Road tubeless sealing problem
Discussion
I took the plunge a week ago and fitted Pirelli Cinturato Velos to my hooked bead Zipp 303s (2017-18 vintage) – tyres have good reviews as a winter tyre. Fitting didn’t go that well:
Initially ran-in the tyres for 100 ml with tubes as recommended to stretch the beads, flatten out any kinks from when they were packed as folding tyres etc.
Then thoroughly cleaned the rims and beads with acetone, after removing old rim tape. Rims were in good nic inside. Applied Hunt tubeless rim tape (one layer on one wheel, two on the other) and fitted tubeless valves.
Then mounted the Pirellis tubeless with soapy water around the beads. Barely needed levers to get them on. Inflated a booster chamber to 160 psi with track pump, opened valve and ……not much action. None of the supposed pops and bangs as the tyres seat. One achieved marginal hardness for a minute, other simply hissed air. Repeated several times with no better results.
Decided to risk inflating with 30ml tubeless sealant injected through the valves, using the booster pump again. One sealed first time with just a few sealant bubbles. Other one just hissed, spraying out sealant from the beads. Added another 15ml and tyre appeared to hold pressure on second inflation. Shook the wheels vigorously then spun them for several minutes and finally a one-mile spin round the block.
Have now put 100 mls on them; ride is quite nice and confidence is building, but the main concern is that each morning there’s signs of sealant weeping/seeping around several sections of the rims, sometimes ‘wetting’ a section of the tyre. Pressures are dropping around 5 psi a day, from 65-70 psi, which may be a bit above normal for new tubeless fitments. However, I don’t believe the visible seepage is normal (especially from both tyres) and I wonder if:-
Pirellis at 24mm section are just too narrow for the rims. Maybe next size up (26mm) would seal better? Zipps measure 18mm across the inner rim and originally ran with 23mm clinchers. Pirelli say not to run the 24mm on rims wider than 19C, so I should be OK.
Hunt rim tape width is 22mm, like the old clincher rim tape. Quite tricky to apply symmetrically, maybe I let it creep up the rim wall on one side in places (black on black means it’s hard to spot deviations). Could this have interfered with the bead seating if it crept too near the hook of the rim? If so, I could try again with say 19 or 20mm rim tape.
I’m using Effetto Cafelatex sealant, which appears extremely runny but is said to seal punctures well. Maybe the ever-popular Stans is more viscous and would seal the beads better?
Sorry for the length of this saga, but my main question is should I try again from first steps, maybe doing something differently, or just put up with the annoying minor seepage? Or is the tyre/rim combination incompatible? Fwiw I’m blue in the face from watching umpteen tubeless fitting videos – ParkTools, GCN, that dour Jim lad, that shouty Juliette girl. They cover similar ground though some omit the ‘blowing onto rim without sealant’ step. One suggests adding more layers of rim tape if sealing is poor, which sounds a bodge. But mainly they illustrate clunky gravel tyres which I imagine are tougher to fit yet seat more securely when eventually blown onto the rim.
Thanks - if anyone is still reading at this point!
Initially ran-in the tyres for 100 ml with tubes as recommended to stretch the beads, flatten out any kinks from when they were packed as folding tyres etc.
Then thoroughly cleaned the rims and beads with acetone, after removing old rim tape. Rims were in good nic inside. Applied Hunt tubeless rim tape (one layer on one wheel, two on the other) and fitted tubeless valves.
Then mounted the Pirellis tubeless with soapy water around the beads. Barely needed levers to get them on. Inflated a booster chamber to 160 psi with track pump, opened valve and ……not much action. None of the supposed pops and bangs as the tyres seat. One achieved marginal hardness for a minute, other simply hissed air. Repeated several times with no better results.
Decided to risk inflating with 30ml tubeless sealant injected through the valves, using the booster pump again. One sealed first time with just a few sealant bubbles. Other one just hissed, spraying out sealant from the beads. Added another 15ml and tyre appeared to hold pressure on second inflation. Shook the wheels vigorously then spun them for several minutes and finally a one-mile spin round the block.
