Dave_Thompson
prophet
Reged: 12/19/03
Posts: 717
Loc: Spokane, Washington
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Dave, I saw the pics of your new bike with the curved seat stays. Beautiful! Do they serve a purpose, ala the DKS?
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Steel lover, but then I like Ti with carbon too.
Licensed bike geek.
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M_A_Martin
new member
Reged: 01/23/04
Posts: 16
Loc: The D
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Yes Sir, Mr. Kirk,
Please s'plain!
I've been trying to get my brain around the vectors and forces and whatnot and I can see where those seat stays would provide suspension, but not traction (so to speak).
They are pretty! And I'm sure the bike is very comfortable..
curiouser and curiouser.
Ginger
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I ride my bike to ride my bike
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Dave_Thompson
prophet
Reged: 12/19/03
Posts: 717
Loc: Spokane, Washington
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Last year when I was in Bozeman visiting Dave, he talked about how he was going to try to develop a rear end that would accomplish the same task, keeping the rear wheel on the ground, as the DKS he designed but without interfering with Serotta's patent. This looks like it may be what he was talking about.
If nothing else, it is very striking and elegant.
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Steel lover, but then I like Ti with carbon too.
Licensed bike geek.
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Climb01742
journeyman
Reged: 12/22/03
Posts: 71
Loc: Concord, MA
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awhile ago dave sent me pictures of an early prototype. i'm sure it rides beautifully, but visually it hit me as slightly out of balance. granted, seatstays are always the thinnest tubes on a frame anyway, but somehow, to my eye, these felt too thin, too delicate. but its a purely visual reaction. perhaps its analogous to sloping TTs. when they first appeared, folks thought they looked odd. now...
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When in doubt, shut up and pedal.
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David_Kirk
new member
Reged: 12/23/03
Posts: 14
Loc: Bozeman MT USA
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Howdy from Montana,
I try hard not to use this forum as my personal ad space but I'm very happy to answer questions directed to me. Thanks for the questions.
The new yet to be named seat stay bends are designed to help keep the rear wheel in constant contact with the surface. they are similar in concept to the DKS but are not rider adjustable. I will be tuning for a riders weight and riding style by varying the bend radius.
They function in a very simple way. If you take a ruler out of your desk drawer and they to compress it end to end its very tough to do. If you flex it into a curve and then compress it it becomes much easier. That what is happening with the seatstays. Normal straight seat stays won't compress much if at all. By putting a curve in the stay to start with it makes it much easier to compress.
The stays are double bent into a long "S" shape instead of a single long "C" bend to keep the "spring" ( i.e. seat stay )more of a constant rate spring instead of a falling rate spring. This is a whole other point on conversation....
The "insert name here" stays will be available as an option on most bikes. There are a few lug and dropout restrictions.
Please feel free to write me directly or call me out here and I'll do my best to answer.
Thanks again,
Dave
P.S. does anyone have a good name for these stays ?
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M_A_Martin
new member
Reged: 01/23/04
Posts: 16
Loc: The D
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If we give you the winning name do we get a free frame? Ok...how about a discount?
*sigh* I'll think about the swoopy stays and contemplate a new name for your surefooted montana mule. Reminds me more of an antelope though...rather than a mustang. (Its odd waking up 3am to a herd of horses tromping through your little campsite...They can have all the BLM land in the world and they'll choose your 20' to trot through. Antelopes always seem to give you plenty of room.)
I'm interested in the fatigue life of the chain stays without a pivot...Whatever that stress point is called.
Thanks for the spring falling rate/constant rate reminder. Time to get out the Mike's Mechanical or Machineries handbook...remind myself of all those fun things. (I only know enough to be dangerous.)
I guess I wasn't too confused about the compression of the spring/seat stay, but more how that translated to downward pressure on the axle rather than only suspension of the rider without causing some sort of fatigue failure in the chainstays.
Thanks for your reply Dave! I hate to think I was calling you out, but my hours have been odd to call Montana when I'm coherent enough to ask questions and more importantly, to understand the answers!
Take care!
Ginger
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I ride my bike to ride my bike
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David_Kirk
new member
Reged: 12/23/03
Posts: 14
Loc: Bozeman MT USA
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Good Morning,
Thanks for the thoughtful reply.
I understand your concern about fatigue life. The reason this all works is that there is such limited movement and due to the shapes of the tubes the flex that occurs is spread over the length of the tubes. This keeps the localized stress to a minimum.
