DIY Trike Conversion?

[blown240]

I'm thinking about making a trike conversion that would bolt onto a normal bike frame. Something that could be taken on and off relatively easy, and that would work on a number of different bikes. The reason for my build idea is so that I can take family rides at the beach this summer with the family, plus trikes are cool and I don't have one.

So my thoughts are a trike conversion that will allow a small bench for the kids to sit on, or a cooler, etc. something that I could put on a cruiser, or maybe a fat bike. The trike will have fat tires on it.

the first version would simply be a stable frame with 2 wheels, then I would make it able to carry something after I know the mechanics of it are solid.

I am looking for ideas on where to start.

Thoughts, ideas, etc from you guys would be great!

 

[RustySprockets]

Were I contemplating a DIY trike conversion, I'd probably pursue a path similar to this Sears bike with Ret-Bar trike add-on.

http://img.photobucket.com/albums/v314/mastrehalo/IMG_1521.jpg

This style of conversion permits a standard bike frame to be attached by the rear dropouts and, unlike many dedicated trikes, uses regular bicycle wheels and hubs. One minus...only the left-hand rear wheel is driven.

 

[blown240]

Thats pretty cool. I will look into those a bit more. I found a cool Worksman trike frame on Craigslist, but its more money than I can afford right now.

 

[RustySprockets]

I had the pleasure of working on two Worksman Adaptables and those bikes are RUGGED...and heavy. They use stub axles with keyed hubs and a modified three-speed mounted as a jackshaft. Overkill for your application, IMHO.

Building something on the cheap might be possible by cutting the rear triangles from two matching donor bikes and tying them together to form the conversion unit. Here's another photo...a closeup where the front frame joins the rear.

http://img.photobucket.com/albums/v314/mastrehalo/IMG_1514.jpg

 

[blown240]

Here is something I came up with. I like the idea of 2 wheels driving, even though I know it will make it harder to steer. There would be a freewheel hub as a jackshaft with a 7 speed. The derailed would be mounted on the trike portion so that it could be added to a single speed bike. There would be a single disc brake and a single gear on the axle.

the frame would be 1" square tubing with kickers running up to the seat collar on the bike.

Do you think 1/2" solid rod is strong enough to use as an axle? It would ride on bearings at the ends and in the middle.

Here is a rough idea:

 

[RustySprockets]

Your diagram is very similar to the way that Worksman does it. Both the shifting and braking chores are done by means of an internal-gear coaster hub employed as the jackshaft. I've never seen one that used a deraileur. Take a look at the DIY projects over at AtomicZombie.com to get some ideas.

 

[blown240]

Thanks for the link.

I see that I should probably use a 3/4 shaft for the axle. I was thinking last night, that if I used half axles, and 2 chains coming from the jackshaft, I could have both wheels drive, and still have easy turning. Im just not sure if its worth the hastle of having to have double rear brakes, and a double rear chain etc.

 

[RustySprockets]

I'm not so sure that half-shafts would cure the problem. Wouldn't both left and right have to rotate at the same speed as the central jackshaft?

 

[blown240]

With single speed free wheels on each half shaft the outside wheel would be able to turn faster than the inside wheel. On corners the inside wheel would be the drive wheel and the outside wheel would basically be coasting a little faster than the inner wheel.

Going straight both wheels would pull because they would have the same gearing.