Saturday, July 17, 2010

Motorized StreetFox recumbent trike - builder forum

Here are a few pictures of my just finished modified Streetfox. I built everything from scratch as I was having a hard time finding old bicycles suitable for what I was doing. I did not want a spring suspension on the back because I wanted it as solid as possible for the motor drive. The front end is built from scratch using automotive bearings because of the higher speeds I was going to be going.

It has the 32cc Golden Eagle Bike Engine and because it is more aerodynamic than a standard bicycle, the top speed on the flat is 48 MPH. The GBE engine has the Hi performance carb and the hi performance K&N air cleaner.

I have not painted it yet as I am still thinking about putting a velomobile body on it and the mounting points will need to be brazed on. The bike is brazed with no welding at any point.

My next tadpole will be TIG welded. Just to be different and also because I am going to build the bike to sell. OF course it will have a motor on it. It will also have Chrome molly tubing as this build is a bit heavy....but it really is not all that noticed even when I am just pedaling with the drive belt off. It really rolls well and straight.

The tires are Schwalbe Big Apple 26 inch rear and 20 inch front. They are like having a suspension on all three wheels. Amazing tires. The sidewalls with the reflective whitewalls are great at night. You can see me from the side a mile away.

I have a V brake on the back and front disk brakes. This thing stops on a dime and is very stable and straight when braking at speed.

The GEBE engine kit got me 170 MPG at 35 MPH on my other bike and I am getting over 190 MPG at over 40 MPH on this new build probably due to the improved aerodynamics.

The red gas tank will be replaced with an aluminum 2 gallon spun tank that I am going to tig weld next week. The headrest is from a junked Honda and the seat is from an older recumbent I had. It is adjustable just as the pedals. I am going to replace the 3rd ring at the front with a larger unit because when at speed with the engine, I still like to pedal....and I want to go even faster!

When I ride it, I am always getting stares and when stopped I get a whole lot of questions.
I even have had a guy in a pickup truck follow me home and took some photos. I am probably the most photographed bike rider in Ohio right now. Constant photos from many many people. The local Harley Davidson riders sure love this thing too.

I rode it for over 4 hours today. I went over 100 would have been more but I was stopped by so many people asking questions about it.

After I get it painted and finished totally, then I am thinking about doing a two week road trip with it. Maybe a ride around the great lakes. I've been on a long road trip with a diamond frame bike and it was a pain...this thing is so comfortable. My next project will be a bike trailer so I can do some real traveling with it.

This bike is so smooth and really stable even at downhill speeds of over 55 MPH. I had my brother clock me going down this one road and on the flats I was doing 48 and down the hills at 62 MPH. It is fast for a trike and being so low, it really makes that speed seem even faster.

I've got to watch as the speed limit for a motor assist in Ohio is 20 MPH. When I see a cop, I have to slow down and start pedaling really fast to make it seem my pedaling was the thing that got me going so fast. That little 32 CC engine really moves this trike...and I'm getting fantastic gas mileage...I only used less than half a gallon to go that 100 miles.

Brazing is a very strong way of joining metal, and if you look at all the table saw blades that have carbide tipped teeth, they are brazed on the saw blade frame.

Brazing does not require the melting of the metals because the heat required to braze is less than the melting point of the metals to be joined. Crystallizing of the metal is not possible with brazing and so makes the brazed joint stronger in that the common point for welded joint failures is not the weld itself but the metal nearest the weld.

Brazing joins the metal together with capillary action. The metal sticks to the metal by having the brazing material fill into the pores in the metal.

You might be surprised to know that in some high end cars that are hand made, brazing is very commonly used to join metal. Also, gluing is commonly used to join metal in auto manufacturing. You would think that glued metal is not strong...but it is!

I have seen many high end bicycles made by professional frame builders and almost every one was brazed. I've never ever seen braze joint failure on one of these bikes after many many years of use.

I have learned a lot about welding and brazing from Lincoln Electric as I attended their school at their factory in Cleveland, Ohio. I like to mess around with metal and from what I have learned, brazing is a viable alternative to welding especially in bicycle construction. In many instances, it is the preferred method of joining metal.

