Triple F Dropouts.

[Dave Kirk]

After who knows how long the Triple F is now available and ready to ship. See all the details on my blog - Kirk Frameworks Custom Bicycles - Blog

Thanks for looking.

Dave


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[dbohemian]

it's a wonderful design David. I look forward to picking up a pair.

I read the blog entry. I was under the impression that 17-4 stainless is of a higher strength than 4130 and fatigue resistance should be about the same. Paragon and others, myself included use 17-4ph stainless and I think it has shown itself to be very fatigue resistant over the last decade. That being said 4130 rocks too so it is all good. Have you considered having this part cast? It may bring the cost down.

[Dave Kirk]

it's a wonderful design David. I look forward to picking up a pair.

I read the blog entry. I was under the impression that 17-4 stainless is of a higher strength than 4130 and fatigue resistance should be about the same. Paragon and others, myself included use 17-4ph stainless and I think it has shown itself to be very fatigue resistant over the last decade. That being said 4130 rocks too so it is all good. Have you considered having this part cast? It may bring the cost down.

Thanks for the note -

Yes you are right.. it certainly depends on the alloy of stainless and the design itself that will determine how well the package deals with fatigue.

I think in the long run they will be cast parts and wanted to get a few machined runs made first to be sure that there weren't changes i'd want to make before having the casting tooling done.

Thanks again,

dave

[EnginCycles]

You originally said they would be 4140. Glad you decided against that.

-Drew

[Dazza]

Thanks for the note -

Yes you are right.. it certainly depends on the alloy of stainless and the design itself that will determine how well the package deals with fatigue.

I think in the long run they will be cast parts and wanted to get a few machined runs made first to be sure that there weren't changes i'd want to make before having the casting tooling done.

Thanks again,

dave

a good idea
and cool project
and we builders live in the time of good products
Bravo Davo

[Brian Smith]

Looks decent, nice job. The possibilities are bendless.

[Dave Kirk]

Looks decent, nice job. The possibilities are bendless.

Indeed!

Dave

[DanBailey]

Dave, these are beautiful. Dear god. I'm glad my wife-to-be has insisted on my getting insurance. I'll be ordering a set for my personal road machine. Damn!

[Freddy]

I know this sounds like a plug? But the design is one that was entertained by G. P. Wilson and myself and the very small tip was always my first choice.
Now that said, we did not continue if fact due to SS issues to find an alloy that could be used that could encapsulate uniformaly and of course that has changed over thirty years.
When this design is installed in very thin tubing it is a hammer. Best methods today would be to use a broad spectrum low creep alloy that will present a smooth transition on the inside without voids. A perfect place to use "System 48" or "Fillet Pro" if the drops come available in SS.
Speed of installation and ease would be an extra bonus.
Glad to see these kinds of efforts being entertained again.

Freddy

[Proparc]

Could we see a shot of these dropouts in the fabrication stage without paint?

[Dave Kirk]

Could we see a shot of these dropouts in the fabrication stage without paint?

Here you go - this what you were looking for?

Dave

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[Proparc]

So that's how you do it!! I strongly agree about the 17-4 ph business. I kinda feel that the seat stay part should look more beefy or, less slender or, less radius on each side(not sure I am saying it right). I know the dropout is structurally okay, but for me, it is more of a visual thing. It is why I never warmed up to Henry James dropouts. I sorta felt they looked a bit "delicate" to me, (they are not).

The chainstay part to me, looks perfetto!!

[Thylacine Cycles]

Weight?

[Dave Kirk]

Weight?

I get 94 grams a pair on my postal scale.

dave

[Thylacine Cycles]

Dave, any chance they're compatible with Keith Andersons' stainless inserts?

[Dave Kirk]

Dave, any chance they're compatible with Keith Andersons' stainless inserts?

They weren't designed to be - as I recall he has a recess machined into the face to allow for the insert. If that is the case then no, they aren't compatible.

Dave