Originally Posted by
Road Fan
These days most of us are not looking for trail higher than 60, rather for lower.
The hard part in all this is to measure the offset. How did you get the offset? Yojimg did not have a database of fork offsets in his utility.
Going to the link for the calculator above, you provide the offset for your OEM fork. According to the geo chart, my rig has a head tube angle of 72.5
° and that with a 45mm offset and 25mm tires results in a trail of 60mm.
Going to 28 tires results in a trail of 61.
Interestingly, staying with 25s but having a head tube angle of 72.4
° also is a trail of 61.
So I'm just reckoning that keeping a 25 on the rear and putting a 28 on the front would be something like 28s all around with a head tube angle of 72.4
° ... resulting in a trail of 62.
Whatever it may be, I like the idea of more rather than less trail as I have a higher seat because the bike has shorter cranks and elevated handlebars with aerobars and it seems like the higher trail should give a more stable ride in the aero position. In any event, I don't seem to have any handling problems.