1988 Kuwahara Shasta - fixed gear mtb conversion.
Even with the wider 2.0 Schwalbe Hurricanes she's a pretty fast bike as the tyres have a small contact patch at 70 psi and the bike will just blow through and over stuff I would be dodging on other bikes and the tyres also handle the trails really well.
The ride is amazingly good with those higher volume tyres and that ratty but uber comfy Lycette saddle.