Big Red S
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nivag aka sand king
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Good afternoon. I have a stupid question for Friday: what should the pressure be of my rear tyre?
The manual says 29psi for up to 199lbs, and 41psi for 199lbs and above. Between me, top box, and junk is somewhere over 200lbs, so have been pumping it to around 32psi. Which had seemed fine.
The reason I ask is the tyre is not that old but the groove around the centre has worn down quite a lot, suggesting it is over inflated. Yet yesterday I only put a light bag of shopping in the box, but when I got on the bike I felt it sink and the tyre looked to be sagging, suggesting it was under inflated. Checking when cold it was 31psi, though.
Not a typo by me, that is what it says in the manual and the sticker on the chain guard. So I am basically doing what nivag says, just adding a few extra psi because it is such a big jump that it makes no sense to follow it literally.
I had Michelin City Pros put on at the start of March (the bike has a weird wheel size and it is the only brand with a tubeless tyre to fit, and apparently not for the front wheel any more) and done around 7k miles on them. I should measure the tread depth and compare with the front tyre as that looks untouched. Still enough to be safe to ride but I reckon it has lost half to three-quarters.
I would have been happy just to go back to 29 to see how that goes were it not for how worrying it was seeing the tyre sag. Although I usually carry my chain, which weighs around 10lbs, in a tank bag, but when doing a hospital and shopping trip I just put it in the box. So maybe I should just increase the pressure for those trips when the weight is less balanced?