aluminum conduit and kee klamps

[clyffcarlock]

i was wondering if 2" and 1 1/2" aluminum conduit could be bent for the main frame tube and cross member. also, if a "kee klamp" or "kee lite" crossover could be used to secure the main frame tub to the crossmember. hope this makes sense. this could mean the bike could be mostly constructed without welding, i think. the conduit that i am referring to could be purchased at any commercial electrical supplier, they even sell to non-contractors. see attachment for pic of the "kee klamp" crossover coupling unit. i do not know if the pipe can slide all the way through the coupling or if there is a flange inside that the two pieces would butt up against. if it is flanged, the flange could be grinded out and a single pipe could be slid through and tightened down with the two screws. the site says that the pieces are cast aluminum for the "kee lite" and cast iron for the "kee klamps". i am reading they are also made of galvanized steel. i see a few sellers of the "kee klamp" fittings on ebay. one off hand is the ebay store "buyrailings". just type in the search box "crossover" and it will bring up the items.

[Sparky]

its an interesting idea.

i would be REALLY nervous about using aluminum tubing to build a bike though. i dont think it would be strong enough. even steel conduit isnt really strong enough for this sort of thing.

i know that welding aluminum is very complex, but just welding it would be quite a bit lighter than even the lightest clamp.


these could have uses, perhaps for mounting baskets, handlebars, that sort of thing.

[Radical Brad]

Interesting ideas. I have never seen or heard of aluminum conduit, but I would wonder of using a bender on it might weaken it a great deal. It sounds like some type of triangulated frame could be made using the ideas presented, but certainly not any of the bikes I have done.

Might be a nice way to support a fairing?

Brad

[clyffcarlock]

the aluminum conduit that i saw at the electrical supply store was in 10 ft lengths and the ones i was interested in were the sizes of 2" and 1 1/2" with i think an wall thickness of maybe 3/8". i am ordering an digital caliper and when it gets in i will find out for certain. the conduit, i was told was for industrial, factory useage and under concrete slabs. so i am hoping the strength is there. i bought a 12 ton capacity pipe bender from harbour freight and am planning to see how this bends. there are other kee klamps avaliable, like for right angles, adjustable angle, 4 way tees, etc... look at the website for other ideas that may be used on a recumbent.

http://www.keesafety.com/products/keelite

http://www.keesafety.com/products/keeklamp

keelite is the cast aluminum and keeklamp is the cast iron or galvanized steel.

[macka]

Using a heavy wall AL tubing is actually almost the same weight as HREW or CREW, delete the clamps, and you will save weight, you could even save weight using grade 8 nuts and bolts (lock washers too of course).

[Odd Man Out]

the aluminum conduit that i saw at the electrical supply store was in 10 ft lengths and the ones i was interested in were the sizes of 2" and 1 1/2" with i think an wall thickness of maybe 3/8". i bought a 12 ton capacity pipe bender from harbour freight and am planning to see how this bends.

3/8th inch thick -- YIKES!!! do you realize that is 3 times the thickness you need? I use 1/8th thick stuff when I build a frame. Might I suggest trying .049 ChroMoly -- it would save you a bunch of weight.

Interesting ideas but with all the forces you are going to put on the frame while riding, you are going to be spending a lot of time retightening your clamps -- does not sound like fun. Might as well just get the frame TIG welded and be done with it (after having it heat treated that is).

[trikeman]

OMO - have you tried bending any aluminum for your builds? I have heard that you have to be a bit more careful bending it than steel, since it work hardens or something. I know my son wanted to bend out something that was aluminum on his motorcycle and people told him it was not a good idea unless he could heat it and then re-temper it.

[TheKid]

Interesting ideas but with all the forces you are going to put on the frame while riding, you are going to be spending a lot of time retightening your clamps -- does not sound like fun. Might as well just get the frame TIG welded and be done with it (after having it heat treated that is).

