I measure with my calipers. You don't know that 42"c" means 42 millimeters? Look up the history of bike tire sizing and you'll learn why they put a C on it.

NO

Vertical dropouts are designed to have the axle tight against the dropout.

Older vintage steel bikes with horizontal dropouts can be adjusted that way, but not the new vertical ones.

As far as tires, it is perfectly fine to mix tire sizes. 28mm in front, and 25mm in the rear. There is also debate on whether the larger tire should be in front or back. The larger front tire will give you more shock absorbing for the hands on your bars, and be the first to impact obstacles. On the other hand, the rear carries more weight.

The 'c' is appropriate when referring to the size of a rim; i.e. 700a vs. 700b vs. 700c vs. 700d (only the 700c is in common use anymore). But when you say you measured the tire width as 42c it's pretty meaningless - the measurement of the the width would be in mm, so why not say that you measured it as 42mm?

Yes I see that now,,, and I may just change out the back because of what you point out about the front wheel absorbing more of the impact,,,,,

I do sometimes. I assumed everyone knows when someone says "42c", which is what is stamped on the tire, they know the number stands for the width in millimeters. I assumed wrong.

Don't know ur budget but maybe u can get a wider rim I have a set of hed Ardennes and a 23 tire looks like a 25 gives a much better ride than a standard rim

I'll investigate this,,,,

I have the opposite problem, 28's slightly too large in the front but fine in the rear. I love the ride that 28's give so I lower the air pressure enough so they work. What pressure are you riding, how big are you? For me 70-75 psi in the rear is plenty and I'm 190 lbs, you can go less if you're lighter.

To me that pressure sounds kinda low for your weight of 190 I use 80 and I'm 5'5" ,150 #s,,, I don't know now,,,

It's at this point we post the tyre-rim comparison picture.

Check this out . A poster here turned me on to this and in my experience he's right. At 150 lbs., you can go a lot lower if you choose to. Worth a try before you sell the tires. Read it and do the approximate 60% rear and 40% front for weight and you'd likely be ok at 70 psi. If you, like most of us, do not ride on fresh blacktop and have to deal with some rougher roads then lower pressures can be faster and more comfortable.

https://www.adventurecycling.org/def...SIRX_Heine.pdf

It's just like me to read directions after all else fails and ask for directions after I'm lost,,,,,thanks..

28's are my skinny tires.