DIY Electric Cargo Trike w Fairing Rohloff + Schlumpf

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mouldfield
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DIY Electric Cargo Trike w Fairing Rohloff + Schlumpf

Post by mouldfield » Dec 25, 2017 9:23 am

Hi,

I'm Mouldfield, a longstanding bike enthusiast in Sydney, Australia and I'm putting together an Electric Cargo Trike with A Fairing.
Essentially, it's the rough and ready DIY version of this: www.youtube.com/watch?v=-M6N2x1FXbU (*or one of these at the bottom of the page). Then I'll add a Rohloff Speedhub and, hopefully, a Drumpf Drive (or similar). In Australia we're limited to 250w, so you need all the help you can get.

I have a Bafang motor, battery & Rohloff hub that I attached to my first cargo bike (a Yuba Mundo) and last week I bought a cheap old 7 speed pedicab in Melbourne, cut off the seating and excess crap, and arranged to ship it to Sydney. It's not ideal, it's heavy "mild steel", but it will arrive soon and will be just fine till I save up for a better frame, or maybe learn how to weld one myself.

My trike needs

1. a front suspension fork
2. a change of head tube angle (info about that at: endless-sphere.com/forums/viewtopic.php?f=6&t=35151 )
3. Repositioning of the saddle (some cutting and welding) and a seat
4. new rear rims and spokes or rear wheels, maybe even non-bike wheels: for stability, strength, low-serviceability and reasonable weight
5. a 50-51" (120cm) axle, with Samaga (or Contes) differential
6. a decision re the hydraulic disc brakes. I think the current ones are motorcycle brakes which I'll keep if good, safe, etc. Otherwise I have a set of Shimano Deore XT Ice discs.

Then I have to build a box and a fairing

Then wire in head, rear, stop & indicator lights

And that will do for now. I'll get it on the road, test how it all goes, then later I hope to add that Schlumpf Drive (but I might wait till I get a better frame).

This will be my third electric bike and it will be the one that I've done the most work on by far. I hope it will also be the most fit for my purposes. And I hope I can get some good advice on these pages.

I'm currently looking for the right axle+diff combo for my cargo trike. Like I said, it's looking like being a 50-51" (120cm) axle, with Samaga (or Contes) differential. Though I don't know what those are currently priced at, and I think I have to learn a bit more before I order.

Cheers,

Mouldfield

* PS
Here's what some European Cargo Trikes are looking like now
www.youtube.com/watch?v=-M6N2x1FXbU
www.youtube.com/watch?v=YvOwBqN7b7U
www.pinterest.com.au/pin/109775309637881004/
www.eltis.org/discover/news/urban-deliv ... s-france-0

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amberwolf
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Re: DIY Electric Cargo Trike w Fairing Rohloff + Schlumpf

Post by amberwolf » Dec 25, 2017 7:46 pm

mouldfield wrote:
Dec 25, 2017 9:23 am
1. a front suspension fork
2. a change of head tube angle (info about that at: endless-sphere.com/forums/viewtopic.php?f=6&t=35151 )
3. Repositioning of the saddle (some cutting and welding) and a seat
4. new rear rims and spokes or rear wheels, maybe even non-bike wheels: for stability, strength, low-serviceability and reasonable weight
5. a 50-51" (120cm) axle, with Samaga (or Contes) differential
6. a decision re the hydraulic disc brakes. I think the current ones are motorcycle brakes which I'll keep if good, safe, etc. Otherwise I have a set of Shimano Deore XT Ice discs.

Then I have to build a box and a fairing

Then wire in head, rear, stop & indicator lights
Have you seen my SB Cruiser trike?
https://endless-sphere.com/forums/viewt ... =2&t=67833
It's not faired, but it moves a lot of cargo easily; handles well, and most of it is made of "mild steel" (at best) so it's also heavy but easy to work on/weld (I'd love to get all-new chromoly to build a new one from, someday).

It's not as wide as what you will be building, but it would be if it hadn't had to fit thru a doorway originally. (it isn't quite 3 feet wide at the axle nubs that stick out from the cargo frame). Even so, it's still stable in sharp turns up to almost 20MPH and recovers well even if pushed to hard and starts to tip, with the weight all down low.

