cheap cargo electric?

[offtheshelf]

I'll get to the tandem part in a minute, but bear with the introduction.
I've been a lurker here and other ebike sites for a year of more. As my user name indicates, off the shelf is all I've done so far. I enjoy all the heady electronic geniuses and machinists that post their achievements, but I'm not one of them. I've bought a couple locally here in Florida USA, at bargain prices and with no particular skill of mine to put on the road. Got 1 Chinese 36V 250W hub motor bike for $200 (new = $800) and replaced the 3 ea 12V SLAs for $75. Works great for the $. Got a Giant Lafree with 2 battery packs (new = $1300 + $499 for the extra battery pack)) a couple of weeks ago for $200. Like the bike, can't beat the price, admire the Panasonic drive unit, but prefer the Chinese bike for its power only mode.
Now, on to the tandem idea to see if anyone has thoughts. Lots of forum users seem to be fretting about the costs of free wheeling devices and load carrying capability. There are the Yubas, extension projects, etc. But what about... (and excuse me for introducing a wally store bike in here), but...
What are some user thoughts on taking a shortcut with a cheaper bike? Wally has the Greenline tandem with independent pedaling system (IPS) for $374. http://www.walmart.com/ip/Greenline-Bicycles-XGB1189/19506222
Seems to me that if a bike is made for 2, it has quite a load carrying capability built in at a modest price. Remove the rear seat, handlebar, etc and fab up extra large (long) panniers, etc. Use the IPS system to allow easy hook up of any of the countless motor kits I see on the site to the rear crank. Bike would still fit (most states I know of) within the legal definition of an electric bike (pedal power, available with electric boost). IMHO, a mid drive hub motor conversion would then allow use of the 7 speed rear.
Beat me up guys and gals. I need the pros and cons before I spend $ for this relatively low cost venture which would be my first electric bike 'creation'.
Steve

 

[SamTexas]

Welcome to ES.
Using a tandem bicycle as a cargo bike has been done many times before. I personally think it's much better than elongating a regular bike, assuming of course that I really want a long bike. If I were to do it, I would not start with a cheap new tandem like the one you propose. Instead I would look for and buy a used, well built tandem, preferably with a chromoly frame. I've seen many used tandems for sale locally on craigslist for 1/3 or less of the original price. Much better value in my view.

 

[offtheshelf]

Thanks Sam. That’s what I’m looking for…some serious counter arguments.
If one is starting out with the thought of a cargo bike, it will most likely be a long bike. Not many others would want a bike that long, but it is almost a given in the cargo variety.
Granted, the Hi-Ten steel frame isn't nearly as good as chrome moly. And it’s heavier.
But, with this bike’s built in IPS system (and elimination of that added cost), it seems like this bike would be a very quick and easy build for the cost conscious cargo bike user.
The drive system could be connected easily to the rear crank and merely remove the rear pedals. Seems like one could be on the street with no more than a weekend of work and no special fabrication. And the driveline is Shimano. That has to be a plus in a price line bike.
This mod idea is aimed at those that need cargo capability and can’t afford many specialized or machined parts.

 

[SamTexas]

I agree with you on the advantage of the IPS if the goal is to use a mid-drive motor. That advantage is lost with a hub motor.

 

[offtheshelf]

I was thinking of a hub motor/mid drive conversion. They are fairly simple to put together.

 

[Drunkskunk]

I think your basic idea is fine. But that bike is a steaming pile of fertalizer. You can get a quality tandem bike used for less money, with a better frame, seats, brakes, wheels, and other parts.

IPS is just a fancy way of saying a freewheel crank. A fertalizer quality walmart bike is going to have a fertalizer quality freewheel crank. A motor, even your little 250 watt motor, is going to produce more power than most walmart bike riders, so you will need a good quality freewheel crank if you chose to use one. Regardless of what bike you chose, I'd highly recomend a good quality freewheel crank as a bad one will bring you nothing but trouble, misery, and sore legs from pedaling home when the bike breaks down. Often.

 

[offtheshelf]

I hear ya skunk. Walking is fine, we just don’t want to do it for 10 mile stints on a regular basis.
I figure that engineering is basically having to determine a cost to benefit ratio every time a product design is proposed. That’s a tough spot to be in. That comes to mind every time I see a video from Vietnam with a 3 person family and 4 chicken cages hanging off a 50cc scooter.
I would like to see real world data on this freewheel crank, but I know that quality verification of Chinese products doesn’t usually happen until they are ‘discovered’ by the American market (Golden Motor, etc).
Lacking mill certifications for the frame steel, knowledge of the crankset manufacturing, bearings, etc, I can honestly say that I don’t know how this bike would hold up used as a light (and cheap) cargo carrier. I would like to put one through the tests…as long as I didn’t have to walk 10 miles.

 

[amberwolf]

I dont' knwo about that particualr bike

but in my experience the wm-level frames and components are not very good; even when made from "steel" it is often not very good steel, and I question the welding quality on some of them.

