Socket style rear dropouts

[bikecycology]

Specifically Henry James dropouts. Does anyone have some good advice on how to calculate the cut point on the chain stays for proper fit of the plug in to the stay. I've ruined one already and would like to avoid the same demise again.

I'd assume you take the plug OD and add twice the wall thickness of the stay, then find that OD and mark for the cut. It didn't work out so hot. For reference, I was using Nova Cycles round tapered stays.

Furthermore, I may have another problem at hand. The diameter on the dropout is the same as the OD of the stay at it's smallest end which means I'd have to cut it off so far up that it would likely be short of a stay for use.

What am I missing here?

Thanks

[e-RICHIE]

Ge longer stays, or file down the spigot/plug to make it work with what you have. The HJ parts are similar to mine and I always cut the stay so the OD mates well. If the interior is loose, I simply flood it with filler material. Note: don't make the frame or frame design to fit the available parts. Get the parts that allow you to seamlessly make the frame and design your plans call for. In other words, expand your material choice horizons.

[Eric Estlund]

Henry James uses what I would call "plug style" where a slug of the drop out "plugs into" the drop out. Not all plugs fit all stays. In addition to the wall thickness and OD, you need to take into account any wall thickness changes from the shaping as they change through the length of the tube. Sometimes the parts can be modified to work, sometimes it's best to select different pieces.

"Socket style", at least as I have used the term, refers to a pocket drop out that allows the stay to fit into it.

[Zimmermanbicycle]

+1 on this,I've used the HJ plug drop outs quite a few times and find them very flexible,they are made oversize on the OD expressly so that you can file them to the size of the ID of your stay also the flange on the but side of the joint is oversized so you can file it to mate to the profile of your stay.
Use plenty of filler,too much is better than not enough.

Stop,inhale,step back,look at the materials and their dimensions,think about it from both ends,generally the answer is rite there in front of you.
Tailwinds!
-Eric

Ge longer stays, or file down the spigot/plug to make it work with what you have. The HJ parts are similar to mine and I always cut the stay so the OD mates well. If the interior is loose, I simply flood it with filler material. Note: don't make the frame or frame design to fit the available parts. Get the parts that allow you to seamlessly make the frame and design your plans call for. In other words, expand your material choice horizons.

[Andrew R Stewart]

First I take it from your post's full text that you are using plug fitted drop outs, not socketed ones. You're missing that you might have to reduce the plug's diameter. If the drop out is Stainless Steel then this reduction needs to be done with some care as to maintain the brazing gaps for silver. If it's cromo then the precision is less vital.

HJ has a number of drop outs with differing plug diameters. have you done the homework to get the best ones for the build? Is this your first frame or among the first few? Andy.

[Jonathan]

Take extra care with those stainless drops. Make sure the stainless is extra clean and you're comfortable with flowing silver in a stainless joint. The supplied silver rings and how they flow can be tricky for a new guy. Maybe file a tiny notch or drill a micro holes in the stay to aid in flowing silver rod. These are not the best drops for a first timer. I assume you've not done this much since your asking the question.

[afwalker]

File the plug to fit the ID you need. Check if there is another size closer on the HJ site if you make another order, but you can make one smaller, it's harder to make it bigger:)
(but probably can be done, maybe nickel welding rods)
cheers
andy walker

[Doug Fattic]

Let’s assume you have taken the advice of the previous comments and you have picked the HJ dropouts that have plugs the closest size to your chosen stays. In addition you have filed either/both the HJ plug or the inside of the chain stay so that the hole is just a bit smaller than the plug. If you are using round/oval/round chain stays you have to make sure that the length of the stay puts the oval where it should be in relation to your tire and on the inside and the crank’s inner chain ring on the outside. Chances are the range of how much you can cut off is very small. If you are using chain stays that are oval into the bb than you have more length to play with. The where-to-cut-to-match-the-plug-principle works easier for seat stays. Here are the steps of what to do:

1. Measure the HJ plug with a digital calipers. For an example lets say it measures 10.0mm.
2. Measure the inside of the chain or seat stay (the ID). Lets say it measures 9.0mm. That’s a difference between the OD and ID of 1.0mm
3. Measure the OD of the stay as close to the end as possible. Lets say that measures 12mm. (We are going to assume that when we find the spot on the outside of the stay that measures 13, that the inside diameter will also increase by 1.0mm.
4. Set your calipers to 13.0mm. Use the little holding screw to fix this width so the jaws won’t move.
5. Slide the calipers up the stay until it reaches 13.0mm. Measure the extra length of stay. Lets say that length is 13mm.
6. Cut off 10mm of stay and then open up the hole with a file until the OD of one matches the ID of the other.
7. Live happily ever after.

