Venge written off as Roval CL50 & Enve TLR tyre part company at 45kmh

[Nadsta]

Hi wise folks of WW.

I was directed here by a reply to my post on road.cc (https://road.cc/content/forum/tubeless- ... e-comments)

To recap, I hit a small but sharp edged pothole on a slight descent that initially threw me off line a little more than I had anticipated- but well within my ability to correct. This was quickly followed by a bang from the front as the air escaped from the tyre and the subsequent sinking feeling/sound of naked carbon rolling on tarmac...then the inevitable touch down. I jumped up out the road, ticked off another one of my 9 lives, then shook my head at the sight of my front tyre inside out on the rim.

.


A trip to hospital and 8 dressings later, I realised the frame was cracked.

I've seen posts here claiming that Roval rims don't keep the tyre bead in place, you'll see from the photos that the tyre has come off the outside of the rim (rather than fallen into the centre of the rim).

I suspect the initial hit burped the tyre which then a few seconds later emptied all in one go.

Enve say their design is both hooked and hookless compatible and the tyre has done 4.5k km since September without any sign of distress. I topped up the sealant and inspected the tyre a week before the crash. Would drop a few psi a day but no alarm bells. I was just about to fit a new pair (now gathering dust on my desk). I'm 74kg. I'd hit over 80kmh on a descent I know well earlier in the day and it felt the same as ever. So I don't suspect tyre life is an issue.

The bike is still with the shop for an insurance assessment but I will inspect the tyre when I get it back. I like tubeless but obviously cannot ever trust this combination again. I would love to hear your thoughts. FWIW for me a good tubeless wheel replacement would be Enve 4.5 ARs as I like the tyre and I'd assume it's optimised around that set up.

[Nadsta]

I will post any replies from Enve or Specialized.

[Ypuh]

Nasty crash and good to read you're still okay.

Gives to think about the way Zipp and other manufacturers are going with hookless rims. It'll definitely work in most cases, but there are possibilities that won't work. In my mind tubeless is a solution to prevent tyre collapsing in descents. On the other hand, tyres are getting lighter and lighter and might not hold up to sharp ridges or other road debris.

[spartan]

quickstep/bora will use cotton clinchers in this years tour de france. i wonder what type of testing they have done . they must be confident no clincher blowouts descending in the alps.

[ParisCarbon]

Wow.. glad you more or less walked away from that one... thats crazy!

[Elmersen]

Doesn't look good. I guess Vittoria Air-liner would work as some sort of prevention for this to happen with tubeless setups.

[easyv]

Glad to hear you made it out OK, nadsta!

I had a very similar situation... Was running Continental GP5000 TLs on CLX 50s and the sharp edge of a pothole took out the sidewall with a 2 cm gash on the tire on a descent when I was going ~48kmh.

Luckily, was able to slow down enough that by the time I finally lost control of the bike and bailed, it was slow enough that I came through relatively unscathed with some road rash on my lower back and my bike just had some marks on the hoods. Yes, the older Roval CL/CLX 50s are known to not retain tubeless tires very well once they go flat -- something to do with the size of the shelf I think I was told at one point -- and I attribute my wheels holding on to the tires to the fact that the Continentals are known to be a pain in the ass to mount due to their tightness. That tightness I think is what kept the tire from separating from the wheel despite the compromised sidewall.

But like all things road tubeless since there is no clear standard, YMMV....

[aeroisnteverything]

For something like a sidewall cut that is big enough to immediately deflate the tyre, clinchers are certainly not safer than tubeless. The key is for tyre to stay attached to the rim, even when deflated. Tubulars are the best for this.

Very possibly indeed, running Vittoria's Air-liner is indeed a very good idea to prevent some of these failures.

For the OP's incident though, the blow up was bad enough that I am not sure an air-liner would do anything. Something clearly went wrong with the tyre/rim. Glad you're ok though, mate.

[Nadsta]

Thanks for yor replies. When I saw the Vittoria air liner a few weeks back I did wonder how it might cope with a blow out.

Although I don't have the bike until the insurance assessment is complete, I can say that we inspected the tyre at the side of the road and it looked fine, certainly good enough to put a tube in and ride home on. I had an unused but old Spesh turbo tube as back up (the fragile ones), but this blew on inflation with a mini pump...probably for the best as things turned out with the cracked frame. I'll work out if the tube exploding is significant when I get the bike back. But I'd be suprised if the tyre itself has punctured.

I have no idea if running an inner tube (2021 quickstep style) with a tubeless tyre would have made any difference here, and as has been pointed out here and on my road.cc post, it seems like in my case the basic rim/tyre interface is less than optimal. There must be other instances of this happening out there.

Attached are shots of the road surface (not sure why they're rotated here, but that's probably closer to my view at the time). Postion wise, I was riding primary

[3phase]

just happy you are alright mate. Crazy stuff.

[Arph]

That is one out of 9 lives wisely spent

Side note: wear gloves, you were lucky your right hand didn't get hurt more.

[rollinslow]

wow, that's crazy. I would pass on the 4.5AR. Why go hookless after this event? Get 5.6 disc which has hooks. No way hookless IMO.

[Nickldn]

Thanks for yor replies. When I saw the Vittoria air liner a few weeks back I did wonder how it might cope with a blow out.

Although I don't have the bike until the insurance assessment is complete, I can say that we inspected the tyre at the side of the road and it looked fine, certainly good enough to put a tube in and ride home on. I had an unused but old Spesh turbo tube as back up (the fragile ones), but this blew on inflation with a mini pump...probably for the best as things turned out with the cracked frame. I'll work out if the tube exploding is significant when I get the bike back. But I'd be suprised if the tyre itself has punctured.

I have no idea if running an inner tube (2021 quickstep style) with a tubeless tyre would have made any difference here, and as has been pointed out here and on my road.cc post, it seems like in my case the basic rim/tyre interface is less than optimal. There must be other instances of this happening out there.

Attached are shots of the road surface (not sure why they're rotated here, but that's probably closer to my view at the time). Postion wise, I was riding primary

On these photos the potholes in the road don't look particularly deep/sharp/dangerous. Par of the course for UK roads.

I ride through damaged road surfaces like this at 20mph (30khp) fairly often and would not consider them dangerous for the tyre/bike, just uncomfortable. 45kph may be a slightly different story, but still.

In general I see many more dangerous pot holes, which are deeper and with sharp edges.

This points to an issue with the wheel/tyre interface, or another fault, rather than just going too fast down a poorly surfaced road.

[Mr.Gib]

That road is rough but should not have caused a wheel or tire failure. We are guinea pigs for an industry that has us beta testing their shit. Tire should simply never come off a rim. You might still crash with a bad blowout, but this type of failure just ain't right.

Looks like you were on a decent sized tire. What size?, what pressure?

[Nadsta]

That is one out of 9 lives wisely spent

Side note: wear gloves, you were lucky your right hand didn't get hurt more.

I'd just taken them off-ride started near freezing temps but got really warm!