84 Ironhead sprocket cover chop (or anti-chop)

[Trip59]

Decided to work on some of the smaller items for the 84 chop, things that would be the same regardless of what I do to the frame, as that project is waiting on some materials to build a frame jig.

The sprocket cover has been bothering me, everytime I look at it I get annoyed. I decided the day I got the bike that I was going to move to forward controls (at 6’1″ the mids are just a wee bit uncomfortable for me), so the rear master cylinder no longer needs to be bolted there, nor do the brake lever, foot peg, brake stop bracket, etc. Combine this with the plan to hand engrave the rocker covers, primary, sprocket and cam covers and a nice big blank area just sounded right.



As removed from the bike, crud and all

The inside was even prettier



Years of road gunk

Little bit of wear from the chain





The chain wear will be repaired before being put back into service.

So I started out with a sawzall, cut the big chunks off

Big chunks cut off and set back in place:



Then it was time for some grinding



A little sharpie to outline areas needing welding


All but the three recessed holes will be filled in.

Not the prettiest welds (the first pass impressed even me) but it’s welded up and ready for grinding back down. I was really surprised how well it welded, until I noticed that a little more heat to even things out brought up some bubbles like farts in a hot tub. We’ll see when it gets ground down if there are any voids that require additional filling, but I think I worked all of them out.



All but the bottom front corner got welded from both sides



Just can't get me enough of that cast aluminum!

[Rambozo]

That sure was a mess. Looks so much better all cleaned up. Looks like it welded pretty nice, too. With die castings you never know what you're gonna get. Sand castings are usually pretty good alloys, but it seems they can make die casting work with almost anything. What filler rod did you use? Are you going to polish that when you're done? I know 5356 usually provides a good match with most cast alloys, but you might have to experiment to figure out what matches best for that.

[Trip59]

That sure was a mess. Looks so much better all cleaned up. Looks like it welded pretty nice, too. With die castings you never know what you're gonna get. Sand castings are usually pretty good alloys, but it seems they can make die casting work with almost anything. What filler rod did you use? Are you going to polish that when you're done? I know 5356 usually provides a good match with most cast alloys, but you might have to experiment to figure out what matches best for that.

It's eventually going to be engraved, but I'll be taking it to a high polish now, just to make sure it's nice and smooth for later. I did use 5356, I was debating on trying to use the cut off pieces to get a perfect match, but... man, what a pain that would be. Where it's at, pretty good will be good enough.

I was really surprised with how nicely it welded up. First pass looked like it could have been cast in, chasing the holes and whatnot was a bit less even. I'd take one of these in for repair any day. HELL of a lot easier than the last die cast crap. I also have plans for the rocker boxes, as well as a few cases to weld up. Sorta 50/50 die and sand project-wise.

[Rambozo]

It's eventually going to be engraved, but I'll be taking it to a high polish now, just to make sure it's nice and smooth for later. I did use 5356, I was debating on trying to use the cut off pieces to get a perfect match, but... man, what a pain that would be. Where it's at, pretty good will be good enough.

I was really surprised with how nicely it welded up. First pass looked like it could have been cast in, chasing the holes and whatnot was a bit less even. I'd take one of these in for repair any day. HELL of a lot easier than the last die cast crap. I also have plans for the rocker boxes, as well as a few cases to weld up. Sorta 50/50 die and sand project-wise.

You could take some of the pieces you cut off, and weld a little on each with a few different rods, then grind and polish to see which one comes out better. Some rods look really great until you polish, then they have a hard line where the weld starts. Don't ask me how I know this.

[youngnstudly]

You could take some of the pieces you cut off, and weld a little on each with a few different rods, then grind and polish to see which one comes out better. Some rods look really great until you polish, then they have a hard line where the weld starts. Don't ask me how I know this.

X2! It's fun to spend all that time repairing broken or rough areas on a casting, only to have everything polish up poorly and your weld area jump out like a sore thumb! Especially if there are any details or special contours that you have to spend extra time shaping correctly! Enough to drive you crazy (or crazier)!

[Trip59]

I've still got the scrap, if I need to surface it with that, but I think I'll be ok. Seen a number of various cover castings for HD done up with 5356 and using 6061 as filler for big areas. Worst case, contour looks great but color/finish doesn't match... I'll send them out to the chromers

[Johnson]

Looks good keep the pics coming!