Kirk Frameworks

[David Kirk]

Early this year I'd started a build and had the lugs prepped and the tubes cut when the client came to me and sadly needed to step back from his order for personal reasons. I set the tubes aside with the idea of using them on a different build at some point but that never happened. Just recently I decided to move forward with the build as originally designed and offer it for sale.....and that's where we are at now.

The frameset is a lugged JK Special and as with all JK Specials it's built with a mix of Reynolds 953, 853 and special seat stays, chain stays and fork blades made just for the JKS by Reynolds. The frameset is designed around a mid-reach caliper brake so it has room for most 32 mm tires.

The design is straight-up stage race geometry but with the added benefit of the extra tire room. It would be a great Tuesday Night Worlds bike or one to spend all day on exploring back roads. The stem shown in the BikeCad image is a 110mm x -6° with 20 mm of spacers under it. Some slight pre-paint modifications are possible - if you have something in mind please ask and we'll see if it's possible.

The frameset will be painted to the new owner's desires and as soon as a commitment is made it will be sent off to Joe Bell for paint. The frameset as pictured (JK Special, optional Terraplane stays, Jen Green head badge and covered with single color paint) would normally retail for $4625 but this frameset will be available for a substantial discount - if interested get in touch and we'll work it out.

This frameset is being offered online here at the Paceline first to give the good folks here a chance at it before moving on to social media. The quickest way to get in touch is by email - info@kirkframeworks.com . I do check PM's here periodically but I get emails in just minutes. If you have questions please let me know and I'll do my best to get you answers.

Thanks so much for looking.

Dave


P.S. - as of Nov 12th 2019 this frameset has been sold. Thank you all for the interest.

[sipmeister]

This is my favorite thread to tune into. Just a lot of sweet stuff to marvel at.

Out of curiosity Dave, have you ever made a fillet brazed fork (for one of your frames of course) and what are your thoughts on those? (Not sure if this topic has been covered yet.) Thanks.

[David Kirk]

This JK Special got the full Dura Ace and HED treatment and is headed to the west coast as I type....should be on the road before week's end.

dave

[Clean39T]

Beautiful color choice and perfectly matched component package - 1" steerer and fat 25s on super-smooth wheels - it just doesn't get any better for ride quality, handling, etc. for a pure classic road machine - congrats to the new owner!

[merckx]

Gios Blue always gets the motor running.

[dimitris77]

Nice color

[David Kirk]

Building forks to match frames today seems like too much work for many builders. I get it. It takes real time to build a top shelf fork and one could get a brand X fork and call it a day.

But frankly leaving so much of the ride and handling up to someone else seems just plain wrong. Instead of using a stock fork that is designed for the heaviest rider that might ever buy one I build every fork to match the rider’s weight and the geometry of the frame. Forks aren’t, or shouldn’t be, generic like a bottle cage or headset but instead should be built with the rider in mind.

This fork is a full stainless Onesto and is raw and ready to ride.

dave

[Clean39T]

Originally Posted by David Kirk

Building forks to match frames today seems like too much work for many builders. I get it. It takes real time to build a top shelf fork and one could get a brand X fork and call it a day.

But frankly leaving so much of the ride and handling up to someone else seems just plain wrong. Instead of using a stock fork that is designed for the heaviest rider that might ever buy one I build every fork to match the rider’s weight and the geometry of the frame. Forks aren’t, or shouldn’t be, generic like a bottle cage or headset but instead should be built with the rider in mind.

This fork is a full stainless Onesto and is raw and ready to ride.

dave

That is incredibly beautiful, as usual, and I couldn't agree more with the sentiments.....

The fork you're holding looks like a 1.125" steerer....can you share a bit about the design/selection process for choosing between 1" and 1.125" for the rider? And is there a similar calculus for the blades, or how do you (in general) play with fork design to meet the needs of different riders?

I had that question put to me the other day when someone noticed my MRB has a 1" steerer, and I think I know why you/we chose that, but I'd still be curious to hear your version.

[PaMtbRider]

Along the same line as Dan's question above, if you would be willing to go a little further I have a similar question.
I know for each person you customize the frame for their given parameters, bike fit, rider weight, intended use... How far down the rabbit hole does this go?
For example, take myself as client #1 and Clean39T as client #2. Assuming we have the same fit requirements, and the same desired ride characteristics, but Dan #2 (that's you Clean39T) is a plump 200 lbs, and I am a svelte 170 lbs do we get the same tubing selection? Do you modify butting profiles to achieve the same ride characteristics for both of us, or are we that close that the frame design will be the same.