You don't include any pictures of what you've got right now to work from, but I'd bet you could easily modify it to do what SB Cruiser does (though via a middrive rather than dual rear hubmotors like SBC uses), and then add your fairing and anything else you need that it doesn't have.
Various views in the post below:
https://endless-sphere.com/forums/viewt ... 5#p1310509
Side view, then side view with seatbox cargo area open
Image
Image


I'm working on a slightly smaller version for my brother here:
https://endless-sphere.com/forums/viewt ... 5#p1342885
that doesn't need to haul giant dogs around so it's backend is built differently.
Image

I'm currently looking for the right axle+diff combo for my cargo trike. Like I said, it's looking like being a 50-51" (120cm) axle, with Samaga (or Contes) differential. Though I don't know what those are currently priced at, and I think I have to learn a bit more before I order.
Chalo has given me some good advice on differentials, as have others, if you want to look thru the SB Cruiser thread (and/or do a search on his posts for diff* ). Money is the main reason I haven't gone that route and am using hubmotors, as I'd need a fair bit of new stuff to rebuild the trike around the diff, and build new wheels, chain, etc. I think most of the diffs I was looking at were in the $150-$300+ range, including the axle, not including any of the hardware to mount it or connect to the chainline/etc. Some included a disc brake mount on the axle with a caliper mount on the diff.

mouldfield
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Re: DIY Electric Cargo Trike w Fairing Rohloff + Schlumpf

Post by mouldfield » Dec 27, 2017 8:33 pm

[/quote]Chalo has given me some good advice on differentials, as have others, if you want to look thru the SB Cruiser thread (and/or do a search on his posts for diff* ). Money is the main reason I haven't gone that route and am using hubmotors, as I'd need a fair bit of new stuff to rebuild the trike around the diff, and build new wheels, chain, etc. I think most of the diffs I was looking at were in the $150-$300+ range, including the axle, not including any of the hardware to mount it or connect to the chainline/etc. Some included a disc brake mount on the axle with a caliper mount on the diff.
[/quote]

Hey Amberwolf,
Thanks for your reply and particularly for your Chalo reference. I'll check that out very soon, as diffs seem destined to be one of my more challenging and expensive purchases (especially when you add shipping to Australia).

I had a look at your build and it looks like it was a lot of fun, even if challenging at times. If I could weld I would have gone for a slightly narrower trike to make it easier to get in and out of gates and to make travelling in bike lanes easier but I can't weld. Then I found this pedicab which provides a decent frame for a few hundred dollars, and I was also thinking about having a trike which could easily take a Euro-pallet (900cm), so it's just the way things worked out.

Mine will probably be a bit lighter as a build, and the fairing is important because I'll be carrying quite a bit more weight and in Australia we use the EU standard which currently limits auxiliary motors to 250 watts, which is about a ⅓rd of 1 horsepower. So I have to go for lightest possible and for cutting wind resistance, or it just won't be fun.

I've posted a couple of pics this time before, and after but palleted and wrapped for freighting. The freight co just let me know it'll be here in 30 minutes. So I better go and make sure I've got some space organised. Cheers.
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Re: DIY Electric Cargo Trike w Fairing Rohloff + Schlumpf

Post by amberwolf » Dec 28, 2017 1:42 am

mouldfield wrote:
Dec 27, 2017 8:33 pm
diffs seem destined to be one of my more challenging and expensive purchases (especially when you add shipping to Australia).
You might look at used stuff, surely there are people with junked riding mowers, go-karts, etc., that have the part you need that could be shipped *across* Australia a lot cheaper than across the oceans. I've been looking for one locally here in teh valley, but no luck yet (did find two, but neither one of them was actually available when I contacted the advertisers. :roll: )

I had a look at your build and it looks like it was a lot of fun, even if challenging at times. If I could weld I would have gone for a slightly narrower trike to make it easier to get in and out of gates and to make travelling in bike lanes easier but I can't weld.
Welding is easy, and relatively cheap. I don't know what your equivalent to Harbor Freight is down there, but I'm sure there is one, that sells cheap tools. If not, used welders ought to be relatively cheap. Here, at HF, you can get a cheap (crappy) wirefeed welder for about $100 USD. About $300 USD will get a much better (less crappy) wirefeed welder that can also do MIG if you ever needed to, and have more than just one setting (mine has four levels).

