Road to NAHBS – Kirk Frameworks

David Kirk’s road bikes are always minimal looking at first glance. It’s not until you really give ‘em a solid once over that you notice the artistry that sets them apart. In addition to his frames, he offers a few bits and pieces that other builders can use and even that you can order to gussy up your existing ride. Here’s what’s new from Kirk Frameworks

BIKERUMOR: What have you been working in since NAHBS last year?

DAVE: I’ve been working on a number of different things. The big, and yet nearly invisible, thing is tightening my sizing, ordering, and building procedures so that they are as quick and accurate as possible with the aim of leaving more time for me to be at the bench making stuff. The big goal is to keep my lead-time as short as possible while still satisfying demand. I’ve also been working on plenty of product related stuff. I’ve been tweaking my tube specs to give an even better ride while keeping the weight down, fine tuning the design of my Triple F rear dropouts, and prototyping and testing road and cross framesets to work with disc brakes.

 

BIKERUMOR: Any killer custom bike builds? 

DAVE: Picking a favorite customer build is like picking your favorite child – can’t be done. However I am excited by one of the bikes I’ll be bringing to NAHBS this year and that is my new fillet brazed cross race bike with disc brakes (shown). It’s my personal bike for the 2012 race season. I’m very excited to be using disc brakes and finally setting aside the cantilevers for those wet and muddy rides and races. Once I get this back from the show it will go off to Joe Bell for paint and then have a DA group and a new set of disc specific wheels hung on it and I’ll be ready to roll. Spring is going to be fun.

BIKERUMOR: Did you see anything last year that’s inspired you?

DAVE: I always leave the show feeling inspired by what I see – Pegoretti, Strong, Crumpton, Ellis, etc., all showed stuff that brought a smile to my face.

BIKERUMOR: Can you give us a teaser of what you’re bringing to NAHBS 2012?

DAVE: As usual I’ll be bringing two complete bikes and one frameset to the show. Both of the full builds are from my JK Special series – the first is a JKS X that is built with XL sized 953, Llewellyn lugs, and special chain and seat stays built for me by Reynolds (Kirk by Reynolds) and it is set up with internal Di2. The second full build is a JKS Classic. It uses a special mix of Reynolds 953 and Kirk by Reynolds stays and is a classic Euro stage race bike. It features hollow fabricated side-tack seat stay caps, Llewellyn lugs, and a full Campagnolo Super Record build. The frameset being shown is a fillet brazed cross bike built from Reynolds 853 Pro, Kirk by Reynolds stays and is designed to use disc brakes. It will be shown in the raw, sans paint.

BIKERUMOR: If you had to race all the other builders, who would you want to inch out for the win right at the line?

DAVE: I think nipping Eddy Merckx at the line might just make my day.

Comments

ChadQuest - 02/22/12 - 8:52pm

That brass is absolutely perfect.
So Clean.

adrian - 02/22/12 - 9:25pm

Very pretty but how in the heck is that wispy fork leg not going to fold in half when the disc brake is applied?

David Kirk - 02/23/12 - 1:12am

Adrian said – “Very pretty but how in the heck is that wispy fork leg not going to fold in half when the disc brake is applied?”

Good Question. There are a good number of things that prevent the blade from failing under the braking load. First is the blade itself – it’s made by Reynolds using their 853 material and is bomber strong. Next is the way the disc tab is designed and made to properly distribute the load up and over the blade. The finger that that extends up the blade does a very good job of distributing the load up the blade where the load is lower and the diameter of the blade is larger and this does a very good job of not point-loading the blade. The other crucial part of the design is that the disc tab mounts to the blade tangentially. It is very important to not load the blade directly square on otherwise brake loads tend to push into the tube and can in time cause it to fail. By mounting the tab offset, so it runs tangentially to the blade, it applies the load to the tube in such a way that it doesn’t try to ‘can opener’ it. I think if one were to just take the ‘normal’ steel fork blade and weld on the little shorty tab onto it and attach it on-center that there is a good chance you would have issues in the long run. But there are other ways to handle it that will prevent the problem.

I’ve been riding a prototype just like the one pictured above for months now and giving it very hard use on washboard dirt and broken pavement and the braking power and modulation is very good and the fork is holding up very well to the abuse. Frankly I’ll be happy when the testing phase is over – I’m getting tired of heavy braking on washboard dirt.

Thanks again for the question.

Dave

Robin - 02/23/12 - 3:58am

Obviously, one of the most experienced and respected frame builders just slapped those forks and disc brakes together without knowing at all whether those “wispy” things would “fold in half” or not. Yeah, that sounds likely. I’ll bet no one has ever put disc brakes on wispy, steel forks before. Nope. There’s absolutely no history at all of anyone ever even thinking about mounting disc brakes to wispy steel fork. Nuh-uh.

adrian - 02/23/12 - 9:52am

Thanks very much to Dave Kirk for the answer.

Topmounter - 02/23/12 - 10:13am

Great stuff, glad to see someone still crafting high-end road bikes rather than just ordering masspro frames from a factory in Chinr.

Steve M - 02/23/12 - 10:37am

Damn nice to see fillet brazing naked.

Joe T - 02/23/12 - 12:51pm

Mr Kirk has got to be one of the most thoughtful (in terms of engineering/function) small builders out there.

city street maintenance thugs will be after his ass when these are rolling around wrinkling up pavement at every stop light. (as opposed to fork folding)

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