My wagon is due it’s 6year tacho calibration at end of April, just wonders if there was a minimum tread depth to have this done as never had anything to do with them before. Cheers.
xfmatt:
My wagon is due it’s 6year tacho calibration at end of April, just wonders if there was a minimum tread depth to have this done as never had anything to do with them before. Cheers.
If they are within legal limits, more than 1mm, leave them on, as they are smaller it will give you an edge on speed when you replace them, if they set the limiter up to the same calibration 
Wheel Nut:
xfmatt:
My wagon is due it’s 6year tacho calibration at end of April, just wonders if there was a minimum tread depth to have this done as never had anything to do with them before. Cheers.If they are within legal limits, more than 1mm, leave them on, as they are smaller it will give you an edge on speed when you replace them, if they set the limiter up to the same calibration
^^ 
won’t do any harm to drop the tyre pressures a bit (a lot) as well, this reduces the tyre diameter too 
Big Joe:
Wheel Nut:
xfmatt:
My wagon is due it’s 6year tacho calibration at end of April, just wonders if there was a minimum tread depth to have this done as never had anything to do with them before. Cheers.If they are within legal limits, more than 1mm, leave them on, as they are smaller it will give you an edge on speed when you replace them, if they set the limiter up to the same calibration
^^
Tyre pressures are checked and recorded on the calibration record sheet
Riverstick:
Tyre pressures are checked and recorded on the calibration record sheet
Indeed they are or should be, but unless the tyre is marked as having a minimum/maximum pressure there is no illegal tyre pressure. The law only says a tyre should be inflated to a level fit for its use, so 40-50 psi for bobtailing to the Tacho Center is more than plenty
legislation.gov.uk/uksi/1986 … on/27/made
Whilst C&U Regs say one thing about tyre pressures, the Tacho legislation has its’ own specific requirements; that tyre pressure must be within manufacturers’ guidelines, so running 50 psi ‘down’ might not be such a good plan. UK Tacho centres are required to have a pressure gauge and air line to deal with ‘flat tyres.’
I thought I’d be ok as long as the tyres were legal but it was a mate who reckoned there was a minimum tread depth of 3mm. I’m hoping the drives I have on now will last till 13th April when it goes in for calibrating.
As Wheel Nut said earlier; as long as the tyres have at least 1mm (the legal limit for tread depth on an LGV) then they’ll be fine for Tacho calibration.
If you had a 3.5 tonne Sprinter or similar or a 4x4 then you’d have to have at least 1.6mm on the drive axle tyres.