Learning to weld will probably use up any "trial" reel of flux-core wire that comes in it. 10lb reels of fluxcore wire run around $50-$70 USD (2lb reels aren't worth it at more than $20 each).

Pretty much anything made of steel is weldable like this, and there's plenty of good resources to learn how (the miller welding co website among others, as well as various forums and youtube videos, and just plain practicing on junk metal).


Then I found this pedicab which provides a decent frame for a few hundred dollars, and I was also thinking about having a trike which could easily take a Euro-pallet (900cm), so it's just the way things worked out.
A wider trike will handle better in turns at higher-than-walking speeds, so if you have to maneuver suddenly, it'll b a little less likely to tip over. Keeping the majority of the weight low (at the level of the deck or below) will do that too, as will keeping your seat low and forward (why mine has the seat where it is).

A narrower trike has advantages too, in that you can use it on bike paths with bollards that keep out wider ones, or fit it thru doorways if you have to take it inside.

Mine will probably be a bit lighter as a build, and the fairing is important because I'll be carrying quite a bit more weight and in Australia we use the EU standard which currently limits auxiliary motors to 250 watts, which is about a ⅓rd of 1 horsepower. So I have to go for lightest possible and for cutting wind resistance, or it just won't be fun.
Keep in mind that a fairing (especially a full one) has disadvantages:

If it's a full fairing, it will add (possibly significant) weight, so starting up from a stop or going up hills is going to be that much harder to do. If it's all lightweight like coroplast or a shrinkwrap skin over really light frame, the weight won't be that bad, but it'll be less aerodynamically smooth (not as important at lower speeds, but still takes away some of the benefit of having one).

The fairing is probably only going to make a significant difference in power usage above 15MPH, though it will make a little bit down to around 10MPH. If your speeds are never really above 15-20MPH, you won't get that much benefit from the fairing.

If it's a full fairing, it's also going to cause problems in side-winds, which will push you around, though if the trike is heavy and low that will be less of a problem than on a bike.

It can also be an oven inside whenever it's not cold outside. (even 75F on a sunny day could make an enclosed fairing into an oven, if you don't have good air circulation it'll be no fun. (this is the primary reason I haven't made one for anything I ride; it's only cool enough to survive in one without an air conditioner for at best 1/4 of the year (usually less).

I've posted a couple of pics this time before, and after but palleted and wrapped for freighting. The freight co just let me know it'll be here in 30 minutes.
:) Post some pics once it gets there, of how it is now. Depending on what you want to do with it, i might have suggestions on things.

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Re: DIY Electric Cargo Trike w Fairing Rohloff + Schlumpf

Post by Chalo » Dec 28, 2017 4:58 am

Peerless differentials are rather crude and rather heavy, but they're industry standard for pedicabs in the USA. They've probably seen a lot more use on various lawn equipment and other implements than on pedicabs. They can take a lot of power and torque by e-bike standards. 3/4" shafts are the most common as far as I can tell, but you can cut and couple them to whatever size shaft suits your purposes. I strongly recommend using tubular axle shafts rather than what comes attached to a Peerless differential, because that's some really easy weight reduction that doesn't cost much in money or structural integrity.

Samagaga diffs are much lighter, more compact, and generally nicer looking-- but whether they can withstand kW and up power levels is an open question. The folks there seem obliging and would probably furnish max torque and power specs if you ask them. I think 17mm axles are their thing. That seems adequate, but you'll want to have bearing support close to the wheels as well as the differential.

That trike looks like a Chinese version of the Cycles Maximus trike from England. The Chinese copies are very common here in Austin, because they're the cheapest available pedicab trikes that pass inspection and hold up to commerical service. They're slow but they work.
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