Welding on a rear hoop

NewHavenMike · Mar 3, 2017

OK, so I have the back of my frame cut slightly after the shock mounts. The spacing is nearly perfect to weld on my rear hoop without any modification to the rear hoop itself.

The problem: The frame piping comes in at an angle and wont be a straight cut, The cuts will be squared off to mate to the rear hoop though.

Now with the way both pipe ends meet, it will be impossible to use slugs, unless I cut more off the frame and add additional bends in the hoop.

I am really leaning toward not using slugs and just going with a piece of flat stock and having about two inches of the stock on both sides of the pipe weld.

The hoop will extend past the seat so it will not be bearing full rider weight, but I want to be able to use it as a handle to put the bike on the centerstand. Does anyone think that the flat stock will be adequate for this application?

Tggraff · Mar 3, 2017

A picture might clarify things. In my opinion slugs are definitely the right thing to do, and I would put in the extra effort to make them work. However, I have welded plenty of cages and other 'structural' members by simply butt joining tubing and I haven't had any major failures. So using the flat bar as a gusset means that in all likelihood you'll be fine. I seems that you have already put a lot of thought into it and without seeing your exact situation, I can't offer much more than the old, "I've heard worse ideas".

NewHavenMike · Mar 3, 2017

Sorry for the crappy pic, The frame is in my attic right now and the lighting is terrible. It should give you a better idea though.

I definitely dont want to do any major cutting off the frame. I want the shock mounts untouched. I have enough room to cut some more off the frame to get and equal width of the rear hoop, which I will end up doing... Just did a rough cut for now.

xschris · Mar 4, 2017

I would use slugs. Then drill holes to expose the slug and outer tubes. Then weld them together. Then weld where the hoop and frame meet. Very strong and you should never have any problems.

NewHavenMike · Mar 4, 2017

I agree Xxchris, I would if the frame pipes were straight. Im not exactly sure how to fit a slug when one pipe meets the other at a 10 degree angle..

I think ill be alright if I cut flat stock to the right shape and weld about 2" on to the frame. Then after the hoop is on, I can weld the flat stock to the hoop. So, ill have <2" of flat stock welded to the frame on both sides of the pipe butt welds. The hoop also needs to be cut down, I havent done that yet. Theres about 2.5" of length I need to remove.

For the record, I will be having a professional do the welding as I want the job to be done by someone who welds everyday all day long. This is the only work besides having the cylinders bored out, that I am reaching out to have professionally done..

Keep in mind that the hoop will not have any constant load bearing on it, The only stress it will take is me using it as a grab bar to prop the bike up on the stand. I guess I will find out more when I confront the welder about it.

Tggraff · Mar 4, 2017

It looks like you could just take some round stock that is the same size as the ID of the tubing and put a kink in it. Some time with the torch to get it red hot and a couple heavy hammer swings should get you the right bend. Then use the grinder to relieve the inside corner of the slug so both pipes butt properly. I also agree with plug welding like what was mentioned by xschris.

Jeff0133 · Mar 4, 2017

Tggraff said:
It looks like you could just take some round stock that is the same size as the ID of the tubing and put a kink in it. Some time with the torch to get it red hot and a couple heavy hammer swings should get you the right bend. Then use the grinder to relieve the inside corner of the slug so both pipes butt properly. I also agree with plug welding like what was mentioned by xschris.

Basically what I did on my seca brat build

NewHavenMike · Mar 4, 2017

I would, but im pretty sure the frame piping ID is different from the hoop ID..

On the hoop, I will need to cut some length off the straight ends to get it down to size, somewhere around 2.5".. That would give me some stock to make slugs. Id be able to cut the stock lengthwise and roll it into a smaller diameter to be able to slip it inside the frame piping.

Im just very very limited on my work space and available tools. I dont have any power tools except a dremel and sawzall and drill. Id feel a lot better if I had a decent vise, chop saw, pipe bender, and a work table lol. Im pretty much going "manual" on this build..

