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-   -   What's wrong with stamped dropouts/fork ends? (https://www.bikeforums.net/classic-vintage/484678-whats-wrong-stamped-dropouts-fork-ends.html)

jonwvara 11-08-08 03:09 PM

What's wrong with stamped dropouts/fork ends?
 
Here's something I've wondered about casually for a long time: why are forged dropouts and fork tips better than stamped ones? Objectively better, I mean--they're obviously characteristic of better quality and more expensive bikes. But why should that be so? I imagine they're more expensive, but are they also stronger, or longer lasting, or less prone to damage or lighter in weight or something? Most of my bikes have forged dropouts, but my old Motobecane Super Mirage has nice heavy stamped dropouts that have been working fine for 30 years and tens of thousands of miles. I just can't see what's wrong with them, or how forged dropouts would have improved the bike in any way.
Perhaps it's that forged dropouts come with a brand name--Simplex, Tange, Suntour, Campy, etc.--so they're a known quantity, while stamped dropouts, being generic (at least I've never seen any with a manufacturer's stamp) are seen as less trustworthy? And obviously the stamped ones do vary in quality. The dropouts on department store bikes are often pretty thin and flimsly, while many low-to-midrange older bikes, like my Motobecane, have very robust stamped dropouts.
Any ideas?

Kommisar89 11-08-08 07:40 PM

Not a clue. In general however, I find that there are many instances where a part or design feature might offer some value in a racing situation but doesn't offer any particular advantage to the casual rider yet gets used because everybody wants what the pros have. It could be a differentiator and marketing thing. There's little doubt that forged lugs are stronger than stamped ones. That might be important if you can put out 400+ watts for hours or you are a sprinter that can crank out 2000 watts but for the rest of us I doubt it matters much. Kind of like those guys who get so excited about file work on lugs. I doubt that makes any practical difference either but it's a differentiator. Peugeot had a number of mid-range models that used forged drop-outs and Bocama lugs to build a frame with the same hi-tensile steel "Tube Special Allege Peugeot" house brand tubing used to make UO8s and I'm pretty sure that was just marketing.

mswantak 11-08-08 07:45 PM

Snob appeal; nothing more. A stamped dropout will perform equally to forged one in 99.9% of all cases.

bassogap 11-08-08 07:48 PM

Thicker forged ends are just inherently prettier....also,they provide a more stable platform to clamp the wheels to....Whish should yield a less squirmy ride....

chewybrian 11-08-08 07:55 PM

Would the stamped dropouts have flat ends inserted into the tubes? Seems like I've seen really cheap bikes where they just smash the tube onto the dropouts. If the dropout is forged, it could, presumably, be shaped just right to fit the tube, maybe making a stronger frame(?).

Grand Bois 11-08-08 08:10 PM

I have to disagree with bassogap. I think that quick releases get a better bite into stamped dropouts because the metal is softer. They're less likely to slip, but more likely to rust at the "bite marks" left by the qr.

bassogap 11-08-08 08:28 PM

The axles will bite deeper into cast ones,true, but as the axle "platform" is so much thinner, i do maintain you might get some chance for shimmy.....Note how thick traditional Campy track droupouts are...

dbakl 11-08-08 09:00 PM

Well, forged dropouts have the integrated derailler hanger and the adjusting screws for wheel position, but stamped dropouts with the proper accessories can function just as well. Many fine bikes were made with stamped dropouts before forged became the norm. One is "slicker" than the other, but I doubt its in any way "better". Forged are thicker, so they may be stronger, though I suspect more prone to break than bend.

cbr2702 11-08-08 09:11 PM

From just a metals perspective, forging makes a stronger piece.

http://www.sheldonbrown.com/dp-forging.html

But whether the extra strength helps on dropouts?

LgReno 11-08-08 09:31 PM

As a materials engineer, i can tell you that forged dropouts give improved physical properties due to the refinement of the grain structure. The Hall-Petch relationship states that the finer the grain size (yes metals are crystalline and are made up of grains) the higher the yield strength is (it has to do with the impedance of dislocation movements within the grain boundaries). I would suggest a quick wikipedia for more info.

So basically forged objects (hot forged) have smaller, orientated grains as oppsed to randomly oriented and exhibit better mechanical properties (stength, ductiliy (toughness)) then the same material not forged.