With so little localized flex fatigue becomes a non-issue.
And...for what it's worth I don't see "being called out" a bad thing. I just want to be sure that if someone has a question that they feel comfortable asking.
Have a great day,
Dave
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Dave_Thompson
prophet
Reged: 12/19/03
Posts: 717
Loc: Spokane, Washington
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Dave: What will be the approximate travel with the curved stays? Would a rider notice any rear wheel hop, or anything while climbing under power?
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Steel lover, but then I like Ti with carbon too.
Licensed bike geek.
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Climb01742
journeyman
Reged: 12/22/03
Posts: 71
Loc: Concord, MA
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i'd just like to claify (or maybe its applify) my previous post. my reaction to the curved seatstays is purely personal, visual and 100% subjective. david is a great builder and the amount of knowledge in his little finger exceeds that in my whole brain, now and forever. i think its like fillet vs. lugs, or sloping vs. standard geo, or painted ti vs. unpainted, or chocolate vs vanilla. rereading my earlier post, it sounded far harsher than i meant it. saying my opinion was my two cents worth was over valuing its worth.
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When in doubt, shut up and pedal.
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Dave_Thompson
prophet
Reged: 12/19/03
Posts: 717
Loc: Spokane, Washington
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Climb: I think you're very right about the rear stays being thin and delicate. That's why I like them. I think a bike is a collection of lines and curves of varying thinknesses and radii, that in total are pleasing to the eye. Modern bikes sometimes become clunky and too angular, somewhat like the new Cadillacs. Being an 'old guy', my tastes lean to the classic designs, a good example being a Ferrari Lusso. But taste is what makes the world go 'round. I should have my 'make-over' frame in a couple of weeks, so time will tell.
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Steel lover, but then I like Ti with carbon too.
Licensed bike geek.
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David_Kirk
new member
Reged: 12/23/03
Posts: 14
Loc: Bozeman MT USA
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Howdy,
thanks for the questions and comments.
The rear stays allow for about 5mm of wheel movement....that is of course dependent upon the weight of the rider and the size of the frame.
Yo Mr. Climb....no need to explain or back pedal at all. No offence was taken and I think your opinion might be shared by others. What's interesting is that the diameter of the seatstays is the same as most of the bikes I've built. It's just that they are curved. I think that the curve might draw more attention to them and that's why they seem different.
As for the car analogy.....I'd like to think that my bikes are in the classic Lotus genre. Colin Chapman was the man. He believed that if possible that all parts should preform more than one function. For example, his formula cars used the engine block as a stressed member that became part of the chassis. My seat stays function as traditional stays as well as springs....I hope Colin would have approved.
Let me know if you NEED pictures of my 66' Lotus Cortina...It's my pride and joy.
Dave
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M_A_Martin
new member
Reged: 01/23/04
Posts: 16
Loc: The D
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Sex Drive...(we'll see if that gets edited)
That was one idea. Very sexy seat stays. (if there can be a Bianchi Eros, and a brand named Fetish...why not Sex Drive?)
With the Lotus connection how about Elan?
Although I guess a Kirk Elan might sell better than a Kirk Sex Drive...or not...
nevermind.
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I ride my bike to ride my bike
Edited by M_A_Martin (01/29/04 05:11 AM)
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Climb01742
journeyman
Reged: 12/22/03
Posts: 71
Loc: Concord, MA
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speaking of lotus, david, are you gonna spring for the new elise when it goes on sale this spring? every article i've read says very positive things. i spoke to the dealer who has the new england lotus franchise and they already have, sight unseen, 50 -- yes, 50 -- orders.
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When in doubt, shut up and pedal.
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David_Kirk
new member
Reged: 12/23/03
Posts: 14
Loc: Bozeman MT USA
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Yo-
I'd love to get a new Elise....I doubt it will happen anytime soon. It is my dream car though. I wonder how well my 6'5' body will fit in one. My Cortina fits with room to spare so it's a keeper.
Dave
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Dave_Thompson
prophet
Reged: 12/19/03
Posts: 717
Loc: Spokane, Washington
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How about "KCS" for Kirk Curved Stays?
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Steel lover, but then I like Ti with carbon too.
Licensed bike geek.
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M_A_Martin
new member
Reged: 01/23/04
Posts: 16
Loc: The D
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That's not quite DKS, but more along the same naming pattern. Much more serious than mule...
