Who says New York is the greatest city in the world? Probably everyone who lives there, or has previously lived there, or has visited there. Still, it’s not the skyscrapers or the bridges or the avenues that that makes NY the greatest city in the world, it’s the people — and characters like Seth Rosko.
Seth builds unadorned — yet unassailable — frames in his tiny Brooklyn workshop for customers that appreciate their typically straight-up NY attitude: honest, hard working mountain and cyclocross bikes devoid of unnecessary decoration.
This 650b MTB was recently finished in-between family duties of skating with his son, releasing a limited-edition Neckface deck and building custom exhaust pipes for a motorcycle, not to mention his supply of bikes to the King Kog CX team. Seth likes to keep busy.
The frame, a mixture of Columbus, Dedacciai, and True Temper tubes, is produced in small batches each year with personal modifications for each customer. His mountain bikes, these days, are almost exclusively based on the 650b format — a good crossover between XC racing and all-mountain riding.
There’s a rugged and proud simplicity here that both Seth and New York is famous for. Braze-ons are supplied by two US-based machine shops, and the geometry is based on East Coast technical riding: a 69.5° static head tube angle, 73° seat tube angle, 425mm chain stays and 299.5mm BB height.
A 44mm head tube caters for tapered steerer forks and there’s a 31.6 seat tube for a variety of dropper posts. Meanwhile, a thru-axle, Stan’s No Tubes and Continental Trail King wheelset, Wolf Tooth chain ring and Shimano XT brakes make for a modern, burly beast that’s hungry for technical trails.
Seth builds these frames for a price of USD$1860, including a single color powder coat and USD$2050 with a ceramic coating. You can contact him through the Rosko Cycles website, and keep up to date with the workshop by following his Instagram feed.
Special thanks to legendary bike photographer and ex-messenger, Takuya Sakamoto for the photos.