Portable Solar + Fat MAC Rear Hub

EDIT: Now Portable Solar + Fat MAC Rear Hub (Trailer will follow..)

I want to build a single wheel powered trailer (like a stretched extrawheel) for my fat bike for long dirt road touring, with solar assist (some assist but mostly fold out when not riding). I want it to be transportable as checked luggage on flights ie. 70x70x18cm max. As I recall it's around 62" LxHxD but our local carrier adds maximum dimensions as an extra challenge.

I had my head full of parameters and constraints so to force a start I bought the panels:



30w x 6

The size fits and the number is probably the maximum manageable (for now), (I plan to have three assisting and fold out to six for charging when stopped... so its pretty modest 90-180w but I think can still be pretty well streamlined with three panels , 1 top 2 sides, maybe a fold flat mechanism for easy roads/ light winds.. I don't need speed, just cruise and hill help)

I initially considered the concept of using a similar 26" fat wheel but there doesn't appear much advantage (other than swapping to getting the bike out of an emergency)

I'm considering a 20" rim on a FB hub.

It seems intuitive that a small wheel on a bike that may see some rough roads and track be powered remotely, ie. not a hub motor?
Any suggestions for a reliable robust cog drive motor that could be linked to a chain or belt drive? Maybe i'm overthinking already and a hub drive would be ok? but its not going to get much airflow (once the trailer is loaded around it), will be 'low' and seems a bit vulnerable.. & A hub wouldn't eat up cargo space..

Any input appreciated (go easy, i'm a newby with little related experience.. other than being able to weld and wire).

Ta.

Thanks, I have read through some of the relevant ones over the last few weeks... good stuff.
I like what you guys are doing.
Seems a huge range of inspirations and purpose out there tbh though, some of the larger panel-powered look like too much a road hazard (but then iv'e never really been a hardtop rider.

Anyhow, not expecting miracles, expecting more reliance on a fold-out solution for long lunchtimes on lonnng rides.
I'm mainly interested in the hub motor reliability/convenience V chain/belt/shaft driven for rough/wet (or dusty) roads.

Only one reason I can see for putting the motor on the trailer, which is that you would buy the bike when you got to your destination.

And even then, I'd just fly with a fat bike hub motor conversion kit, rather than put the motor on a pusher. I just don't see myself liking the trailer pushing me on dirt, even just washboard roads that are not that challenging. But you can build a trailer to run with all your panels deployed flat, or if not windy, possibly tilted to the sun some.

I'd say the most reliable thing you could go with, would be a hub motor on the rear wheel of the bike. Preferably a direct drive motor.

Check out Parajeds solar trike, using similar panels. He uses one small battery to actually run the motor, and so could you, a battery small enough to fly with.

Thanks dogman dan.
I had read parajeds trailer (https://endless-sphere.com/forums/viewtopic.php?f=3&t=80117&hilit=solar) and watched marissas tour vid, inspiring stuff!

(and yes, , buying a bike, sending/bring it home, spot on. Was thinking along the lines of a big tour in your collective neck of the woods actually & for a few months . I'm really keen to paddle the Escalante R and a grand loope down south.. but will miss the snowmelt this year, so have some time to tinker)

Was thinking more of the trailer carrying, ie. the panels with some in use.. and camping gear.. and maybe cheaper SLA batteries from baulking at the rules on carrying eg:




My concerns are what you mention, rough roads, maybe it will bump along spinning.

(another thought included carrying a hub mtr/ wheel as well as an extrawheel trailer, both, packed with camping gear would pass checked luggage.

Ok plans evolve, I took on board the advice, read a bunch abt mac and other sparse comments on powered extrawheel and ordered a rear hub (that i'll set up on the bike before playing around with the trailer).

Torque Arms:

I grabbed the grin tech arms but how to fit with these drops? They are never going to reach the seatstay with the second arm attached.
Ids there a better option for this style of dropout or any thoughts on the best way to secure?



(given 4 possible positions, they sit in the recessed section above the axle in the pic but not really anywhere to clamp)

I would point it down, then clamp to the chainstay, if possible.

If there is a hinge point I don't see in the pic on the chainstay, then you do have a problem to solve. Might have to make a TA from scratch.

Thanks. I was focused on instructions and not thinking outside the box
(it is 2 piece but instructed to point up and clamp the seatstay).

