In 2013, Russia’s Алексей Кочубеев read an article about an ambitious rider building a custom bike from plumbing pipes, alloy sheets and inexpensive materials. He found the story rather interesting, but it didn’t launch him into action right away. Almost two years later the desire struck Кочубеев to own a custom bike with plenty of integrated adjustment, so he decided to put his own ideas into motion.
Кочубеев found a small company called Kuvalda Bikes who were producing prototype frames. He contacted them in January 2015 and started designing what would eventually be called the Kuvalda Grimlock. Кочубеев’s creation boasts a huge amount of adjustability with four different travel settings, three chainstay lengths and compatibility with 26″ or 27.5″ wheels.
With such a wide range of set up options this frame is sure to spark engineering debates over its built-in versatility and how it’s ride characteristics might be affected as the rear shock position is altered. Read past the break to see how it works…
Кочубеев and Kuvalda set out to build his custom frame for a cost of about €800 ($895 USD). The design went back and forth between the manufacturer and Кочубеев, and after revisions around the bottom bracket area, some additional gusseting and a redesign of the suspension linkage, the third phase prototype (pictured on the right) began to resemble the final version of the Grimlock.
The Grimlock is made of aluminum, and the frame weighs in at 9.04lbs (with the 27.5” dropouts). Its head tube angle is 66°, and the seat tube sits at 74°. The 1x specific frame has no front derailleur mount and features ISCG 05 chain guide tabs, a 1.5” head tube and a 73mm BSA bottom bracket. It also features internal routing for a stealth dropper post, and a passage through the chainstay for the rear derailleur cable.
Now here’s where the adjustability comes in: The Grimlock’s interchangeable rear dropouts will accommodate either 26” or 27.5” wheels, and adjust the length of the chainstays with three settings at 420, 427.5, and 435mm. Кочубеев lists the bike’s wheelbase at 1150mm, but did not note which configuration was measured.
The Grimlock employs a single-pivot suspension design with four mount options for the inverted rear shock, allowing for several different travel settings at 155, 162.7, 170 and 185mm. The frame is designed to maintain its BB height and geometry regardless of your travel choice. While it aims to retain a familiar feel in all configurations, the compatibility with different wheel sizes and multiple travel options are intended to make the Grimlock a highly adaptable bike for tackling different types of trails.
Кочубеев says he intends to continue upgrading the complete bike with better components, but funds got a little low so this is the best build he can afford for now! He plans to replace the tires, seatpost, cranks, pedals, brakes and rear shock seen in the photos. Кочубеев is apparently very happy with the current iteration of the Grimlock frame, and anxious to get it out on the trails.