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The KRUCH Gnartail Project

Driven by a desire to get a locally built, progressive, versatile hardtail MTB into as many hands as possible - I have taken a bit of a leap and begun to build a "batch" of 20 MTB frames. Once they are ready (Late January 2022), a frame can be in your hands as quickly as two weeks from placing your order. This is significantly quicker than being on my waiting list (10+ months), and the frames will be less expensive than my "deep custom" frames.

The Medium/Large Gnartail. 29 for days.

So why buy a Gnartail frame from me? Please read on to find out what makes these frames unique and special.

T47 Bottom Bracket

One of these things is not like the other one.

The standard for handmade or small run steel bicycles is the ubiquitous BSA bottom bracket shell. With an OD of 1.5" and being internally threaded, hundreds of options exist for installing a bottom bracket into this prolific shell. However - it is not without drawbacks.

Modern spindle sizes of 30mm (29mm DUB, Race Face, others) have challenged the humble BSA. In order to run a 30mm spindle the bottom bracket cup bearings must be made smaller to accommodate. A hardtail mountain bike is especially hard on bottom bracket longevity, and frankly if you are like me - a rotational squeak from the crank area is one of the most annoying sounds a bicycle aficianado can hear. Cringe worthy.

Enter the mighty T47. Like Iron Man's pulsing heart, the T47 bottom bracket shell forms the heart of every gnartail. Super beefy. Future proof. Able to run an eccentric bottom bracket (more on that later). The T47 embodies what the gnartail project is all about.

Konga Yoke in 4130 chromoly steel

From Finland with Love.

I had purchased several weld-together Konga yoke kits from Atlee Konga, Finnish designer of the Konga yoke - when I decided to purchase the rights from Atlee to have my own yoke pieces laser cut locally. My local laser shop cuts me the component pieces now from the OG .step files, and I form them in my press then fusion weld them up myself. They are made from 3/16" 4130 chromoly plate steel, and allow fitment of a 29+ tire with plenty of room to spare (for large side lugs, or studs).

In my opinion this is the nicest looking, strongest weld yoke available. It comes standard on every gnartail frame.

Super Boost 157mm spacing, with modular drop outs and room for a 200mm rotor.

Modular Drop Outs - Shimano Mountain Standard Hanger above, one option.
Paragon Machine Round Dropouts. Light, simple and very strong.

I decided to make the Gnartail frames "superboost" 157mm rear spacing for two reasons. First of all, the increased spoke bracing angle of a superboost rear end offers strength beyond anything previously seen in the MTB world (bracing angle increases the lateral stiffness of a wheel - excellent article here:

Second, even major bicycle companies are moving towards superboost as the rear hub standard of choice. I want your frame to be as future proof as possible, and relevant for many years as far as standards and geometry are concerned.

The dropouts I have chosen are fully modular, and the associated derailleur hangers are easy to procure and switch up. The design is a proven one, supplied by Paragon Machine Works, and is strong light and versatile. The dropouts will be paired with an ISO brake mount, and the frame will allow for the fitment of up to a 200mm rear rotor.

As a Shimano dealer I have a pile of 157mm Shimano SLX Superboost rear hubs in stock, with a micro spline driver. I can supply this with the frame if required.

Progressive Geometry, and designed around a 160mm fork. 210mm dropper - all three sizes

The geometry listed above encompasses the three available sizes of Gnartail. The frames are progressive, long - low and slack. Each frame is designed around a 160mm fork. The cockpits are roomy, and the bottom bracket height is set at a level that allows for wheel size versatility.

Note: I have recently become Fox and Marzocchi dealer. If you need a fork with your frame, I can hook you up.

There are eight riders currently testing the Gnartail geometry, and in each case the riders have reported the following attributes: Great handling at speed, excellent climbing characteristics, and confidence inspiring downhill attitude.

Each size can fit a 210mm dropper post. For the terrain these frames are designed for, it is critical to get the seat completely out of the way so the rider can get as low as possible when descending.


Heck, even the stickers are locally made! @twinbatstickerco

Due to the frames being unfinished prior to delivery to you, YOU get to pick the colour. Either choose from 80 colours available from my powder coating shop of choice (included in the frame price), or choose from the following link for a $50 upcharge (custom colour of your choice, even the two-stage stuff):

The available customization options are:

  • Custom colour as above

  • More mounts (rear rack mounts)

  • Internal cable routing (front triangle)

  • Extra bottle cage mounts (top tube, under down tube)

  • Custom artistic frame details (laser cut embossments)

4 different wheel size combinations possible, a multi-season "quiver killer"

There are two tire size configurations with the Gnartail frames when using a standard T47 bottom bracket (like these

  • 29+ with up to a 3.0" wide tire

  • Regular 29er

However if an eccentric T47 bottom bracket is used (like the two featured at this link , the above two configurations are possible as well as the configurations listed below:

  • Mullet - 29er front, and 27.5 rear

  • Plus Mullet - 29+ front, 27.5 rear

No overseas parts and no overseas labour = lower carbon footprint. Powder coating is a lower VOC product than paint.

A tight miter. A little OCD goes a long ways.

In these days of climate change and global unrest, I feel that every person needs to choose where they can make their personal difference - however small it may be.

Every component in the Gnartail frame was sourced from North America sources, and the steel that was used to make the components themselves was created in North America. Every person that put labour into the frame (from manufacturers, to suppliers, to me and the people that help me) was paid a fair working wage.

The powder coating process is significantly easier on the environment than painting. This links to a great article on that fact:

These aspects perhaps don't matter to everyone but they matter to me.

Lifetime warranty against failure (my lifetime!), "pro-moly" 4130 chromoly tubing

Frame bones awaiting welding

Due to the materials chosen, I am confident you won't be able to break your KRUCH Gnartail. But in the very unlikely event that you do - I will fix it for free (re-coating is charged to you at my cost) - as long as I am around. And I expect to be around for at least 40 more years!

I haven't used butted bicycle tubing for this project. Frankly, it dents easily (ask Gonzo!), and these frames are made to be ridden hard and are an "enduro grade" hardtail - not road bikes! As well, the weight savings gained by using butted tubing are irrelevant when you factor in the use of 36mm stanchion suspension forks, plus-sized enduro tires with inserts, dropper seat posts, alloy cranks and other relatively heavy items. Furthermore, non-butted tubing doesn't require additional gussets to make the frame robust.

I have chosen a made in North American 4130 chromoly steel named Pro-moly, built by a mill in Illinois. This same tubing finds it's way into F1 race car suspension and performance airplanes. It is really good stuff, and it didn't come across an ocean to get here.

Stay tuned, deposits being accepted now.


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