RC reduction Simplified

[farmkid4]

Will you be selling them with a motor?

[Thud]

Which motor?

I haven't rulled the idea out....

[farmkid4]

Which motor?

I haven't rulled the idea out....

I was thinking with a 63mm outrunner or similar.

Keep up the good work!

[kevo]

Inexpensive ($35-40) motors useful for Thuds reduction unit are linked in adrian's thread over here
http://endless-sphere.com/forums/viewtopic.php?f=31&t=34586&start=30

[deVries]

I really think a re-wound & terminated 80/85 would make a awsome BB drive set up & I will test that on my old FS Marin some time this summer.

When you say "awesome BB-drive set-up", you mean a mid-drive unit? Now we're talking about something I want to buy!

Elaborate more on your mid-drive offering please!

Look'n good... keep on, keep'n on... Thudster...

[Thud]

You need to be very pro active when shopping motors at leaders. They have (what apear to be) some awsome sales form time to time....but they are not allways on top of inventory. I bought prolly the last 80-100's they had. but I had no problem getting re-funded for the back-order. The motor linked in adrian's thread is now back to $90.00

Hello deVries,
Just to be clear, "mid drive" typicly describe a hub motor not mounted in the hub....it can either drive the wheel directly or run through the bicycles main gearing. (what I refer to as the BB drive systems).

I have posted a couple pictures of a little reducion unit that powers my buddys kid hauler bicycle around with a 6374 turnigy & CCice100 controller. bike is starting is 3rd year of service & he still loves it,(kid is getting heavyer & it still pulls hime & her all over town) & from my experiance, this is my favorite "assist" to ride as a bicycle. It make you feel like superman. properly geared for the bike (road or mountain) it is pure enjoyment.

Most of the high power stuff I tend to gravitate too is really moped class stuff...& frankly the pedals are usualy in the way of progress.
thanks for the props, I am getting my old F.S. Marin out of mothballs to make a BBdrive set up with this soon. We'll see what motor confiuration works best for it.

[adrian_sm]

The motor linked in adrian's thread is now back to $90.00

Unfortunately the 6374-200kv never went on sale, but the 6364-230kv motors I linked too are still cheap, US$33 + shipping.

Here is the direct link: http://www.leaderhobby.com/product.asp?ID=9394001224158

I have posted a couple pictures of a little reducion unit that powers my buddys kid hauler bicycle around with a 6374 turnigy & CCice100 controller. bike is starting is 3rd year of service & he still loves it,(kid is getting heavyer & it still pulls hime & her all over town) & from my experiance, this is my favorite "assist" to ride as a bicycle. It make you feel like superman. properly geared for the bike (road or mountain) it is pure enjoyment.

Have you got a link? Would love to see it.

Oh and I love this reduction unit. Well done.

[deVries]

I have posted a couple pictures of a little reducion unit that powers my buddys kid hauler bicycle around with a 6374 turnigy & CCice100 controller.

This new drive system you have in this thread would also work well with the 6364 too, right? KV is 230.

Does the motor "ideally" have to have the two support bearings for the shaft or will just one side work fine with this drive? I think it's called the skirt bearing? Does your setup here really need the skirt bearing support too?

Also, is this the same drive here that is going to be used also for the Marin mid-drive through the BB crank gearing? Or, is that another design yet to come?

Thanks!

[Thud]

I stand corrected & thank you for the support.
Here is the bottom bracket drive mounted on a very lightweight Giant frame. it looks large in this photo, but thats a 6374 in there. Its running on 8cells.

the batteries & ellectronics are now mounted inside the frame also , this photo was the "Hurry up & lets try it out" configuration.
batteries & controller are too far apart. The finalize the design was tweeked to house all the reduction internaly except the chain to the crank of course, but have never revisited it. something allways comes up.

As far as a skirt bearing required....definatly not. they are needed for a friction drive to stablize the can & on a larger motor that is going to subject to jumping or substantial impact force. the skirt bearing came form the 3D aero guys. the gyroscopic force of a propeller & the airframe stressing it from all angles would let the can flex enough to have magnet strikes.....especialy on the long can style motors.

& yes this same unit as a BB drive. I am thinking a lower kv wind & a bit lower voltage & you have a resaonable assist to the human side of the bicycle. It won't be a braggerts 10kw set up....but thrugh the gears, it will do everything you want a bicycle to do. & the biggest plus is the ease of maintaining a 6cell set up over chaining a pack in series...then parallelling them up for capacity.

[adrian_sm]

& the biggest plus is the ease of maintaining a 6cell set up over chaining a pack in series...then parallelling them up for capacity.

+1. It does make life easy doesn't it.
- Easy to scale the battery. Run a single pack, or parallel as many as you like.
- easy to charge
- easy to balance using charger, and a one of these
- ESC can do LVC & charger can do HVC, so no BMS required if you don't want.

Now you have me thinking about a BB drive through the gears on my FS bike with this reduction unit. Damn you.

[Thud]

[adrian_sm]

So freewheeling cranks. Where? How much?

[farmkid4]

:evil:

So freewheeling cranks. Where? How much?

