Thursday, July 4, 2013

My TimberWolf Delta Trike Project

By Dennis Martin

Two years ago while on vacation in Iowa after mentioning RAGBRAI (Register's Annual Great Bicycle Ride Across Iowa) my wife said to me, "Why don't you do that again?"

I hadn't ridden the ride since RAGBRAI XVI (1988), but after thinking about it for a while I thought it might be fun to do it again. The first thing I decided was that I wasn't going to do it on a regular bike!  I've got too many memories of aching back, shoulders and wrists from riding a regular road bike. I wanted a recumbent! Wow, I couldn't believe how expensive they were, and I didn't really see one I liked that well. That's when I ran across Atomic Zombie and their TimberWolf Delta Trike.

Photo 1: Chain guard on tension pulley.
I watched the video and thought to myself, "What a cool trike!" I ordered the plans and spent several days reading through the plans to get ideas on where to get the parts and various items I would need. I immediately started browsing Craigslist for cheap parts. In that way, I got fairly lucky.

I found a mountain bike for cheap and was able to scavenge the bottom bracket, derailleurs, shock and frame pivot. I also used the pedals and the brake levers.  I managed to get the whole front end on a 20" bike from Goodwill for $5! I found an estate sale on Craigslist from a bike shop owner and managed to get brand new chain (a carton of 10), complete crank and bearings and the disk brake. All were new in the box and at a significant saving over retail.

Thanks to AZ for selling the hubs and I was ready to start assembly. Assembly is pretty straightforward per the plans, but I found as I went along that there were a few changes I'd recommend to others if they want to try this (or similar) construction project.

The first thing I found was that the tension pulley really needs a chain guard. I found that if back-pedaling, the chain would drop off the pulley wheel and then get caught between the pulley and the frame when forward pressure was applied. A very simple piece of strap steel bent into a long "U" shape and attached to the pulley bolt will keep the chain in place.  Nice, simple (and inexpensive) fix (see photo 1).

Next, on the advice of my local bicycle shop, I went with a two-bolt mount for the handlebars.  The kind shown is the plans is hard to find and in reality it is much easier to mount the handlebars if you use the two-bolt assembly. That way, you don’t have to pass the entire handlebar assembly through the mount if you need to attach/detach the handlebars (see photo 2).

Photo 2: Two-bolt handlebar mount.

I discovered while assembling the seat that a better way to mount the wooden seat to the frame is to use T-Nuts and bolts rather than using wood screws. This offers a much easier way to attach the seat and won’t strip out if you have to remove the seat very many times (as I found you will do) during construction.

The plans call for a rear cargo area which is actually a Coleman cooler.  AZ told me they got theirs from Canadian Tire; I was able to order one online from Target. I chose the red one and that decided the color for the rest of the trike. I wasn’t happy with the plans where they actually have you drill holes in the cooler, so I devised a mount that wouldn’t require you to ruin a perfectly good cooler by drilling holes in it.

Instead of 3/4” tubing, I used some left over 1/2” tubing that I had left from a gate project and made a rectangular frame that just fits around the cooler. I attached a 1/2” tube on the back with some angle braces and it now attaches to the 3/4” tube that comes down from the back of the seat rest using a bolt to hold it in place. The 1/2” tubing fits perfectly inside the 3/4” tubing, and as you can see in Photo 3 the bolt is held by a wing nut to make for easy removal. I also made another carrier for the back with I will use on RAGBRAI to hold my camel back pack rather than transport the weight of the cooler on the whole trip.

Photo 3: Rear cargo carrier mount.

In Arizona, bicycles are required to have tail lights. I had difficulty finding something that would fit and be bright enough to be seen even in bright sunlight. Problem solved thanks to a couple of LED flashlights available from Home Depot (they come in a two-pack for about $9). Some inexpensive tool brackets and they are ready to go. These flashlights have a four-way light system: white, red, green and flashing red.

I mounted two of them on the rear frame and turn them both on to flashing red. They don’t blink at exactly the same rate, which works well in giving a random flashing pattern which is very visible (see photo 4).  In order to mount these evenly, I used the short stub on the right side of the rear frame for one light, and welded a bracket to support the other light. The bracket is made from a scrap piece of frame tubing. These clamp on really tight, and the flashlights are weatherproof, so I shouldn’t have to worry if I get rained on. The flashlights run on 3 AAA sized batteries each and should run for a long time in flashing mode.

Photo 4: Rear light mounts (one on each side).

The last modification was to add a bicycle flag. Sitting low to the road as this trike does, I wanted all of the added visibility of a bike flag. Unfortunately, bike flags normally mount to the axle nut on a regular bike. No rear axle nuts on this trike! Problem solved by making a bracket from some 1/8” angle iron and welding some gussets to make a sturdy frame.

Photo 5: Bike flag holder.

Next, I took another scrap of frame tubing and cut it out as seen in photo 5. An end cap is welded on to make a base for the frame to provide a way to mount to the bracket. I used a piece of 16 Ga. steel to make the clamp. By heating and striking it with a chisel while setting on top of a vise with the jaws open slightly, I was able to get a “V” shape and get the shape you see in the photo. Three 1/4” bolts with wing nuts hold the clamp in place. This makes it easy to remove the flag when transporting the trike so that the flag won’t get damaged or get in the way.

Photo 6: The finished product.
I’m looking forward to riding this on RAGBRAI XLI this year (July 21 - July 27). Maybe I’ll see some other AZ bikes on the ride. Happy pedaling!

Dennis Martin, Sun City, Arizona

Thanks for this excellent article and pictures, Dennis. Great building tips, too. Have a good time.