Not really a Mistake...
 

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I did this today. I've been building my second gravel/grovel frame, hoping to tweak some of version 1's details, and had attached the chain stays a couple of days ago. The brazing had gone pretty well and I cleaned them up yesterday. Today i chased and faced the shell and did an alignment check and that was acceptable, although not perfect. But the tire clearance was huge and the ring clearance tight even after a crimp. So today I took the stays off and prepped the dropouts and shell for the replacement stays (yet to come). I figure I spent about 6 hours on the stays up to this point, for no good but once again learning to go slow and really think out all the aspects.

I've started a Flicker album on this build here. #550 Grovel V2 | Flickr There's only a dozen shots so far and more will have to wait for the replacement chainstays but you will be able to see this frame's BB with the stays attached and what it was up to a few hours ago:) Andy

I have cut up 3 sets of stays for my gravel bike and given up on the first two sets. I just ordered parts for my fixture to put them together and they should be here this week. Years after starting this project conceptually, I might actually burn metal.

Eric- Glad to know that I am not alone in figuring out how to work best these wider tires and bent tubes:) I have found myself falling into past habits and making assumptions based on thinner tires and straight tubing. Glad I'm doing this for myself. Andy

I really should trust bikecad a little more. The issue is setting up the dropouts is a total thesis on there, and my eyes just glaze over. That's why I'm building a stay/bb specific fixture so I can just mock it all up. The support for forks is even worse, so I have stuff to allow me to mock those up too.

Thanks both of you, this discussion has been validating. I find the chainstay diagrams challenging at best. Question for Andrew, what stays are you using? I'm trying to get my head around using the same dropouts and bent stays.

I recall John Clay did some experimenting in this area a couple years ago. He hangs/hung out on Velocipede Salon. There might be some threads there with deets.

I find it helpful to draw out the parts and clearances needed and lay the parts on top of the drawing. I have several of these drawings that I use for gravel or MTB frames with the centerline, bottom bracket, rear axle, crank arm end locations, chainrings and tire size/location on them. It helps that I make and bend my own stays from 3/4" .035" wall 4130 tube, so I can bend and smash them wherever needed for clearance.

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The stays were Deda Zero Uno. They offer a few different versions with various amounts of bends and shapes. I believe they were called the MtB oval 1mm, sorry but I didn't record a specific part number. The first groval bike also used Zero Uno 1mm but in what I believe is called "CX/Gravel" and have slightly less amount of bend. With the 42mm tires (584/650B) the need for much bending to clear tires and rings isn't much and these "CX/Gravel" stays were about right. But they are not what I had on hand when I got the bug to build this frame and figured I'd make the MtB ones work. And they could have if not for my haste. I knew that the tire clearance would be no problem with the amount of bend the stays had so really didn't pay that much attention.

I completely agree with drawing full scale plans and using them for the initial fit up. I find having a similarly set up bike at hand to compare with helps too.

This second time around I think I have a better handle on the various goals I have with them. I'll up date my Flicker album as I go along and likely post here when all done. Andy

I settled on the Deda gravel stays, I don't know if they are the same ones Andy is using https://www.bikefabsupply.com/chains...stay-107-sfnkw I really like the straight section at the back. My all city has that and it seems a lot cleaner given the dropouts I'm using, which are longer on the non-drive side. Columbus has a similar bend, but they are huge, and fitting the dropouts to them turned out to be a problem I didn't want to solve. I didn't want to use the brazed on brake mounts for a couple of reasons, and I didn't like the dropout choice that would go with them. Not a fan of Wright style droputs, but maybe I should get over that.

I was consider doing the same when I came across a stash of 4130 in my shop. How do you finish the ends? To you flatten and/or taper them? Fill and shape with brazing material?

I just had a very similar experience, but with less excuse. Gravel-style frame with 26" wheels but road cranks. This means a 68mm shell but I also hadn't realized just how much closer together the cranks are on a road crankset. Had to do some rather deep dimpling on both sides for the ends of the cranks and also on the right for the chainrings. Not ideal. Perhaps I should just cut the stays out and try again. Much more tyre clearance than I need (26" wheels make the tyre clearance much easier).

I think I would have worked something better out if I had got the cranks in time before attaching the CS. Then I would have seen how they fit when everything was just tacked. But all these bends are very tricky. Mine were single-bend CS and I tried to put them so the bend was about where the tyre was, which seemed logical. But it's not that simple.

I weld my frames, and use "bullets" or plugs for the end of the stays when I'm using plate style dropouts. For hooded dropouts, I just squeeze the end to slightly ovalize it for more room to weld it to the hood.

This picture shows the type of flat dropout plugs that Paragon Machine works sells, which are also visible in the other picture I posted. They get welded to the dropout and the tapered end allows them to be welded at an angle to the tube. I don't think these would work very well for brazing.
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This picture shows some "bullets" that I made on the lathe. These would probably work for brazing and then the end of the bullet would be slotted for the dropout. Paragon used to sell a similar bullet, but they no longer have them listed.

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Thanks, that makes sense. I saw the bullets in the first picture, but I didn't see how they fit in and/or think much about them. I was focused on the dropout. That 3/4" diameter would be a pretty big space to fill with braze. Maybe cutting a V and squashing around the dropout if one were going the brazing route.