+1

[Thud]

I buy all my wide bottom brackets from these guy's. Its a tiny garage internet side buisness but I have talked to the owner & he is a complete motored bike enthusiest & looking at the ellectric side more every day. They will ship international.
http://www.sickbikeparts.com/catalog/pr ... qfgl3vlf24
& all the chainrings & goodies to bolt to the freewheel:
http://www.sickbikeparts.com/catalog/in ... qfgl3vlf24
same cranks as you get with a cyclone kit AFAIK.

After my experaince with these cranks, I will now recomend not using the White freewheel.(or the chepo dicta) Instead use a ACS cossfire & make the adjustments to the sprocket teeth (to fit the chainring bolt pattern) with a dremel tool.

why? the Dicta has a pr of weak pawles but with dual angular contact bearings it remains a fairly true set up...(till the pawles fail & you smash your nads on the top bar!)
The white industries unit is great under pedal power & with 3 pawles it is rock solid....the fault there is the single bearing suport when it is freewheeling.(under motor power & not pedaling) it gets very flopy very fast. does not insire confidence.

the Crossfire is a huge step up from the Dicta & still keeps the sprocket running true, has 3 pawles for secure pedaling & are reasonably priced. I haven't actually used the crossfire in this application yet....but I have nothing but confidence it is the solution.
Unless recumpence shows his full bearing supported freewheeling crank design....That would be the ultimate fix.

[Miles]

why? the Dicta has a pr of weak pawles but with dual angular contact bearings it remains a fairly true set up...(till the pawles fail & you smash your nads on the top bar!)
The white industries unit is great under pedal power & with 3 pawles it is rock solid....the fault there is the single bearing suport when it is freewheeling.(under motor power & not pedaling) it gets very flopy very fast. does not insire confidence.

the Crossfire is a huge step up from the Dicta & still keeps the sprocket running true, has 3 pawles for secure pedaling & are reasonably priced. I haven't actually used the crossfire in this application yet....but I have nothing but confidence it is the solution.
Unless recumpence shows his full bearing supported freewheeling crank design....That would be the ultimate fix.

See also: viewtopic.php?f=28&t=25153

[kevo]

Adrian wrote: Unfortunately the 6374-200kv never went on sale,

Oops, my error. Edited out now.

Thud and Adrian, how well does the 8085 perform compared to the 6474?
Is the ACS Crossfire any quieter than the White freewheels?

[adrian_sm]

Okay I am new to this whole free wheel crank thing. So bare with me.

So the cranks are mounted to the BB as usual, but you have a freewheel screwed onto on crank. Then you have to mount two chainrings off of that. One for the motor chain, one for the drive chain to rear wheel.
And you need a wider BB or some offset or something to give you enough room for the freewheel?

So the shopping list would be:
1) ~$20 - wide bottom bracket
2) $25 - freewheel cranks
3) $20 - ACS crossfire freewheel
4) 2x $22 44t chainrings

Still requires a bit of customisation to get two chain rings mount on the freewheel. Slot the freewheel teeth, and sandwich it between chainrings with some appropriate spacers. Nothing too tricky.

Does that sound about right?

Oh, and your reduction unit of course to drive it all.

[EDIT] @Miles. Thanks for the link will read through that now.

[Thud]

You have it right Adrian.
The hardware package form SBP has the spacers & such for bolting the chain rings to the freewheel & to each other...the bits & pcs are not the top of the line bolts,washers. I upgrade the fasteners & use the spacers.

Actualy you can put the FW cranks onto a standard bottom bracket. but the wider options allow for some seriouse clearance for battery boxes & huge motors. if you know what i mean
(edit to add)the wide BB are actually offset far more on the left, for clearance of the china girl 2-stroke engine kits.

As far as compairing the 63mm to an 80mm motor.....apples & oranges. The 80mm motor starts out with a 27% size advantage directly in the leverage ratio that makes outrunners so atractive.

when it comes to delivering tourqe, size allways wins. There is no replacment for displacmet.

[Green Machine]

I want one of these units for sure. thanks thud for building this.

I have been looking for simple solutions not involving hub motors.

Subscribed.

[deVries]

Now you have me thinking about a BB drive through the gears on my FS bike with this reduction unit. Damn you.

Isn't Thud just about the most tempting or the most lusty open-source porn on ES?

I'm addicted to reading about everything he does... remember the good'ol daze "back in the day" of crotch fireworks & controller fries! & the eventual triumphs!

the wide BB are actually offset far more on the left, for clearance of the china girl 2-stroke engine kits.

Why not drive the front crank on the left side then? Too complicated or too expensive to do or ?

As far as compairing the 63mm to an 80mm motor.....apples & oranges. The 80mm motor starts out with a 27% size advantage directly in the leverage ratio that makes outrunners so atractive.

Apples & oranges recommendations for the following typical scenarios please! ...

Would the 80 drive a moped frame/build to 35mph with typical car-speed acceleration to maintain that speed for 5-10 minutes for stop-n-go in city traffic/driving?

Would the 6374 be a "perfect fit" for a 35mph flats-max. 25mph nominal for 50-lb. bicycle with excellent but typical car acceleration (non-racing) city riding in traffic vs the possible "overkill" of the 80 for same setup?

