I recently updated the wheels on my Diverge to Fulcrum Rapid Red DBs. I've set them up tubeless - they came taped and with valves - and put WTB Raddlers 700x40 on. They won't hold pressure. The tyres are on correctly as far as I can tell by viewing the 'bead line', and they'd popped when dry inflating, before putting sealant in. Set up at 40psi (tyre markings recommends 30-60).
I noticed on the first ride that the tyres seemed to be losing pressure and when I got home sealant was evident on the rims in various places. The pressure had dropped to about 20 in each tyre.
Pumped them up to 55psi and noticed air leaking from one side, however, after I'd spun the wheel a couple of times that stopped. Decided to check again today and from 55psi they'd dropped to 30psi over 3 days of no use.
Pumped back up to 55psi just now, and used soapy water to see if there was any leaks evident. There was nothing obvious, yet pressure has dropped by 10psi in 15 minutes. Given there are no 'obvious' leaks I'm a bit stumped as to what to try, other than stripping them down, re-taping etc. which I'd love to avoid. Any advice gratefully received.
I would always strip and re-tape in this situation
I would just add some more sealant in and make sure it's well distributed around the wheel. Some news tyres just take more time to settle down than others. If you've got a suitable syringe then you can take the valve core out and measure how much free sealant is in the tyre. Oftentimes you will find that the most of the sealant had gone after the first fill.
Aye I had this with some road tyres. Losing 30psi overnight. I put the wheel/tyre in some water to identify the leaks and kept adding more sealant/shoogling as necessary. They're Al now and hold pressure as well as an inner tube.
Quite possibly leaking air from the spokes, which means it's getting under the rim tape and could need re-taping. Dip wheel in bath to confirm.
I just had this on some Prime/GP5k’s.
I added a layer of MucOff tape I had laying around, including taping over the valve hole, pierced a new hole, topped up with sealant and it stays up now.
Cheers so far gang! I will 'employ' the bath tomorrow as a test pool. If nothing obvious I'll strip them, clean them, and re-tape etc. Cheers
When my tubless leak as much as this I find it's almost always the valve. It's always worth just tightening the stem down a couple more turns
A fresh install generally takes a few rides and a sealant top-up to consistently hold air (IME).
The latex has to get into all the potential leak paths and porous bits of the tyre walls splash a bit more in there, shake it about and go for a few more rides before striping and retaping.
I had some trouble getting some tyres to seal on UST rims, then saw a video instructing you to leave the wheel on its side for 5-10 min per side once inflated. Use a bucket to ensure the wheel is flat, by resting the wheel on its spokes on the rim of the bucket.
Worked a treat for me, your leakage may be different as I was 7sing non-tubeless tyres.
Well, the 'bath' test proved absolutely nothing at all. No obvious leaks indicated by a little stream of bubbles. I did try deflating before inflating again and there was a reasonable amount of sealant appearing at the time edge/bead - beads did not come away from rims. So, next step is to add a smidge more sealant, reinflating using the bucket method mentioned above, and a few more rides, before I go through the faff of removing everything, cleaning, and re-taping etc.
I've been converting my gravel wheels to tubeless this week. Took the bike out on Friday night and they lost a fair bit of air probably due to some fairly rooty sections. Took the bike out today for an 80 km ride on easier terrain and tyres were fine. I'll probably add a little more sealant just to replace the leakage during the process but today seems to have done the trick. Tyres are WTB Nanos.
Just a little update, and thanks for everyone's responses/advice. I can report that a month down the line my tubeless set-up seems to be working well. In the end, I topped up the sealant a bit and swapped one of the presta valve stems (I think I may have over-tightened the original one); did a number of short rides and 'bumpy' rides, and the wheel/tyre combo is playing nicely. They do still lose a smidge of pressure but only in the same way as my mtb ones for too. 😁
Yep, the best thing for "no obvious leaks and not total pressure loss" issues generally is just ride the things enabling the sealant to fully distribute itself.
The worse thing to do is leave the wheel static and fret about it.
See also leaving the wheel static with thorn hole at the top and all the sealant at the bottom. That scenario occurs more than you'd expect when taking to customers in the shop who say "tubeless is useless" 🤦
That scenario occurs more than you’d expect
Yup. My first ever experience was commuting to work. Pulled the thorn (size of a full grown tree honest) out, thought "I best spin the wheel to move the sealant..." - cue me bring splattered in sealant on each rotation 🤣 eventually worked out how to use the rubber things in the puncture kit 🤦🏻♂️ cue arriving at work, flustered, sticky with sealant and half an hour late 😳
Thanks folks, useful background. Just fitting some fulcrum wind 40 dbs, and front was holding pressure, even without sealant. Rear was dropping to nothing overnight. No POP when the bead seats like on my mtb tyres.
Got to the point I could actually ride my winter project with the new wheels, and waited with the sealant until I was ready to go. After 90 minutes on road the rear seems to be holding pressure.....fingers crossed that's sorted
