linking a non updatable query to an updatable table

I have a query which performs a calculation calculating totals of many fields linked by BikeID This is not updatable due to the calculated field. Now i want to join this query to the BikeDetails table to create a form. So this means that i would have all the data from the table which i can update and the calculated field which i cant. But when i join the two tables/query all the data becomes non updatable.

Thanks
Sci

Thanks for your responce.Im calculating the total hire income and repair cost on each bike + the cost of the bike. Take a look at the database i posted for the calculation, its in Bike Parameters. All this is displayed in a subform in datasheet view the hope is that i would have one non updatable field with the calculation and teh rest would be updatable.I did not post the forms as the file size would be large.

I dont see how i can do that as the information is already stored in a subform and the calculation is more complicated than just the sum Ive posted all the relevant forms. so that i can show you what i mean and what end result im trying to get.
Thanks again, sci