There are a number of people today, that upon reading this are realizing they already own a fat bike. Well, part of a fat bike, anyways. The Ibis Tranny is transitioning from a super versatile 29er into an even more versatile 4″ fat bike. Better yet, the conversion isn’t permanent…
If the Ibis Tranny is new to you, the basics include a light weight carbon frame built around 29″ wheels with a unique rear “swingarm.” The swingarm initially allowed for three things – the ability to run single speed without eccentrics or sliding dropouts, the ability to run belt drive, and the ability to break the frame down for travel.
Now it has a new trick. Since the swingarm can be completely removed, it can also be completely replaced with something, say, with clearance for a 26 x 4″ fat bike tire. So while the Trans-Fat will be available as a complete, it is also available as a retrofit kit for existing Trannies for $699.
While the swingarm allows for the big rubber to clear the frame, the Tranny needed a few other tweaks to become the Trans Fat. Since the standard Tranny runs a BB92 bottom bracket, something had to be done to allow for fat bike sized cranks. To fix this Ibis created a pressfit to 100mm threaded adapter to allow you to run your favorite fat bike cranks. Geometry is the only small change between the Tranny and Trans Fat with the fat bike getting a one degree slacker head tube and seat tube angle at 70/72º to make sure the big tires aren’t twitchy. The retrofit kit also includes a 3mm thick crown race which is there to provide downtube clearance for the wide Bluto fork crown. We’re told that the Tranny geometry will remain the same going forward.
Other details include a 177×12 rear thru axle, 120mm fork compatibility, internal dropper post routing, and a tapered head tube.
Thanks to a 3.25lb carbon monocoque frame, the Trans Fat should build up to a weight that belies its name. Calling it a limited edition, Ibis’ Scot Nicol tells us the first batch has been completely sold to dealers and distributors and will be in short supply. A second batch is due for February which is when the retrofit kits and framesets ($1700) will be available. Complete bikes will be available in a single Shimano XT 1x build with a Race Face Turbine Cinch crank, RockShox Bluto 120 fork, KS LEV Integra dropper, Sun Ringle Mulefut 80SL wheels, and Jumbo Jim 26 x 4″ tires at $5099. Frames will be available in orange or black and in medium, large, and X-large.
