Why won't my tyres seat?

[fair weather cyclist]

Problem with tubeless conversion here.

I'm looking for possible explanations and solutions before I bring the wheels to my lbs.

I am trying to convert a gravel wheelset to tubeless. The wheels are tubeless compatible, meaning the rims have hooks but you have to put tubeless tape.

Here's what I did, chronologically:
- removed the yellow tape
- cleaned the rims. I used a microfibre cloth and wee spray of wd-40, cleaned it nice and then dried it off completely with paper towel.
- installed muc-off tubeless rim tape (to be on the safe side I did 2 rounds of tape for each wheel)
- installed the tubeless valves (also muc-off)
- put the tires on
- sprayed a bit of soapy water to help with the seating

The tyres don't seat. I tried with a track pump, nothing. Then went ahead and bought a tubeless air tank, still nothing.

A lot of air seems to be coming out of the tubeless valve, then I had this thought: is it because I have asymmetric rims? The wee rubber ring that goes around the valve does not sit around the valve hole.

Can this be it? My thought is it shouldn't matter because there should still be the tape preventing air going out.

Can it be a combination of a dodgy taping job plus the asymmetric rims? Another suspect is the use of wd-40. Maybe not the best thing to use and it's making the tape not stick nicely? I don't know...

It's my first tubeless conversion so I'd be surprised if I didn't f**k up something at some point.

I can take photos if you wanna see it.

 

[bikingdad90]

Are you using tubeless tyres too? I believe that tubeless ready rims mount the tyre in different ways depending on which set up you use?

 

[fair weather cyclist]

Yes I have tubeless tyres

 

[HarryTheDog]

Do you mean the rims dont "pop"onto the rims when you use the air tank?, I usually put about 100Psi+ into the tank before releasing the air into the tyre ( valve core removed so it really rushes in) I then hear the tyres "popping" onto the rims . Have you got the sealant in at this point? I find it always starts to leak somewhere usually the valve. Then I bounce the wheel and spin it, the sealant then usually does its job.
Maybe you dont put enough air into the tank before releasing it into the tyre? I am using 33mm to 40mm tyres but pressurise the tank to a good 100 PSI +. If you have no sealant in the tyre it is usuall to leak air.

 

[Ian H]

Depending on the cross-section shape of the rim, the O-ring kind of valves seal may not be right. Both mine use a wedge-shaped rubber seal.
The tape should go over the valve hole. Pierce a hole through the middle but don't try to clear the tape from around the hole.
Do your rims have flat seating for the tyre beads?
I use up to 160psi in the air-tank to pop the tyres on.

 

[si_c]

As @Ian H you might need a different valve core - a lot of the ones which come with kits have a core with a round wedge and o-rings on the top which may not be sealing properly. If you have one of those you might be best getting a set of valves with a wedge that sits in the rim well and generally get a better seal. Something like these however lots of manufacturers make similar - Giant do a set of similar. I'm using the Bontrager ones which came with my wheels and work really well - again they have a wedge which sits in the rim well, and I think you can get them online, I know I've seen them in my LBS who stock Trek.

 

[fair weather cyclist]

Do you mean the rims dont "pop"onto the rims when you use the air tank?, I usually put about 100Psi+ into the tank before releasing the air into the tyre ( valve core removed so it really rushes in) I then hear the tyres "popping" onto the rims . Have you got the sealant in at this point?

So, Yes, I mean the wheels don't pop onto the rims. I loaded the tank with 120psi but nothing, the wheels don't move, they stays in the centre of the rim.

No, I don't have sealant at this point. With the tyres not seated, the sealant would go everywhere. The only other time I dealt with tubeless I first seated the tyre, then deflated it and and at that point I added the sealant and spinned the wheel. BUT it was on a rim that was tubeless ready (with that plastic cover rather than tape) and the rim was not asymmetric.

I am using 33mm to 40mm tyres but pressurise the tank to a good 100 PSI +. If you have no sealant in the tyre it is usuall to leak air.

I'm trying to seat a 40mm tyre. With the tank loaded to 120psi, the tyre beads don't move at all and stay in the centre of the rim.

 

[fair weather cyclist]

Depending on the cross-section shape of the rim, the O-ring kind of valves seal may not be right. Both mine use a wedge-shaped rubber seal.

Are you talking about this type of valve?

https://www.tritoncycles.co.uk/comp...RHMbMmJcr58l_PLv6K7zIe-MypA6HPJRoChEMQAvD_BwE

 

[Dogtrousers]

( valve core removed so it really rushes in)

This is my only thought. Have you taken the valve core out?

I've had ones that were very stubborn about not seating, but got there in the end.

 

[fair weather cyclist]

This is my only thought. Have you taken the valve core out?

Yes, tried it but the tank head doesn't stay in place. Can't lock it to the valve so even if I keep it in place by hand as best as I can, it doesn't work.

 

[fair weather cyclist]

I'm trying one more thing. Will report back in 5 minutes

 

[fair weather cyclist]

Ok, nothing still

So, I tried to change the wee round insert with the one that should sit better on the rim.

I then repeated the same process and nothing, still the tyre won't seat, the beads won't move from the centre of the rim and a ton of air comes out of here where the valve doesn't fit the asymmetric rim.

 

[JhnBssll]

I dont like the sound of wd40 on the rim - I always clean the rims with alcohol before applying the tubeless tape under tension to get as good a seal as possible but wd-40 would potentially have the opposite effect. Any contamination on the rim surface could see the tape lifting which would certainly cause the problems you're reporting. Have you had the tyre off again and checked the tape? It's critical to get this bit right before you blast too much air through it, aluminium rims should be ok but I've heard of carbon rims delaminating under these conditions.

 

[fair weather cyclist]

I dont like the sound of wd40 on the rim - I always clean the rims with alcohol before applying the tubeless tape under tension to get as good a seal as possible but wd-40 would potentially have the opposite effect.

I'm not convinced of wd-40 either. Looking back at it it may have been a bad choice.

This is why I'm removing everything and starting from scratch. New tape, new valves (I bought a pair of those dt swiss valves for asymmetrical rims).

Live and learn I guess.

 

[HarryTheDog]

Yes, tried it but the tank head doesn't stay in place. Can't lock it to the valve so even if I keep it in place by hand as best as I can, it doesn't work.

Err dont understand this, a pump or air tank does not grip on the valve core but on the valve stem itself . My tank which is a air shot

https://www.merlincycles.com/airsho...ng&utm_campaign=phg-GB&ucpo=145269&source=PHG

Screws onto the valve stem for a really proper fit. I think you really need to take the valve core out and determine why your tank isnt locking onto the valve stem. Is it missing something?
Also you can try pushing at least one side of the tyre onto a rim shoulder from the other side of the tyre.