Frame Swap - F to SF frame

[Prothec]

I'm on to my next project. I bought a titled 79SF that was butchered and burned along with a 79F parts bike w/o title and a couple boxes of extra parts. The 79F has 6200 miles on the odometer.

I finished disassembling the SF and will start working on getting the F running while getting the titled SF frame stripped and powder coated, which will be a first for me.

The only problems I have found with this SF frame are:

• Rear seat brackets are missing
• Front wire brackets missing near neck for routing harness
• Left rear upper shock mount broken (just a couple threads left)
• 4 small holes drilled in frame above airbox

Is the rear shock mount something that should be a big deal to cut out and have welded?

Anyone have any thoughts on anything else I should be concerned about?









Here's the 79F:

[TopCatGr58]

Hey there,

Okay, swapping good untitled 79F engine/parts onto 79SF titleable frame, so I assume you're going to be making it into a 79F, using all of the parts, forks/TT's, tank, wheels, etc.. Okay, the 79F frame is for salvage. The shock mount bolt is unique in that it has a larger shoulder area than the threaded portion. SO...you might want to take photos of the mount area showing the broken threaded portion, along with photos of the 79F's normal mount to see what the welder would want you to cut off so that he/she could perform the transplant weld. Same for the SEAT mounts, both size and position on frame rails. The welder should be able to FILL IN those small holes so you can keep water out from the inside of the frame. Also photos of front neck of frame, I'm sure the welder could put in some wires there IF you really want them vs. just using some zip ties!?

Have fun!
T.C.

[Prothec]

Yep, everything that is good will be moving from the 79F to the 79SF frame. The donor 79F is about 99% complete and missing or rotting bits will be replaced.

The burned up 79SF had self-tapping screws holding the hacked up rear fender on. A single-throw knife switch at the main ground was melted from the fire. I'm pretty sure they used that in lieu of an ignition switch I salvaged all the connectors I could from the torched harness and there were quite a few extra wires run and splices everywhere.

There's probably no reason to put those wire retainer brackets back at the neck. I'll be trying to find a welder. I might end up going back to the shop that outsourced welding the exhaust for my 81SH, but I'd rather find someone I can deal with direct.

[TomB]

Am I right in thinking you're swapping everything from an F onto an SF frame?

If so you will have problems around the ali footrest brackets and the rear brake lever pivot, the bolt holes for the brackets are different on the frames, and the F will have the brake pivot in the bracket rather than the SF welded onto the frame pivot. The seat brackets are a different height, higher on the SF meaning using a Standard seat will make it not touch the frame with the rubber "feet" at the rear, the side panel lugs don't match.

[Prothec]

Thanks for the info, I'll take a close look at those areas and see what can be done. The right footpeg/rearset from the SF is cracked in half as I've seen on a lot of bikes, so if it's easier to stick with SF parts, I'll need to find replacements.

I'll start hanging some parts on the frame to help see what I can and can't use and help see what will need modified.

All input is much appreciated!

[Prothec]

I was thinking about it and I've always wanted to learn more about welding, so this would be a good excuse to buy some equipment and try to learn some new skills.

I was talking to a coworker who is looking at buying this MIG setup, which looks like a nice beginner option:

http://www.eastwood.com/mig-welder-1...5a-output.html

[DiverRay]

MIG is easy to learn, just buy a few flat bars of mild steel from your local hardware store, and practice cutting and putting together on them. I would get the thinner material, as the frame is thin walled, not 1/8". An Auto-darken helmet is a big advantage, as you can line up and hit the trigger without the head nod to drop the face plate.
You should be able to do a good job after about one or two hours of practice. Be sure you chop through the practice welds to see how well your penetration is on both sides. If your friend has done some welding, he may be able to give you a little help while your learning.
Harbor friegt unit with great reviews:http://www.harborfreight.com/welding...der-62719.html
Oh, and I use a TIG welder, but I did take a class at the local community college. I grew up with welders at home, so I know gas and stick from way back.

[TomB]

+1 on the welding MIG is great if you're not doing lots of work, TIG is way better but costs a lot more so only really worthwhile if you get well into it.

For inspiration here's what you can do with MIG (keep scrolling)
http://xs1100.com/forum/index.php?to...90257#msg90257

With MIG remember to turn it up as far as you can without blowing holes so you get good penetration and as Ray says, do tests and cut open to check weld depth penetration, I've seen weld just laid on top but not connected to the job, looks good but NO strength.
Even Yamaha XS1100 factory welds can have NO penetration

[Prothec]

Cool, it's nice to see some real-world examples (including TC's Godzilla rebuild thread!). I'm excited to give it a go. My coworker has only done a little arc welding in the past, but is getting ready to replace some rusted sections of body panels on his truck.

I'll need to run a new 20 amp circuit to my garage. I've been getting by with a 15 amp circuit shared with my garage door opener and some indoor lights that barely supports my air compressor.

I'd probably get a cart from Harbor Freight along with other accessories, but not real quick to jump to try their welders. Maybe I'll focus my energy on getting the 79F running and wait for my coworker to buy the Eastwood welder and report back

[Prothec]

I added a dedicated 20 amp circuit to my garage today. My air compressor is a lot happier now

Time to do more research to figure out what what welder and accessories I'm going to buy. So far, I'm leaning toward the Eastwood 135, then a harbor freight cart and auto-darkening helmet. I also need to figure out where to get a CO2/Argon tank.

Now that I see how easy it was to add the new circuit, I now see how easy it would be to add a 220v circuit in the future

[DiverRay]

I added a dedicated 20 amp circuit to my garage today. My air compressor is a lot happier now

If your compressor will run on 220 as well as 110, go for the 220! Your compressor will be ecstatic.
Also, don't look down on the HF welder. For the money it's a great deal, and from the reviews I've read it should last a while. The mig I had years ago was made by Schummaker(sp), the same company that did all the battery chargers. The unit was built in the EU, and was about $175 over 15 years ago. I've since sold it, as the tig does just about everything I need it to.

[Prothec]

The bottom HF mig is gas-less, so the only option is flux core, from what I understand. I was reading a bit and have seen multiple comments about needing to mod it to make it useful. There are also comments about the output is AC rather than DC, creating a lot more splatter.

I have a garage full of HF tools, some good and some bad. Usually it's worth the risk, but when it's bad, it can be baaaaaad

My compressor is a small 110v 1.8amp Kobalt (Lowes) 8 gallon hotdog. I plan to move before I upgrade to a larger compressor. It just sounds healthier on its own circuit. Turns out the 15 amp circuit to my garage is shared with two bathrooms and a master bedroom.

[Prothec]

I bought a used Eastwood MIG 135 welder setup last week that came with a custom cart, auto-darkening helmet, angle grinder, magnets, body panel clamps, a couple new spools of MIG wire, remainder of a spool of flux core wire and plastic toolbox with some other small extras.

I had a chance last evening to pretty much just set it up, put good batteries in the helmet and test it. Today I picked up a welding blanket and some bar stock and should be able to get some practice in tonight or tomorrow.

I laid down a couple of beads last evening on some scrap and when I stopped, there were a few people stopped at the end of my driveway staring into my garage... Anyway, after getting over the nerves of firing it up for the first time, I'm totally stoked.

In the next couple of weeks I'll find a bottle of shielding gas.

[DiverRay]

I bought my bottle. You can lease them, but then it's back to the same shop every time for a fill. With my own bottle, I can go anyplace that has gas, so I get gas at the cheaper place, about $10 per bottle! I think the bottle was about $135, and it came full. 70CF size, IIRC, is what I have. About 4' tall.