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How a Mountain Biker can Fix a Broken Heart

When the mountain bike frame cracked a couple days ago, I was resigned to the worst: a new frame or maybe even a new bike. It is too bad that the industry has gone to 5-year frame warranties.

Annie, of Twin Sisters bicycle shop in Silver City NM, surprised me when she mentioned a local guy who has done TIG (tungsten inert gas) welding of aluminum bicycle frames. Here is the happy outcome:


A TIG-welded aluminum bicycle frame repair job.

His price was ridiculously low. Since the bicycle shop deprived itself of selling a new frame (or even a new bicycle) by providing this information, I went back and gave her a generous "finder's fee," which surprised and pleased her.

A commenter, Brian, recommended welding a triangular gusset at the broken joint. I agree with him. In this case the welder chose not to do that because he thought he'd get too close to the carbon-fiber suspension parts (the little black swing arm, in the photo). Instead, he chose to build up the thickness of the TIG weld. He also sliced completely through the cracked aluminum tube so that the new weld would go through the entire thickness of the tube, not just the outside.

With hindsight, I should have removed anything bicycle-specific because the welder is naturally cautious about parts that are outside his expertise.

So then, is this a success? Maybe it will re-crack after leaving town and migrating north. So I took it out for a test drive on single-track trails and pushed the envelope a little bit. In fact I had an "end-over-the-handlebars" crash that send me sliding down the side of the mountain for 20 feet. It took about 5 minutes to get back on the trail. The result was: nothing was hurt but my pride. The new weld held.

If you are ever in the Silver City NM area and need some welding done, I highly recommend Mike Holloway, 257 Arenas Valley Road, 575-388-5329.

The diving board style rack, which clamps to the seat post, has been decommissioned just in case it was responsible for the original cracked tube. With a little effort, my junk found new homes elsewhere on the bike. 

Perhaps you already know of the "Anything Cage," made by Salsa. It holds larger water bottles (and is mounted in the usual threaded holes, like any other water bottle cage.) I installed one and am encouraged. You are supposed to be able to hold a half-gallon plastic bottle, of the kind that take up a double row at the average grocery store these days. I need the extra water for my Coffee Girl, a kelpie, who usually accompanies me on rides.

The "Anything Cage" from Salsa allows you to strap large water bottles to your bike.

Comments

Brian said…
That build up almost looks like a small gusset! :) I love it when a GOOD welder does a job. I've been afflicted over the years by "gentlemen" who proudly proclaimed their Weldiness with certificates and association memberships; that when it came to actually doing the job couldn't lick a stamp and stick it on a post card!

Often times a properly repaired piece is stronger than the original. Excellent.

Wildsider said…
A note about the welding of aluminum frames -
If it is 6061/63 series aluminum, the entire frame needs to be heat treated (high temperature)to reach maximum strength. If not, it will surely fail again. If it is 7005 series aluminum, it needs to be artificially aged (lower temperature) to reach maximum strength.
Wildsider said…
A note about repairing aluminum frames -
If the frame is made from 6061/6063 series aluminum, the entire frame needs to be heat treated (high temperature) after welding to reach maximum strength. If not, it will surely fail again. If it is 7005 series aluminum, it needs to be artifcially aged (lower temerature) after welding to reach maximum strength.
Wildsider said…
One more thought-
Go ahead and use the seat rack, They are handy. Your body weight puts far more stress on the frame than the rack. The weight rating is for the rack itself.