Front rim split on the seam, talk to me 83 430WR

Being a welder, fabricator with cracks we drill a tiny hole at the end of the crank so it can't continue if it flexes. I would rotary file the crack from the inside with a dremel or die grinder and weld it from the inside.

I'm sure with trails some are dried up stream beds that's used for the winter runoff. There's plenty of rocks and boulders for everyone in Lee,Mass at October Mountain. Killer trails for miles.

Most of my old 77/78 original rims have what appear to be cracks. It isn't ! They are where the rolled rim was joined and they are only welded in the middle.
If the crack is anywhere else, then a weld will probably do the job. Distortion aside ....

bring it to some one who welds aluminum for a living. they will know what to do.

I welded magnesium cases, clutch covers, etc. no biggie.
My second thing on my to do list is set up my welding shop. (Mig/TIG)

Whatever you do don't delace it and leave it sit.

thanks Guys, much appreciated

Had a crack in mine also but had another rim to use . By the time I finished de-lacing it the crack at the seam was all the way thru . Good friend of mine found a crack in his rear rim and had it welded , that was years ago , still good .

I assembled a few rims with small cracks with new tires and the cracks never spread.

Yup, i'm not going to sweat it. going to finish the bike, get it running then see how it goes. Besides, they probably have been that way for years and didn't get any worse.

What I meant to say was that the crack/split let go before I was done de-lacing that wheel , completely broken . And that being said , also met a rider at Bigbill's riding area , Thomaston dam . He was on a 78-80 cr250 . When I asked about the crack in his front wheel that was completely broken across the seem , it didn't seem to bother him . He rode some more loops .

Came up with an idea to repair these using a Engine cylinder head crack repair setup.
It used little dogbone shaped links and you drilled tiny holes across the crack and belted the dogbones in.
$1000 a kit put an end to that idea.

Just did up a 2001 CR80rb [ the big wheel version ] that had a cracked front rim.
The rim is a special at 19" x 28 holes .
Delaced it , held it together with a couple of turns of twitched high tensile fencing wire.
Mate welded it up and it came out pretty good.
Then he tells me that it was his first go at alloy.
The trick is to NOT weld it laced up because the stresses make the rim go all funny and not to go mad with the welder.

Like Grouty said, I read some place the rims are rolled and joined to make the hoop. There are pins that hold them together at the joint.

I take no responsibility for your cracked rim....or your decision to not replace the main bearings while we had the patient open. And stop ogling the nice powder coated frame and get back to work.