[bike] found something on craigslist, does it look like a good option?

[davester]

I had an early mountain bike (pre-shocks) made of high end cro-mo steel that I used extensively in wilderness areas of Nevada, and I can tell you with absolute certainty that there is no way that any amount of compliance in the frame can come close to equaling the shock absorption of a bike with shocks. The claim of your 29er friends sounds like bike macho to me, just like the macho silliness I hear from fixie riders who claim their bikes are faster than multispeed machines (which is only true at one speed, which is only reached long after a multispeed rider has pulled away from them).

I definitely disagree with your statement regarding frame breakage. Frame breakage is very common among mountain bike riders. Most frame breakage is due to metal fatigue, something that aluminum frames are more susceptible to than steel.

[kj]

I guess it depends what you would call "very common". There are a lot of pics on the web, but when I broke my frame, every person who passed me stopped to look because they hadn't ever seen it happen. I'm also not sure most breaks happen due to metal fatigue, unless that includes munging frames off 6' dropoffs. Mine happened over a rocky section of trail that utilized all available travel on my shocks. I guess that's sort of fatigue, but not really. I agree aluminum isn't as durable, but it's certainly a viable material for bike frames. It depends what you value. kj.

[davester]

kj wrote: Mine happened over a rocky section of trail that utilized all available travel on my shocks. I guess that's sort of fatigue, but not really.

No, there is no "sort of" about metal fatigue. It either is or it isn't. As I stated above, metal fatigue is a very specific term that describes the lowering of a metal's yield strength due to cyclic loading. It is possible that your frame was already suffering from fatigue effects which made it more susceptible to a failure due to a traumatic impact, but dropping off a cliff could easily exceed the yield strength of any frame material even if it was not fatigued.

[Black]

I guess if I've ridden my share of Aluminum and Steel bikes, I have to wonder why I need Sheldon Brown to tell me what I should think of the ride quality?

[kj]

>>It is possible that your frame was already suffering from fatigue effects which made it more susceptible to a failure due to a traumatic impact

Which is exactly what I meant by "sort of". But my impression is that most mountain bike frame breaks are due to traumatic impact, so I wondered at your assertion that most breakage is due to fatigue. I've never seen an aluminum bike break due to fatigue, but I guess it might be hard to know exactly why something breaks (as you pointed out). kj.

[kj]

Black wrote:
I guess if I've ridden my share of Aluminum and Steel bikes, I have to wonder why I need Sheldon Brown to tell me what I should think of the ride quality?

I just thought Sheldon made some pretty good points, and I don't think it's fair to give the impression aluminum isn't a valid choice of materials for bike frames. kj.

[davester]

kj wrote: ... I don't think it's fair to give the impression aluminum isn't a valid choice of materials for bike frames. kj.

Where would fairness enter into such a discussion. Aluminum is just a material. It has a certain set of properties relevant to bike frame suitability. If those properties render it a poor choice then that is just the way it is. You can argue about the validity of the choices but fairness doesn't enter into the discussion.