I recently purchased an older (2008?) Specialized Allez from a local bike recycling operation. Aluminum frame, carbon fork Shimano Sora 3300 groupset, Alexrims DA16 wheels. I plan to strip everything off and rebuild as a winter project, as I have a cache of older Campy Mirage/Centaur components.

I am curious about the quality of non-CF frames from the major bike manufacturers. Would a large manufacturer like Specialized use basically the same aluminum frame, and upgrade only the components (from Shimano Sora to Tiagra/105/Ultegra), or doe the quality of framesets improve with the quality of components?

I'm assuming not much to improve with an aluminum frame, but probably significant differences with CF frames. I don't have a scale to measure the weight, but it seems to be fairly light. The tubes are welded, which is a "look" you either like or don't like (I like it).

Second question: the BB is a standard BSA threaded (thank you Lord!). The Mirage BB is a cartridge-style unit. Should I use Part Tools multi-purpose grease on the BB threads, or Permatex anti-seize? I was thinking the anti-seize would be better. Is there a rule of thumb when to use one over the other?

Generally there's a few steps in frame "quality" (as viewed by the easily led public) over the line of models a big company offers. So the least expensive has the thickest walls of tubing and maybe the lower cost alloy make up. At some point higher in the line up the wall thickness lessens and/or alloy becomes one with a higher strength to weight ratio. Perhaps a third step happens too.

It's not too hard to read the spec sheet and note the changing descriptions of the frame to figure this out. Usually bike companies like to give their "better" frames a cool name and these change with the grade changes.

Is this noMadic? Andy.

The only knock on Al. is the finite life of the frame depending on the weight of the rider.

I've never worried about frame longevity. All bicycle frames are one serious crash away from oblivion. Assuming that doesn't happen, I've never had a bike frame that didn't last longer than I wanted.

So far as frame quality otherwise goes. Manufacturers tend to build different frames for "families" of bike models. The more expensive models will have features the cheaper ones won't. There's all manner of subtle geometry differences too.

I had a 2003 Allez Sport that I wish I had kept. IMHO the combination of aluminum frame with carbon fiber fork and seatpost gave a nice, affordable ride. Bicycling felt it was a bike/frameset well worth the cost of upgraded components. Certainly not a super light ride but neither am I. In 2003 I believe Specialized used the same frame throughout the Allez line.

While not the OP's bike/company, Trek has a few different levels of Al tubing. Currently in their road line up are 100 series Alpha tubing and 300 series Alpha tubing. Now what do these labels really mean is another topic. Andy

The 1997 Cannondale F-1000 and the 1976 'Techniart' Bridgestone in my garage would like to know what that finite life is.
The Dale is a retired XC racer, and 3x week commuter. The Bridgestone did some touring BITD, a couple of audax events the last few year and is now retired to 'Townie/Path Bike' oh, and pulling the tag-along.
They're concerned that they don't have much time left. I weigh ~200# Should I scrap my bikes?

Engineering now used some of the material properties of Aluminum to be shaped according to the stresses it will see
a prime example Hydroforming..

One type finite life testing ends in counting the flexing cycles it takes to destroy it , sure you want that ?






....

"Ferrous alloys and titanium alloys[2] have a distinct limit, called the endurance limit, which is the amplitude of completely reversed bending stress below which there appears to be no number of cycles that will cause failure. Other structural metals such as aluminium and copper do not have a distinct limit and will eventually fail even from small stress amplitudes" https://en.wikipedia.org/wiki/Fatigue_limit

So a steel frame has an unlimited life as long as the stresses are below some threshold and Al will fail at some point no mater what the stresses are. That is why you don't see Al springs as example. Andy

I'm aware of the different properties of steel vs aluminum, and why we don't make aluminum springs. You can break anything. I've broken steel, (carbon and stainless) Aluminum, and Titanium. I guess it's whether you view a bike frame as a rigid structure or a flexible one.

I think it's the 'Steel Frames are Infinite, and Aluminum Frames WILL break!' mantra that gets tossed around every time frame material comes up.
If an Aluminum bike is on borrowed time from the moment it rolls out of the shop, what's the lifespan, then? 5,000 miles, 10K, 100K?
I suspect that it's long enough that none of us will be able to 'just ride' an aluminum bike to the point of failure.

Make that 3 then, the Domane ALR is 200 series aluminum tubing.

To the OP. Yes, some companies to have different levels under the same model name but I've not known any to try to obscure that fact. Cannondale has 2 CAAD models but ID them as the 12 and Optimo. The cheaper Optimo is claimed to have the exact same geometry and the 12. Those are the only 2 brands I've really looked at extensively but would expect other brands such as Specialized and Giant to be the same.

