I’m new to tubeless, having taken the plunge with a new wheel-set for my road bike.
My choice was influenced by the very positive feedback from some riding buddies.
Wheels are 23mm internal width Bontragers, hooked rims in carbon.
Trusted LBS set them up with 28mm wide Continental GPS5000 ‘s’ tyres. I supplied the tyres and the Stans Race sealant they used. I noticed they didn’t appear to have used the tape that came with the wheels but it seemed did use the circular plastic strip that came with the wheel instead. I didn’t ask (I know I should have) why / if they maybe used their own tape.
I was intending to do it myself as I enjoy doing my own bike maintenance/ work and have the right tools but I don’t have access to a compressor and after reading up on the GP5000 related challenges people have had I decided to go the lazy route and get my LBS to do it.
All looks fine and no obvious signs of any leaks yet.
My question is around deflation over time. I haven’t had a ride on them yet as I want to wait for better weather before christening them on the road.
I inflated to 72psi rear and 68psi front, based on the guidance from a couple of on-line pressure calculators. (I’m 94kg at the moment).
Within 48 hours the pressures had dropped noticeably in both wheels. A further 24 hours saw a smaller but still noticeable drop. Track pump this morning showed 35psi in one and 30psi in the other (I forget which was which).
Is this normal for newly set up tubeless wheels? Will it improve after a bit of use?
Yes - usually it takes a little while for the tyres to completely seal on the rim and a few rides usually sorts it. Generally tubeless do deflate faster over time than tubed wheels as well, but if you check them frequently its unlikely to be an issue
It’s hard to say for sure, but my experience is this is not surprising. You can expect PSI to go down overnight, maybe not 30 PSI, but the wheels just may need to spin for a ride or so to fill in all the nooks and crannies. If it doesn’t get better after that, you might try adding a bit more sealant before taking it back to them. However, even after that, you will need to pump them up for every ride as they will lose air over time.
Thin rim tape helps with tire mounting. For what that’s worth. Sounds like you got a great setup. Just get some miles in and that should help with deflation issues. Oh and unless things have changed that tire in that size is harder to come by. You might want to get a spare on hand sooner than later.
Usually. Often the sealant needs to plug tiny holes which it’ll do over time. The gyroscopic forces of riding can force it to extremities of the wheel and disperse it better. Sometimes when I set up a wheel, the tyre will refuse to seat first time a couple of spins will encourage the sealant dispersion and leaving a bit before I try again. Bingo, it’ll seat first go after a break. But overnight it’ll go down and I think I then go out for a ride though and its solid and never goes down noticeably again
If they were the stock Bontrager alloy rims, the rim strip is needed to convert the wheels from ‘tubeless compatible’ to ‘tubeless ready’. If someone didn’t read the manual* and tried to use just normal tubeless tape, they’d find the tyres a ridiculously easy fit and impossible to seat without a compressor, with no bead retention once even semi deflated.
Agree with everyone else here. One thing to look for is whether air is leaking from the stem. Make sure the stem is tight to the rim and also that the valve core is tight inside. Finally, some stems don’t have a good design where they connect to the rim (the rubber seal on the left side of this pic). If you find you can’t stop leaking there, this design works great. I’m sure lots make a similar one, but the Stan’s ones are pictured.
Good luck with them, a good choice! Here’s one more (unsolicited) tubeless startup tip!
At the same time as you top up pressure, as part of your routine just loosen and tighten the lock nut (the black nut on the stem pictured above) on the tubeless valve stem a tiny amount to ensure it hasn’t seized. It only needs to be finger tight to keep the seal. If the valve gets seized and you get a major flat, you won’t even get as far as seeing if you can get the tyre off at the roadside to put a tube in, unless you have pliers in your kit.
My tubeless error the first time I set a wheel up confirms that (kind of ). When I first set up my Tubeless disc wheels I extended the tubeless stem with a valve extender which was smooth (no lock nut). Amazingly and not realising my error after several seasons of TTs it never failed. It was only when I couldn’t seat a new tyre that I realised it was needed but didn’t need to be tight
What I do with a newly mounted tubeless tyres is after inflating them give them a spin and lay them on their side for 30 minutes. Give them another spin and lay them on the opposite side for another 30 minutes. Pump them back up to pressure, re-mount on the bike and go for a ride. After this you might even see a little bit of sealant leaking at the bead/rim interface.
I then go out for a ride though and its solid 
and never goes down noticeably again 
