Tubeless tires...
 

Greetings,

I'm very new to tubeless tires, as in last week new. I've ridden tubulars for over forty years.

I bought a bike last week that came fitted with Campy BORA WTO 45 two way fit, and the previous owner had Continental 5000TL's installed. Man, I love the way they roll.

I noticed however, that the pressure in them drops by quite a bit over a couple of days. Is that indicative of an improper seal, or is that normal?

Presumably, rotating each tire in the bath tub would real any leaks.

Advice is appreciated.

Regards, JP

Ya goop them? Put some sealant in them?

Do what Old Spud says for sure but this said, you will lose some pressure over time in my experience.


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I haven't done anything to them. I was told by the seller that the wheels/tires had less than 500km's on them, and based on the appearance, I didn't doubt the guy.

I took one of the wheels to a high end bike shop that's a Colnago and Campy dealer and the owner of the shop looked at the wheel and confirmed that they had barely been used. There didn't appear to be any need to do anything to them. At that point, I hadn't ridden the bike aside from the test spin in a parking lot where I met the seller.

It was only a few days later, after the weather had cleared up and I was able to take it for a spin two days in a row, and on the second day, as I was getting ready for the ride, I checked the pressure and it had dropped from 80psi to around 60psi, assuming that the gauge on my Topeak pump is accurate.

When I met the seller, he told me that he ran the tires at 80 psi. I had never heard of a racing tire being run so low, and he struck me as being quite an inexperienced rider, and he also came across as totally inexperienced with bike maintenance. He told me he didn't work on his bikes at all.

Having heard that, when I got the bike home, I immediately grabbed my pump and pumped the tires up to 105psi, as the rating on the 5000 TL's is 109psi. The next day, I called the same store that I took the wheel to and spoke to a staff about TL tires, and I mentioned to him what I had put the pressure at. He said it was way too high, and I should back it off to 80psi, which I did. It was the next day that I noticed that the psi had dropped to around 60psi.

Thanks, will do. I have found Continental Sprinters to be the most reliable tire I have ever ridden with respect to maintaining pressure. I don't usually need to top them up for over a week.

As I mentioned, I am totally new to TL tires and their overall set up and maintenance. However, I have watched a few vids. I have also since purchased the "goop" and a Lezyne TL patch kit. Man, they roll!

Unfortunately with tubular tires, there seems to be an inverse relationship between ride quality and the need to reinflate, sometimes daily. Butyl inner tube vs latex inner tube.

IIRC, the pro teams would even calculate the anticipated air pressure loss in cobbled races like Paris-Roubaix…

Guess it depends on your priorities.

Indeed. There's also a price point that I'm not willing to exceed. I've always found the Sprinter to be reasonably priced, rolls well, and is durable enough. If I manage to get through a season without a flat, I can usually get two season out of the same tire, barring any skidding. My racing days are long over.

The 5000TL is also a reasonably priced tire, and good enough for my needs. Those rims deserve something decent on them, and I'm guessing that the store that built up the bike chose those tires for the original owner. I looked at the reviews, and it gets a pretty much 5 star review everywhere.

Would you say the front and rear lost about an equal amount of pressure in the same time span?

Seeing as you bought them already set-up, in your situation I would probably add a few ounces of additional sealant to both tires and ride on. Just get in the habit of checking the pressure before every ride. In reality, I just do the pinch test, and I'm not a stickler for strict tire pressure, I pump them up high and let them drift down until I think they are too low.

The continental tires are nice, and test well from a rolling resistance standpoint. I prefer the Vittoria offerings myself though from a ride quality standpoint. Shopping smartly, pricepoint is about the same for the vittorias vs the contis.

Your first question is a good one, and unfortunately I don't have the answer! However, I'm going for a ride today, so I'll check the pressure before I go.

Right now I only have a cheap pressure gauge that I keep in my car, that I haven't tried on any of my bike tires (ever) and the pump mounted pressure gauge on my Topeak. I always assumed that the Topeak gauge was accurate. It has a relief valve on it that allows the user to back off the pressure, which is what I used when I back the pressure off from 105ps to 80psi. I think what I'll do later is put some water in the tub and see if there's any bubbles coming out from the rim or valve.

My tubeless setups are lower pressure than yours but I don’t see more than one or two psi drop in a day or two. I wonder if your tires have no sealant. Check recommendations for your size tires, I’m guessing that two ounces of sealant would be enough, that’s what I run in my 650x38 road tires.

I didn't see a rim strip mentioned at the Campy website, but if it's required, that can be a leak source. Sealant must be used and if you don't know what kind is in them, the tires need to be removed and the sealant cleaned out. I prefer orange seal endurance.

Try the pressure calculator at zipp.com. That’s what I use. At my weight with 28mm tires it recommended 62 front and 64 rear.

Wider tires are often used with tubeless. You get a great ride and low rolling resistance.

I chose fulcrum racing 3 wheels that require no rim strip.

https://www.campagnolo.com/US/en/Wheels/bora_wto_45

The rims don't require rim tape as they are not drilled. The spoke nipples are inserted via the valve stem port, and guided into place with a magnet. Wow, that sounds like fun!!

It's actually not that big of a deal.

https://www.youtube.com/watch?v=PoVOspzNoW8

So that's how thread the nipples without access holes. I always wondered how that happened.

Cool.