StreetFox: Over vs Under? Does it matter?

OK, I've had the StreetFox plans for a while but due to limited vision (legally blind) I am unable to build it myself.

Cross boom: Two metal bars that connect the tires section together.
Main boom: Connected to rear of trike and connected to cross boom in original plans with
the cross boom section welded to the top of the main boom.

I did see a post where someone who built the Fox had their welds stressed to the point of possible failure.
My question is, Instead of putting the 22° cross boom on top of the main boom that runs from the rear of the trike to
the front, putting that bar on top of the cross boom as that would seem to be stronger?
Here's my reasoning (being the somewhat logical ham operator I am):

The cross boom takes the weight of the rider, as does the main boom.
The main boom being on the bottom of the cross boom has no support, thus stressing the weld.
Should that weld break, your main boom would be on the ground with your cross boom still being
supported by the tires.

With the main boom being on top of the cross boom, the weight on it would be transferred to the cross boom and
tires. This not only shouldn't stress the weld due to no support, but would seem to eliminate a point of possible failure.

Result:

Cross boom: Two metal bars that connect the tires section together.
Main boom: Connected to rear of trike and connected to cross boom in original plans with
the cross boom section welded to the bottom of the main boom.

Thoughts? Comments?
 
Six of one and half-a dozen of the other really.
Properly welded there should not be a problem. My Streetfox never had an issue.
I do understand that some folks have had issues and have applied gussets/plates etc.
 
Hi Danny, thank you for writing.

Welding is definitely not my thing. I'd probably blind myself totally,
Being that you have a Street Fox, how do you like it?
If I do get it built, I'd have to modify it to make it easier to get in and out of.
What are your thoughts on that? I was thinking vertical bars at the end of the
cross boom, It would also be a nice place to mount a couple of ham antennas. :)
 
I don't build tadpoles however the only person I remember who came on here claiming weld failures had not properly diagnosed the problem ?
They had poor steering geometry causing severe wheel shimmy.
Instead of fixing it they fitted a steering damper , this transferred the energy of the shimmy into a single point in the frame.
Despite them having the weld repaired it was not actually failing , the metal was tearing alongside the weld where the metal was thinnest.

If you want ' easy to get in and out ' build a delta , also then you can't get ' bad steering geometry ' as they have a single wheel ;)


Paul
 
Hi Danny, thank you for writing.

Welding is definitely not my thing. I'd probably blind myself totally,
Being that you have a Street Fox, how do you like it?
If I do get it built, I'd have to modify it to make it easier to get in and out of.
What are your thoughts on that? I was thinking vertical bars at the end of the
cross boom, It would also be a nice place to mount a couple of ham antennas. :)
My first ever recumbent was a StreetFox. My brother (a welder by trade) helped me make & powder coat it in one weekend.
As a first ever recumbent it was ok. I no longer have it, I have a different Tadpole and a Hase Kettwiesel Delta trike and a home made Python Delta Trike. Of all three of these the Hase Delta is the easiest to mount/dismount. :)
 
Hello again Danny,
I'm so glad to talk to someone who has built one and ridden it.
Being a member of the grey haired mean old grouch society, I was looking
at both the Catrike Expedition and the Catrike 700. The 700 seems to be too
laid back, and while the Expedition does have a place to put bars to help one up,
They want close to $3000 for a Catrike and while that's not a bad price, it is a bit
too rich for my blood. I figure if I'm going to build one, I want it built to fit me and my needs.
The problem for me has been finding a welder who will take on such a small job.
As I have never ridden a trike, I'm still apprehensive about it.
They say you don't forget how to ride a bike, but these things are new to me.
Your brother built one in one weekend? Impressive.
If you don't mind my asking, did your brother do the powder coating himself?
I'm not even sure where to start. There are plenty of bikes at the Goodwill that
look like they work.
 
Distance it the issue, but I'm always willing to help a fellow Zombie. Maybe some travel, weld a few days, problem solved.
 
As I have never ridden a trike, I'm still apprehensive about it.

They're hilariously good fun. You just do a controlled fall into the seat, and after that it's like sitting on someone's too-low couch. You're sitting in a real seat, not perched on a stick with a skinny saddle grinding into your wedding tackle. If you get tired, you just pull over and take a break. Or a nap, if you have a headrest. Then you ride off again.

The only problem is when the seat is very low, particularly with tadpoles where the frame crossbar is where your feet want to be when standing up. That can be worthy of a YouTube "fail" video. Some designs, it's no trouble at all.
 
Well, that's the thing, if the seat is too low, I might fall back and cause the seismographs at the University of Washington to register a .9.5 tremor. :) Still though they do like a fun ride. A controlled fall isn't the problem, it's that fight against gravity that worries me. :) I was thinking I could roll off to the side, do half a push-up to get on one knee, then use the other leg to reach a standing position. I do think a recumbent would be fun to ride though.
 
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