Sunn & Formula: The Meeting of Two Prototypes

At the Mountain Bike Connection Winter in Massa Marittima Formula is there with a new fork, still in the prototype phase, which I’ll provide more information on in the coming days as I was able to test it on the beautiful trails of Monte Arsenti. Formula presented the Selva prototype mounted on a prototype chassis from Sunn, with truly unique and captivating lines. The Sunn bike was unfortunately only available for an exhibition while for the actual field test, the prototype of the Formula Selva fork was mounted on another bike, so all we can do for now is to show you what we saw…

The front triangle has sharp and angular lines, with a very radical looking head tube area, which is joined by a raised graphic made directly out of the carbon structure on the front of the top tube.

The suspension system seems extremely elaborate, but in reality it is a four bar l with Horst link that compresses the shock absorber on both sides, therefore technically a “full floater”. The chainstays are of a considerable size have a mudguard in front of them to protect the rear shock from spray and mud.

The position of the shock absorber is actually the most peculiar detail of this Sunn frame. It is placed inside and surrounded by a structure that joins the bottom bracket housing to the seat tube. The very wide sides of this box literally hide and protect the shock absorber, leaving only the reservoir and external adjustments exposed. The linkage that drives the shock absorber is made with the dimensions and shape that are in line with the design of the frame’s heart that forms a sort of box that encloses the shock absorber, sealed at the back by the removable fender. There’s also a sneaky routing for a remote lockout.

Sunn   //   Formula