Terraplane or no Terraplane

[JackB]

My JKS is coming up quicker than scheduled which is great for me. I'm going to build this machine into a 14-14.5 double century race bike. For all of the Kirk owners who have the terraplane option, what's your overall opinon? I think it might be a cool option but I need to read some of your thoughts.

Thanks

[Greg Costello]

Jack - feel free to contact me by phone if you want a more in depth conversation (541.554.8337).

I went with the terraplane on both my Kirks based on Dave's advice and preference for using them. I trust his judgment and engineering sense so when he says it gives some vertical compliance I believe him. In actually riding, it may be all subjective or pyschological but on rough pavement the bikes do seem more planted than on other bikes I've had, including my Peg, Merckx MXL and Merckx MXM, all of which bounce or bounced around a bit more.

BUt I think just as important frankly is whether or not you like the aesthetic. For me it was an acquired taste; and I'm happy that I did. For me it is part of what makes a Kirk a Kirk and distinguishes it from the other fine builders bikes which have their own distinctive characteristics.

Greg

[arik]

Seems like you go through a lot of bikes because you like novelty and experiencing what each new frame has to offer, so there is no way you can get a kirk and not try the terraplane out for the 1st time.

I bet $100 you get a terraplane.

[Shinomaster]

What are the advantages of the design? Are there any drawbacks? I'm assuming it smooths out the ride like the DKS?

[Greg Costello]

from Dave's website:

The curved seatstays of the Terraplane allow a small amount of vertical movement and are designed to keep the rear tire in firm and constant contact with the surface. Each set of stays is bent by hand to a given radius determined by the size and weight of the rider and the intended use of the bike. The feel and stiffness of the frame is regulated by the amount of bend in the stays. Heavy riders generally would have less bend to allow less movement. Lighter riders would have more bend and more travel.

With the Terraplane option you'll feel more confident cornering and descending, and you'll enjoy true all day comfort. The Terraplane option is available with both fillet brazed and lugged bikes and with most any type of brake system.

[Shinomaster]

from Dave's website:

The curved seatstays of the Terraplane allow a small amount of vertical movement and are designed to keep the rear tire in firm and constant contact with the surface. Each set of stays is bent by hand to a given radius determined by the size and weight of the rider and the intended use of the bike. The feel and stiffness of the frame is regulated by the amount of bend in the stays. Heavy riders generally would have less bend to allow less movement. Lighter riders would have more bend and more travel.

With the Terraplane option you'll feel more confident cornering and descending, and you'll enjoy true all day comfort. The Terraplane option is available with both fillet brazed and lugged bikes and with most any type of brake system.

Sounds sweet for a cross bike.

[maunahaole]

Jack - sooner or later you are going to do it, so why not now?

[flick]

If you can swing a Kirk without a doubt get the terraplane, for me that would be the main reason to get a Kirk, but not the only one.

[znfdl]

Jack:

You need to get the Terraplane in my size, so when you tire of the bike, I can finally buy one of your cast offs.

[dirt]

I went NON Terraplane on my JKS for two main reasons-

I already have a Terraplane

I personally think that the Terraplane option looks the best on larger frames- ie non compact

Jason

[Sasha]

I'm sure Dave has thought of this, but I would think that under extreme cornering pressure, the back end would begin to twist ever so slightly. This would seem logical, given that the stated advantage of the terraplane is compliance and it actually moves quite a bit. Under all other circumstances, it probably handles and feels dreamy. Anyone experience this? This is not to disparage Dave's work at all. It is, in fact, very purposeful design.

For a double century, get the terraplane. Why wouldn't you?

[Catulle]

Either way you'll be more than pleased. However, only the Terraplane has the terraplane; and if you look around, you'll find many builders and manufacturers trying to reach the same results in their own way. Hell, you might as way get the house's special.

[pdb]

I have a terraplane and love it, although I don't know that I could quantify it. I used to think a Kirk looked funny without the terraplane option, like something was missing, and to me thats what makes a Kirk a Kirk.

That said, I would probably order the JKS without the terraplane. I think the JKS looks perfect and smoking hot in its minimalist form with the straight stays. I lust for one of those frames! :adore:

Just my 2 cents and probably no help whatsoever...

[hampco]

how could the rear move when cornering?

i'd get the terraplane: it's what distinguishes dave's frames from everything else and it doesn't make it a worse bike.

[JackB]

Thanks for all of the imput concerning the Terraplane. I'll be off the fence by the end of the weekend.

[Shinomaster]

What does Dave suggest?

[Sasha]

The same way any component of a bike moves, twists, or otherwise.

Dave has said elsewhere that a terraplane stay can move as much as ~6mm when compared to other straigt seat stays. That's a lot of travel. I assume that's designed to move primarily in one direction. I won't speculate anymore and let Dave comment if he wants. I find the design of stays very intriguing after reading another very long and informative thread somewhere else.

[hampco]

i'm skeptical that there is much twisting happening at the rear of a bike during cornering but i can't prove it one way or another. and 6mm sounds like a lot of travel but i wouldn't call dave a liar, either.

if it were me - and it ain't - i would choose or not choose the terraplane based on aesthetics, not on perceived performance enhancements. but that's just me.

[Fixed]

it is his signature ..
. if you want hip cats to know what you are riding without reading the decals
i bet they both ride great
d.k. doesn't know how to make a bike that doesn't ride great imho
cheers
butch

[Vax]

Had I ordered a JKS like I thought, I would have got it. It's Dave's signature. It's not like you don't have enough standard race bikes. Of course, I drank the Kool Aid after talking with Dave for an hour or two at the bike show. Dave likes it. Good enough for me.