Back In the day (not that long ago snigger snigger

) early Nineties, when I raced Mtn Bikes I used to race a rare then Cannondale hardtail with only a Girvin Flexstem to absorb some of the front end punishment and I did run a 54 x 11 for the down hill course also used that for training on the road and according to the Cateye speedo I clocked 90 km/h which is about 55 mph down a long downhill road up in Canberra (where I lived at the time) and that was on dirt tyres and at the bottom there were a few curves .... it got real scary real quick