Arrowtalon

I've searched around other threads and found some good info on this topic, particularly:

https://spokesmanbicycles.com/page.cfm?pageID=330

However, this article was written in 1994(?), and I'm not sure what advances have been made since then. I'm considering new bikes. My budget allows steel or aluminum. I have my eye on a 7005 (T7 DB) Kinesis frame, or a Reynolds 520 DB frame.

Here's what I know: I know the differences in how each ride. I know that the properties of the specific type of each frame material matters.

Here's what I'd like to know: Is 7000 series aluminum (7005) as durable as Reynolds 520? Is a 520 steel frame bike more likely to last longer than a 7005 Al frame?

*EDIT: By " last longer" I'm asking about fatigue, not failure. I'm not trying to start another firestorm on this topic. What I'm wondering is whether or not Aluminum loses its "feel" as some riders/bike shops claim.

big john

Nobody can tell how long a frame is going to last. Any frame can break. I've broken 4 frames, 3 steel and 1 aluminum.

ElJamoquio

7005 is (one of) the best aluminum alloys to built a frame out of.

Either will almost certainly outlast your own commitment to it, be that commitment two years or twenty.

unbelievably

My guess is that they don't call you "big john" for nothing...

big john

Here is my mtb, finally failed 2 weeks ago.

Here is a LeMond, owned by Mr Beanz, who is bigger than me.

Arrowtalon

After reading along a bit I decided what I'm really worried about is aluminum fatigue. Though I don't think anyone has an empirical conclusion about bike frames yet, at least for AL bike frames in the price range I'm after (lower than most).

Sounds like either is fine for 10 years given 2000 miles/year.

AEO

it's all in the design, usage and maintenance. Aluminum frames have been around for 20ish years and those frames are still around.
I'm sure aluminum frames from today will last a good 20 years of use if you don't crash it.
My vote, CAAD9 or scandium-aluminum frames.

When things break, they break, doesn't matter what material.

DiabloScott

Steel and aluminum both fatigue. Small nicks and dings in critical areas greatly increase the speed at which fatigue happens in both materials.

The MTB crack photo looks like the tubing was damaged during welding leading to fatigue. The blue Lemond crack photo looks like crash damage on the downtube leading to fatigue..

If you crash a lot, steel might be a good choice.

notfred

They make airplanes out of aluminum and fly them millions of miles over decades of daily use. I'm pretty sure an aluminum bike will last two or three years until you get bored with it and want a newer one.

People have this stupid hang-up about wanting to buy bikes that will last a lifetime, but hardly anyone keeps them for more than a couple of years anyway. Do you really plan to still be riding this same bike in 2028? You'll probably ruin it by accidentally backing your car over it before then, even if you buy the steel one that will "last forever".

Arrowtalon

Steel doesn't have a fatigue limit. My brother's an engineer and has educated me about steel vs aluminum, as have many of the threads here. What I'm wondering about is whether or not aluminum "loses its feel" after a few years as many claim.

I enjoy the comfort of steel, but I'm not sure it's worth the price jump if both materials are similarly resilient for typical cycling use.

ElJamoquio

There you go.

ElJamoquio

Steel fatigues. My sister's a 'special-needs' teacher.

Arrowtalon

You're speaking like someone with money to burn. Buying a bike every few years sounds like buying it simply for the materialistic appeal rather than for the enjoyment of cycling.

I don't have the cash to buy a $1200+ bike every few years. I have been riding the same, obsolete, heavy, too-big-for-me steel Centurion for 4 years. If the frame weren't so big, I'd just keep riding it. I believe in buying quality stuff that lasts (assuming I can afford it). Hell, I've been wearing the same winter jacket for 9 years.

I do intend to keep the bike at least a decade, unless I wear it out (maybe likely) or out-perform the bike (unlikely).

AnthonyG

I'm a fan of steel bikes and my current ride is custom built from Columbus Zona tubing. Steel is still a good all-rounder for use in bicycle frames. I would expect the Reynolds 520 frame to have a long life if it was manufactured to high quality standards. Mind you Reynolds 520 isn't really high end steel. I believe its plain gauge tubing rather than butted. Good for sturdy touring frames but not particularly light although its not like its plain gauge mild steel tubing. Much better than that. A modern 7005 aluminum frame would be quite a bit lighter.

Regards, Anthony

Arrowtalon

Steel doesn't have a fatigue limit. Aluminum does. I'm not talking about damage. Obviously damage will screw things up. I'm talking about how a material "feels" after extensive use. As I said. I have an old, well-ridden 80's steelie. It rides just as nice as a modern steel bike, but it's too big for me.

I'm not trying to push steel here. I'm not one of those people. I just want people who have ridden aluminum bikes extensively for more than 5 years, say, to give me their opinion on whether their aluminum frames "feel" different with age and use.

Phantoj

Aluminum doesn't.

Steel does have a fatigue limit. But that's irrelevant because the stresses will exceed the fatigue limit on a lightweight bike. Or else steel bikes would never fail in fatigue ... see the previous posts in this topic.

Arrowtalon

The 520 frame I'm looking at says its double-butted. I think it's reasonable quality. I believe it's the same frame quality as a Raleigh 520 frame (manufactured at the same place) but with classic geometry.

The 7005 frame is identical to those on Fuji Roubaix/Roubaix Pro.

The 520 bike is 19-20 lbs (verified by other consumers' measurements), the 7005 bike is listed at 17-18 lbs.

Phantoj

The frame is only 3-5 pounds of a bike's weight - the rest is the other components.

Arrowtalon

You're right. I had it backwards. The point is that small cyclic stresses effect Aluminum. They do not, in principal, effect steel.

If steel is bent, it will not deform unless it's limit is reached. Aluminum deforms (on a small scale) under light stresses.

But I'm not talking about the frame failing. As a poster above said, a frame may fail regardless of material. I'm wondering if old aluminum frames feel different than new ones.

Arrowtalon

I forgot to specify that the component group on both bikes is virtually identical. So, the majority of the weight difference is due to the frames. That said, I'm not concerned about a couple pounds since both bike weights are reasonable.

logdrum

There was an article about a pro-rider (TDF or world's) who used a Vitus alu frame... Was noodly but he made it work.

I also got an aluminum frame and steel

Look at your wheels. Spokes are alu and they are stressed to begin with taking the brunt of road vibration and always in motion. It's not like they break everyday. Something to think about alumimum, used in hot stressed engines as blocks and many planes are still flying with aluminum wings and other components.

ElJamoquio

I don't know, my sister says otherwise. I believe her - she may teach English to special-needs children during the day, but at night she's a materials-science-superheroine.

ElJamoquio

Is alu a new trade-name for stainless steel...?

Arrowtalon

Again, I'm not worried about aluminum breaking. I find as soon as someone starts pointing out the properties of aluminum everyone gets defensive. I'm not suggesting Aluminum will break more readily than steel. But, will Aluminum fatigue a few years down the road?

531Aussie

nah, don't get 520 -- it's low-end, heavy, 'basic' CroMo. Although it depends what you want it for. If you want a 'fast-feeling' road bike with any kind of 'zip', I wouldn't be getting 520. The only people I know who get that stuff is to use it for moutain bikes, cross bikes or for touring bikes designed to carry lots of racks. Even in these situations people often go for soemthing better/lighter than 520.

However, it should be much more durable than 7005.



that's a myth. Frames don't go 'soft'. The only time a frames goes soft is the possibly the few minutes or seconds before it breaks. The only thing that might lose 'feel' is the wheels, but only if the spokes eventually drop tension