Rostra Disc Flat Bar Tiagra Mechanical It is the perfect aluminium all-season bike that is capable of handling year round British weather, long commutes and fun weekend rides. A Lightweight 6061 T6 aluminium frame with carbon fork. Without mudguards the bike can take up to 38mm tyres, when fitted, tyre clearance allows for up to 35mm. 2 x 10 Shimano Tiagra groupset Mechanical disc brakes. Size small, colour silver.