spokenfork

Howdy folks first post:


I bought a BMX bike 11 years ago. A FELT BMX 24 Cruiser. I just bought some taller handlebars and a soft seat to suit my old man needs. I was hoping I could ride the bike for another decade or longer, replacing parts as needed.

Then I read that Aluminum frames can "wear out". Is this true? Does this happen from miles ridden?


Im totally guessing, I think my bike has 5 to 10K miles of mostly street riding. I have looked over the frame and can't see any issues such as cracks or dents. I have heard some creaking sounds from the crank area occasionally.


In your opinion do I need a new frame since it is 11 years old?

Would it be better to buy a new frame or a new complete bike? Most of my current parts are in decent shape, may need rear wheel.

Budget is a factor so if I could just ride it that would be the preferred option but I also don't want to get hurt if the bike may fail in a dangerous way.


I would love any feedback!

Thanks!

Trakhak

One change from the early years of the Bike Forums website is that only a few people here seem to still believe the myth that aluminum frames won't give adequate service life and are less reliable than steel or titanium bikes. Maybe that's because the majority of bikes sold in bike stores since the early 2000s have had aluminum frames and have proven their reliability over the years.

For myself, I bought my first aluminum-framed bike (Cannondale SM-500 mountain bike) in 1987 and have ridden many tens of thousands of miles exclusively on aluminum bikes since 2003. No frame failures, of course.

I worked in bike stores in the 1980s and 1990s and saw a few steel frame failures each year, but that didn't mean that steel frames were unreliable---only that almost all of the bikes ridden in those days had steel frames. I imagine that, if I were working in a bike store these days, I'd see a few aluminum frame failures and almost no steel frame failures. Same reason---lots of aluminum bikes on the road, comparatively few steel frames.

That's all anecdotal, though. There's only one report of empirical data on the subject that I know of, based on fatigue tests of aluminum, carbon fiber, steel, and titanium racing bikes performed in a lab in Germany in the late 1990s.

Short version of the test results: two aluminum frames and one carbon fiber frame survived the testing; all of the steel and titanium frames failed the testing. The testers noted that frame design was demonstrated to be a far more important factor than frame material with respect to fatigue life.

12 High-End Frames in the EFBe Fatigue Test

Charliekeet

Lots of questions, requiring lots of opinions. Nobody can tell you for sure what’s going to happen, so again, just my thoughts:

1. BMX cruisers are hard to find (less common than 20” bikes), so I’d be inclined to keep it until I had another in hand.

2. Yes, aluminum fatigue is real, and yes it’s due to repetitive stresses. If you search you’ll find many threads here with learned answers from folks who have a good handle on the materials science, but yes it can crack, and once it does, it’s usually means the part is done for unless some sophisticated stuff is done, and therefore it worth it to continue.

3. But Al is plenty able to have long lifespan, and most people ride all manner of bars, stems, frames, rims, etc for a long time without having any cracking issues. I have a 1985 Cannondale that is still going strong. Unless you know your frame was beat on, or ridden a ton, there should be nothing to worry about.

4. If you are considering getting something new and want steel instead, you could look at the 24 or 26” models from Sunday, Stolen, and Fairdale. Maybe Colony or GT and Haro make one too?

spelger

pretty sure the aircraft industry would be interested to know about aluminum wearing out. amazing that some of those planes are still flying after 50 years.

https://blog.framingtech.com/aluminu...inum-fortress/

indyfabz

Might want to ask the mods to move this thread here:

BMX - Bike Forums

Iride01 

How true to BMX cycling are you when you ride? Or do you just do a few hops or pop a wheelie every so often? Or do you just simply ride it?

If you aren't every day working your bike to the edge of it's design tolerances, then I wouldn't worry about it. Just learn to be aware of what you are looking at when you look at your bike or anything else you use.


If you do this every day, then maybe you should retire a bike periodically, no matter what it's made of...

msu2001la

Theoretically true with enough eventual wear, but in reality not so much.

The creaking is likely the bottom bracket or drivetrain, and not the frame itself.

No. Unless there are obvious signs of damage that frame should be fine to ride for many more years. There are many many people riding aluminum frames much older than that.

Wildwood 

Any bike frame ridden gently on the road or dirt (and stored dry) should last several lifetimes.

There were some manufacturing practices with early Al frames that led to failure. Corrected decades ago.

There are also some qualities of Aluminum alloy that frames repeatedly stressed near max load/impact are more prone to failure over time than steel or titanium. Bikes of all materials are generally overbuilt to withstand their designed usage.

Where are the engineers to explain?

cbrstar

If you are racing on the track then YES you should retire a frame after a few years. But I think you are more then fine if you are just cruising around and doing the odd jump here and there. Just check by the welds for signs of cracks. 80's - 90's Aluminum frames wore out pretty fast but more modern ones like yours where beefed up in joints and are a lot stronger.

spokenfork

Thanks so much everyone for all the information!

I am relieved to hear that I may have more years with this bike. I like the idea of repairing and replacing parts.
I mostly just cruise the streets these days with maybe a hop now and then.

i really learned a lot thanks so much! Very informative !

Trakhak

With a few exceptions at the high end of the market, European press-fit and "screwed-and-glued" aluminum frames earned a reputation for failure. The well-designed aluminum frames produced by Klein, Cannondale, Schwinn, and Raleigh USA were far stronger.

cbrstar

I don't know the reason why but early Aluminum MTB's have far outlasted early BMX frames. I have a aluminum Race Inc BMX from 1980 and it's the only one in my collection I won't ride. The reason is my friend had a early 1980's aluminum PK Ripper and the seat tube cracked all the way down from him simply sitting on it (I saw it happen) and I hear that's a problem with mine. Some in the 1990's like Haro's and Mongoose broke from being a bad design. But they now have things pretty figured out. I have a Chase RSP 2.0 which is a bit older but still solid. Hydroformed tubing is amazing stuff.

Retro Grouch 

Examine the welds at the headset and bottom bracket areas. If you see what looks like a hair at the edge of the weld, that's a crack and the frame is done.

Wildwood 

Below is an article about heat treating Al frames after welding.
It took a few years for everyone to perfect the manufacturing technique in production.

Not just European aluminum frames, as suggested by Trakhak, were problematic.
The earliest Cannondales earned the nickname 'CracknFail'. Cannot speak for other manufacturers.

To the Point: Heat Treating Aluminum Frames - Pinkbike

Trakhak

I worked in large Cannondale dealerships from the late-1970s pre-bike era through the mid-1990s. I saw a moderate number of cracked steel frames (some from crashes, some from overheating) during that time but no---zero---non-crash-related Cannondale frame failures. (I crashed my own year-old 1987 Cannondale SM-500 mountain bike into a tree at pretty good speed---the steel fork bent, the frame was fine. Rode the bike tens of thousands of miles off-road and as a commuter for decades after that.)

The same wiseass bike store employees who came up with "Crack-'n'-Fail" also called Campagnolo "Cramp-and-Go-Slow" and Shimano "Shi#mano." All equally meaningful.