And besides all that... forged parts are much less proned to failure as they are virtually defect free. (stamped dropouts... could have say a porosity from the metal sheet it was stamped from. This is possible as sheet metal is usually continuously cast then hot rolled... and from experiance in a steel plant, porosity is a major concern and rolling doesnt always close the pores.)

therefore in a practical sence... the more you ride... the more you go over pumps..etc... the longer you forged drops will last.

Otis 11-08-08 10:34 PM


Originally Posted by mswantak (Post 7815786)
Snob appeal; nothing more. A stamped dropout will perform equally to forged one in 99.9% of all cases.

A qualified Genius.

jonwvara 11-09-08 09:05 AM

And besides all that... forged parts are much less proned to failure as they are virtually defect free. (stamped dropouts... could have say a porosity from the metal sheet it was stamped from. This is possible as sheet metal is usually continuously cast then hot rolled... and from experiance in a steel plant, porosity is a major concern and rolling doesnt always close the pores.)

therefore in a practical sence... the more you ride... the more you go over pumps..etc... the longer you forged drops will last.

In other words, forged dropouts are less prone to random failure? I guess that makes sense, but having never heard of a stamped dropout failing, it seems like a fairly academic virtue.
And of course, forged dropouts do look nicer. They must, because you see them on costly bikes, and costly bikes look nicer than cheap bikes (as a general rule, anyway.)
JV

CardiacKid 11-09-08 09:17 AM


Originally Posted by LgReno (Post 7816239)
As a materials engineer, i can tell you that forged dropouts give improved physical properties due to the refinement of the grain structure. The Hall-Petch relationship states that the finer the grain size (yes metals are crystalline and are made up of grains) the higher the yield strength is (it has to do with the impedance of dislocation movements within the grain boundaries). I would suggest a quick wikipedia for more info.

So basically forged objects (hot forged) have smaller, orientated grains as oppsed to randomly oriented and exhibit better mechanical properties (stength, ductiliy (toughness)) then the same material not forged.

And besides all that... forged parts are much less proned to failure as they are virtually defect free. (stamped dropouts... could have say a porosity from the metal sheet it was stamped from. This is possible as sheet metal is usually continuously cast then hot rolled... and from experiance in a steel plant, porosity is a major concern and rolling doesnt always close the pores.)

therefore in a practical sence... the more you ride... the more you go over pumps..etc... the longer you forged drops will last.

There really isn't anything else to be said on this issue, but that won't stop people from trying.

iab 11-09-08 09:35 AM


Originally Posted by CardiacKid (Post 7817620)
There really isn't anything else to be said on this issue, but that won't stop people from trying.

There was never any question forged is stronger, but heavier than stamped. The question is, does it matter?

BTW, the answer consists of a typical BF pissing match. Let the games begin. ;)


Maybe the question is, if you are building a great frame, why would you cheap out on the dropouts?

CardiacKid 11-09-08 10:49 AM

No, the question was whether forged is OBJECTIVELY better than stamped. Everything else is subjective.

roccobike 11-09-08 10:59 AM


Originally Posted by iab (Post 7817680)
There was never any question forged is stronger, but heavier than stamped. The question is, does it matter?

BTW, the answer consists of a typical BF pissing match. Let the games begin. ;)

Maybe the question is, if you are building a great frame, why would you cheap out on the dropouts?

The drop out question follows one of the sacred rules of cycling (drum roll):

Forged must be better and faster because they cost more. (cymbal sound)

So let it be written, so let it be done.

iab 11-09-08 11:13 AM

Objectively, forged is better, any engineer will tell you that. How much better, is it necessary? That is subjective.

Booger1 11-09-08 11:22 AM

Like was said above,the maker has more control of the finished product.You have endless choices of materials,can be degassed,control the grain structure,make it any shape you want and have the grain follow the shape,they can be made thinner,lighter stronger than castings/stampings,ect, ect.

I agree,for joe six pack,it doesn't make much difference.

LgReno 11-09-08 05:57 PM

the engineer once again:

The price difference is purely due to manufacturing costs (Economics)

Stamping... (being self explanatory) is like making cookies out of a dough with a shape. easy. fast. cheap.

Forging reguires dies = EXPENSIVE (why? design, modelling of the metal flow etc, .. )and btw.. you get better size tolerances.. so each part is identical.

