I'm thinking of trying to cut some weight. I currently ride a steel Team Miyata frame that, while a trusty steed, is rather portly. I am about to do some very long hilly races in which I think I can be competitive and I think it would be helpful to figure how how to drop some weight.
I am very cheap when it comes to cycling components. Very. It's just a habit. I don't know that other than bike clothing I've ever bought anything new. Anyhow. There is a used Giant TCR alloy frame for sale locally. I think it's about 6 years old. It's in fine nick visually, and nothing's visibly dented or bent. I do understand that, at least in theory, alu frames degrade slightly over time. (Actually I guess what must happen is that they work-harden and then become brittle. Which I guess would not be terribly handy in a crash, but shouldn't affect performance rubber side down.) They'll sell it for $130.
Any opinions on buying a used alu frame? It's just so dirt cheap, it's much much lighter than the Miyata and the geometry is very similar so I believe I could just swap over the parts. I could even use my old fork, as this one has the old 1" steerer. Any thoughts?
You've obviously gotta check for cracks, especially under and around the whole bottom bracket area (not forgetting behind the BB where the chain-stays join), and all around the rear drop-outs. Cracks aren't always obvious, and often only show themselves as suspicious paint movement that kinda looks like a scratch, but kinda doesn't.
From my understanding, alu frame failures usually aren't sudden and catastrophic, but are more likely to first show up as a small crack, so it's just a matter of making regular checks while cleaning.
(Actually I guess what must happen is that they work-harden and then become brittle. Which I guess would not be terribly handy in a crash, but shouldn't affect performance rubber side down.)
Work hardening requires plastic deformation. Aluminum fatigue involves crack formation from cyclic tensile stresses well under the yield stress. The best thing to do is take a look at the guy who's selling it. If he's a 200lb sprinting machine who's been racking up 20k miles a year, it's probably pretty close to the end. Otherwise just check it for cracks and dents. At the price he's asking, I wouldn't be upset if the frame only lasted a year or two.
Well, I bought it. Didn't include the cool Giant fork :-( so I'll have to re-use the old Kestrel. But I didn't see any cracks. I hope it saves some weight -- swapping over all the parts and getting the position right again will be a pain. I've never had a really light bike and I'm hoping this one now is. Pretty funny to put my medieval handbuilt 32' wheels on a modern Giant, but they should get the job done I trust. It is sweet that I believe every single component on the Miyata will be usable on the new frame. If I don't post here any more you'll know the dropout fell off in the hills and I pulled a Beloki ...
artmichalek said:
Work hardening requires plastic deformation. Aluminum fatigue involves crack formation from cyclic tensile stresses well under the yield stress. The best thing to do is take a look at the guy who's selling it. If he's a 200lb sprinting machine who's been racking up 20k miles a year, it's probably pretty close to the end. Otherwise just check it for cracks and dents. At the price he's asking, I wouldn't be upset if the frame only lasted a year or two.
I don't know, is that a lot or a little? The fork I have is just a threaded Kestrel EMS so it is probably not the lightest. But surely this rig will be lighter than my old Miyata. It doesn't say on your list how much a Miyata in fact weighs, but it's gotta one of the heaviest race bikes I've ever seen even though it has '96 Campy Record stuff on it which I wouldn't think is all that heavy.
no, there are no Miyatas on the Weight Weenies list. 🙂
The average "light" steel lugged 531 frame from the old days is around 1800g to 1900g, depending, of course, on the size. So, you'd have to be dropping over a pound on the frame.
If you wanna go crazy you could get a really light full-carbon fork at under 380g!!! 😄
Thanks. I hope it's better than a pound difference. Otherwise why bother with all this wrenching. But we'll give it a shot!
531Aussie said:
that's pretty light, even for aluminium
no, there are no Miyatas on the Weight Weenies list. 🙂
The average "light" steel lugged 531 frame from the old days is around 1800g to 1900g, depending, of course, on the size. So, you'd have to be dropping over a pound on the frame.
If you wanna go crazy you could get a really light full-carbon fork at under 380g!!! 😄
