In the Bike Shop: The Unfixable

For the past few months there has been a titanium frame floating around the bike shop. A guy walked in with an mtb frame built by McMahon Racing. He wanted to get a new BB and suspension fork, and maybe have a disc brake tabs welded on. The frame must have been old since it had a U-brake and a head tube for a 1” steerer, which sounds like late 1980s. I had to tell him how difficult it would be to put a disc tab on the rear triangle and how 1-1/8’ steerers have been the standard for years now. But the deal killer was the BB. It was some sort of non-standard unit that fit the extra wide, small diameter shell; the aluminium cups stubbornly frozen in place with no means other than a pin spanner to remove (there’s a reason Shimano uses a spline interface here).

One of the skills a good mechanic needs to acquire is the ability to quickly evaluate a problem that is maybe unfixable and/or unprofitable. Learn to avoid the tar baby bicycles. Wrenching bikes isn’t the same as practicing medicine (if it was, I ‘d pay doctors less, or you’d pay me more), there’s no Hypocratic oath. Sometimes you give the same advice as Kenny Rogers: you gotta know when to hold’em, know when to fold’em.

McMahon.jpg

I told the customer how hopeless it was to change the frame to fit modern components or even replace the oddball BB. Even replacing the cartridge bearings would first require removing the soft aluminium cups, and the very act of forcing out the cups would almost certainly destroy them.

He left the frame abandoned in my hands. I’ve tossed the frame in the garbage twice, and someone in the shop has pulled it out each time. I had a good chuckle watching someone try to remove the BB with various tools of desperation, obviously thinking that they’d make it into something salvageable. It’s titanium, after all. I actually was hoping he would succeed (especially after a ridiculous amount of effort), just so I could point out the futility of removing a BB for which a replacement was not available. Alas, he gave up.



5 Comments

who the hell puts titanium in the garbage?

But a titanium frame is “the last frame you’ll ever buy”—how can it be?

How much should I be worrying about all the trendy push toward funky forks, press-fit bearings and their special fitments?

I worry about the same things…but at least the modern press-fit bearings like BB30 and BB86 are industry standards and are reaching fairly mainstream market acceptance (meaning replacements should be available well into the future…hopefully). 

The MTB days were like a wild frontier—McMahon used weird proprietary stuff, as did Klein and many other makers.  Then you had all the various tiny manufacturers whipping out nearly one-off CNC’d parts that were impossible to find replacements for when those businesses went tits-up.  There weren’t a whole lot of standards at the time.

A shame about that titanium frame…time for the hacksaw:  that frame is great raw materials for a wicked waterpipe!

Donate it to BikeWorks and let their mechanics learn from it.

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