Have now put 100 mls on them; ride is quite nice and confidence is building, but the main concern is that each morning there’s signs of sealant weeping/seeping around several sections of the rims, sometimes ‘wetting’ a section of the tyre. Pressures are dropping around 5 psi a day, from 65-70 psi, which may be a bit above normal for new tubeless fitments. However, I don’t believe the visible seepage is normal (especially from both tyres) and I wonder if:-
Pirellis at 24mm section are just too narrow for the rims. Maybe next size up (26mm) would seal better? Zipps measure 18mm across the inner rim and originally ran with 23mm clinchers. Pirelli say not to run the 24mm on rims wider than 19C, so I should be OK.
Hunt rim tape width is 22mm, like the old clincher rim tape. Quite tricky to apply symmetrically, maybe I let it creep up the rim wall on one side in places (black on black means it’s hard to spot deviations). Could this have interfered with the bead seating if it crept too near the hook of the rim? If so, I could try again with say 19 or 20mm rim tape.
I’m using Effetto Cafelatex sealant, which appears extremely runny but is said to seal punctures well. Maybe the ever-popular Stans is more viscous and would seal the beads better?
Sorry for the length of this saga, but my main question is should I try again from first steps, maybe doing something differently, or just put up with the annoying minor seepage? Or is the tyre/rim combination incompatible? Fwiw I’m blue in the face from watching umpteen tubeless fitting videos – ParkTools, GCN, that dour Jim lad, that shouty Juliette girl. They cover similar ground though some omit the ‘blowing onto rim without sealant’ step. One suggests adding more layers of rim tape if sealing is poor, which sounds a bodge. But mainly they illustrate clunky gravel tyres which I imagine are tougher to fit yet seat more securely when eventually blown onto the rim.
Thanks - if anyone is still reading at this point!
Have you dunked them in some water to see exactly where air is leaking from? It may be the valve (or around the valve) rather than the tyre/rim interface.
Edited to add as I've just read your post again! Could be due to you using soapy water and maybe that's not helping the bead seal?
I've run tubeless on my road bike for 18mths or so now and I don't think I've ever had seepage around the rim (currently have a leaky valve though hence my initial comment!)
Maybe try letting all the air out and check that the tyre stays seated all the way round when deflated - you should have to pop it into the middle of the rim rather than it coming away by itself
Edited to add as I've just read your post again! Could be due to you using soapy water and maybe that's not helping the bead seal?
I've run tubeless on my road bike for 18mths or so now and I don't think I've ever had seepage around the rim (currently have a leaky valve though hence my initial comment!)
Maybe try letting all the air out and check that the tyre stays seated all the way round when deflated - you should have to pop it into the middle of the rim rather than it coming away by itself
Edited by addey on Saturday 4th December 19:22
Did you take the valve core out when you inflated them?
Mine initially went on with just a track pump there was no pops or bangs even when inflated to the max pressure, just the springiness of the tyre from being packaged flat and rolled up appeared to be enough to seat it. Maybe a tiny bit of sealant leakage from one spot, I can't remember, certainly nothing after the first day.
One of them deflated over winter and unseated itself. It wouldn't seat with a track pump anymore, air leaked like a sieve from all around the wheel. So I got an airshot, with the valve core still in not much difference. With the valve core out, it really snapped into place when I opened the valve.
I don't think they were not seated properly the first time, but how it snapped into place the second time definitely gave more confidence.
Mine initially went on with just a track pump there was no pops or bangs even when inflated to the max pressure, just the springiness of the tyre from being packaged flat and rolled up appeared to be enough to seat it. Maybe a tiny bit of sealant leakage from one spot, I can't remember, certainly nothing after the first day.
One of them deflated over winter and unseated itself. It wouldn't seat with a track pump anymore, air leaked like a sieve from all around the wheel. So I got an airshot, with the valve core still in not much difference. With the valve core out, it really snapped into place when I opened the valve.
I don't think they were not seated properly the first time, but how it snapped into place the second time definitely gave more confidence.
Thanks for all the helpful ideas.
Yes, for the non-sealant inflation attempts I think I left the valves in as I assumed tyres would deflate pretty rapidly without. I gather the name of the game is to get as much air in as fast as poss, so I can see that valveless might assist.
I've had one accidental rapid deflation - one valve was gummed up with sealant so cautiously loosened it until explosive deflation occurred. Good news is that the beads remained on the rims with only a couple of sealant bubbles when I reflated with just the track pump.
Confidence is growing gradually after 130 miles now - for my first ride I carried a back pack with trainers in case a long walk was called for! Ride quality is nice also. Still have worries of a rapid deflation on a 40 mph descent, so have decided to try a fresh installation - clean everything thoroughly, use 20mm rim tape instead of 22mm and an Airshot booster tank which screws onto the valve body, unlike the Giant booster I borrowed which has the standard presta lever attachment and possibly lost a bit of pressure at that interface.
