Frame tube thickness

Does anyone know how think the steel is on the chassis of a 77 KZ1000? I'm going to start bracing the frame and have decided to braze them in. I don't have a TIG nor do I know how to use them. I like the idea of brazing anyway. It has been a while though so I want to practice on something that is NOT my bike.

IIRC the down tube I sectioned for repair on my frame was 0.095". Brazing can be a tricky art. Cleanliness is very critical.

Alan

Haybus wrote: IIRC the down tube I sectioned for repair on my frame was 0.095". Brazing can be a tricky art. Cleanliness is very critical.

Alan

Thank you Alan. I will make sure to have the surfaces prepped properly. I know a lot of MIG but its my understanding that it can make the frame brittle at the weld location. My brother has this pistol grip torch that has a very small focused flame that will work perfect to braze this project.

14ga tubing should be what you're looking for.

I thought the brittleness was from trying to mig to dissimilar metals, say a cro-moly brace to a mild steel tube? Correct me if I'm wrong

I'm not sure about that. Hoping someone will speak up. I was planning on using cold rolled steel for the braces unless someone corrects me.

Is brazing really suitable for this? Sorry, my only experience was with trying to repair a bicycle frame, and the brass came apart within a couple of days. I can't imagine it would do well with the vibrations of a motorcycle? However I also know now that brass will harden when allowed to cool slowly, which is the opposite of steel. Maybe it needs to be properly tempered in order to survive the conditions?

I welded my kz frame with a mig. For the projects I do, I only use mild steel wire which does not air-harden like some types of welding rod will do. I suppose I should weld up a test piece with some scrap frame tubing and beat it with a hammer to see how tough the weld really is. From what I could tell when I was chopping up the donor frame (and I am by no means an 'expert' on this) the original frame looked like any standard hot-rolled mild steel.

I have seen pictures of the Sanctuary boys brazing them in. Here is some info I found from Leon(Black Banshee)

Great thread 531. I like the gussets you build. I don't see a problem with an extrusion in the front frame braces. Saves weight, adds strength, and you can paint behind them then.

At the beginning of the thread, there is mention that the Japan guys don't weld to the plates to their frames. I'm thinking they hammer weld(forge)the plates in. Obviously that isn't an option for your average weekend warrior in his home shop.

Tig is by far the best process to weld these braces. Proficient welders can weld with anything, just look at the gasless welds that were pictured a page or two back.

"Good choice on filler rod too Leon. I've known some builders to take a torch and draw the welded areas to around 4-600 degrees to temper the joints. I believe the AWS ER70S-2 filler takes care of any brittle joints created when welding CrMo.

Did I mention I like this thread.

Here is a couple good articles on welding CrMo:
www.netwelding.com/Heat_Treated_4130.htm

www.weldingtipsandtricks.com/welding-4130.html "

I would still like to know what you find. My thought was it's pointless to brace if I am going to cause the frame to be brittle at the welds.

This is the thread I found it in.
www.kzrider.com/forum/5-chassis/294594-frame-bracing

Either fusion welding , brazing or bronze welding your frame will be fine.
It is (hot short) alloy steels i.e Reynolds 531 etc that have to be bronze welded to prevent brittleness and fracturing due to overheating.
If done CORRECTLY the brazed/Bronzed joint is extremely strong , flexible and won't come apart.
Ideal for building entire motorcycle frames.

Here is the Bronze welded suzuki XR69 frame.

Had to log in with my phone to see this for some reason .
Sounds like zed got it all squared away tho.

Leon