I collect bikes from Freecycle/etc to use for my projects, and have had quite a few that originally came from wm and the like. Some of them are not that bad, but others have been awful. I had a red 24" non-suspension bike that was to be part of my first recumbent, ReCycle (never finished) that was such poor steel I could easily bend some of it's tubing by hand, and could flex all of it even when it was still a bike. I think at one point I partly crushed a tube by stepping on it bu accident--not something I could have done with cromoly bike tubing. It's only saving grace is it was very light. The wheels taht came on it were also questionable--while trued well enough, they werent' very strong, and would probably have not lasted very long in use on our bad roads with any real weight on them. It had only basic caliper brakes in front and I forget what shifter it had; I think it may have only been a single-speed maybe with a coaster brake in the rear.

However, I also have a Magna kids' bike that I think was a 20", which has served as the front have of CrazyBike2, my daily commuter and heavy-cargo bike, for more than 3 years now (maybe 4? I forget when I started it now...). Hasn't broken yet, and isn't very flexy (compared to others I've tested out). I don't remember anything aobut components on it, if it even had any when I got it, but the frame has been good, and is light. It might even be cromoly, but I dunno.


So, until you actually get to handle the bike, it's hard to tell what quality it might be.


Personally, if I were to go for a tandem cargo conversion, I'd either look for a used cromoly one, or I'd take a couple or three regular old cromoly ten-speed bikes and combine them to make a more ideal version.

If you have brazing or welding capability, you might look at the first two links in my signature fro frame ideas; tthey are both stiffer laterally than a regular bike or a tandem, because of the other triangulation in them. But theyr'e also heavier. They look crude but could easily be improved upon by someone with better skills than I.

 

[NeilP]

Umm big cargo bike..can feel a new project coming on

 

[dogman dan]

Tandem bike is not a bad idea. But that cheap one will have... cheap wheels. Made the same mistake myself with my first ebike. I bought a $300 or so schwinn trike. I'd never seen quite so cheap wheels in the decades since the sixties. Even used at 5mph they do poorly, and at ebike speeds of 15 mph, with about 40 pounds of cargo, they collapsed in about 200 miles.

I suspect a similar quality wheel will be found on that bike. But weak wheels is an easy fix. The frame, I'd prefer a more traditional shape, high bar, strong triangle sort of thing.

Sam's got it exactly right, a better framed vintage tandem would be stronger.

Why does it matter? Because lateral strength is what you need to haul cargo. The problem isn't that the frame will taco, it's that it will flex sideways. Loaded up, it will wag it's tail like a happy dog. The new cheap frames from china are notorious for it. They are built for exactly how they will be used. You know, bright idea one spring, one ride, wow that was WORK! Parked in the garage till the old guy dies and his widow sells it. They know it, and build it to last 100 miles.

Repeating in few words, great idea but get a bike that was made to carry two for thousands of miles. Happy hunting at the flea market.

 

[offtheshelf]

Well, I think I've made up my mind. I know the Chinese bikes are notorious for their lack of quality and it just wouldn't do to invest $375 and a lot of time into a project that might fail in 100 miles.
I was just thinking...if they made this thing to carry 2 people...
Thanks everybody. It's off the craigslist.

 

[veloman]

My tandem ebike is just a $200 Walmart Pacific Dualie (steel frame). It does absolutely fine with my gf on the back and a 9c front hub motor, no complaints. It would be nice to have independent pedaling, but eh. I got it for $95 off craigslist. If you are in a city, it shouldn't be too hard to find a cheap used tandem. The older ones tend to not have v-brakes, but disc brakes could be a good idea. I swapped in an Avid vbrake on the front and it stops the tandem fine. It has all steel bars and seatposts, stems, the wheels were generic 36 spoke Weinmans, the rear hasn't had an issue yet. It even has an eccentric front bottom bracket to adjust the chain tension to the stroker crank. Good stuff.

I've used it myself to carrying my gf's ebike really easily. Well, it handled awful and I couldn't pedal, but it loaded up in a minute. Converting to a cargo bike would be easy.

Just know that tandems are like driving tractor trailers. HUGE turning radius. But very stable at speed. They are also a PITA to move around while off it, like into a house or any tight area.

If you want independent pedaling on a basic drivetrain, just cut the stroker crankarms off to be flush with the chainrings. They shouldn't get in the way of your cargo too much then.

 

[dogman dan]

No problems with the wheels themselves? That's a bit suprising if you are loaded up. Do they look beefier than a normal cheap walbike? The ones on my trike were shocking bad.

The frame? is it a step through or a normal diamond. As I was saying, the wheels can be fixed easy enough. What really made me shy of this particular one was double step through frame at that price. It just looked to me likely to be weak. A cheap tandem with a traditional diamond frame would also allow a much better battery carry space. That would be something you could work with a lot better I'd think.

This one, would have a lot more appeal to me. Cheap still, but the frame looks strong. http://www.walmart.com/ip/Kent-Dualdrive-Tandem-Bicycle/3663045

Do the free ship to store, it means you assemble it, but not much different than normal, where you need to RE assemble it anyway.

 

[veloman]

Wheels don't look great, maybe what you would find on a $300 bike shop bike. I think if they are built right, they can't be too bad.

Here's what mine looks like. Definitely strong.