Re long-term storage - I imagine it helps to add air every week or so when a bike isn't being used and to store the bike without weight on the wheels.
Yes, for the non-sealant inflation attempts I think I left the valves in as I assumed tyres would deflate pretty rapidly without. I gather the name of the game is to get as much air in as fast as poss, so I can see that valveless might assist.
I've had one accidental rapid deflation - one valve was gummed up with sealant so cautiously loosened it until explosive deflation occurred. Good news is that the beads remained on the rims with only a couple of sealant bubbles when I reflated with just the track pump.
Confidence is growing gradually after 130 miles now - for my first ride I carried a back pack with trainers in case a long walk was called for! Ride quality is nice also. Still have worries of a rapid deflation on a 40 mph descent, so have decided to try a fresh installation - clean everything thoroughly, use 20mm rim tape instead of 22mm and an Airshot booster tank which screws onto the valve body, unlike the Giant booster I borrowed which has the standard presta lever attachment and possibly lost a bit of pressure at that interface.
Re long-term storage - I imagine it helps to add air every week or so when a bike isn't being used and to store the bike without weight on the wheels.
Stain’s Race Fluid was on another level to all the other sealants about 3 years ago when I was really into cycling.
I’m not sure if the other sealant brands have caught up more recently?
Downsides are you can’t mix it with other brands and you can’t add it via the valve (well you can, but it’s not recommended).
I’m not sure if the other sealant brands have caught up more recently?
Downsides are you can’t mix it with other brands and you can’t add it via the valve (well you can, but it’s not recommended).
Thanks for the further comments. I went for the CaffeLatex as 2nd recommendation here https://www.bikeradar.com/features/which-tubeless-... A friend put me off Stan's Race sealant as said it has a reputation for short life before drying out and being hard to remove once everything's gummed up. Maybe I'll try Orange next time.
Also found this review that says '' I've been fitting a lot of tubeless tyre setups and I can safely say that the Pirellis are easily the biggest faff so far. No matter what wheels I tried to fit them to, they would not seat just with the use of a standard track pump, which I find a pain.'' https://road.cc/content/review/255700-pirelli-cint...
Anyway, the good news is that this was the first morning that neither rim was showing signs of fresh seepage. So, after 8 days, maybe they've finally settled in - fingers crossed!
Also found this review that says '' I've been fitting a lot of tubeless tyre setups and I can safely say that the Pirellis are easily the biggest faff so far. No matter what wheels I tried to fit them to, they would not seat just with the use of a standard track pump, which I find a pain.'' https://road.cc/content/review/255700-pirelli-cint...
Anyway, the good news is that this was the first morning that neither rim was showing signs of fresh seepage. So, after 8 days, maybe they've finally settled in - fingers crossed!
TheTardis said:
Try OrangeSeal, this has particles in it to aid sealing.
This is brilliant stuff, get the endurance version though. Cafe Latex is garbage imho. It was recommended to me a few years ago and it wouldn't even seal a tiny thorn puncture, just covered my frame in sealant.As for tyres. If you are looking for something to get through the winter months I'd strongly recommend Bontrager R3 Hard-Case lite https://www.trekbikes.com/gb/en_GB/equipment/cycli...
They seal perfectly and didn't lose a single PSI for the 3 days I left them in the garage before putting sealant into them.
I haven't heard of the 100mls with tubes first thing, perhaps you've stretched the tyre a little too much? I've not done this on any of the ones I've fitted, just straight on from the box, as there is no tube its pretty easy to get them on the rim as you can use unlimited brute force without worrying if you'll pinch the tube.
moonigan said:
TheTardis said:
Try OrangeSeal, this has particles in it to aid sealing.
This is brilliant stuff, get the endurance version though. Cafe Latex is garbage imho. It was recommended to me a few years ago and it wouldn't even seal a tiny thorn puncture, just covered my frame in sealant.As for tyres. If you are looking for something to get through the winter months I'd strongly recommend Bontrager R3 Hard-Case lite https://www.trekbikes.com/gb/en_GB/equipment/cycli...
They seal perfectly and didn't lose a single PSI for the 3 days I left them in the garage before putting sealant into them.
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