wondering what amount of psi loss on a tubeless road tire you typically see overnight or after a few days? 0? 5? 10?
I had a schwalbe pro one tire that was losing a minimum of 15-20psi. Finally determined it had a couple sidewall spots that had tiny leaks. Air would hold long enough for rides but overnight or more that air would leak. I finally had to lay it on it’s side to let the sealant close up the tiny leaks. Hopefully that does it
I don’t even bat an eye for 10 or probably even 20. It’s going to depend on a lot of things and likely will get worse over time as your tire wears the sidewalls become more porous. frequently my tires sit at 40 or 50 psi before i air them up and go about my business. If you dump sealant in to try to prevent this you are probably just making your tires heavier than they need to be.
Not sure if it’s super common with my tires but they’re schwalbe pro one tires and I did fine a few people posting of similar issues.
Yeah, IDK. I ran road tubeless for a while ~10 years ago but went back to tubes as it was more trouble than it was worth since I didn’t ride the road bike much. I’ve been totally tubeless on mtbs and gravel. Years ago tires would weep a lot. It’s the propylene glycol in the sealant coming through porosities. I never equated it with pressure loss as tires that didn’t weep seemed to lose pressure at about the same rate as those that did. Nowadays, tires are much better wrt weeping, though I have one gravel tire that’s doing it while an identical one isn’t. They still lose pressure about the same rate, roughly 10% over 24hrs, so I always check the pressure and air up before going out to ride.
Not enough Sealant. Make sure you ride the bike for a couple of minutes to get the sealant sloshing around if it’s a new job. I can attest Orange seal is good to create a secondary uniform skin on the inside of the tire. Unless you are getting multiple seasons of use, the sealant, once dried, weighs next to nothing. Usually I get 0-2 PSI loss per day.
I’d get that on my tubes wheels/tyres, but since I switched - store fitted giant wheels and tyres, they might lose 5 psi over a week or so.
Yeah. I have tubeless on all my bikes. MTB and gravel for sure lose air more slowly sitting around. The road bike tires were losing it faster. Mostly the rear. The front it might lose 20 psi sitting around for a week. But the rear was losing more like 40-60psi over the week. But I did always fill my tires before rides.
I had 2+ oz in the 700x32 tires it just wasn’t reaching onto the specific tiny leaks. I had dunked the tires in water and could see very tiny stream of bubbles from 2 different sidewall areas. After laying the tires on sides yesterday and then refilling with air, I checked this morning and it had lost <5psi which is more reasonable
It varies based on temperature, elevation, seal quality, sealant amount, and maintained PSI, among other factors. Regardless, make it a habit to check and top off the PSI before each ride.
…what pressure are you using on your tubeless?
Rear 65psi and front 63psi. 700x32 tire. I just use Silca pressure calculator. Granted I have not played around with lowering it but 63-65 feels fine riding. I could play around with lowering it a bit.
Okay maybe I’m misunderstanding, so the rear tyre is going basically completely flat over the week? That doesn’t sound right at all.
Time to go to the bike shop. 
Yes. That WAS the case. But yesterday I went laid the wheel on each side for like 30 minutes so the sealant could hit the sidewalls. Pumped it up. Overnight it was down < 5psi. So maybe it’s fixed. Googling I’ve find a few mentions of my tire, Schwalbe Pro One, having this issue.
FWIW: I figure going for a ride over rough surfaces (mtb) will splash the sealant around on the sidewalls and beads. However, I have a manual method I use to splash the sealant around the inside of the tire getting it on the sidewalls and beads. I hold the wheel/tire vertically in front of me with both hands near the bottom, then vigorously shake the bottom toward and away from me. I rotate the wheel a bit and keep going until I’ve gone all the way around.
When I add sealant I always shake and spin the wheel in all directions.