There are a couple of companies claiming some new welding technologies, The Emonda ALR advertises "invisible weld technology" and one of them advertises "smart weld" but I don't know how either is better or different. The biggest advance in aluminum frames is hydro-forming the tubing and that process being more common now. I would definitely expect anything being manufactured now to be far more advanced that offerings from a decade ago at 2 to 3 times the price point. I doubt there was a production bike made 10-12 years ago that's as good as the Emonda ALR but that's not a statement I'm qualified to debate, so take it as just interweb opinion.

I think the real life of warranty claims and such would show the numbers. But these are not disclosed by brands and many are known for underestimating stuff when it's in their favor. So we will never likely really know the true count.

I will say this as a general observation over 45+ years in the trenches of the LBS and a sometime builder. Statistically I see more Al failures that are in the tubes then steel. Steel failures have generally been from poor joining. Weld cracks at the root, over heating brittlement, failure to have proper braze flow/penetration. But very few failures away from a heated area. Not so for Al. Cracked down from ends of head tubes, at stay indentations, and then there's the corrosive ones. Sorry but IME Al isn't as long lived over the average. Andy

https://www.bicycling.com/bikes-gear...ter-than-ever/

Perhaps the OP was speaking of the cosmetics of the welds. Some frames have distinct weld beads; you can see the puddle and how it was pushed along. This is not very visible on other frames, where it seems the bead has perhaps been ground smooth or had some sort of filler applied to smooth it out...making it almost seem as the frame was cast or something and not actually welded.

1st ? - One would think they improve with $$$, but also they have improved with time, but it depends so much on the rider. I tried a few early frames and think I loosened a filling riding one and I still have a Vitus 979 as I liked it so much and a grocery getter/library bike is a cheap late 2000 Al frame.
2nd ? - Grease will work fine in all but unusual circumstances, I use a specific aluminum to aluminum zinc oxide anti-seize, Permatex most likely makes one for aluminum/aluminum. These are commonly sold in little tubes for spark plugs.
Your statement on welds - I agree, I have a nice Zurich with noticeably ugly welds and a beautifully fillet brazed custom frame, while the Zurich is a fine ride I try not to notice the head tube welds.

I know two big men who rode aluminum frames and both had cracks after 30 or 40k miles. Fred owned a Fuji and it cracked at the junction of the sear tube and bottom bracket. I had a 5 year guarantee and was replaced. The second frame cracked in the same place after the guarantee expired. Fred weighted over 200 pounds.
I don't know the mileage of Travis' Cannondale's , but Cannondale replaced them under the lifetime guarantee after they had cracks..

Now there is Friction Welding , which is just like it sounds like rubbing while pressing 2 surfaces together , until they melt there, and then cool form one piece..



.... more NASA than bike making ..

My $0.02;
The risky area of an aluminum frame is its surrounding material of a weld. The weld can be the strongest & the areas far away from the weld are likely to be almost as strong. The weaker areas is the nearby material to the conducted weld. The heat during the welding stresses the aluminum that is not fed the filler rod & shielded by the inert gas.
As long as everything was done as it should have been, as well as necessary QA checking, an aluminum frame should outlast its responsible owner.

If the choice is grease or anti-seize, go with grease. Better yet, get some Teflon plumbing tape (be careful with the direction you wind it on!). Once the BB is torqued on correctly (i.e., TIGHT), it's unlikely to come off before the BB needs to be replaced. Teflon tape helps keep the two surfaces apart so corrosion won't lock it in place.

I like the Teflon tape idea. The have a Campy Mirage square-tapered crankset installed on a Mirage BB. I wasn't real happy with the chainline, so I computed the front and rear chainline in accordance with Lennard Zinn's repair manual. Long story short, I have sent off for a Chorus square tapered bottom bracket. The Chorus BB is 102 mm and the Mirage is 111. I suspect I am worried about nothing here, but is the nature of a Winter Build to spend much time staring at the work in progress, drinking beer, and pondering my next move. My options are somewhat limited, as there are not a lot of Campy square-tapered BB options out there.

If anyone chimes in that the Chorus square-tapered is different than Mirage square-taper, then I will just have to shoot myself! ASAIK, there is JIS and Campy, period.

You have to realize that most frames these days are welded up by robots in Taiwan if you are lucky, or China if you are not. The main difference is the paint job and the name that is painted on the frame.

Apart from handmade steel frames I understand most frames are made in Taiwan or the RPC these days. Most have large obvious welds which may seem ugly to some but should be stronger than theybwould be with the same weld filed down smooth. I have a 94 Cannondale which has no apparent welds at all but it alleges on a frame sticker it was made in the USA.. Being a Luddite I prefer steel frames but the two Al frames I have work well. Something I have heard a lot about is ride quality with steel being more lively,supple etc. And yet the the part of a bike that is subject to the most flex would seem to me to be handlebars but Al bars have been the norm for 50 years at least.