Does it make sense to replace just one tire with treadwear?

[staehpj1]

According to Sheldon the tire that is least likely to fail should be on the front. Sheldon's words on tire rotation are as follows: "The idea is to equalize the wear on the two tires, but this is a serious mistake, don't do it!"

I happily break that rule regularly.  I don't see it as all that likely to be a problem.  I never found handling in slippery conditions to be a problem with a more worn front tire and the rear tire is always more likely to fail even when the front is more worn due to the fact that it is carrying more weight.

I consider that rule to be mostly a case of over thinking things and looking for a problem that really doesn't exist.  It is one of very few issues where I disagree with Sheldon.

[PeteJack]

I happily break that rule regularly.  I don't see it as all that likely to be a problem.  I never found handling in slippery conditions to be a problem with a more worn front tire and the rear tire is always more likely to fail even when the front is more worn due to the fact that it is carrying more weight.

Have you ever had a front tire blowout while going downhill at speed?

[staehpj1]

Have you ever had a front tire blowout while going downhill at speed?

Short answer...  yes.

Long answer...  In literally hundreds of thousands of miles of bicycling over a 55+ year period I have had sudden flats on the front and on the back some of them on fast descents.  Since the rear wheel carries more weight, far more flats were on the back than on the front, probably by a factor of 3 or 4 to 1.  None of them resulted in crashing, not that I haven't crashed quite a few times especially in my road racing and mountain bike racing days.  The crashes were never the result of a flat though, and the flats were generally not at all spectacular.

Besides, if I thought a tire was worn to where it was unacceptable risk on the front why would I run it on the rear wheel, especially since flats are far more common on the rear.  If I trust a tire, then I'll happily run it on either wheel.  If I don't trust it I won't run it at all.