non-welded ebike frame?

[mud2005]

Hi all, I was wondering if anyone has ever heard of a bike frame that has no welds?

I know it sounds a bit ridiculous, but I was just wondering if it's even possible

and by no welds I don't mean a brazed frame I mean a bolted together frame.

I saw this and it made me wonder if there were some products out there that would make it possible to build a bike w/o any welding

 

[vanilla ice]

Sure why not. Bolt on bracket everything.. bolt on lugs.

My kid uses one of those things in your pic for our tandem ebike, but ours has four bolts. I think it was a Santana kidback bracket. They are welded though.

 

[vanilla ice]

Ah you mean commercially available.. I guess you could screw and glue a steel frame together with the advanced adhesives that exist these days. If glue is good enough to bond airliners and building parts together, should be good enough for bicycles. I have a bonded aluminum Italian cross bike that has no welds, and that is twenty year old tech.

 

[mud2005]

interesting, so lugs and good metal epoxy = bike frame with no welds. I wonder what the best epoxy would be? Luke recommended Devcon in a different thread, but when I looked at their products I was overwhelmed with the different types of epoxies they sell.

 

[wasp]

they make bamboo bikes...

 

[dequinox]

E.g.-

 

[Mark_A_W]

My friend made a similar bamboo bike (well, it's a fixie, but the bamboo bit is similar).

Nice bike, could use a couple of thousand watts

 

[amberwolf]

I suspect it's not quite what you're talking about, but I am working on a bolt-together longtail cargo bike, made from two preexisting bike frames (that could be any type, welded or not, as long as they'll fit together right, but mine happen to be welded cromoly), and other assorted easily-found hardware. It'll sort of end up like a cross between Justin's Cross-Canada bike and CrazyBike2.

I'm sure that with the right tube braces one could make a totally-bolt-together bike. If one had premade pieces like the brazed-together bikes do, that create all the angles and provide fixing points to perfectly clamp tubes down, then it'd be a fair bet it could be almost as strong as a welded or brazed bike.

I'm imagining solid CNC'd steel brackets that would have a circular notch in them for the tube (as if you put a hot tube into ice, it would melt out only the tube shape) to leave anti-crush support inside the tube, to help pass clamping forces all around and thru the tube. Part of the outer bracket would be clampable down onto the tube's outer surface to secure the ends in place.

Lots of other ways to do it, too, I'd bet.

 

[whiteblade]

Here a recumbent bike that is riveted togeither.There is only one aluminuim brazed part on it.

Here's a link to there web site

http://rivetrecumbentbike.com/index.html

Here's a few picture's from there web site

 

[docnjoj]

My old trike has no welds. Great bike that is still operational after 10 years of hard use.

http://www.americruiser.com/

otherDoc

 

[gtadmin]

About 1968 or so, Husky had a 500cc 4-stroke motocross bike where the frame was made from aluminium tubes that were aircraft quality epoxied together.

Cheers,
GT

 

[Harold in CR]

If a guy were wanting to build a bike, he could cut off the used parts off other frames, and leave the tubes a bit longer, so he could slip slightly larger tubes over the originals ???
I am planning to cut parts that way.

 

[evblazer]

Here a recumbent bike that is riveted togeither.There is only one aluminuim brazed part on it.

Here's a link to there web site

http://rivetrecumbentbike.com/index.html

That is pretty cool. I put my little friction drive mount together that way but a whole bike!.. There is a back to back recumbent tandem made with rivets for sale on the bentrideronline forums but I had never seen a single..

 

[whiteblade]

Here a recumbent bike that is riveted togeither.There is only one aluminuim brazed part on it.

Here's a link to there web site

http://rivetrecumbentbike.com/index.html

That is pretty cool. I put my little friction drive mount together that way but a whole bike!.. There is a back to back recumbent tandem made with rivets for sale on the bentrideronline forums but I had never seen a single..

Helicopters are mainly riveted togeither they don't tend to fall apart and they have alot of vibration to deal with and travel faster than a bike.
( work on helicopters for 18 years strip repair build function & modify)

 

[michaelplogue]

Aluminum I-beams attached together with "lugs" cut from thick plate bolted on each side. You'd still probably have to do some fancy milling for the bottom bracket and head tube, but it would be doable without any welding.......

 

[michaelplogue]

 

[vanilla ice]

http://www.alanbike.net/2009/about
Bonded bicycle frames since before I was born.. If pros were doing it in 1972, with 2010 tech should be able to get it done shadetree styles I'd think.

 

[spinningmagnets]

Thats a great find, Mud, thanks. For years I was a hydraulic tech and I've bent a lot of strong tubing. theres a thread somewhere around here with pics of a home-made tubing bender, easy to copy and not expensive.

Once you start looking and gathering, its not hard to get a pile of old bike frames. Especially the cheap steel Chinese bikes. Ive wondered recently if I could cut out the head-tube, drop-outs and BB with several inches of tubing still attached, and then find tubing a hair larger than the existing tubing stubs. Cut, bend, and slide over with some adhesive (as you've suggested) and it might work.

I've found 3 bikes so far with a frame geometry I like, but the cheapest is $800. I'm in the process of attaching a rear supension arm to a hard-tail MTB to make a full-suspension long-tail cargo bike. The seating posture is semi-recumbent, similar to a beach cruiser. Thats why I started the wooden bike frame thread, and also the DIY carbon fiber frame thread,...to gather ideas and experience from the ES think-tank.