Headtube repair?
 

Ran across this ad on Craigslist a little while ago. https://losangeles.craigslist.org/la...718803436.html

Just thinking this might be a fun, little first build project if that headtube is repairable. That's what I don't know. The price is certainly right and I have a spare set of wheels, CF fork and tri bars. Only things I would really need would be front and rear derailleur, brakes and shift hardware. I think I could probably put together a decent back up bike for under $500 taking my time and some careful shopping.

But that headtube is the wild card for me. I don't know what would be involved in repairing. Can it just be straightened (re-rounded)? Or would that need a lot more work than what it's worth?

I don't know if you could successfully bend that back or not. I have done it with steel, but aluminum might crack. It might already be cracked. Price is about right though. I don't see a welding fix work out, but I don't weld aluminum.

I see people talk about using exhaust pipe expanders for this. I have no experience with them.

I'd throw down a 20 spot on that thing, if in the market for such a bike. I think you can bend that head tube back, but getting the surfaces truly...true, will be the bigger challenge. Only one way to find out...

The vast majority of HT cracks I've seen have not been what i would call a "safety critical" one. Sure they suck, and one should replace ASAP. I doubt the worst case scenario here would be instant steering loss. Given that and the cheap cost to gamble I'd consider it (were it not that I hate AL for a frame material).

But these type of projects tend to expand cost wise. Like the wish to ream and face the head tube after the rounding efforts, or have new tires and tape. Andy

A top flight welder would have no problem with that.

Andrew-why do you hate AL as a frame material?

Cheers, Mike

Mike- I don't like AL's softness and crack propagation tendency. I don't like the increase of stiffness that is done to combat the fatigue limit problem. I don't like how one has to join it (rivets, bonding as example). My aesthetics are not attracted by the shape and construction of many Al frames (and carbon or wood/bamboo for that mater). Since I don't weld and have a heat treatment oven I also don't like how AL repairs have to be done. Andy (who grew up on steel and if it was good enough for me it's good for you...:))

I have aluminum bikes, they are generally a good value. But once they break, it's questionable if they can be fixed. Even if you find a "good welder."

There is a YT video of FTW doing a HT repair on a Yeti. It seems how he approached that repair would work here. I'd be inclined to simply try to straighten it reasonably and then ream the ID round and ride it. I raced the S5 from that era and the P3 will be a weird bike for anything other TTs. As a TT bike, it probably won't see the hard miles that a typical road bike would so, it's probably fine. Just keep an eye open for cracks.

Can you link up the video so I can see how reasonable the repair might be? Still haven't committed, mainly because it's a drive down there. Only reason I would do it is if I was heading down there for something else anyway.

Frank makes it look easy.

Thanks. Will check out.

FTW used to post in C&V a lot, but they annoyed him somehow. Or maybe we annoyed him here, who knows? If you can get FTW to do the repair, it will be fine though. With some of the stuff I have seen him do, I wonder if he charges enough.

I started watching the video but it didn't take long to figure out that is way, way more work than I would want or care to put into this thing. Hell, I'm talking about a $20 frame for a project bike. I wouldn't ask someone to do all that work even if they volunteered to do it for free. Far too much trouble. If there's no way to bend it back and true it with what I have on hand, then I'll let someone else pick up a project.

Aluminum tube welding repair is really only practical on 7005 or other "naturally aged" alu metallurgy. Majority of commercial aluminum frames use 6061-T6 with T6 heat treating needed to restore strength after welding. Big manufactures can efficiently perform the post-construction heat treating in large ovens with batches of frames held in jigs to prevent warpage but attempting to DIY or pay for a single frame to get heat treated is really not practical for a repair.