94 Fat Chance Ti Garage Find

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sriracha

New member
I will absolutely treat her well!

Thank you for the XTR offer. I might be able to source something from a friend.

Glad to own a unicorn!

I removed the parts and gave the frame a nice cleaning. It is spotless. Your welds look amazing Scott!!! I will be sure to take some detail pictures of your craftsmanship. The toptube/downtube/seat tube/chainstay butting is impressive! The welds are tight! It's a beautiful frame.

Unfortunately, one of the Grafton cantilever brakes is failed. It looks like it was over-tightened at some point or experience a severe impact. The aluminum surrounding the bushing is bent and there is a crack inside. I would not feel safe using this brake under extreme conditions.

Everything is detailed and clean at this point.
 
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Stingercut

Active member
It always amazes me that people can forget or loose interest in something like this. Its the bicycle equivalent of parking up a Ferrari in a shed and just letting nature take its course over 25 + years. Maybe the owner passed away or maybe im just a bike nerd :beer:
 
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sriracha

New member
Good news about the XTR shifter pods! After talking to an older mechanic and an older shop manager, they both informed me that the old era of XTR shift pods notoriously "failed" because of old grease. What happens is the shift engagement ratchet pawls get sticky with old grease and don't return to their position, giving the impression that the gears are stripped. Half a can of degreaser and the original XTR shifter pods are snapping through gears like they were brand new!!!

Also, I'm talking with a local frame builder about getting a custom rigid fork welded up along with a custom shorty 1"-threadless stem. In the meantime, I found a place holder that will do.

In progress, complete factory tear-down and rebuild, a 1996 limited edition blue Marzocchi Z2 with the ultra rare disc brake mounts and 1"-threadless steertube, upgraded 1998 forged/machined brace and optional blue knobs. New factory dust/oil seals, new topcaps and yes, dust boots. The latest in 90's suspension technology, 68mm of buttery travel:

 
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greogoryraliche

New member
I'm loving it

Me catching up on this thread:

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sriracha

New member
making some progress:



I just slapped some tires on that I had laying around until I make some decisions.
 
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I-ROBOT

I-ROBOT

Active member
As always, I appreciate the compliments. It was fun while it lasted. Of course just as soon as I finally had TI really figured out, Somerville went under. C'est la vie!

Scott
 
I-ROBOT

I-ROBOT

Active member
I would like to think so, but there's a lot of things I can't do as well as I could when I was younger!

It's been many years since I welded every day, I'm sure I would need a lot of practice. There are some quirks to welding titanium that other metals don't seem to have.

I do pick up the torch here occasionally just to keep my hand in it, but having to wear glasses for close-up work presents a whole new set of challenges. We don't work with anything exotic here either, just carbon and low-alloy steels, stainless and a little bit of aluminum.

Part of me misses it terribly, part of me is glad I don't have to do that any longer. Depends on which side of the bed I get out of in the morning!

Scott
 
I-ROBOT

I-ROBOT

Active member
One other thing that was different on the TI frames was how the ends of the seat and chain stays were done.

The domes on the chrome-moly tubes were done in a machine we called the "domer" which had a small cutting head taken from a lathe and an oxy-acetylene torch mounted on a stand. The tubes were inserted and spun and the torch heated up the end. When it was red-hot, a forming tool was pushed against it to form the pointed dome. Typically, this was the least favorite job in the shop, everybody hated doing it. I built a better stand for it and that made the process much less dangerous than it was but the dome quality was directly influenced by the operator's ability and we wasted a lot of tubes. Also the rate of heating was not very well controlled and that would influence the microstructure of the 4130. I wasn't that worried about it since the domes were welded to the dropouts with a more controlled heat input and that tended to temper any hardened zones that may have been formed. We did some fatigue tests that helped to prove that out and I don't recall any tube or weld failures at the dropouts. There may have been but they would have been few and far between compared to what we would usually have to repair.

Since titanium is so reactive, you can't just heat it with a torch and hot-forge the end of the tube. Chris designed a tube dome that was machined from solid 3/4" bar stock and then those were welded to the tubes using a purgeable rotating fixture. I built a little box that fit over the tube end and it had just enough of an opening to hold the torch over and see the weld bead. The box was back-filled with argon to shield the entire dome end from atmospheric contamination. There is a photo of this in the June 1994 edition of Mountain Bike Action. I used the same set up to weld the head tube inserts and the seat tube insert. I bet you guys didn't even know that the seat tubes have welded inserts.

If you look closely at the photo that shows the dropout welded to the dome, you can see the circumferential weld that joins the dome to the tube. This had to be done first, and then the domes were slotted to fit to the tabs on the dropouts.

So there's your titanium welding lesson for today.

Hopefully spring will come back here some day
Scott
 
I-ROBOT

I-ROBOT

Active member
Here's an illustration - taken from sriracha's photo
 

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    ti chainstay.JPG
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S

Stingercut

Active member
I-ROBOT said:
I would like to think so, but there's a lot of things I can't do as well as I could when I was younger!

It's been many years since I welded every day, I'm sure I would need a lot of practice. There are some quirks to welding titanium that other metals don't seem to have.

Part of me misses it terribly, part of me is glad I don't have to do that any longer. Depends on which side of the bed I get out of in the morning!

Scott
Click to expand...

Aint that the truth ! :p:beer::beer:

I cant get enough of these particular details.....please keep it coming Scott. :beer::beer:

So much went into these Ti frames. I have seen so many Ti frames of this era but nothing comes close to having the technical input these had. So much pioneering design as a result of real problem solving went into them. Too many Ti frames of this era are cracked apparently and most were too noodly to ride hard. These Tis are stiff, so comfortable and still incredible to ride. I doubt there is anything made today that rides better, taking disc brakes out of the equation of course.
 
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sriracha

New member
Yeah, thank you for sharing, Scott! Super cool to hear technical inside information from one of the creators!

I'm sure you have plenty of stories. Would be interesting to hear more!
 
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