My two cents on the trailer ... I really like my Travoy. It trails really nice.

I have made some changes (don't we all) and the hitch is now mounted on standard rack to get the seat lower and the trailer a bit further back. One of the things that I like is you do not have a really long object dragging behind you. I have also seen an example of someone doing something similar with a two wheel dolly and a couple of casters for the hitch. I would consider something like that (with 10 inch Pneumatic tires) if you are serious about toting a few SLA batteries ... can handle a lot of weight with a nice low center of gravity.

I like my Travoy also, and often also use it as a handcart once disconnected from the bike, it's just real handy overall. The folding feature is pretty cool also.

I like my Travoy also, and often also use it as a handcart once disconnected from the bike, it's just real handy overall. The folding feature is pretty cool also.

Can you give me the link / data sheet from the seller...?

Ozzzz said:

I had my head full of parameters and constraints so to force a start I bought the panels:

Click to expand...

http://www.aliexpress.com/store/product/18W-high-efficiency-flexible-solar-panels-mini-solar-panel/1282404_32264258703.html

(yes, even them iv'e changed, 30w were a bit too long)

--

Iv'e seen those trailers, they look like a good around town option. I'm building for gravel roads and sngle tracks
The push trailer is still in mind but will need more time than I have, the motor went in the rear rim, i'm trying to do without a trailer for now.

Ozzzz said:

http://www.aliexpress.com/store/product/18W-high-efficiency-flexible-solar-panels-mini-solar-panel/1282404_32264258703.html

(yes, even them iv'e changed, 30w were a bit too long)

Click to expand...

Did you buy those already?

I have one of a very similar 18W Panel for tests and this is "shit". The problem is not the Sunpower cells inside but the module construction with PET-EVA-cell-EVA-PET. The PET front side is highly reflective and decreases performance significantly(!) when sunlight hits at an angle. It will also blind other people like a mirror. Imho this one is unuseable for a trailer!

Also PET will degrade very quickly, life time of those modules will be very short. My test module is also very fragile and easily bends and keeps "out of shape". This may harm the cells.

Most likely a solar module using a ETFE front and aluminium or fiber glass back side would be a much better idea for a flexible module. Look for marine grade modules. They are more expensive and weight more though...

The module from your first picture does looks like an ETFE module, this is why I asked for the link to the seller.

I thought they are ETFE laminate? I'm not entirely sure tbh I looked at so many, thought I had but it's not clear. I specified the same build as the 30w panels, definitely dull/matt, almost woven finish, they are on a hard board, semi-flex.



PS Here:
http://www.aliexpress.com/store/product/30W-All-black-background-flexible-solar-panel-high-efficiency-sunpower-cell/1282404_32565023678.html

All i'm seeing is aluminum /plastic, room to move there I guess.

Ozzzz said:

Thanks. I was focused on instructions and not thinking outside the box
(it is 2 piece but instructed to point up and clamp the seatstay).

Click to expand...

kdog explains it well:

kdog said:

Subject: 1000w rear hub on aluminium bike

All hub motors get at least one torque arm, two if more than your average 250w'r. At 1000w having No torque arm will destroy your soft ally frame first good twist of the throttle. Then your stuffed.
Two piece torque arms need to be installed correctly, and yes done poorly they can twist at the joining bolt. The two pieces where the bolt joins them need to intersect at or close to a right angle (90deg) so the bolt takes a shearing force not a turning one.
K

Click to expand...

I'd improve your current TA installation by putting some sort of solid, non-compressible material between the TA and the stay and use two more hose clamps. The way its installed now isn't protecting against axle rotation very much. There's too much potential for enough movement to ruin your aluminum dropout.

Do you mean TA stays where it is? This is actually the only position it will reach anywhere near the stay and at full extension.
It's far from 90 degrees isn't it

I did wonder. It's actually just in place in that pic I did put two clamps and a piece of thick PVC wrapped. There's also a TA each side
.. have car hub nuts and only max 25a.. 1000w but the tork will be there still i gather.

maybe though I need a bigger TA?

I can imagine the forces just not the amount.

Thanks for your comments.

hmmm, yeah:

I actually like the way you had it mocked up, just without the gaps that would allow movement.

That last drawing looks like it would just pull the hose clamps down the stay.