Lug Style and Plug In Dropout Origins?
 

I am guessing the Lug Style ones came out long ago, before the Plug In ones. Does anyone know when they first appeared?

Why would you assume that a socked dropout came first? A plug style is easier to form and, IIRC, the earliest bikes were fillet brazed. Some have said that lugs were more about production ease and needed a lower skill then fillet does. Andy

I am not sure I understand what a plug-in dropout is. Internal lug? Plate style was second to squishing the blade or stays and cutting a slot for the axles. I may not know of some older lugged or plug dropouts, but I think any variant to plate or squished came much later and contemporaneously with each other with the advent of investment cast bike frame parts.

https://cimg2.ibsrv.net/gimg/bikefor...117405717d.jpg
I hope someone revives Henry James. It would be hard to spend $2500 CAD on a frame without the above. Only dropouts I like, except if I may want to build for a 15mm axle.

HJ didn't have them cast for quite a few years so I wonder if the tooling is still available somewhere. Your best bet is to find somebody with old stock.

Traditional forged dropouts used a tab that fit into a slot cut into the stay/blade. This design allowed a single forging to accommodate a wide range of frame sizes and styles. Forging from relatively mild steel meant the dropouts were somewhat malleable, allowing for adjustment and alignment.

Cast, socketed dropouts are less forgiving, and either must come with a range of angles between the stays to accommodate different frame sizes/styles, or use a two-piece system such as Nagasawa:

https://www.tracksupermarket.com/med..._joints_02.jpg

Investment cast dropouts also tend to be unmalleable, and require much more effort to bring into alignment if/when that becomes necessary.

I've seen plug-in (male/female fit) dropouts on frames gong back to the original Six Day era. The style is hardly a modern or time/cost-cutting feature.

I'm a fan of the external socket type dropouts. Partly because they look like a lug which I personally like, but for the even greater reason having to do with ease of build. As someone building in the garage without a lot of hard tooling I find it challenging to get tab style dropouts properly aligned when brazing. Also, with the external lug design it's easy to sweat flow the braze into the gap just like a lug; feed in the filler until the joint won't readily take anymore and you then know there is 100% penetration all around.

As Clint says, a man's gotta know his limitations. I'm confident with brazing lugs and all, but less so with filling big gaps like on a dropout.

https://live.staticflickr.com/7901/3...004ef251_k.jpgP1040221 by nessism, on Flickr

I've got a set of those HJ dropouts that won't get used anytime soon. If anyone has a hankering to acquire them feel free to hit me up. Nifty trade offers accepted.

What are the diameters of the plugs? I'm sad there isn't HJ IC parts for my framebuilding class students anymore. The variety of lug angles and his horizontal dropouts had an ease of use that prevented students from getting frustrated or discouraged on their very 1st frame.

9.9 and 11.5 mm. The angle between sockets is about 70 degrees

For those that don't know, the angle between the plugs are fairly easy to bend to any angle. I have a bunch of 1' long rods with a diameter of about 3/4" with holes drilled in the ends to match the diameters of the HJ plugs. Those rods gave me the leverage to bend the dropouts to fit whatever the angle required of the frames.