View Full Version : Ironhead welding the kickstart ratchet to the clutch shell?
21st December 2010, 23:47
Anyone ever done this? I was thinking it would be easier and stronger to tig weld the ratchet plate to the clutch drum instead of the rivets. Anybody have any advice on this
21st December 2010, 23:58
hi lucky23 i would not weld the ratchet in place due to heat distorsion of the ratchet plate and clutch hub this is only my opinion not only that when you need two replace it you could grind to much metal away and have problems engaging the ratchet with kicker gear but its your call goodluck
22nd December 2010, 00:46
If the whole thing was heated up before hand it would minimize distortion but still a tricky operation.The clutch drum is probably hardened also, so you would need to get it heat treated after welding.
22nd December 2010, 01:02
weld away.....the starter ring gear can be welded with no distortion or problems.
I have never had a problem with rivets....probably due to the fact I have a brake manufacturing company down the street that sets rivets for me for free using the correct equipment and high quality materials.
22nd December 2010, 05:24
I welded mine (mig) without any problems. Four short welds of approx 1/2. I was going to tack it only then drill for rivits but it came out so well I skipped them. Never set rivets before and didn't feel comfortable with the process. Heat wasn't a problem (the starter ring gear was welded in spots).
Setting rivets 101 would be a great stickie post here in the forum,..any pros?
22nd December 2010, 09:10
Thanks for the replies! I guess I could take it in to a brake place here, but Im just not sure exactly how the holes on the inside of clutch shell should be drilled. Do the holes have to be counter sunk on the inside to leave room for the rivets to expand when you flatten them?
22nd December 2010, 09:43
I have the rivets along with 4 small welds to hold my ratchet plate in place. I believe the ratchet plate is countersunk slightly for the rivet heads but the holes are a little too deep to properly contact the rivet when peening the end using the alignment tool. Results in rivets that are not as tight as they should be if they were backed up individually. Mine appeared fine at first but when I opened the primary later on after some miles, the ratchet plate had a slight amount of movement on the rivets. That's when I tacked the plate in place.
22nd December 2010, 09:56
Interesting. I remember reading somewhere that you can drill and countersink shallower holes next to the existing ones on the ratchet and that does the trick for getting the rivets at the correct depth for a tighter peen?
22nd December 2010, 09:58
But Im still wondering if i should drill and countersink holes on the INSIDE of the clutch shell?
22nd December 2010, 15:56
I know mine is welded,it was done before I got the bike. I can't remember if the holes inside are counter sunk or not.
22nd December 2010, 21:43
my father was an engineer for "National Rivet" of waupon wisconsin and they are the largest supplier of "NON" pop rivet rivets for industrial useage in the world, and I'm a welder :)
I could go either way on this one, nothing wrong with properly set rivets, and nothing wrong with well preped welds.
hell I welded my rear sprocket to the cast iron brake drum with my 110 welder and set 4 aluminum pop rivets to help prevent rotation. I used four 1 inch welds with high heat and slow cooling (bury in clean sand and let sit over night) the small welds make for less grinding to fit a new sprocket later on, and the aluminum pop rivets were just something I had on hand that perfectly fit the hole (yes, I'm a cheapskate)
23rd December 2010, 00:54
I went down to the work room and looked at a stock 73 xlch clutch drum. The rivets are countersunk on the inside and flat pressed/ground on the outer side of the plate.
23rd December 2010, 16:39
Man did this subject come along at the right time. I just got done last night machining the couple of pieces I needed for the center and the anval to make a jig to set the rivets in my hydraulic press. The problem with these clutch drums is wear. The holes get egged out to the point, that there is no way you could get a tight hold from the rivet. So after reading this, this is how I’m going about it. I’m going to bolt the kicker plate to the drum. This should keep it clear of any distortion when I hit it with the welder. Next I’m going to counter sink all the holes in the inside of the drum evenly, then tap them. Going to use countersunk allen heads in the holes and hit them with Glyptal. That should seal everything up. Why do all these great Ideas come together on a holidays eve when you can’t get anything you need to make it all happen yesterday. Thanks guys and Merry Christmas, Bob L
23rd December 2010, 20:40
I don't have a pic of the plate and can't remember what mine looks like but couldn't ya just plug weld the rivet holes?
back the hole up with copper and fill the hole with weld. a quick zap with a mig, or controled heat with a tig should keep warpage down to a minumum.....
just thinking out loud, :smoke
23rd December 2010, 21:20
bolts, rivets, welds. all ways to fasten 2 or more things together. factory uses all 3. riveted assy take more time for manufacture, then comes bolts, then weldin. so why one or the other? and why did the factory use so many time intensive riveted assys? because they can do thing the other 2 cant as easliy. and riveting is pretty much a lost art. airplanes are still held together by thousands rivets, i think. riveting is one of the ironhead arts, imo.so here are some things to think about: a cold headed solid rivet works in a way that most of us didnt think about. compared to a bolt whos primary function is to hold by tension. to squeeze a gasket or, pinch a fork tube, or act as a spoke. a rivet can "pin" parts together so they cant move in relation to each other(your sprocket. or rachet plate, or cluch drum dogs on dry cluches). they do this by expanding into the holes in whitch they fit, when they are headed correctly. if you look at the headed ends of factory rivets you will see that the "punch" they used was concave on its business end. that, rather than just flattening the rivet, it expands the shank of the rivet till it get tite in its hole. then the flatting can begin. this is why a rivet is used. now there isnt any play between parts that starts the loosing process. the most common mistake is over peening. or not hitting straight with the rivet whitch "bends the nail". when riveting using a anvil, drift, & hammer. you will notice that the 1st few blows feel "dead" this is the rivet expanding. when its gets to hole size blows feel more solid. at this point you only need a few more blows. or your gonna have a less rightous joint. when done rite rivets are a solid assm.
23rd December 2010, 23:15
Honestly, at this point im wondering if 4 tig welds might just be enough, screw the rivets.
24th December 2010, 12:00
I did get the tool from Eric (thanks, buddy!), so I may try that, not sure though. After the divorce, i lost my garage so im using a buddys. The rivet thing might be too intensive considering my situation.
25th December 2010, 17:06
I welded the ring gear no problems...4 welds equally spaced approximately 1" long and then grind them flat to avoid metal grinding on the back of the clutch hub.
25th December 2010, 20:51
im a bit concerned about warpage to the ratchet plate, but my buddy said it would be fine.
25th December 2010, 22:38
six #8-32X1" flat head screws. Check your washer clearance and weld away.
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