'77 Ironhead Drum Brake & Sprocket Broke TWICE!!

I gotta '77 Ironhead long chopper with an old drum brake/chain/sprocket set up. About a year & a 1/2 ago I was stopped at a light, the light turned green, I put in 1st, & the bike wouldn't go!! The rivets holding the sprocket ( chain drive ) to the drum had either sheared themselves off or pulled thru. I was debating on whether or not to replace em with an OEM Harley rivet kit or some small bolts with nuts & Thread Lock. I got talked into using the rivets... About a week ago, the same thing happend!! I put in first, & nuthin!! The fuckin chain was spinnin, but I wasn't moving!!
Question is, has anybody ever had this happend, what did you do, & how did it work out? Any help is greatly appreciated!!

I think with bolts there might be clearence issues, Mine is welded, but a lot of guys told me that is not a good idea either, but i havent had any problems

I just re riveted mine but haven't had a chance to test it yet. I was told not to weld it also due to the fact that you will never get it off when you gotta change it again. If this shit happened to you twice though I think you should weld that shit.

Pretty odd that it even happened at all. Gotta be something wierd going on there. I've never had trouble with them on two different Ironheads.

I heard about the welding deal... The bolts have clearance so I mite try that this time... I'll let you guys know what happens.

Weld it up you'll be done deal!!!!

Weld it just jump around with the weld so that you don't warp it and mark how far down your chain goes so that the weld doesn't get it the way. And if you want the rivets and a spare sprocket hit me up I got a new one stashed never used.

my rivets sheered off like two weeks ago on my '59 at 130am about 5 miles from home.

walked it home and tore it down the next morning and bought the last stock of them that the local harley dealer had...

Are you riveting them with a pneumatic rivet gun or just hammering the crap out of them?
are you bolting every other hole so that the sprocket is tight when riveted? If you don't the rivets will be loose when you are done.

If the rivets you are using go in the holes real easy , throw 'em in the trash. A farm supply store or McMaster Carr will carry rivets you can use. Redrill the holes with a sharp drill the same size as the rivet and clamp the sprocket before peening the rivets. The bolt trick won't work. I've been running this setup on my scooters for over 35 years and when done right it's very strong and reliable. A rivet thats smaller than the hole it's going in will let the sprocket act like a shear,thats why you're shearing them off.

Originally Posted by Hubbard

If the rivets you are using go in the holes real easy , throw 'em in the trash. A farm supply store or McMaster Carr will carry rivets you can use. Redrill the holes with a sharp drill the same size as the rivet and clamp the sprocket before peening the rivets. The bolt trick won't work. I've been running this setup on my scooters for over 35 years and when done right it's very strong and reliable. A rivet thats smaller than the hole it's going in will let the sprocket act like a shear,thats why you're shearing them off.

Bingo !!

Well, I changed my mind... I'm gonna re-rivet it. Last time, I didn't know about bolting the sprocket in every other hole to hold it in place. I'll do it this time. (I was wondering what those other holes were for!) I'll either make sure the rivets are tight, or redrill. I do have to hammer & punch, though... I don't have a pneumatic. Thanks again, guys!!

Another option is to take it to a shop that re-lines pressure plates and clutches. Any farm or industrial type shop should be able to handle it. I really think welding it is a bad idea. Yeah it's not coming off but that's also the problem when you wear out the sprocket and still have tons of life left in the drum.