Not only that, but the cost would be outrageous. You could probably prevent the clamps from loosening by epoxying every joint, but that will just add to the cost. One other thing, those clamps would make the bike look plug-ugly. OMO's right. Just get the frame properly welded and post heat treated. You'll save money and have a much nicer looking bike, and a much lighter one as well.

I have heard that you have to be a bit more careful bending it than steel, since it work hardens or something.

FWIW, Rick Horwitz's plans for the T-Bolt calls for aluminum tubing. He recommends having it bent at a muffler shop. But you have to make sure they use good benders. Once the dies are worn to a certain point, they'll crimp the tubing. While this may not be critical for muffler pipes, it's unacceptable for bike frames.
He also recommends using aluminum that can be artificially post heat treated, which means staying in an oven for 8 hours at a lower than a normal temp for real post heat treatment, and can be quenched with water instead of glycol. He mentions something about a pizza oven at a friends pizzaria.
While he seems elitist on using aluminum, he says you could use 1 1/2" steel tubing for the frame, but it'll be heavier than the 2" aluminum frame. Lately, he seems to realize most builders don't have a TIG setup, so he's recommending cromoly for those who don't TIG weld. But I digress.
Any ill effects of bending aluminum will be greatly reduced or eliminated after post heat tratment.

[Odd Man Out]

OMO - have you tried bending any aluminum for your builds? I have heard that you have to be a bit more careful bending it than steel, since it work hardens or something. I know my son wanted to bend out something that was aluminum on his motorcycle and people told him it was not a good idea unless he could heat it and then re-temper it.

I have recently taken up the practice of making my own handlebars out of 7/8th by .049 6061 AL tubing by bending it to shape. From everything I have learned, I am hesitant to use bent AL in a frame where it is stressed -- more problems than benefits.

BTW the Kid, I also have the T-Bolt III plans. It was going to be my next build before the Warrior plans were introduced. Now the T-Bolt is in a filing cabinet and the Warrior is at the front of the line. Why waste time with the complexity?

[clyffcarlock]

the kee klamp would be hidden by the seat, and keeping the screws tight with loctite would keep it secure. i do not plan on going off road with it, so not a lot of vibration is expected. the klamps could also make it portable or easier to disassemble. plus a few kee lite swivels could make the seat adjustable. as far as the aluminum, i wrote that i think that it is 3/8" thick. that was with a quick look. i will need a digital caliper (that i ordered and will receive soon) to see for sure how thick it is. i want to make this trike as customizable and adjustable as possible. as far as the structural strength of the kee klamps and kee lite clamps, they are used to support railings at parks and sports fields, also scaffolding. the reason i also would like to use the crossover clamps is that both holes for the pipes are made as one piece making sure of a perfect right angle. they could be used for a first time builder who does not know how to weld and will give them the option a weld-less way to construct a bike. kind of like legos. i guess. doesnt have to look pretty, just rideable.

[Sparky]

we dont mean to rain on your parade- out of the box thinking is what brought us here in the first place.

just feel its worth restating- none of AZ's plans are designed for aluminum.


build it! post pictures! teach us new tricks!

(mostly the pictures part. we once voted a guy off the forum for never posting any pics.)

[Odd Man Out]

just feel its worth restating- none of AZ's plans are designed for aluminum.

And yet some (the DeltaWolf trike) are built in AL with high success. Don't let anyone make you afeared of the "evil metal". :rockon:

[TheKid]

BTW the Kid, I also have the T-Bolt III plans. It was going to be my next build before the Warrior plans were introduced. Now the T-Bolt is in a filing cabinet and the Warrior is at the front of the line. Why waste time with the complexity?

I was going to build it out of steel, but never got around to it. I had the pieces for the frame bent, but even making adjustments to the seat and BB height, after dry fitting it seemed it would be too low for me to ride comfortably, i.e. without pain. I was toying with the idea of using cromo, but now I'm glad I didn't go for the extra bucks. I ended up using EMT, figuring if it didn't work out, I'd only be out less than 20 bucks, plus the 10 bucks I was charged for bending. I used most of the pieces for something else, so it wasn't a total loss. I never got around to the seat, which to me seemed the most complex part. I do like his steering knuckle system, which allows for camber adjustment, so you don't have to be too critical with angles. However, there are easier ways to implement it.