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I ride my bike to ride my bike
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Dave_Thompson
prophet
Reged: 12/19/03
Posts: 717
Loc: Spokane, Washington
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Ya, I agree. I would hate to tell folks about my all new Kirk Mule. But then someone might mistakenly take me for a rugged outdoorsman.
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Steel lover, but then I like Ti with carbon too.
Licensed bike geek.
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David_Kirk
new member
Reged: 12/23/03
Posts: 14
Loc: Bozeman MT USA
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Thanks for the suggestions ....
I was thinking along a few different lines -
1)Pay tribute to my father who passed away when I was a kid. He was a legendary race car mechanic who worked for British leyland amoung others. His initials were JBK .
2)Pay tribute to my stepfather who raised me and taught me how to think outside the box...in fact he taught me to forget there is a box. He's a great guy, a wonderful dad and a serious cyclist even now in his 70's. His initials are JDT.
3)Pay tribute (see a trend here ?) to the first guy to use suspension on a road bike. He patented a suspension design in Nov. 1888 ( patent # 392,523) and his name was H.S. Owen. For what it's worth he truly invented the unified rear triangle design that John Castellano "repatented" about 10 years ago. I firmly believe that was a serious mistake on the part of the patent office as the idea firmly existed for over 100 years before Castellano "invented" it. No disrespect to Castellano intended...he's a gifted designer.
4) Pay tribute to Colin Chapman of Lotus fame. A truly great mind that established the way all of our cars will be built in the future....once the big three pull their heads from the behinds.
5) Last but not least...and not a tribute in any way. I love the name "TerraPlane". It was used by the Hudson car company in the 50's - 60's. I love the idea of anything that flys over the surface. That is what we are trying to do isn't it ?
Opinions ?
Thanks,
Dave
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kio
new member
Reged: 01/23/04
Posts: 5
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Call it 'Tribute Stays'...That should have everyone you mentioned on the wall...
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Dave_Thompson
prophet
Reged: 12/19/03
Posts: 717
Loc: Spokane, Washington
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Dave:
Being the pragmatic sort, I'm inclined to name your rear end(!)something that can ring with all bicyclists. If your curved stays become an item, I think they should be named something catchy and descriptive. Perhaps something like Montana Road Stay. You've got the Montana Road Bike. Now it can come with the Montana Road Stay option. Montana is perceived as rugged, different and the roads not too good. (Marlboro-type cowboy, standing waist deep in snow during a blizzard, in deep gruff voice..) "Yeah, I've got the Montana Road Stay option on my Kirk. Smooth as hell!"
Edited by Dave_Thompson (02/06/04 03:20 PM)
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M_A_Martin
new member
Reged: 01/23/04
Posts: 16
Loc: The D
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I usually try to provide positive feedback...but today..
It depends on what you do with it...
Kirk Montana Road Bike
Kirk Terraplane (..very retro...)
Unfortunately, people want initals to mean something. If you called it a J stay, or CC that would really confuse people.
As I was driving along the other day, due to the lack of pivot on the suspension, I thought of KSS as very close to the KISS (keep it simple s...) theory of advertising... but I guess it could stand for kirk seat stay
In part, I'd like to say that whatever you pick I hope you market it better than Serotta marketed the DKS! Few people ever "got it". It even took me a while to slog through their marketing to figure out what the DKS actually did...
Oh...
And there isn't a tractor big enough to pull the big three's heads out of their collective asses.
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I ride my bike to ride my bike
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David_Kirk
new member
Reged: 12/23/03
Posts: 14
Loc: Bozeman MT USA
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I've made an executive desicion and desided to call it the Terraplane option.
So it is written and so it shall be done ( I've been watching too many Sparticus movies).
later,
Dave
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Dave_Thompson
prophet
Reged: 12/19/03
Posts: 717
Loc: Spokane, Washington
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Dave:
It's really a very good thing your last name isn't Hudson. I'd have a devil of a time explaining my bikes name!
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Steel lover, but then I like Ti with carbon too.
Licensed bike geek.
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David_Kirk
new member
Reged: 12/23/03
Posts: 14
Loc: Bozeman MT USA
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I could have named it after such wonderful and memorable products like the Ford Probe, or the Edsel, or the Gremlin,
or my recent favorite...the Aspire....what the hell were they thinking ?
Dave
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