DIY tandem or trike

[Christ]

I almost like the idea of the recumbent reverse trike better... plus, I can add any motor up to 1.5 HP and still keep the pedals, and it's a street-legal moped! (Needs lights and stuff, but still.) I bet a weedwhacker motor would drive one of those nicely, if made from fairly stiff reinforced plastic or aluminum tubing.

Once I figure out the bills, I might just have to buy myself a few of those plans.. or see if I can find them for free elsewhere... love to support an artist, but I can't see tossing out money for a simple plan like that.

[zjrog]

Bought a regular adult trike for my wife. She has significant balance issues. First thing I notice, the riding position SUCKS! Seattube lays back a lot. I might have to get a longer post and have it tweaked. I KNOW its not a bike, but comeon... The trike is a Miami Sun, has a 3 speed internal geared hub with a coaster brake. It rolls on 24" wheels, the coaster brake hub acts as a jackshaft and has a gear attached instead of a flange for spokes, which drives the rear shaft with the right rear wheel fixed to the shaft, the left rear hub has sealed bearings and spins on the shaft. Anyway, my wife loves it, and isn't doing too bad. THis coming weekend we'll see how she does on a bike path loop...

Tandem. Still on track. Had a couple more pressing projects to clear up. Ordering the tubing this week. Enough to run a tube between bottom brackets, another from the headtube on the front to the bottom bracket of the second bike, and to stretch the top tube of the second bike. Will get some pics as the carnage/er/construction begins...

[zjrog]

What I suggested as riding position sucks, is not that the seatpost is laid back so far... But the crank is so far forward of the seatpost (which is 70*, just like the Trek 950s I will make into a tandem...). Of course, we never intended this to be a serious cycling machine...


As my wife gets faster and has more stamina (of course, lots depend on the recent hip issue mentioned in another thread), I have been thinking of ways to make the trike faster. The easiest to do is to swap the rear sprocket for a taller geared one. After that, it gets more difficult. I might be able to swap the input sprocket on the Nexus hub just not sure yet. Next would to build new wheels at 26" instead fo the 24s... But that would look funny. I think.

We are still building the tandem, tubing will be ordered soon. But we might end up buildign the tandem as a trike. Or, be able to make it work either as a bike or a trike. Parts for the trike aren't that expensive, a rear conversion is under $200, the hard part will be gearing... But I think I have that part figured out. We'll see how that goes. Why the tandem as a trike? We are concerend my wifes balance issues might make her feel out of control relying on me for balance. And seriously, I don't intend the tandem to be a speed machine anyways.

[Christ]

Can't wait to see what turns out!

[Bicycle Bob]

That riding position is worth a premium price to some people. On that trike, it lowers the CG and makes mounting easier.
Gearing alone is seldom the issue with speed potential, but I'm not going to write a new book on the subject here.

[zjrog]

Oh yes, step in rather than over is big. Which is why one of the Treks is a small frame, but I'll still stretch the top tube out.

[VRdublove]

Looks like a fun little trike!

If you are considering going electric, I'd recommend using a hub motor, the Crystalyte Phoenix Racer 5 series is my favorite. It's very torquey, and is very clean and simple. Just make sure you use a torque arm if you are going to go the hub motor route.

EVcomponents.com sells lightweight LiFePO4 batteries for very good prices. You could use anything from a 36V 10Ah pack up to a 48V 20Ah pack. There's lots of cargo room onboard those Delta-style trikes for some great battery capacity.

Have fun with it.

-Tommy

[zjrog]

Thanks for the link! I got into a few other projects and the tandem is on hold for a bit...