I once thought that brazing was the weaker in the braze vs welding arguments. My instructor told me to braze some metal together and weld some metal together. Then by using a hydraulic device, test the welded vs brazed joint. To my surprise, the welded joint broke first not at the weld but at the point nearest the weld. The brazed joint failed at the exact joint...but it took longer to fail than the welded piece.

So from my experience, I have total confidence of a brazed frame and not afraid to go even faster than 40 with it. I just hope my tires don't fly off the rims going faster than 60 down a hill!

I own my tanks...they are not large ones so rental is not required. I bought my welding outfit at a pawn a great deal on it...I buy the uncoated bronze brazing rods and have a can of it is cheaper than buying the pre-fluxed rods.

Brazed joints can, depending on the joint design, withstand force of up to 69,000 lbs. per square inch. That is way more than the weight of me, the bike and any force applied to any of the joints on my trike.

Brazing is still used on production Formula car chassis in England. Also used on light aircraft frames. I think I am quite safe with my brazed modified StreetFox.

I have been a member of EAA (Experimental Aircraft Association) for many years and some, not all, of the aircraft I have seen built use silver braze to join the structural parts of the fuselage. Others such as the Dyke Delta, a homebuilt, used silver brazing for the wing rib structure.

The very same argument about brazing vs welding has been going on in the EAA for years. Silver brazing of chrome molly tubing is often preferred by some to tig because tig causes crystalization of the metal due to the fusion of the metal although in a very localized area. Brazing on the other hand, uses less heat over a wider area but the heat is not enough to transform the structure of the metal. Fusion welding has a habit of causing metal fatigue right next to the weld. Not so with brazing.

I have seen some restorations of aluminum framed aircraft that were aluminum brazed down at Wright Patterson aircraft museum. Some older aircraft frames were brazed due to not having tig because it was not invented yet.

The Boeing B-70 Valkarie Delta Bomber used brazing of the stainless steel and Titanium in many of its parts. Not sure if anything structural on that aircraft were brazed though. I am thinking that it was tig brazed or furnace brazed.

Today, structural brazing of aircraft is limited to high end processes of honeycomb construction as many of the parts of modern aircraft have been furnace brazed or tig brazed. From the numbers, brazing is strong enough to handle any of the stresses that we put on our bicycles.

Update:  Been riding around without paint for a couple of weeks...cables taped to the bike...not ready for prime time for sure..and it was bound to happen.

I had a flat tire and a rear derailleur go on me at the same time 10 miles from home. Never going to use a cheap used derailleur again! It was partially my fault as I had the derailleur adjusted wrong...but I wanted to ride and did not take the time to adjust it. It bent the derailleur mounting tab and elongated the hole...the derailleur bolt actually broke out of the tapped hole.

I had to take apart the bike and drive it home in the back of my Honda CRX. Decide because I had it apart it was time to finish it and paint it. Finished up the brazes and ground down the braze points. Fixed the bent rear derailleur mount by making a new one and tapping it.

Greased up all the steering bearings and wheel bearings. Thread locked all the bolts. Geesh there is a lot of things that need to be done before a bike can be road worthy. Spent about 6 hours today working on the bike.

I am using Rustoleum pickup truck bed paint. This stuff is awesome! Tough as nails but it takes a while for it to dry. I am using POR 15 prep liquid and so I do not need primer. After painting, let it sit for a day before putting it together! Pickup truck paint takes a while to dry.

Before all this, I was riding in the local Metroparks here in Cleveland and I had several people asking about the bike and the motor. I even got stopped by a cop who wanted me to build him a bike. I've had several women pull up to me as I was riding and took some photos with their cell phones. Women seem to love this thing. Guys like it too but I would rather talk to the ladies. Seeing how it was not painted, I was surprised that so many people asked where they could buy one.

Still have some assembly to do and am going to replace all the cables.

Read more of the motorized StreetFox build blog: