63 votes
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How is this damaged aluminium frame likely to fail?

How is this damaged aluminium frame likely to fail? Sorry. It's not going to fail, it has failed. It's no longer ridable. The head tube is near vertical making the steering very unstable and the ...
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18 votes
Accepted

What are the most basic parts of a bicycle which cannot be upgraded over a period of time?

Certain parts of a bicycle are more easily upgradeable than others, while other types of upgrades require special tools, much more money investments or are limited to whatever standards are used in ...
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17 votes

How is this damaged aluminium frame likely to fail?

Oh, that frame is done. It’s not worth saving a few hundred bucks now and spending thousands in the hospital later. Make sure to check over the rest of the bike, especially the fork. It might have ...
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  • 10.8k
15 votes

Drilling hole in aluminium frame

Do not do that. Although the question you referenced is about carbon fiber, the answer mostly applies. Aluminium alloys used in bicycle frames are quite fragile. Drilling may easily start cracks that ...
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14 votes

What are the most basic parts of a bicycle which cannot be upgraded over a period of time?

Any and every part of a bicycle can be replaced, including the frame. (Many people would probably regard a different frame as a different bicycle though.) You ask whether there are components that '...
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13 votes
Accepted

Are curved aluminum forks safe?

It depends on how the fork is engineered for safety. While its plausible that the curved shape does add to some shock absorption, that is determined by the width and construction of the fork tubing. ...
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  • 45.5k
13 votes

How is this damaged aluminium frame likely to fail?

The problem with aluminum is, that it tends to break abruptly. Aluminum can bend under pressure, but it does no stretch significantly under tension before being ripped apart. You get no warning, you ...
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12 votes

carbon vs aluminium frame vibration absorption? bumpiness?

Aluminum has gotten a bit of a bad reputation from the early generation of frames which were overly stiff. This is less the case today as manufacturing technology fixed most of these earlier problems, ...
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  • 29.8k
12 votes

Very tiny dent on new aluminium frame -- anything to be worried about?

That is your bike's first "war wound" and should not compromise the integrity at all. It is disappointing to have a new-thing and is now no-longer showroom clean, but that's life - keep ...
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  • 99.1k
11 votes

Is it ok to sit on the top tube of my Cannondale CAAD12 (2017 model)?

If sitting on your top tube causes damage to your bike, the bike wasn't very safe to begin with. I imagine while sitting you have at least one foot on the ground, so your entire mass is not resting on ...
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  • 501
11 votes

What does the frame material name of "SC7 Scandium" mean?

Yes. Scandium is an element with atomic number 21. It is rare with the annual worldwide production being 15-20 tonnes total, so the pure metal commands a price of over $140 USD/gram, and Scandium ...
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  • 99.1k
10 votes
Accepted

What's the strongest way to bond a cable stop to an aluminum frame?

Since you have a relatively "flat" spot there (at least flat in the longitudinal direction) you have two options: You can epoxy on a replacement boss I did this on a recent Al frame with the exact ...
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  • 836
10 votes
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Crack/fissure in the headtube

Q: "[W]ould a competent welder be able to fix that crack[?]" No, that frame is done for. By attempting to weld such a crack, a welder would prove their incompetence. Even if you fix that crack you ...
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  • 8,962
8 votes

Steel vs. Aluminum Wheels

Others have answered the second part "what are the differences..." Here's an answer for the first part "why not many at the dump" In in my city 2015 light grade clean steel is worth $0.02/kg. ...
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  • 99.1k
8 votes
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How long will this alum frame last?

A crack developing there, is most likely too much seat post out of the frame, or in actual fact, not enough seat post being in the frame. The biggest problem with a crack in this location, is that it ...
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  • 399
8 votes

Is this aluminium rim saveable?

Result DISMAL FAILURE I attempted to use a large 12" adjustable spanner to gently tweak the rim back to place. On the first pass along it worked okay, and took out about a third of the offset. It ...
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  • 99.1k
8 votes
Accepted

Can I cut the steerer tube with a pipe cutter?

A pipe cutter is an excellent tool for this application. Properly used it results in a perfect, burr free cut that is 90° to the longitudinal axis of the steer tube. The outer aspect of the cut ...
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  • 6,928
7 votes
Accepted

Should I force an 130 mm hub into my old vintage alu frame

First, try to find a modern wheel that's the right size. They are still made and you can get very shiny ones that will match the bike very nicely. Or get a 120mm fixie hub and add 3mm of spacers each ...
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  • 23k
7 votes
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Can this frame be saved?

The frame is 100% trash. Do not attempt to use it at all. What you can do is to carefully remove everything from the frame. Discard the frame, and now you have a whole bunch of valuable parts. You ...
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  • 2,133
6 votes

Aluminum seatpost stuck to a steel frame

Eventually got an aluminium seat-post out of an old steel Peugeot road-bike frame. It had been in for a couple of decades, never moved and was completely 'welded' in place. Tried penetrating oil, ...
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  • 61
6 votes

Should I force an 130 mm hub into my old vintage alu frame

I don't necessarily recommend it, but I own a Vitus 979 and did this about 10 years ago so I could upgrade to a 9 speed cassette and STI shifters. I haven't had any problems with it. But I haven't put ...
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  • 449
6 votes

Last grand tour won on aluminum?

Abraham Olano won the 1998 Vuelta on an alloy frame. That might be the last Grand Tour win on alloy - as the Vuelta is the last Grand Tour of the year.
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  • 3,051
6 votes

What's the strongest way to bond a cable stop to an aluminum frame?

Good epoxy is known to bond metals, especially aluminum very well. Make sure the surfaces are clean and slightly rough for a better bond. I use the same two part epoxy hobbyist aircraft builders use ...
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  • 369
6 votes
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Aluminum frame quality - how much variation can there be and how to tell?

You actually point out two important characteristics in your photos: welds and hydroforming. The more expensive frame (looks like specialized bikes) has shaped tubes and very clean welds, while the ...
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  • 29.8k
6 votes

Reconciling the two aspects: carbon is stiffer for power, but offers a softer ride

A simple explanation I've heard is that metal tubes are isotropic - their material properties are identical in all directions (tube shape and thickness being constant). Carbon fiber can be made ...
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  • 19.4k
5 votes

Last grand tour won on aluminum?

According to this article, the last Tour De France win on an aluminum frame (a Bianchi ridden by Marco Pantani) was 1998. It also says that the last TDF win on a steel bike was 1994. It's ...
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5 votes
Accepted

Specialized Allez - Upgrade to Carbon Seatpost for Long Distance Comfort?

There are a lot of more potentially useful avenues to investigate first, because you feel that chamois pad quality is not the culprit next most obvious choice is the saddle: Stock saddles are often ...
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  • 29.8k
5 votes

Slipping aluminium seatpost in aluminium frame

I had an exactly same problem: Ritchey WCS seatpost, Merida frame (both alu alloy) and a lightweight clamp, like in @Frisbee's answer. What I tried: Beefy clamp with various torque settings. Didn't ...
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5 votes

aluminium fatigue how to know if some thing is going wrong?

I have a 1998 aluminium road bike, and it made creaking noises in the stem when pedaling hard. Could replicate this by siezing the bars while stopped and wiggling. So I tightened the quill stem and ...
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  • 99.1k
5 votes

Aluminum frame quality - how much variation can there be and how to tell?

DRH has pretty much answered it in the comments, but the variation can be a lot and its going to be hard or impossible to tell just by looking at a frame, especially if you encounter a counterfeit (...
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  • 45.5k

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