Another tubeless question

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RussellZero

Wannabe Stravati
I have tubeless on my CX bike that I use for most of my trail and offroad riding. I've been out at times when the sealant has worked and fixed 2 or 3 flint holes without hardly any deflation, but recently I've had a couple of occasions where the hole's been a little bigger - the sealant has managed to seal it but usually too late (the pressure's got so low that I don't want to ride it for fear of damaging the rim or the tyre). I think this should be a rare occurrence (it looked like some of the sealant had gunked up a bit in the tyre and when it sealed a load came out at once - usually I see the white sealant spraying out for a few seconds when a hole is made), but I'm guessing once the tyre's been plugged with the sealant in the tyre during the ride, if it's any kind of size I should do something with it when I get home, else the same hole's going to keep giving me problems... is this where liquid sealant comes in, or should I be using some kind of rubber plugging tool?

As is, I could just go and pump the tyre back up again and set off, I think it'd be ok for a ride or two but likely to re-puncture in the same place I think.

Question 2 - when the tyre deflates like above, but has sealed, I'd like to be able to re-inflate on the ride, top it up etc. However, whenever I've tried with a hand pump that screws onto the valve, it's let enough more air out before I can get onto the valve fully, that the tyre pops of the rim and then it's all bets off, long walk home. I've heard a CO2 cannister would work but will destroy the remaining sealant in the tyre. Is it as simple as getting a press-on bike pump? Or should I go CO2 and just replace the sealant if I have to use it?

Thanks in advance - done lots of googling for the above but most tubeless guides only tell you how to setup, not how to live with it!
 

lane

Veteran
With regard to not being able to reinflate on the ride I would definitely use C02 to inflate on the ride and check if you need to put some sealant in at home presumably after letting the C02 out.
 

Venod

Eh up
Location
Yorkshire
I've tried with a hand pump that screws onto the valve, it's let enough more air out before I can get onto the valve fully, that the tyre pops of the rim
I suppose it depends on your tyre rim combo, I have to push mine away from the rim to get them off but I am using proper tubeless ready tyres and rims, I did run some non tubeless, tubless for a couple of years, these were a slacker fit and may have done what you stated. I have one of these, but don't take it with me, If I was having problems I would.
https://www.sigmasports.com/item/mi...IAkHCo5G54erx8usMfcnBmQxNd2C6CtRoCXOQQAvD_BwE
 
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wonderloaf

Veteran
If I get a hole that I think will cause me future problems then I use a tubeless tyre repair kit to like this one to patch the hole from the inside:
https://www.leisurelakesbikes.com/3...ir-kit.aspx?currency=GBP&chosenAttribute=VT40
I also carry a spare inner tube just in case the sealant can't seal a hole, only had this happen once in about 3,500 miles of tubeless riding. In my case a flint got stuck in the hole so as the wheel rotated and the flint hit the road surface the movement split the sealant and the air escaped. By the time I had realised what was happening I'd lost a lot of air and sealant so had to resort to the tube. I also carry Skab repair patches, just in case the tube gets a puncture!
 

lane

Veteran
Don't necessarily agree that it shouldn't come unseated mine does and I have tubeless rins and tyres. The cycle clinic website explains the differences in tubeless rim design that may cause this to occur. He recommends that if you have a tyre that unseats and the repair does not seal then on the road you may need to resort to an inner tube rather than a tubeless repair to get it reinflated. However my experience that won't always be the case.
 

YellowV2

Veteran
Location
Kent
Sorry, yes you are correct.
I think this is in part is why some have a bad experience with tubeless, not sealing or seating well and then give it up as a bad idea. I also think it is important to carefully select rim/tyre combinations when using tubeless tyres, which shouldn’t really be the case.
I use IRC tyres supplied by the cycle clinic, IMO they are probably the best tyres currently available for tubeless and as good as any tubed tyre I have used. The wear and grip levels of the Formula Pro are excellent .
 

Ming the Merciless

There is no mercy
Location
Inside my skull
If you do use a tube on the road, inspect the tyre very carefully for old thorns and flints which may still be embedded. If you don’t you may just puncture the tube before throwing your bike over a hedge.
 

lane

Veteran
Thanks for the advice @YukonBoy had not thought about that.

I have a full length pump with me on the bike and when tested previously at home was able to re-seat with that and never had an issue with the track pump so was relatively confident that I wouldn't need to use a tube providing the tubeless repair kit I have works. Not had any puncture yet (as far as I am aware) so not been able to test anything on the road as yet.....which is no bad thing.

However........

Over Christmas decided to check and top up sealant. Because I use Stand Race sealant it is not recommended putting through the valve. So I broke the seal and topped up and re-seated the rear tyre easy and quickly. Then onto the front same procedure but could not get the front tyre to re-seat with track pump - which was a surprise because it has been so easy in the past. I had noticed the valve was gummed up a but so removed and cleaned the core; still no luck. Put a different core in altogether still no luck!! Then decided to give the tyre a good spin and had another go pumping quite hard and it re-seated. Now I am not sure what all this means but I don't think it was the valve. I think there was some part of the tyre that for some reason was letting the air out - something not quite fully sealed - and by rotating the tyre and spreading the sealant around the tyre then inflated because the gap was sealed. Any thoughts on this?

Anyway I am now less confident of re-seating the tyre on the event of a full deflation so carry a tube and C02 with me. On the other had I am not sure the tyre did unseat when I deflated I think over time it had got to the point where it was quite firmly stuck on the rim and it was only me breaking the seal which caused the issue.

Some detractors will see this evidence to support their theses that tublesss is an unholy abomination and has no place in road cycling.

I however see it as a bit more of my learning experience with the "new" technology.

Each to his or her own.
 

CXRAndy

Guru
Location
Lincs
Valves do gum up. I tend to remove, clean rubber from valve, and stick a rounded steel rod down the valve to clear the valve stem. ive never had any issues than other described.

Sealing the bead usually requires rolling tyre around to coat the surfaces .

I have used non tubeless ready rims, with no problems for general riding. If you use enough sealant, then the bead to tyre becomes glued in place. It would need a sudden rapid deflation whilst cornering hard to roll the tyre off.

Pretty much the same scenario as a inner tube, except tubeless very rarely deflates rapidly
 

Ming the Merciless

There is no mercy
Location
Inside my skull
I've used a tube a couple of times in five years of tubeless. So you will get the odd one where the bead has come unseated and won't reseal. I was also caught out in November, and found out it wouldn't seal because I hadn't topped up the sealant for some time, and the old sealant had dried. So there was nothing to plug holes! I checked the tyre very carefully as I only had one spare tube, it was cold, and I didn't fancy patching the tube in those conditions.
 
Anyway I am now less confident of re-seating the tyre on the event of a full deflation so carry a tube and C02 with me. On the other had I am not sure the tyre did unseat when I deflated I think over time it had got to the point where it was quite firmly stuck on the rim and it was only me breaking the seal which caused the issue.

This is exactly the same problem that I had. If the tyre doesn't mate back on the rim in exactly the same position, then you'll find that dried on sealant will prevent a good seal. If you have problems, you'll have to thoroughly clean the rim and tyre interface.

It's a huge ball ache when it doesn't work right, and takes a fair bit of elbow grease to put right. In the end I gave up and started riding with tubes again. Next time get a sealant that you can inject in the valve core, and don't wait for the the sealant to dry out, top up every couple of months at a minimum.
 
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lane

Veteran
Just looking at a video by stans giving instruction for their dart tubeless repair kit. They say if inflating with CO2 let the air out when you get home to preserve the sealant. Sounds as though it isn't much of an issue in the short term.
 
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