[bob heinatz]

That sure looks nice Dave. That's how a custom bike should be built with a fork made for the specific rider not a off the shelf carbon fork. Steel forks also look better on a steel bike imho.

[David Kirk]

Originally Posted by Clean39T

That is incredibly beautiful, as usual, and I couldn't agree more with the sentiments.....

The fork you're holding looks like a 1.125" steerer....can you share a bit about the design/selection process for choosing between 1" and 1.125" for the rider? And is there a similar calculus for the blades, or how do you (in general) play with fork design to meet the needs of different riders?

I had that question put to me the other day when someone noticed my MRB has a 1" steerer, and I think I know why you/we chose that, but I'd still be curious to hear your version.

Good questions....I have just enough time before the lasagna comes out of the oven to respond.

The fork pictured does have a 1 1/8" steerer. Steerer diameter is chosen for a mix of performance and pragmatic reasons. If the rider is big and heavy and very aggressive that pushes me toward the larger size.....light and smooth makes me think smaller. Does the rider prioritize smooth ride over hammering? Smaller. Does the rider like to spring against his buddies for green signs like their lives depend on it? Larger.

The pragmatic consideration boils down to what size head tube does the frame have? If the tubing is normal sized and the frame is lugged then that pushes us toward 1" because nearly all quality lugs for OS sized tubes (the norm today) are designed for a 1 1/4" head tube so the steerer will need to be 1". Larger lugged frames that use XL sized tubes will use a 36 mm HT and this needs a 1 1/8" steerer. With fillets I can go either way.

One thing to keep in mind is that steerers come in different wall thicknesses too so a big guy who wants a smooth ride can use a thicker walled 1" steerer and the ride will be awesome and it will be way more than strong enough.

Fork blades - I have Reynolds make two different thicknesses for me and my JKS model so that I can fine tune the ride. My blades are my own part numbers and they are done a bit differently.....they look pretty normal on the outside but the inside is different and it cuts weight and gives a wonderful ride.

One last thing about steerer size.....it's not a phallic thing....bigger is not better. One needs to remember how we got here with massive steerers. For 100 years 1" steerers were the norm and life was fine. Then the mountain bike came on the scene and the loads were higher and the forks got longer (more leverage) so the steerers got bigger to deal with these loads. A bigger steerer was indeed a good thing here. The steerer material changed to aluminum and carbon and to deal with stiffness and fatigue resistance the steerers got even bigger and tapered. Again - a good solid engineering reason for the change. But just because these "standards" worked well in other applications and materials doe not mean that they will be better in steel. Full. Stop. One needs to pick the right specs of a tube based on how it's going to be used and what the material is and not out of some misplaced sense of being modern or fashionable. It just doesn't work this way.

Time to check on dinner - thanks for reading.

dave

[David Kirk]

Originally Posted by PaMtbRider

Along the same line as Dan's question above, if you would be willing to go a little further I have a similar question.
I know for each person you customize the frame for their given parameters, bike fit, rider weight, intended use... How far down the rabbit hole does this go?
For example, take myself as client #1 and Clean39T as client #2. Assuming we have the same fit requirements, and the same desired ride characteristics, but Dan #2 (that's you Clean39T) is a plump 200 lbs, and I am a svelte 170 lbs do we get the same tubing selection? Do you modify butting profiles to achieve the same ride characteristics for both of us, or are we that close that the frame design will be the same.

Dinner's not quite ready and Karin's not home from her work out yet so I have a bit more time..........

If I have two identical riders who want the very same ride and one weighs 30 lbs more than the other do I change the tubes? Is that the question? The answer is probably. I'd need to sort it out. I might chose tubes that have longer butts or slightly thicker walls for the heavier guy. I might also cut the c-stays differently so that there's more large diameter section used for the bigger guy (I have my own stays made and they allow me to trim either end to get the desired length and thereby change the stiffness - I also have a version made with a thicker wall for BIG guys). I can do the same with the fork blades....cut more off the small end to effectively make the blade stiffer.

With only a 30 lbs difference I'd be making only small changes to the build. I routinely see riders of similar heights that have a 50-70 lbs difference and larger changes are made to deal with a larger weight difference.

Make sense?

dave

[Clean39T]

Originally Posted by David Kirk

Good questions....I have just enough time before the lasagna comes out of the oven to respond.

