StreetFox out of aluminum instead of steel?

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DeeplyShrouded

I still have not found a local welder, I'm curious if the StreetFox can be built out of aluminum instead of steel to decrease the weight of the trike.
I assume, one would have to have a welder that knows how to weld aluminum?
Also, the bike parts would also have to be aluminum because welding dissimilar metals results in weak welds due to galvanic corrosion?
Ideas on building the Fox out of aluminum? Advantages? Disadvantages? Thoughts?
 
You're correct - All the welded parts would, of course, have to be aluminum.
The problem with aluminum frames, is that they really should be heat treated after welding - Something not practical for home building.
You can compensate somewhat for this by oversizing the tubing, but by the time you get done with that, you're close to the weight of steel.
BTW, I believe commercial trike manufacturers have shorter warranties for aluminum frames, than for steel ones - They must know something.
 
Welding aluminium is a job for the more expensive welders. An AC tig is the ideal but an AC mig can work too. The problem with a recumbent chassis is it is used as a beam. Aluminium makes poor beams. It doesn't bend but does fatigue and crack. Regular diamond frame bikes are perfect engineering examples of two triangles putting all the forces along the tubes where they are strong instead of across whee they are weak. Almost all the aluminium recumbents use either oversize tubes or make every effort to put triangulation in or as a minimum make the chassis in as many planes as possible to spread the loads such as making the seat tubing part of the stressed chassis. Brad is emphatic that his designs are not suitable for aluminium and given how I've bent a few in steel he's right. Ally can be done by a competent welder who understands where the loads are going and can design a chassis accordingly. As a bare minimum you'd need a dropped front cross chassis member so you could then add triangulating braces back to the main chassis tube. Given the extra metal and thicker tubing I doubt any saving will be worth it. Better to use lighter wheels and tyres. Fat tyres look good but add a lot of lard.

Buy a welder and learn. Mig is simple to learn for steel.
 
If you build a Streetfox in aluminium , with the tubes/box section correctly oversized, you would have a 15% weight advantage . But the more expensive way of building, would end up with a simular, or even higher pricetag than a premium brand tadpool with the same capabilities.
 
Popshot said:
Welding aluminium is a job for the more expensive welders. An AC tig is the ideal but an AC mig can work too. The problem with a recumbent chassis is it is used as a beam. Aluminium makes poor beams. It doesn't bend but does fatigue and crack. Regular diamond frame bikes are perfect engineering examples of two triangles putting all the forces along the tubes where they are strong instead of across whee they are weak. Almost all the aluminium recumbents use either oversize tubes or make every effort to put triangulation in or as a minimum make the chassis in as many planes as possible to spread the loads such as making the seat tubing part of the stressed chassis. Brad is emphatic that his designs are not suitable for aluminium and given how I've bent a few in steel he's right. Ally can be done by a competent welder who understands where the loads are going and can design a chassis accordingly. As a bare minimum you'd need a dropped front cross chassis member so you could then add triangulating braces back to the main chassis tube. Given the extra metal and thicker tubing I doubt any saving will be worth it. Better to use lighter wheels and tyres. Fat tyres look good but add a lot of lard.

Buy a welder and learn. Mig is simple to learn for steel.
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I'm legally blind so I don't think welding would be a good idea. :)
I still want a Fox but may end up buying an Expedition if I can find a used one cheap enough in my area.
 
DeeplyShrouded said:
but may end up buying an Expedition
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You have to be realistic about your circumstances- A Catrike Expedition is a fine, well-made machine, and you'd be happy with it.
Also, there is lots of scope for modifying and personalizing a commercially made trike - No one here would have an issue with that.
I think it's more important that you just get riding :)
 
True, an Expedition is a well made expensive machine.
I like the Fox because you can modify it to your own specifications.
I'd like a Fox with suspension. I just need to figure out how to mod
the plans and find the parts, and find a person who can weld.
Details, details....so many details... :)
 
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