[TheKid]

they are used to support railings at parks and sports fields, also scaffolding.

Bear in mind that railings and scaffolds are not under anywhere near the stresses of a bike. I've used the system for scaffolds, and they work quite well, but there's little if any stress on each individual clamp.

[clyffcarlock]

from the keeklamp website

"A Kee Klamp fitting (size 5 to 9) can support an axial load of *2000 lbs. per set screw with the set screw tightened to a torque of 29 lbs./ft. This is normally obtained when the set screw is fully tightened using a ratchet wrench."

this is for the galvanized steel kee klamp.

[Odd Man Out]

I do hope you go ahead with your project. I just add the following comment to inform and not discourage.

I think the clamps would be great on scaffolding as designed where at most they get a person leaning or walking on it. Not sure they will stay tight as used on a HPV unless you ride on glass smooth roads. Don't underestimate the stresses that bike frames are put under on a daily basis -- riding over each pothole or bump in the ground would be like subjecting a scaffolding to an earthquake. Jus sayin.

[John Lewis]

I saw a commercial aluminium trike that had the cross member held to the main tube by a clamp something like that but purpose made. The main tube if I recall was about 3" diameter. Probably 6061 and fairly thin.
Using the thick tube and industrial clamps you would save nothing in weight and steel might be a better choice. None the less it would be an interesting experiment.

John Lewis

[Radical Brad]

Hope to see some photos and a report of your interesting project soon.
With all of this controversy, it HAS to be done now! Be a pioneer.

The only thing I would consider when testing something new that may or may not work is...

What would happen IF 100% failure happened at the worst time, which is usually at high speed along a busy street?

I like steel because 100% failure means a slight bend in a frame that is was not made strong enough. The same failure on an aluminum frame means complete separation of the joint with no warning, sending you to the ground instantly. (I have experience this myself several times)! Carbon fibre and PVC frames would be the same.

I guess that's why I will never bother trying to shave off 5 pounds when the risks are so high. Bend a steel frame, and you ride home looking like a dork. Fracture an aluminum or carbon fibre frame, and I can imagine 1 of 3 things...

1) Eat the road, look like a dork, then look like a bigger dork as you carry your pieces home with numerous cuts and bruises (I know that story).

2) Eat the road, and then end up under the cube van that was riding in the lane right behind you.

3) Eat the road and then become impaled by the open tubing that just fractured and is now digging into the ground ahead of you.

2) and 3) really freak me out, which is why my allegiance will always be to steel.
I do like seeing those with knowledge of other materials show off their work though!

Brad

[badcheese]

With all of this controversy, it HAS to be done now! Be a pioneer.
Yes!

3) Eat the road and then become impaled by the open tubing that just fractured and is now digging into the ground ahead of you.
I'm sure that was meant as a warning, but you make it sound pretty spectacular!

[macka]

I have a very close friend who is a paramedic in Brads neighbourhood. He picked up a guy this past summer, who was impaled on a failed aluminium handlebar. SO that being said, even professionally made units can fail. I still think you are wasting time using the kee clamps, just on the grounds of weight. Those things will add more weight then using simple nuts and bolts. I also feel that the nuts and bolts are less likely to slip off like a kee clamp can, regardless if the screw is loctited in place. The best AL tubing is extruded aka DOM which is Drawn over mandrel in longhand. You can get pieces made to insert inside the tubing which would bear more weight and impact then a cast kee clamp ever could. They do that in the aircraft industry all the time.

[ken will]

IMHO this sounds like

An "extraordinary statement of individuality" and A "beautiful piece for a museum"

but not so safe or efficient as a daily rider.


I say go for it !!!