Do Dropouts really matter?
 

I am wondering what makes a forged steel dropout nice, or not nice as far as ride quality and performance go. Is a Suntour GT going to deliver a different ride than a Campagnolo? I assume they're made of different materials depending on the maker and vintage. Anyone have any experience with this sort of thing? Is there even a way to know since it's extremely unlikely that any gets to ride identical frames with different dropouts. Thanks for your thoughts.

I doubt is one can feel the difference between different brand/design dropouts on frames......just not enough flex to happen within the thing to make a difference that can be easily felt,............at least for most of us "mortal" cyclists....

Practically, derailleur hangers and axle adjusters are the only things to be looking for. They're just too small to impact ride quality.

I think with the level of attention you pay to the relative few parts on a bicycle, one would want a "crafted" part vs. a stamped part. Just so you know some attention was paid to it. There's a refinement to the idea of forging and an element of brutishness in going through a punch press. (from someone who used to work at a punch press in a metal shop)

Add into that the manufacturer stamping the name- so if you wish to associate that name to the quality of your bike...

more fun to look at when working on bikes.....

Most forged dropouts are made from fairly mild steel in order to remain malleable for alignment purposes. Dropouts don't really affect ride quality in any way, but hanger design may influence what derailleur you will use on the dropout, what size cluster can be accommodated, etc. Slot design influences what type of drive train will work (e.g. vertical dropouts don't play well with fixed gear set-ups) and ease of mounting accessories like mudguards and racks. Rear-facing slots don't work well with mudguards, but facilitate wheel changes on tightly-coupled track frames. Vertical dropouts play quite nicely with mudguards. Eyelets facilitate mounting racks and mudguards, etc.

So, yes: dropouts do matter, but not because they affect how the frame feels while riding.

Circa 1960 Otto Cap used an interesting variation in his top-of-the-line bikes -- he brazed an elongated C-shaped piece of steel over an ornately carved stamped dropout, to give the appearance and thickness of a forged dropout. The extra thickness of a forged dropout or Cap's fake forged dropout arguably makes alignment more critical, but axle breakage less likely on a well-aligned frame, and it provides additional wiggle room in setting axle QR axle length.

Your profile pic leads me to believe you are to be trusted on the topic of dropouts.

The middle 70's Suntour GS dropouts had an interesting feature, the "web" that arced up to the seat stay tab swept outboard in profile, this allowed the seat stay to remain round all the way and still provided lots of clearance for the chain and a sixth cog. This design was only seen here and there, there was a push to get them in the hands of US craftsman builders in 1974, those samples are how I first saw them. Not a bad idea that never caught on. Campagnolo was king. A frame with Campagnolo dropouts just was given a higher pedigree than others.

Just found this thread, because Suntour GS dropouts are of consuming interest to me right now. I have a 1973 Carlton Corsair with Suntour GS dropouts and the offside rear one (ie drive side) is broken. Does anyone by any chance have a replacement available? Or a knackered Carlton frame from which a dropout could be salvaged? I have about five other Carlton frames, but none of them use the GS dropout...

Just for fun, interest's sake and comparison, test the difference...

Grab a frame with stamped or pressed steel drops and, using one hand, try to squeeze them together. Now, do the same thing with a frame sporting forged drop-outs. My experience has been that the forged drops don't move nearly as much. True, there are other factors that impact this test but my money is on the forged drops, as opposed to the stamped steel ones. And...

Keep in mind that we are talking, mostly, about racing bicycles that are designed for competitive use. As an ex athlete (used to wrestle at the collegiate, national and international levels), I know that I would do everything I could to prepare for competition. That is the same situation that presents itself to the professional bicycle racer - he will pay attention to the details, seeking the best possible machine he can to increase his, or her, competitive edge. With that in mind...

He, or she, will opt for the stronger and precision made forged drop set, the lighter tube set, the better functioning components and the like. He, or she, will not try to compete on a department store offered entry level gas pipe road bicycle. It would be foolish for him, or her, to do so assuming that her or she wished to be competitive.

That is all just my opinion, of course, but if you take a look - virtually all high end road bikes, mountain bikes, hybrids and just about anything else high end will sport the forged drops (not sure how this applies to BMX since I have absolutely no interest in that style of bicycle).

Which has everything to do with the frame and absolutely nothing to do with the dropouts.

