I'm running a 140 rear because. . A..I prefer the look and B..it's an Avon Distanzia and most (at least 80%) of my riding is on the road...albeit tiny narrow lanes around the South Downs. However. ...the previous comments are right. ..on the original rim a 130 is probably better off road as the tyre will 'dig' in more. An example of this is once a month there is a 4x4 off road event at some disused sandpits near here....one of the marshals drives an early Series Landy with the skinniest tyres and NEVER gets stuck...in fact he frequently tows out fat tyred shiny 4x4's!. Jo75's is different. ..he is running an 18 inch rear and a fairly aggressive tyre and is a frequent off roader. Steve