Repairing cracked aluminum frame

Repairing aluminum frames is challenging because the heat of welding will affect the temper of the alloy, and the frame needs to be heat-treated after welding in order to regain its intended strength. But heat-treating a frame can also potentially cause alignment issues (and the frame might also need to be completely stripped of paint). There are very few manufacturers, frame builders, or welders who will repair a cracked aluminum frame, unfortunately.

What ^^^ he said. I've tried a few times in the past, but it ended up being a huge waste of time and money. Your best bet will be to get a crash replacement from Santa Cruz or just buy another frame.

A good welder is your first priority, next make sure you find the ends of the crack magnifying glass whatever but drill a very small hole right at both ends of the crack before it’s welded this will stop the crack from growing further then weld the crack at the lowest possible temp

There are places that specialize in frame repair, just have to hunt around a bit. JB weld or glue wont do you much good and if its growing I would be a little cautious riding it.

I'd imagine pre-heat and post-heat is very important. Lots of heat stress happens with welding, and welding on "cold" aluminum causes it. You will likely see tears next to the weld, also known as the HAZ zone.

Aside from that, I think the welding part is pretty standard TIG.

I would not ride the bike at all if I saw the cracks getting longer. Make sure you have good dental insurance.

The drilling I spoke of is also refered to as stop drilling as it stops the crack from growing

An aluminum welder is east to find. I’d say having it welded without heat treatment is better than Jb weld. Being that the crack is on seat tube I’d feel more comfortable than if it was headtube. You are at a point where you need to keep an eye it and decide when it’s too risky to ride.

It's possible in theory, but in practice it's a huge waste of time and money.

The welding will decrease the structural integrity of the aluminium, so the frame would have to be heat treated again afterwards. That comes with it's own set of problems, as it could easily warp the frame out of alignment. On top of that you'd need to find shops that do the welding and heat treating for an acceptable price. Repairing the frame could end up costing close to what a new frame would cost.

And even if you did go get it repaired: The frame cracked for a reason. And if you continue riding like you did before hand, it's likely to crack again.

Bottom line: Just buy a new frame.

Have you contacted Santa Cruz and asked them if they will warranty it or sell you replacement front?

I'm in the "it isn't worth the effort to repair" camp, because it will probably break again, and it could be dangerous. If you are riding a Nomad, you probably aren't riding XC loops right?

Friend cracked his Ransom not long ago, warranty replacement was accepted, however delivery time was like 3-4 months due to the parts shortage and he had the crack welded so he can continue riding while the new frame arrived. There are cases where this makes sense, but once the frame is cracked you wont ever make it 100% again!