I know it sounds like im in over my head, but im not. Im very mechanically inclined. Its just that since I purchased this bike, other things in my life happened too and it slowed my progress down a lot. Ive had to move 3 times so I ended up leaving all my tools at my mothers, so its a huge hassle going back and forth. But, I have a setup at my place where I can get some work done..

smurf · Mar 7, 2017

7/8 DOM tubbing with 0.096 wall. Get a piece of round bar that fits the ID of the 7/8th steel tubing and it should be very close to the ID of the frame.

I cut mine back a bit further where the frame was straighter to avoid this problem

rshutchinson · Mar 7, 2017

Bend the slugs to match the frame bend and install them in the frame first. Then you should be able to slide the hoop over the slugs.

Here is what I did for my FZR600 Blaster. You're in the same situation.

NewHavenMike · Mar 7, 2017

I would cut the frame right where you did Smurf, but then I'd have to make the hoop wider. It almost sounds easier to do that...

Problem is, I'm very stubborn and want it done the way I imagine it lol. I did some more cutting last night. I nearly have the pipe ends lined up to be welded. Just need the get them a little more straight.

After this is done, my next hurdle is rebuilding the front caliper. Which I may need to replace because the piston is frozen solid, then tires and electrical.

Jeff0133 · Mar 8, 2017

For your caliper...I had one that was frozen ....drench in pb blaster, tap with a hammer,heat up the caliper,tap with a hammer....after a few rounds of this put the nozzle of an air compressor to the caliper and have the air pressure push the cylinder out...
Warning!...put safety glasses on and get your fingers out of the way!...cause when it gives...it shoots out, believe me I had sore thumb for a while..
With some luck the cylinder will just be gunked-up and not pitted...so a good clean, a rebuild kit (cheaper without the cylinder)...and your done

xschris · Mar 8, 2017

Better yet and much safer, use a grease gun to push out the piston. All you need to do is put a grease nipple where the bleed screw is and pump it out. Or cut off the end of the bleed screw so it is open and put the grease gun on. Remember to plug the hole for the hose. I use a bolt with plumbers tape on it. I have fixed calipers the have been sitting for 30yrs by doing this.

Jeff0133 · Mar 8, 2017

xschris said:
Better yet and much safer, use a grease gun to push out the piston. All you need to do is put a grease nipple where the bleed screw is and pump it out. Or cut off the end of the bleed screw so it is open and put the grease gun on. Remember to plug the hole for the hose. I use a bolt with plumbers tape on it. I have fixed calipers the have been sitting for 30yrs by doing this.

View attachment 28618

...But I Do not own said gun...So the redneck method was the way to go for me...

xschris · Mar 8, 2017

No grease gun? It should be one of the first things a person that works on his own stuff buys. Spend a few bucks and get one!!!

NewHavenMike · Mar 8, 2017

Great advice here guys thank you. I did put some oil in the caliper just to get things wet. PB blaster was the first thing I thought of too. 99 times out of 100, I'd rather salvage the parts I have rather than just start buying aftermarket stuff. I want the build to be period correct so this is all good info for me to have. Nothing on the bike will be "more advanced" than 1976 hopefully... except the electronics. But I will get into that once I get my actual build thread updated.

Thanks for the advice

Welding on a rear hoop

NewHavenMike

1976 XS360C

Tggraff

XS400 Member

NewHavenMike

1976 XS360C

xschris

XS400 Guru

NewHavenMike

1976 XS360C

Tggraff

XS400 Member

Jeff0133

XS400 Junkie

NewHavenMike

1976 XS360C

smurf

XS400 Enthusiast

rshutchinson

XS400 Addict

NewHavenMike

1976 XS360C

Jeff0133

XS400 Junkie

xschris

XS400 Guru

Jeff0133

XS400 Junkie

xschris

XS400 Guru

NewHavenMike

1976 XS360C

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