Some tips for brazing HJ stainless steel dropouts:

1. Make sure the diameter of the 50N silver ring fits against the wall of the stay. It can be reduced in size by squeezing it in various places in a vise holding it with needle nose pliers.
2. Bevel the very end of the HJ plug a bit
3. Clean the surfaces very, very well before adding flux.
4. Once the unit is assembled, tap the silver ring against the plug with a long rod of some kind.
5. Focus your heat on the dropout for some time before moving the flame up the stays.
6. Stainless requires more heat than 4130 (the unit will probably be just barely getting red when silver is ready to flow) but at the same time not tolerant of overheating that will oxidize the surface and prevent the silver from sticking. It is a narrow temperature window.
7. Make sure your flame pattern circles the entire seat stay. Just because silver comes out around the entire end of the stay does not mean it flowed down the entire inside. It could have come down a smaller channel and then flowed around the end. The only way to make sure you have successfully brazed the unit is with your heat pattern.

[Dave Anderson]

As usual, Doug's post is extremely thorough and spot on. I use these drops a lot and the only thing that I do differently is that I don't use the ring of silver that comes with them. Rather, I make a coil (wrap it around an allen wrench, while holding the end of the silver with a vise grip) that has a couple of more turns on it. It's prob excessive, but I like to know that I have enough silver and then I can flow it around and out the bottom. The photo below shows how they look before I start filing them down.

Also, as Doug notes, I often file down the plugs to fit the end of the chain stay, rather than cut off the stay, especially with the vertical drops. You can use the full length of the chain stay that way without any problem. It doesn't take long to file them down and since they are solid and not hollow, you can take off as much as you need. If you measure the inside of the chain stay you can then file opposing flats on the top and bottom of the plug so that the OD of the two opposite flats is slightly less than the ID of the stay. Then file opposing flats on the sides of the plug in the same manner. Then file opposing flats around the plug making it into an octagon shape or etc. Its then just a matter of quickly going around the plug with the file to make it round and the correct OD all the way around. Hope this makes sense...not sure if I explained it well.

Dave

[Alistair]

I don't have anything to add to what Doug and Dave have already said. Here's some pic's of how I dealt with the HJ dropouts. These are the touring ones with the cast in eyelets. I made a basic fixture to hold the DO so that I could turn down the spigot for a good silver brazing fit inside the stay, then used the four jaw to clock things into place for machining. Brazing heat is directed at the DO of course, until filler flushes out from the melting of the pre placed rings inside the stay.





















Alistair.

[Zimmermanbicycle]

This is pretty much exactly how I do it!
-Eric

As usual, Doug's post is extremely thorough and spot on. I use these drops a lot and the only thing that I do differently is that I don't use the ring of silver that comes with them. Rather, I make a coil (wrap it around an allen wrench, while holding the end of the silver with a vise grip) that has a couple of more turns on it. It's prob excessive, but I like to know that I have enough silver and then I can flow it around and out the bottom. The photo below shows how they look before I start filing them down.

Also, as Doug notes, I often file down the plugs to fit the end of the chain stay, rather than cut off the stay, especially with the vertical drops. You can use the full length of the chain stay that way without any problem. It doesn't take long to file them down and since they are solid and not hollow, you can take off as much as you need. If you measure the inside of the chain stay you can then file opposing flats on the top and bottom of the plug so that the OD of the two opposite flats is slightly less than the ID of the stay. Then file opposing flats on the sides of the plug in the same manner. Then file opposing flats around the plug making it into an octagon shape or etc. Its then just a matter of quickly going around the plug with the file to make it round and the correct OD all the way around. Hope this makes sense...not sure if I explained it well.

Dave

[bikecycology]

All,

I finally have a minute to reply. I appreciate all of the input from everyone. I think it is great how much knowledge can be had from this forum. Furthermore, I think it is even greater that so many people share their thoughts and ideas. There are some real heavy hitters on here and all of you are so open to helping others.

With that said, I took an accumulative response from the feedback I was getting and decided to leave these dropouts in the parts bin for a while. I have had them for a couple of years all ready, what is a little longer? I will try my hand at something more straight forward. I will share when it comes to fruition. If for no other reason than to get more feedback.

Thanks again, Wil