Dropout Stay Connection

I’ve been fabricating my own dropouts from steel plates (sendcutsend), and am working on an updated design that allows 30mm of adjustment so I can play with my CS length.

In another thread there was a sub-conversation where @anon91558591 mentioned just butting the stays to the drops and welding. My previous design used a plate that acted like a hood for easy stay attachment (see photos), but Walt’s comment is making me think the added plate is redundant in terms of strength.

Can anyone comment on the the attachment shown in these renderings (red lines are weld areas)?

Should this be structurally sufficient? Note, I’m still a pretty crappy welder so structural redundancy is not a bad thing.

Any input would be greatly appreciated!

-Garth


IMG_4418


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Should work great.

-Walt

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image

Very very slick and simple design. I like it! I am assuming this is for a thru axle? I don’t see many examples of them being used with sliders. I wonder how hard you can crank down onto the axle…

The nut-style track dropouts have the advantage of having two bolts, so double the clamping force (in theory).

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On my track dropouts I added in some tabs that slot into the stays. I just cut the stays flush then the dropouts fit into the stays right off the laser, no cutting or filing needed.

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I use bolt-on hubs. I have an old Chris King SS hub with fun bolts, and a newer Onyx SS hub with bolts. I don’t think a thru axle could get tight enough to keep it in place.

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No experience with these dropouts, but surly’s use a through-axle with their sliders:

https://www.reddit.com/r/Surlybikefans/comments/o9u878/axle_slipping_with_horizontal_dropouts/

I am still looking for an application for these fancy diamond coated 3M friction shims. They make an M12 shim that is 13mm ID and 20mm OD.

They sent me some free M8


samples:

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One of my bikes has a 10mm thru axle. Currently a qr type in sliding dropouts that slips occasionally but my plan is to get a length of 10mm centerless ground SS rod and thread both ends

I don’t think thru axles and specifically thru axle hubs will be able to hold in a horizontal dropout.

The hub end caps aren’t designed to provide the necessary friction, so maybe those abrasive washers are the ticket between the hub end cap and the dropout?

I’d also guess it would affect the bearings to have that much force squeezing the hub. With a traditional bolt-on axle you’re just pinching the frame between the axle and bolt, so the hub bearings are unaffected.

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That’s exactly what the Surly axle does, and many TA hubs convert to being clamped with a QR axle with just a swap of the end caps.

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This was an informative video for me regarding thru axles vs QR.

I also wouldn’t think thru axle would be fine on a sliding dropout. I think you’d have to use a plate attachment style like PMW.

A through axle is a big bolt, with the nut captive in the frame. It can clamp the wheel just like any other bolt can clamp things. Take the nut out of the frame and make it it’s own piece, it still clamps.

This doesn’t require speculation. There’s a Surly frame pic just a couple posts up that shows it.

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I think the possible clamping force of a thru-axle is less than that of track bolts and a QR. Probably why people get slippage. Even on track bikes track bolts can slip, and especially on BMX’s even when cranked down to ungodly levels of tightness.

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Is wedge locking washers an alternstive?

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I presume you weld the disc tab to the SS too? ( no red line)

I added a disc tab to a frame with track dropouts . It came out similar to your design. Not so clean though

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Yes, that tab gets welded to the stay as well.

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Thanks for all the input. Here’s where my design is now after lots of tweaking. I decided to go with the BMX style of notching the dropout plate for the stays. This will save four miters, and I hope should be structurally sufficient. The dropouts allow 30mm of adjustment. Next step is a test print.

-Garth


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Are those stainless surfaces/plates brazed on where the end caps contact the dropout?

Yeah. 4130 dropouts with stainless faces silver brazed on.

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Sweet! That is a really nice and practical detail.

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