The bottom line: forged drops cost more to make. they are (theoretically and practically) more durable and stonger. So high end bikes will have forged drops.


enough said.

Mike Mills 11-09-08 06:17 PM

Snobbery?

If by "snobbery" you mean that all the really good quality bikes come with forged dropouts and many people want a good quality bike, then so be it. I see it as a mark of quality that the makers use to their advantage. Personally, I think calling it "snobbery" entirely misses the point.

More likely, forged dropouts are a hallmark, a benchmark, a minimum threshold below which you do not want to spend your hard-earned money. The maker is saying to you, "This bike is good enough that it was worth investing the extra money to get the best dropouts I can get."

I remember when Fuji and other makers were just beginning to move into the marketplace, they switched from stamped to forged on their higher end bikes. They were making a statement to the customers - compare this bike to the best out there.

There are probably some advantages to the custom frame builder, too, but as I am not a builder, I cannot be totally sure. What I am thinking of here is the interface between the dropout and the tube. With a flat, stamped drop out a lot of filler is needed, you need to crimp the tubing over the drop out, or both. The forged, round-ended dropout mates to the tube better and requires less/no filler - the transition from round to flat is built into the dropout, rather than being made of filler metal and crimped tubing. To a builder, it will come out looking better and be faster to do, as well as offering the other metallurgical (strength, hardness) and functional features (deraileur bracket, wheel stops) described above. All that, in a package that also looks as clean as possible. What's not to like?

soonerbills 11-09-08 06:56 PM

I'll put the question of the value of a stamped vs: forged in a perspective we all may understand by askinf a different question:
You are riding down an Alpine mountain road in your completely loaded tourer. As you cruise down the winding and sharply contorted hills you struggle to maintain control of the bike due to the weight and speed. the road is not a smooth as it would appear in an auto and your bike exaggerates all the dips and ruts in the asphalt.
My question is: Would you be willing to pay extra for forged forks and hangers that you are 100% sure will be able to handle the stress the above scenario poses? Or would you be comfortable with stamped items that may or may not hold up?
Your answers may be different but I'm willing to bet that the average would lean toward the forged.

Bikedued 11-09-08 07:35 PM

As a 215 pound(and dropping) person. I don't generally even consider a bike with stamped drops. I have a few, but they were made when the norm for forged was only the highest end bikes. Two examples my 73 SS, and an early 70's Falcon San Remo. I go 20+ mph on many occasions, it just gives me a little more confidence doing it with a forged drop bike.,,,,BD

dbakl 11-09-08 07:53 PM


Originally Posted by soonerbills (Post 7819931)
Would you be willing to pay extra for forged forks and hangers that you are 100% sure will be able to handle the stress the above scenario poses? Or would you be comfortable with stamped items that may or may not hold up?

Except, racing bicycles were ridden in those exact conditions for many, many decades before forged dropouts became the norm. If it was really risking serious injury to ride stamped dropouts, I imagine forged would've taken over much sooner than they did.

I'd guess forged dropouts started making headway in the 50s; they were one of the signs of the "better" bike, though if you rely solely on that you could be mislead; lots of really great bikes were build with stamped dropouts. Probably towards the end of the 60s it became a "must have", desirable feature, so much so that it began to work its way down the quality range. I bet most bike store bikes had forged dropouts by the early 80s, at most levels.

Are forged "better"? Possibly. Is a quality bike that's properly built, used and maintained, but has stamped dropouts going to fail you in some way? Probably not, in fact, extremely doubtful.

My favorite bike ever was a 60s Carlton I bought used with stamped dropouts; I rode it hard for over 10 years, active training, centuries, race type conditions, loaded touring; a broken spoke once was my only real problem; the stamped dropouts never gave me a care or really a thought. Many times we rode down Cuesta Grade (the steepest stretch of 101 in CA), passing cars at 60 or more in the left lane... nobody was thinking about their dropouts.

If someone hadn't stolen that bike I'd still be riding it now.

ricohman 11-09-08 08:05 PM

Stamped vs forged?
Ever see how an axle flange is built?
I'll take forged anyday.

CharlesC 11-09-08 08:30 PM

Everyone here seems to be assuming the thicker drop outs are forged. They could as well be cast steel. Lost wax cast steel has been vastly improved. For example Ruger revolver and semi-automatic pistol frames and slides are made from lost wax cast steel. Very precise and very strong.


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