The only possible functional advantage of forged over stamped is the thicker forged could possibly assist in axle alignment.

While one could make an argument about having the "best" part for the "best" bike, why isn't that true for track bikes? I don't know of a stamped Campagnolo road dropout but they certainly made stamped ones for track ends. I can't imagine a place where strength more is needed than in a sprint.

Campagnolo did make theirs pretty thick. If you don't forge, use mass.

But I am curious to know why they didn't just forge all of their dropouts? Why offer stamped track ends?

There is one difference between forged and stamped DOs not generally discussed here. With no integrated hanger you must use a claw, and that takes more axle length. Of course it is accommodated by the fact that stamped DOs are thinner so that the outer-edge-to-outer-edge distance is roughly the same. The point never mentioned here is that the extra width is required on the drive side only. So if you move a wheel over from a bike with one type to a bike with the other you may have to re-position the bearing cones on the axle to move the axle left or right. It's all obvious so it goes without saying. But I said it anyway.

Otherwise I'm sure I can't tell the difference while riding.

But try this test with a wheel installed, and neither one is going to flex much.

Forged dropouts do seem stronger than stamped; I have no empirical data but that's how it appears anyway. One benefit to a racer would be less likelihood of mis-alignment in a crash, which would equate to less time off the bike. Not every racer has a team car behind them with a bunch of replacement bikes, and in the old days, none did.

The thicker tangs for insertion into the stays on a forged dropout allow a stronger and more elegant looking brazed connection of stays to the dropout. On some frames using stamped dropouts, the builder would resort to flattening the ends of the stays in order to avoid thick fillets of brazing material.

I believe the brand of dropout can also make a difference in strength. I recall a biking friend who bought a new Lotus bike high-end road bike in about 1981 or 1982. Soon afterwards, one of the dropouts cracked near its connection with the chainstay. Fortunately, the importer and dealer replaced the frame under warranty.

Another example of justification for haveing a "hard to find parts" thread.

You may want to post this question (replacement DO) in the frame builders thread.

The "Gran Sport" vertical dropouts were stamped:

http://www.os2.dhs.org/~john/double-eyelet-1.jpg

As you note, the track dropouts were quite thick, and even Blanchard ground for smooth faces. The Gran Sport dropout is just a little thinner than a 1010 forged dropout, but thicker than the stamped dropouts on entry level bikes.

i've always wondered like lab about the track campy DOs being stamped. but their shape is so nice !!! like lobster claws.

my garlatti has stamped DOs *with* a hanger. they are noticeably thicker than all the stamped dropouts i've seen. maybe as thick as campy track ends...

my main grudge w/ stamped DOs is their fragility... i've worked in shops and coops and I can tell.

Interesting the stamped dropout has enough metal for threads on the derailleur hanger. As best I can tell, that is the best reason to have a forged dropout, to accommodate a hanger. Track ends don't need a hanger, don't need to be forged. Not a lot of derailleurs prior to 1940, not a lot of need for forged derailleurs. Sure there always exceptions, but I can't think of a better reason for forging.

...just as a point of interest, forging steel does change the character of the
material to some extent....and for the better. As Mr Thompson has already
indicated, the resulting product in a dropout results in a functional item that
has a good mix of stiffness and malleability that you want in the part.

But it's not like a hammer or other forged tool that's made from a higher carbon
tool steel that can be manipulated in the annealing or hardening process for
both hardness and malleability in the same piece of metal...

When most hear about "stamped" steel dropouts, they usually think of the big, flat, ugly looking ones you might have found on entry level and boom bikes from the 70's.
There are nice enough looking stamped steel DO out there. Ones that stick in my mind is the one used on some entry level Peugeots from the 80's like the ones on their PH10s. They are stamped but Peugeot bothered to add in window cutouts that make them look like they are forged. They even have what looks like thickened areas at the slot loke forged DO's do. I bet you can grind, round and smoothen them out at the edges that they can fool most people to think they are forged. Never heard of any failures with those Peugeot stamped DOs.

Another feature that cause me to question is the radius of the edges. Secondary operations could easily make a part look like a forging or casting but adds cost negating the cost advantage of a casting or forging. In additon, you would expect to see tooling marks or irregularities from the secondary operations as well as the elimnation of the "parting line". I don't intend to be argumentative, just trying to make sense of what I see.