Tyre question

[Grahamm]

I have a BT 023 on the front fitted in April 2011 manufactured October 2010 with plenty of tread left but it is maybe a bit old now.
Back is a BT 021 fitted May 2009 manufacture date of 08 and that is ready to change almost down to the marker and done 7 k.

If those tyres are really that old you really should replace them! After 5 or 6 years, even if they've not been used, the rubber in them may well have degraded to the point that they could fail catastrophically without warning.