2.8 tyres to 2.6

[s90gav]

I've tired using the search function but couldn't get the answer I was looking for

Ive just changed my 2.8's on my kenevo to 2.6's and I was wounder if I need to change the 2275mm wheel size or does the bike automactially know that the diameter has changed?

 

[steve_sordy]

It will not know automatically unless your bike cost over £100,000!

To establish the new wheel/tyre dia, I would mark a line on the ground and line up the valve with it. Then ride the bike in a straight line until the valve comes at the bottom again. Mark a new line where the valve is, then measure how far apart the lines are.