Does anyone use snapring style dropouts?

[babyfood1217]

Well, first non-intro post, so here goes:

I'm in the final stages of figuring out some frame specs for a bikepacking/singletrack build I'm gonna to eventually tackle, and I'm getting all wishy washy on choosing a dropout style. The primary specs I NEED (want?) to have is spacing of 12x142 (non-boost) for the 29r wheels I've got, and it has to have a replaceable dropout hanger/chip. The conundrum is weighing the pros/cons of the various options out there. Obviously, there are countless options for dropouts with replaceable hangers. I've been leaning towards the Syntace setup, which if nothing else, would provide a little leniency in fabrication re: aligning the wheel (through the different offset capture nuts), but I'm curious about the snapring dropouts PMW offers. It seems like a kinda nifty concept, having the hanger floating(ish) until captured and tightened via the axle. Obviously, one would still need to be able to grasp the snapring for removal if the hanger was ever damaged and needed to be replaced, and that in itself requires a tool with tiny enough tips for inserting into the snapring holes. Most other DO systems, the hanger can be replaced with the same hex set one usually has with them on rides/trips.

For what it's worth, I really can't find too much on the web, and definitely not on here (Velocipedesalon) re: this style of dropout, that alone suggests it's not something that's used much. Maybe there's a reason why?

PMW DR2096 snapring dropout The dr2095 is a lighter/thinner version of the same thing. Steel of course.

-Chris

[VertigoCycles]

Am I assuming correctly this this is your first or one of your first frames? If so, get the Syntace. There's no room for error in aligning TA dropouts and if you don't have your process dialed, you're not likely to be able to adjust the alignment after the fact

[babyfood1217]

Am I assuming correctly this this is your first or one of your first frames? If so, get the Syntace. There's no room for error in aligning TA dropouts and if you don't have your process dialed, you're not likely to be able to adjust the alignment after the fact

Hey Sean,

I'll be tackling a frame or two BEFORE I get to the TA build. Some QR ends on a road frame and possible gravel frame are likely to be my first builds, largely for the practice and experience alone. The TA frame I have intentions of building will LIKELY have those very Syntace dropouts, primarily to accommodate the error you mention (everywhere I look, people talk about the precise alignment requirements of TA builds!) My interest in the snapring style DO is perhaps one more of curiosity, I guess.

If I'm thinking about the Syntace setup correctly, it COULD actually allow someone to evaluate the nature of distortion and address it where/how it's needed. By looking at the offset capture nut, and taking into account both its offset AND how it's clocked, one could then look at fitment, alignment, and braze/weld pattern (order) and suss out what caused the distortion in the first place, yes? I like the idea of a setup that allows for accommodating varying tolerances in the build stage, but I also like the idea of being able to trace back through the process and look at set parameters to establish where thing went askew.

[VertigoCycles]

Hey Sean,

I'll be tackling a frame or two BEFORE I get to the TA build. Some QR ends on a road frame and possible gravel frame are likely to be my first builds, largely for the practice and experience alone. The TA frame I have intentions of building will LIKELY have those very Syntace dropouts, primarily to accommodate the error you mention (everywhere I look, people talk about the precise alignment requirements of TA builds!) My interest in the snapring style DO is perhaps one more of curiosity, I guess.

If I'm thinking about the Syntace setup correctly, it COULD actually allow someone to evaluate the nature of distortion and address it where/how it's needed. By looking at the offset capture nut, and taking into account both its offset AND how it's clocked, one could then look at fitment, alignment, and braze/weld pattern (order) and suss out what caused the distortion in the first place, yes? I like the idea of a setup that allows for accommodating varying tolerances in the build stage, but I also like the idea of being able to trace back through the process and look at set parameters to establish where thing went askew.

The Syntace setup COULD allow you to evaluate the nature of distortion, but that's not the whole picture. You can start there, but it's not JUST filler contraction that can cause all the potential misalignment on the back end. Why is the filler able to pull your tubes so much? Where are the gaps? Why are there gaps? Even when you think you find a sequence that works for you, is your heat input consistent enough to use that sequence all the time? Is it even appropriate for you to use the same sequence if there are any small variables on your next frame? How will you be mitering the tubes? Can you consistently keep the stay miters in appropriately in phase while making them gap free? Does your workholding situation even allow you to make "perfect" miters? What about the tubeholding situation when you're ready for stays? What kind of gap is acceptable for you and your joining method?

The good news is that you can definitely build a "straight" frame early on. It'll take some patience, forethought, humility and failure, but you can do it. If you haven't been doing this for a while, just go slow, check your alignment often and adjust where possible in your process. I don't have any idea what kind of fixtures you're working with, but it's irrelevant. There enough variables in play for someone without a lot of experience that no one can prescribe something that's definitely going to work.

If you want to use a TA dropout and want to give yourself the highest chance of success (with back end alignment) use the Syntace if you're dead set on hooded dropouts or use plate dropouts to significantly reduce the variables present to get a good outcome. If you use plate drops and slot your stays, you can lock in the stays to the BB and ST ends first and then tack the dropouts in place in a reliable fixture. Since the tabs float in the slots, the stays are free to contract without affecting the dropout position and the filler contracting doesn't affect the stay length much because of the direction of contraction.

One method is basically this...miter and slot all of your stays. set everything up in your fixture and tack the stays to the BB, ST and DO's. Fully join the stays to the BB and ST. Use whatever you're going to use...a reliable fixture, and sub fixture...and you can break the DO tacks if needed to float the DO in the slot. Tack them again with everything aligned correctly, check again and then finish them off.