I want a bike thats going to be awesome today, and last me 8-10 years (at least the frame) of long hard riding. what material will last this long, still being just as awesome as the day i bought it. As a correlary (sp?) to that, what companies provide what types of warranties. If im on a superlight frame, and i fall and the frame dents, bends or cracks, which companies will replace it, without having to buy a new one? Im leaning toward the litespeed vortex at this point.
I would venture to guess the most durable frame would be titanium, followed by steel. But what the hell do I know, I am a paint salesman.
Material choice isn’t a significant factor in bicycle frame fatigue. The quality of the design and construction is far more significant . I have seen as many frames fail in carbon, titanium and steel as I have in aluminium.
Bikes almost never fail due to the material, its usually poor welding, heat damage (from welding) or poor design which causes “stress risers” which leads cracking.
Keep in mind when people hassle aluminum that the main structural memebers in most aircraft are aluiminium and there are plenty of commercial aircraft which are heading for their 30th birthday!
Find out what runs the mouths of three year old girls. THAT is some kinda’ fatigue-resistant stuff…
I would say titanium. It is also a comfortable material, so the bike will be fun to ride as well as performing well. But keep in mind that while many frames come with lifetime warranties, those do not cover your situation of falling and denting, cracking, or bending the frame. That is what is called rider error, and NO company that I know of would warranty the frame if there was evidence of this happening.
Also one other thing…
Be a little careful over “lifetime warrantys” for many companies they define the lifetime as the lifetime of the bike. I have been turned down for a warranty on a cracked frame (steal frame mulitiple cracks in multiple welds obvously poor welding as had never been crashed or thrashed) which was only three years old as they said it has had a “reasonable life”, I still feel that I should of fought this. Another friend had the same situation on a ten year old carbon frame…perhaps in this case it was reasonable ten years is quite a long time.
I think I prefer 5yr or 10yr warranties…there a bit more clear and defined.
Steel and Ti have fatigue limits. This means if the frame is designed such that the max stress in any location is less than the fatigue limit, the frame will never fatigue. This does not mean a steel or Ti frame cannot/will not fail, just that it will not fail due to fatigue. As pointed out frames are most likely to fail due to bad welds and/or weakening due to the heating from welding.
Aluminum has no fatigue limit. Therefore Al will always eventually fail due to fatigue if subjected to any cyclical stress long enough, no matter how small. Obviously a well designed frame will minimize stresses to the point that the amount of cycles required to cause fatigue failure is “infinite” in the practical sense (Ie so large it might as well be infinity), hence the example of airplanes with 30 year+ service lives.
Bottom line, fatigue is not an issue in a well designed and properly fabricated bicycle, no matter what material is used.
Also don’t confuse strength, with modulus. Modulus is the material property that characterizes stiffness (overall frame stiffness is a function of the material, tube diameter and geometry, although tube dimater has teh most significant impact (This is why Al frames are stiff, due to oversized tubes, not due to the material, because steel has three times the modulus of Al!!!) Modulus of a frame is not subject to fatigue, so the stiffness of a frame will not change over time (unless the frame has actually yielded (ie the elastic limit has been exceeded) in which case stiffness could change, but this would be due to the dimensional change, not because of the property of the material.
I bought my Serotta Legend Ti in 1994, got delivery in March of 1995 (rode it the first time the same day as my first date with my wife). In the summer of 2003 I noticed a crack in the bottom bracket bridge (that little tube behind the BB, between the chain stays). Serotta repaired it and repainted the frame (and fork) under warranty, no cost.
no offense to you but this question seems to come up quite often
please dont confuse just material properties (strength, stiffness, hardness, fatigue limits etc) with the expected life of a lightweight structure composed of welded or bonded elements. It is more likely that any of the joints will fail long before any tubing fails provided that no stress risers are present
you may want to do a search on the many frame material threads that have been discussed at lenght…here is one such example:
http://forum.slowtwitch.com/gforum.cgi?post=348670;search_string=frame;#348670
Ti, steel, aluminum, carbon it doesnt matter what they are made of - they will break - Despite all of the claims many high end bikes made out of these materials will fail - but you cant tell just by looking at them and finding out what material they are made of to predict whether or not they will fail…the only true way is to test them and these guys are one of the best at testing and breaking frames -this is where all of my frame searches start
http://www.efbe.de/defbefrm.htm
As for warranties - well no company will replace a frame if you crash although there are some that have been rumored to give you a discount on a new frame as long as you send your old one back to them for analysis. YMMV - warranties typically only cover manufacturing defects (typically weld cracks).
I think part of the point of the original poster was lost. Aside from failure or not, I believe he was talking about how the frame would feel/respond over the years. The concern may be more attributed to lightweight responsive steel frames where people would keep the frame for one or two seasons of hard use and then dispose of them as they became more flexy. This is probably less of an issue in some of the other materials like carbon and aluminum, or with heavier gauge steel frames. All may hold up in terms of not failing, but the ride characteristics might change over years of use.
huh … a frame – no matter the material – will ride the same today, as it will 5-10-15 years from now. frames, unlike wine and cheese, don’t age in the sense that their fundamental properties change.
go to litespeed.com and click on the technology tab. Litespeed provides a completely unbiased comparison of bike materials with regards to strength and fatigue. Suprisingly, titanium seems to be the ultimate material. I’m sold.
I don’t know how long it will last, but I have had a Vortex for several years and I still love it. Another great thing about ti is it looks as good today as it did when I got it new.
I have never had to use it, but I’ve heard that Litespeed’s customer service is very good too.
Jeff
Ken,
There are many who feel or believe Serottas are over priced. I guess they don’t know what you discovered or knew already.
I’m guilty. I own three and have purchased four. Serotta is a great bike frame manufacturer that makes great frames and stands behind them. They continue to push the envelope in designing great bikes.
Actually, I think that Serottas are overpriced; especially the ones with the CF stays and whatnot (Ottrott). Ridiculous prices. The people on the Serotta forum think the bikes have some mystical qualities. Nonsense. It’s a bike; a high quality bike to be sure, but still a bike.
huh … a frame – no matter the material – will ride the same today, as it will 5-10-15 years from now. frames, unlike wine and cheese, don’t age in the sense that their fundamental properties change.
It is not a matter of aging with time. I’m talking about fatigue over 1000s of cycles of flexing, etc. Specifically with thinwall steel frames. This has nothing to do with aging, just the amount of hard use.
Here’s a non-cycling example. Take a piece of spring steel. You can flex it back and forth. As you continue to do this, it will weaken to the point of not springing back (failure point), but before getting there, it will become more and more flexy. The same thing can happen to a steel frame, but not necessarily as extreme or dramatic. It just might not have that same snappy feel that some steel frame fans are looking for.