The fork pictured does have a 1 1/8" steerer. Steerer diameter is chosen for a mix of performance and pragmatic reasons. If the rider is big and heavy and very aggressive that pushes me toward the larger size.....light and smooth makes me think smaller. Does the rider prioritize smooth ride over hammering? Smaller. Does the rider like to spring against his buddies for green signs like their lives depend on it? Larger.

The pragmatic consideration boils down to what size head tube does the frame have? If the tubing is normal sized and the frame is lugged then that pushes us toward 1" because nearly all quality lugs for OS sized tubes (the norm today) are designed for a 1 1/4" head tube so the steerer will need to be 1". Larger lugged frames that use XL sized tubes will use a 36 mm HT and this needs a 1 1/8" steerer. With fillets I can go either way.

One thing to keep in mind is that steerers come in different wall thicknesses too so a big guy who wants a smooth ride can use a thicker walled 1" steerer and the ride will be awesome and it will be way more than strong enough.

Fork blades - I have Reynolds make two different thicknesses for me and my JKS model so that I can fine tune the ride. My blades are my own part numbers and they are done a bit differently.....they look pretty normal on the outside but the inside is different and it cuts weight and gives a wonderful ride.

One last thing about steerer size.....it's not a phallic thing....bigger is not better. One needs to remember how we got here with massive steerers. For 100 years 1" steerers were the norm and life was fine. Then the mountain bike came on the scene and the loads were higher and the forks got longer (more leverage) so the steerers got bigger to deal with these loads. A bigger steerer was indeed a good thing here. The steerer material changed to aluminum and carbon and to deal with stiffness and fatigue resistance the steerers got even bigger and tapered. Again - a good solid engineering reason for the change. But just because these "standards" worked well in other applications and materials doe not mean that they will be better in steel. Full. Stop. One needs to pick the right specs of a tube based on how it's going to be used and what the material is and not out of some misplaced sense of being modern or fashionable. It just doesn't work this way.

Time to check on dinner - thanks for reading.

dave

Originally Posted by David Kirk

Dinner's not quite ready and Karin's not home from her work out yet so I have a bit more time..........

If I have two identical riders who want the very same ride and one weighs 30 lbs more than the other do I change the tubes? Is that the question? The answer is probably. I'd need to sort it out. I might chose tubes that have longer butts or slightly thicker walls for the heavier guy. I might also cut the c-stays differently so that there's more large diameter section used for the bigger guy (I have my own stays made and they allow me to trim either end to get the desired length and thereby change the stiffness - I also have a version made with a thicker wall for BIG guys). I can do the same with the fork blades....cut more off the small end to effectively make the blade stiffer.

With only a 30 lbs difference I'd be making only small changes to the build. I routinely see riders of similar heights that have a 50-70 lbs difference and larger changes are made to deal with a larger weight difference.

Make sense?

dave

Dave, thank you for sharing that with us.. It filled in a lot of blanks for me. And gave me an even deeper appreciation for all of the decisions that go on behind the scenes to deliver on the level that you do. I couldn't be happier with the ride of the fork you built me - and that's really all that matters - but it certainly is fun to understand a bit more why it feels so good out on the road..

[OtayBW]

Originally Posted by David Kirk

Dinner's not quite ready and Karin's not home from her work out yet so I have a bit more time..........

If I have two identical riders who want the very same ride and one weighs 30 lbs more than the other do I change the tubes? Is that the question? The answer is probably. I'd need to sort it out. I might chose tubes that have longer butts or slightly thicker walls for the heavier guy. I might also cut the c-stays differently so that there's more large diameter section used for the bigger guy (I have my own stays made and they allow me to trim either end to get the desired length and thereby change the stiffness - I also have a version made with a thicker wall for BIG guys). I can do the same with the fork blades....cut more off the small end to effectively make the blade stiffer.

With only a 30 lbs difference I'd be making only small changes to the build. I routinely see riders of similar heights that have a 50-70 lbs difference and larger changes are made to deal with a larger weight difference.

Make sense?

dave

How about handling characteristics due to fork/trail? Say someone likes high trail handling - other factors equal, do you vary tube selection here as well, or just fork and HT to get the desired characteristics.
I have to say: your forks are just awesome......

[PaMtbRider]

Thanks Dave. I know at some point we reach diminishing returns. Getting that last 5% or whatever it is, puts a smile on my face whenever I ride my Kirk and realize everything is just perfect about it for me.
I have some off the shelf bikes and they are good bikes. I don't think the majority of riders realize how good a bike can be, until they have a custom bike made by you or one of your peers.