own tooling is before school starts... But problem with the new swing arm is that i wouldn't trust it! I guess I can over engineer it.

Any real advantages to a mono shock?

I like your idea of just extending the stock shock. Mucheasier setup and safety features. I can bolt on the torque plates to the existing dropouts, get them adjusted and at the right length, then have them welded.the bolts I can leave in as extra reinforcement in case of a weld failure

[hillzofvalp]

I just noticed that the flats of my swingarm are not parallel. They are angled away from each other.. Wider on bottom then on top. Are yours lik ethis too? I would have to make a .5-1.5 degree angle compensation on the extensions to ensure that I'm not snapping axles

[Drunkskunk]

My swing arm is perfectly parrallel. yours may have gotten tweaked at some point.
No bigl advantage of a monoshock at 50mph. it just lets you use the ready made longer swing arm. but it looks like it would go too far forward.

The holes in the top tube, left to right. the square bracket with the single hole is the top mount for the air filter box. the rectangle bracket with 2 holes is the mount for the ignition coil. On the oppisite side, the hole is for the bottom mount of the oil tank.

The gas tank mounts to the two threaded holes in that hump between the top tube, and the two downtubes. The tank sits on rubber pads there. At the rear, it mounts to the two non threaded holes on the arch that goes over the back wheel. (not in that picture) it uses some tiny #6 bolts with rubber grommets. There is also 2 rubber blocks that the tank sists on for support under the seat. those blocks are held on buy pressfit tabs on the flat part of the rear tubes, into the two non threaded holes on either side.

[hillzofvalp]

Cool.. I'll use them to mount the bms or something.

Today I took the grinder to the dropouts to get ready for welding. Took off one of the tensioning lips.. Modified the other to hold the phase bundle.

I worked a lot today on making a jig to place the new torque plates/swingarm extenders as close to parallel to the swing arm cup faces possible... Still experimenting. I think I will extend the swing arm by about 1.5 inches. They will be about 16mm thick or around 5/8" each. Existing spacing is 182mm minus 144mm minus 6mm drive side spacer (divided by two). I'm going to try my best to get these plates as parallel as possible so I don't over stress the axle.

It might be a bad idea to work on torque plate alignment without having the swingarm fully assembled.. But I figure worst case comes to worse I can cold set the legs later.

[hillzofvalp]

THis is 12p28s configuration.

gettin' there.. I found some leftover carbon fiber sheet from an aerospace company sitting around.. so the blue panels will be carbon fiber. Sides are milled out .25" and .5" aluminum. Also scrap hopefully... I wonder how close to the nominal weight I will be with all wax, aluminum, and carbon fiber. I'm hoping within 6-7 lbs of the 51.85lb nominal weight.

I left the front module flush with the bottom like in the rear for the sake of simplicity.. fewer parts to make.. and I guess lower CG. I may choose to cover it all up anyways with custom fiberglass fairings.

Drunk skunk, is the top tube near parallel with the ground when bike is built up? If not, how much of an angle? Looks like 5 degrees or so. I may choose to mount pack at an angle from top tube to make it parallel with ground for cosmetics ( and lower CG?).

[Drunkskunk]

Its not horizontal at all, its at an angle down. the head tube sits at a 25 degree rake, so if you tilt your frame back to that, you'll see it.

Random internet pic of how it sits: