Your enquiry:- The bike appears to have no tension when pedalling i.e.it is freewheeling.Checked cable going into back of display unit -it is ok.When pedalling no speed etc shown on unit.Is it just the belt that could have gone -not sure how to open base to check.
You may need a special tool to remove one of the crank arms to get inside. You can get these from Halfords for about £20. Alternatively, we can do a diagnosis which will include removing the covers, finding the problem and working out a solution as to why it has come off (assuming this is the problem!). If the bike is 10 years old or more then the belt could have failed due to old age or general wear and tear – these can be easily replaced but it can be difficult getting the correct size belt as often the belt identification marks rub off.
Please let me know how you wish to proceed. If you wish to book yourself in for a visit, we have an online booking form or you can reply to this email with your full address and I will make the arrangements for you! We are currently working on a 7-10 day lead time to arrange a visit.
I look forward to hearing from you.
Northwick Associates Limited
27 Aintree Road
Keytec 7 Business Park