In it's 5th revision, the Rootdown has undergone only a few updates for 2021. We have increased the reach and dropped the seat tube length across all sizes, but other than that it remains largely unchanged. If it ain't broke...
Built with our custom-drawn tubes and featuring a 12x148mm Boost rear end and stealth post routing, this is the evolution of Chromag frame design in 29er form compatible with 27.5+. An agile ascender and a dominant descender that is ready for anything.
The Rootdown is by far and away Chromag's most popular frame.
Almost all Chromag frames are made from quality 4130 chromoly steel tubing. Chromoly is an abbreviation for chromium-molybdenum indicating the materials that the steel is alloyed with.
The added chromium helps increase the steels hardenability and also provide some corrosion resistance.
The molybdenum helps to increase the toughness of the steel.
It has a high tensile strength but is also malleable which is what gives our frames their notorious ride quality and feel. Chromoly is often used when more strength is required than that of mild carbon steel.
It falls under the AISI (American Iron & Steel Institute) 41XX designations which is where the “41” comes from. The “30” indicates it contains approximately 0.30% carbon by weight.
Chromoly is much stronger than traditional 1020 steel and it has a higher strength to weight ratio and high tensile strength, which means we can use less material and achieve a product that can withstand the abuse that riders love to throw at it.
Hub Spacing // Boost 148mm (Axle and Hanger Included)
Headset // 44-56 Semi Integrated
Seat Clamp Size // 35mm
Seat post Size // 31.6mm
BB // 92mm Press Fit (PF92)
Wheel Size // 29" or 27+
Recommended Fork Travel // 150 - 170mm
Head Tube Badge
Your bike is special. The head tube badge is the finishing touch so we’ve always made a point of taking the time to do something interesting with it. Our head tube badges have changed over the years and are an indication of the time each bike was made. Whether it’s a cast bronze, or polished stainless steel, water cut aluminum or a 3D CNC carving, each one represents our commitment to detail.
As 12mm through axles have proven to be solid, reliable and convenient, we have committed most of our models to utilize this format. Our 12mm dropouts are accurate and tough and feature a removable derailleur hanger with a sturdy interface for strength and reliability. All 2017 models (excluding Monk and Nice Dreams) will follow the 148mm boost spacing.
Our ‘Yokel’ design is a small machined junction on the chainstay that helps accommodate both tire clearance and chainring clearance. Our first versions were huge CNC yokes that bridged the entire front end of the chainstays. Over time we refined this to minimize weight by arranging our chainstay layout asymmetrically and reducing the yoke to a minimal size. It’s one of our most unique frame features and has been copied by other frame makers.
Chain Stay Protector
All Chromags now ship with our injection moulded chain stay protector to help keep the paint fresh and the noise low. These have an adhesive applied, but also slot for zip ties if they come unstuck years down the line, or if you want to apply it to another frame.
|Fork||Rock Shox Lyrik Select 160mm Boost 110x15mm|
|Headset||Cane Creek Forty ZS|
|Rims/Wheels||Chromag 29" Ally Rims / Chromag R4 Hubs. (Magna40 Rims for 27+)|
|Tires||Maxxis Minion DHF/DHR|
|Chain||SRAM GX Eagle|
|Rear Derailleur||SRAM GX Eagle|
|Cassette/Rear Cogs||SRAM NX Eagle 10-50t|
|Shifters||SRAM NX Eagle|
|Handlebars||Chromag OSX 25mm Rise, 800mm Wide|
|Stem||Chromag HiFi 40mm|
|Brakes||SRAM G2 RSC 180mm|
|Saddle||Chromag Trailmaster DT|
|Seat Post||Chromag Dolomite|
* Subject to change without notice.