You can almost certainly go up 2 sizes, if your wheels are true.
40/42
(Although you didn't picture the Chainstay Bridge- there's often a pinch point there to allow narrow q factor and triple chainset)
You can probably just measure the gap between the stays/forks at the tyre bulge.
But...
Manufacturers don't follow the same method - one brand's 42 is the same size as another's 38
Your rim width affects the overall tyre width.
Watch out for knobbles.
Sometimed they aren't included in the size![]()
Thanks for the help ,anything above 622-44 not done then ? GrtsYou can almost certainly go up 2 sizes, if your wheels are true.
40/42
(Although you didn't picture the Chainstay Bridge- there's often a pinch point there to allow narrow q factor and triple chainset)
You can probably just measure the gap between the stays/forks at the tyre bulge.
But...
Manufacturers don't follow the same method - one brand's 42 is the same size as another's 38
Your rim width affects the overall tyre width.
Watch out for knobbles.
Sometimed they aren't included in the size![]()
If you push it, you won't know until you've fitted the tyre and take a look.
Flex in the frame and wheel can cause rub if its too tight, and things get stuck between the tyre and frame.
You could buy a single 45 - one end will be tighter than the other - try it out both ends, and then get the same or different once you know.
The more you push it, the more likely it won't fit.
We get bikes in - the owner wants the largest tyre - we can guess and then swap out until we've got the right result, but then we've got hundreds of tyres to choose from.
So you could take it to your lbs and get them to sort it, or risk buying a