Having explored Bikepedia a bit more, it seems that CFA might have been a form of Cr-mo after all.

For instance, looking at 1997, Mongoose produced a hybrid called a "Crossway" at various levels.

The Crossway 250 was the $249 base Altus/Tourney model and was described as having a Tange Cromoly frame.

Next up the totem pole came the Crossway 450 at $329. Along with its Acera-X/Altus components it also had a Tange Cromoly frame.

Next rung up was the Crossway 650 at $415. This Alivio/Acera-X variant is described as having the mysterious CFA tubing.

Top of this rather low tree was the Crossway 850. At $549 it picked up STX and Alivio bits and another unique-to-Mongoose-terminology frame called a C(a)2 frame, whatever that means. I think its aluminum.

So putting this together, and assuming that the more expensive bikes got the better tubing, and seeing as even the base model bike had some form of cr-mo tubing, crummy though it might have been, it seem reasonable to assume that the middle-of-the-range bikes might have got a better form of cr-mo.

Following this logic, I'm guessing that the Sycamore was somewhere in the middle of Mongoose's 1997 mtb range, and the frame tubing was at least one level from the bottom. Seeing as my current backup bike is hi-tens except for the cr-mo seatpost, I'm inclined to think the Mongoose might be a better ride.

If think that 1997 was about the time Mongoose started to go down the toilet. With stupid, brain-dead, ambiguous terminology like "CFA" and "C(a)2" that nobody can interpret, it's no wonder they crashed and burned.

[Edit] Yep, Mongoose 1997 mtb heirarchy from bottom to top was:

- Switchback (Tange Cr-mo)
- Sycamore (CFA)
- Hilltopper (CFA)
- Rockadile C(a)2

So it looks like CFA is probably a form of Cr-mo.