Mavic yksion tubeless tyres

[straas]

I've got these tyres, came with my Mavic kysrium wheels and I've run them as tubeless since I got them.

No issues - until today.

On a fast descent I must have hit a grid or pothole I didn't see and had almost instant deflation. Thankfully stayed upright.

Tried pumping up, but the hole seemed too big to seal.

Had a spare tube for emergencies, but ended up pinching it because the tyre is SO tight to the rim. I run gatorskins on the other bike and thought they were bad, but they go on like a dream compared to this.

Ended up having to get a lift home. Nightmare.

Looking at the damage, it's similar to a pinch flat on a tube. To be honest I thought the sealant would do its work on things this size, but I haven't refreshed it in a while. Does sealant go bad? It was still liquid.

Does this damage look repairable, or is it new tyre time? (£50, ouch!)

 

[Specialeyes]

As well as potentially drying out, I think the particulates in some sealants can clump a bit over time, leaving the liquid a bit too 'watery'. Stick a note in your phone to top up every 4 months or so.

I had a similar sized tear in a WTB Byway tyre, and as I didn't have any plugs on me at the time, fitted an old-fashioned glue-on patch on the inside of the tyre, and it seems to be holding up just fine. I dare say someone will be along to tell me that there's some chemistry-based reason it's a bad idea, but so far, so good!

 

[JhnBssll]

To my knowledge there's no reason why a glue on patch on the inside would cause a problem, and indeed that would be my first port of call if I were going to try to repair that tyre.

For what it's worth, I banished both of the 25mm Yksion's that came with my mavic UST wheels to the spares cupboard (and later the bin) after they let me down multiple times. The rear was first to go, slicing up quite badly on a ride and failing to seal, requiring the use of plugs to get it to hold pressure to complete the ride. It was beyond repair, so I replaced it with a new 28mm Yksion. A few weeks later I got slicing on the front tyre which again needed a plug to get me home, and on later inspection I found the brand new rear tyre was also damaged. I'm now using 28mm GP5000 tubeless on both road bikes and so far have had no issues since swapping over despite riding the same routes in the same conditions. Of course it could have been fluke, but I'd rather stick to what I know in this case

 

[JhnBssll]

Just found the photos from the original failure. I presume it was a piece of flint that caused it, but it whatever it was it went through the brand new tyre like butter

 

[Ajax Bay]

On a fast descent I must have hit a grid or pothole I didn't see and had almost instant deflation. Thankfully stayed upright.

Very well done staying upright. Straight downhill/run out? Do you recall what technique you employed to do so eg use of brakes, moving your CoG? I was not so lucky/skillful in similar circumstances (discussed passim).

 

[straas]

It was a fairly straight downhill - I just feathered the back brake, kept fairly loose on the bars and prepared to hit the deck.

Also - this tubeless system 'clicks' the bead into a recess in the rim, so the tyre remains seated even if flat, which might have helped me stay up?

was pretty happy not to!

Might order some new sealant and try a rubber patch, but I've certainly lost confidence in the tyres now.

 

[straas]

Just found the photos from the original failure. I presume it was a piece of flint that caused it, but it whatever it was it went through the brand new tyre like butter

View attachment 525009

I think sometimes we can just be unlucky - I had similar damage to a nearly brand new gatorskin on my other bike.

 

[straas]

Patched the inside with a standard tube patch - took quite a bit of effort to get the tyre seated.

Got the tyre up to 100psi to see if it would hold at max pressure - the salmon coloured part of the patch was bulging through the tear and after a while it went.

Guessing the tyre is unrepairable?

 

[JhnBssll]

Yeah, sounds like the tyre carcass is too badly damaged. Not worth risking, its scrap I'm afraid

 

[derrick]

As well as potentially drying out, I think the particulates in some sealants can clump a bit over time, leaving the liquid a bit too 'watery'. Stick a note in your phone to top up every 4 months or so.

I had a similar sized tear in a WTB Byway tyre, and as I didn't have any plugs on me at the time, fitted an old-fashioned glue-on patch on the inside of the tyre, and it seems to be holding up just fine. I dare say someone will be along to tell me that there's some chemistry-based reason it's a bad idea, but so far, so good!

Did the same thing a while back, had forgot all about till i read your post.