I use worn-out high rollers II’s on my rear wheel as a semi-slick option. They are super fast, and also an economical / green solution, as opposed to buying a dedicated fast-roller (which would then wear out and become useless). Anyone else doing this? Is this a good idea, or a great idea?
Tires are expensive and I always try to use them for as long as possible. However, tire wear is more than just the tread getting shallower. The casing breaks down and the sealant weaps through the sidewall and the tire flats more easily from both punctures and tears. Knobs get torn off. The bead stretches and sealant weeps and the tire is more likely to burp or come off the rim. The rubber ages and cracks. With every mile you ride and day that passes the tire gets weaker and weaker, so don’t push this to far and end up injured or stranded. Inspect that tire before every ride. If you have very smooth trails you might get away with a lot. If your trails have a lot of sharp rocks and roots, you’re playing with fire.
“Is this a good idea, or a great idea?” How about it is a funny idea. I am about using every ounce of a component or whatever to save money. Choosing a used whatever for anything though seems a bit unsafe as pointed out by Bike Nerd. If speed is the important I would probably run higher pressure or pedal harder than use a worn out tire.
I wear out side knobs as fast or faster than center knobs on my proper singletrack bike so no go on that. but sure, I have had the same tires on my vintage rigid bike for over 10 years of occasional use (tires are 10+ yrs, frame is almost 20) and they are only getting faster for what I use it for.
The HR II is a solid tire. I did exactly the same thing, i.e. used as a front tire and then rotated to rear after I decided to swap it for a DHF. I got an extra 300+ miles on that tire putting it on the rear. Sure, if you ride a lot of rocky terrain (i would not be as concerned about roots) a used tire is more susceptible to punctures but any tire can be punctured regardless of age or wear. If the tire looks ok (sidewalls and knobs) and hooks up as expected I’d keep riding it.