[Thud]

hmnnn. If pressed for a recomdation,
I have to say the biggest motor you can afford will be the better value.
A bigger motor will handle any stress better & the larger bearings, shafts & everything will have the advantage of mass working for it.
A smaller motor will be operating much closer to its "critical" point.
For those reasons alone I would allways recomend the bigger motor.
& is not about speed or wheelies. running a motor at less than its full potential will just extend its life...& if the situation arises, you have the power on tap to conqure that hill.

But a 6374 will pull you along at 30+ fairly easy also. It will just be a little closer to the red line in doing so.

I have found the tiny 5065's will push my big butt to 30mph. but it requires flat gorund (or better yet a down hill ) fully inflated tires & a 2-speed unit to get it rolling.
I just bought 5 more for experimentaion (new cooling system design for racing) & I have a couple 16" kids bikes that will be fun to try this reduction unit with. (neices & nephews will have a blast...grand kids are still too small yet)
http://www.leaderhobby.com/product.asp?ID=9394001224329
the price is right to play with....the key to happyness is low expectaions

but seriously, bigger is better.

[deVries]

Any thoughts, comments, opinions, or recommendations about this... ...

the wide BB are actually offset far more on the left, for clearance of the china girl 2-stroke engine kits.

Why not drive the front crank on the left side then? Too complicated or too expensive to do or ? Advantages vs disadvantages?

[Miles]

Any thoughts, comments, opinions, or recommendations about this... ...

the wide BB are actually offset far more on the left, for clearance of the china girl 2-stroke engine kits.

Why not drive the front crank on the left side then? Too complicated or too expensive to do or ? Advantages vs disadvantages?

As I understood it, Thud was just stating a fact. If the offset isn't needed for the freewheeling mech, it doesn't matter that it's on the left-hand side. In any case, it's easy enough to rebuild them with the offset on the right-hand side.

Yes, you can drive the left-hand side, but it's not a simple matter if you want to retain the freewheeling cranks: viewtopic.php?f=28&t=35846&p=520537&hilit=bottom+bracket#p520537

[MitchJi]

Hi,

So freewheeling cranks. Where? How much?

One option for freewheeling cranks is Matt's (higher quality and more expensive than the sickbike parts). Not sure about price and availability but he did say he'd sell individual components of his system:
http://endless-sphere.com/forums/viewtopic.php?f=28&t=34753

I am pushing to make the highest quality crank drive that uses the stock derailer and pedal system that I can while keeping an eye on the cost. It looks like the kit consisting of motor, drive unit, FW cranks with chainrings, all mounts, motor and all hardware will come in at around $1,500.

#4 The freewheeling crank. This is one thing I am really excited about! It will use a second support bearing to eliminate the overloaded freewheel bearing issue that is so common with freewheeling cranks. It will also use standard 130mm BCD chainrings for multiple ratio options. I am very excited to have come up with a solution to the FW crank bearing issue. I am not the first to do this, but I think it is the first to be readily available. My system will come with this new FW crank system and a new lengthened bottom bracket.#4 The freewheeling crank. This is one thing I am really excited about! It will use a second support bearing to eliminate the overloaded freewheel bearing issue that is so common with freewheeling cranks. It will also use standard 130mm BCD chainrings for multiple ratio options. I am very excited to have come up with a solution to the FW crank bearing issue. I am not the first to do this, but I think it is the first to be readily available. My system will come with this new FW crank system and a new lengthened bottom bracket.

His motor would probably be a good fit for Thud's drive:

#1 Motor. This system will be compatible with Astro motors, but for those who are looking for lower power, lower cost, and lighter weight while retaining quality, it will also be compatible with a small outrunner based on a standard Maxx Products outrunner. This motor will retail for under $200. The normal motor is $180. However, my motor will use a longer shaft and a few other minor changes. Also, this motor is readily available and I can pick them up 15 minutes from my house! And if someone manages to smoke the motor, the stator/windings retail for $50 and are easy to replace! This motor uses high-end bearings and is, overall, a very high quality motor! I am thrilled to find this option so close to my house. Also, these motors have been tested in very dirty environments. So, I am confident it will run well in this application. It is also a very quiet motor.

[Thud]

Why not drive the front crank on the left side then? Too complicated or too expensive to do or ? Advantages vs disadvantages?

Disadvantages to left side driveing a crank:

Lefty loosy: The right side already allows for acceptable freewheel solutions. the left side would reqiure southpaw threading & freewheels that barely exist....& none that exist currenty in a quality we can accept.

Stay too the right: Since drive lines are already on the right side...why not capitilize on the established engineering & component compatibilities?
There is a good argument for this. Since your clogging the right side with drive lines, it frees the left side for batteries & other items....driving both sides of the crank will consume valuable space between the pedal circles.

Advantages: None present in my current thought pattern.....other than it would be "different" & unique which allways adds 5 Kool points

Add that I have enough ideas for crap to build, to fill the rest of my life 20x over.....bike cranks are refined enough for me dissmiss them as perfected & focus on other things