Yesterday I was at a neighborhood bike shop (Build-A-Bike) and saw this in their used parts stack:
My first guesstimate at the store was that it was 24" only, but it looks like it might take 26" too if they're not fat tires.
As soon as I got it home I had to mock it up and the closest bike to hand that was partly together was the Mongoose disc brake one I'd gotten the prior week:
WHile this bike is not what I'd actually want to use (heavy frame) it gives the impression of it's typical form.
Since it wouldnt' really take the standard bike wheels with cassettes,
and only does lefthand drive, I did a quick check and the 24" Fusin geared hubmotor wheel I made for the front of CrazyBike2 fits in there ok:
The only real issues are
A) The dropouts are thin, and will need reinforcement for a hubmotor's torque
B) The dropouts are cut in that nonstandard pattern, and would not allow me to rotate the hubmotor into the slots to give it something to torque against (at least, not without some considerable filing to round a corner and allow it to pivot into place).
So I'll need to make a torque plate that bolts to the frame on each side of the wheel that actually does the work of the dropout's torque-reaction, and let the dropout just handle the vertical loading to the axle.
At first I was thinking that since a cassette-type wheel wouldn't fit, I'd have to relace/redish one into a single-speed wheel, and then find a single-speed freewheel to go on it. But then I remembered the 3-speed hubs from Spinningmagnets, which I still want to try to use with powerchair motors on my tadpole trike idea ARTOO.
This is what these trike adapters were DESIGNED to work with!
You can even see the little pulleys for the shifter cable.
So that's what I'll use, which will give me at least 9 pedal speeds if I use a 3-ring on the pedals, and a derailer locked in one position on the rear of the bike chainline to the input of the trike adapter.
In the pic above, it's the Sachs 3-speed with coaster brake, and I'll probably lace that into a 24" wheel and use the smoothish road tires like I already have on CrazyBike2. Maybe I'll lace it into a 26" wheel, but that puts the weight higher (unless I sling the battery box below the back of the trike frame).
If I do use 26" wheels, I already have a Fusin 26" wheel courtesy of Dogman this last week, because he brought me a bunch of Fusin stuff to go with what I already have (much of it is interchangeable). More on that in the next post.
I thought about it a lot, and decided at least for now that I will use the Trek frame originally intended for the CrazyBike2-descended cargo bike, as that's still on hold while I sort out rear-suspension options. It's the smallest lightest strongest frame that is still suitable for the disc-brake 1.125"-headset shock fork off that Mongoose. Since except for the coaster brake on the left wheel's Sachs 3-speed IGH, it'll be the only brake on the trike, it better be a good one.
I'd kinda like to use the 26" Manitou adjustable fork on this instead, but I don't yet have an adapter to let me use disc calipers on it, and I really think I'd like to have that. Plus I'd have to build a 26" disc-compatible wheel, which I am not sure I have the spokes for (I didnt' have them for the 24" version, either, until now I have the whole 24" wheel right off the Mongoose).
The frame is actually about 3/4" too wide for the trike adapter bracket, but being steel it can in theory be bolted down anyway, letting it bend the stays inward as teh bolts are cranked down. I don't think I'll do it that way, but it would be possible.
Oddly enough, the U-bolts I'd gotten supercheap from AllElectronics happen to be exactly the right size to go thru the existing trike kit seatstay bracket and clamp it to the frame. They aren't what it originally used, probably, but I don't have that hardware, and I think they would suffice. However, I don't think I am going to need them....
I think I'm gonna make it a full-suspension trike instead.
I'd need to make mounting plates to bolt onto the bike's dropouts (which can also be filler-spacers for the too-wide dropouts), and then will need to use pivoting bolts for the mounting point at the dropouts for the trike kit itself. Not totally sure how I'll do that yet, but I think I will probably make a plate that bolts to each side of it with something that bolts to the flanges of a wheel hub, and then bolt the wheel hub into the dropouts. That'll give me a good pivot point, and if I make the extension plates long enough, it'll also extend the trike kit back some distance (probably necessary for where I want the seat to go.
That's the skateboard that might eventually become the seat on the FS cargo-bike, but for the moment it cna represent whatever seat moutning I am going to use. Representing the seat itself is one of those bleacher-back half-chairs:
Also you get to see about how the bars would be setup, pretty much like the ones on CB2 are. The difference is I will almost certainly bolt the steering section (headstock/stem/tube) to a seatpost (as Barrytrike did) instead of welding, like I did with CB2.
Right now the seat shows over the axle, and would be tip-prone to the rear, but I'll be moving the trike kit backwards some distance (at least a few inches, and possibly a whole foot).
That wheel leaning on the left side is a 27" or 28" or maybe 700C cruiser wheel with a SA 3speed IGH in it. Without a tire it'll fit in the frame, but not with even an old skinny 10spd tire on it. So I'll definitely have to build a wheel to use on this, and can't just bolt an existing one in for the left side, unlike the right side with the Fusin in it.
CrazyBike2 next to the trike mockup:
You can see some of the differences and similarities in how I'd like the trike to end up. Same handlebars and what will eventaully be the same steering setup, remote with a bar from pivot on bars to pivot on front stem.
Different wheel sizes
From the big cruiser wheel down to the 26" rim from Ianmcnally, down to the 24" wheel off the back of the Mongoose (only one with tire on it).
Then I'll need to work out a way to use either the standard chainstay-clamp trailer hitch on it that's part of the kids' trailer I have yet to do much with, or make -a hitch like DayGlo Avenger has for my kennel trailler and/or chariot trailer, so that I can haul really big loads with it. Stuff I can't do on a bike because I can't go slow enough and still stay upright, etc.
(EDITED to alter thread name 11-12-10)
It's an old bolt-on trike "kit". Left side drive only, but that's ok, as it gives me some options a differential drive wouldn't.
There are a few things that I may have to modify on it to allow use the way I'd like, most especially the dropouts, as they are not standard ones. Instead, they are made to feed the wheel axle up into and then back into a slot, so only a standard 10mm round axle actually inserts properly.
They are also made for narrow-width rear wheels, like single-speed cruiser wheels, rather than the wider multi-gear cassette types.