I like to think I am pretty mechanical and technically savvy… That doesn’t mean I cant or wont royally screw things up from time to time!
I want to say that for the record all bikes I own are tubeless, road, gravel mtb and multiple different wheel sets. I am not too unfamiliar with tubeless things.
I borrowed a pair of Rene Herse Barlow Pass 700 x 38 with Extralight casing. I am using NXT45AGX hookless rims and you can see the dimensions here;
While I was mounting the tire they never made the locking pop that I am use to hearing when mounting tubeless tires, so I took the tires to the max pressure 60psi. They never made the sound, I stopped at that pressure.
I set the tires on the floor next to my work bench and 3-5 mins later when I start to walk away and those suckers straight up blew off the rim.
I half saw it all happen but what I can say was the wheels jumped up off the floor and the tires completely shot off and landed a few inches away from where the rim landed.
Of course fluid all over the freaking place, it was so epic.
That leads me to the biggest question;s i have for anyone on this fourm.
was it as simple as the tire pressure was too much?
is this tire trash or can it still be reused?
would you mount and use them at more reasonable pressures (30-40psi)?
I have been running Pirelli Cinturato H tires in a 700 x 35 for the last two seasons at a 40-45psi range without any issues. When mounting those tires they make a very clear pop/set in sound.
I wonder if the internal width is an issue. This link has a max of 27mm internal, even though the tire-specific link says 29mm is ok. You’re outside of ETRTO specs…that’s not to say they won’t work though. Seems like you’ve had good luck with other tires.
My thoughts…and note I’m not a pro mechanic or anything…
No. If a tire explodes consistently at 60psi there is something horrifically wrong/dangerous…I’d never ride it under any corcumstances. I bet the tire just didnt seat properly…portion of bead stuck in center channel giving enough slack for tire to squirt off of the opposite side.
I’d use it and not worry at all.
Wouldnt worry about the pressure. Just make certain the bead is seated all the way around/equidistant from rim.
It’s probably also worthwhile to ask how tight fitting the tires are. Were they particularly easy to get on the rim? If so…you probably need more rim tape to make a more secure fit.
Added: Given the explosion…I’d personally just take it to a shop and have them set it up for $10/wheel or so. They’ll make sure the tape fit is correct. They might also give some insight on what happened…like fit wayyyy to loose or too tight.
I don’t know exactly what happened but I don’t think you can ever ride that rim/tire combination. I mean, what if that had happened while you were descending? Yikes. Be safe, bro!
In a lot of ways, lucky it happened on the shop floor instead of on the road.
It is funny you mentioned the lawsuit, I just received a text from a really good friend and a high-end bike shop owner that said he had another customer that bought some Rene Herse tires have their tires blow off the rims also the other day. That could be 100% coincidence but he does not sell them at the shop anymore as he historically had sealing/holding air issues with the brand.
I 100% agree with you @FrankTuna , the rims are VERY larger ID and that can be a factor too and although I cannot recall, I am fairly certain that I have taken the Pirelli tires to 50/52psi for road rides without issue. They claim a max of 73psi for those tires, but different sidewall compounds and stiffness - the RH Barlow tires are so freaking soft feeling its insane to me.
I race the Pirelli tires on these rims typically at a 40/42psi for all the gravel races (they measure actual 39mm on the rims).
These wheels do not have tape and do not need them, they are hole-less.
I’ve mentioned it somewhere before but I truly think these rims are the evolution for gravel rims when then main stream companies make all the money they can on current generations.
The tires were fairly easy to get on by hand, I didnt need any tire lever’s to put them on. I am going to remount the Pirelli tires tonight to see how hard they are by hand (I did work in a bike shop for 8 years and Automotive for a long time, I do have pretty solid hand strength).
That might be the issue then IMO. Tape use is twofold…it creates an airtight seal, but ALSO functions as a shim…adding tape is like tightening a belt for the system to make it more secure. That’s not to say it HAS to be used…but you’d need to be pretty lucky to randomly get a perfect rim/tire fit without adjusting.
I only have had brief experience with RH tyres getting my first set last summer. I‘m using Snoqualmie Pass EL on my Gravelbike, Fleecer Ridge on my Hardtail and the 2.2“ slick tyre that I forgot the name of. So not the same as you but close enough.
I personally think your rim is too wide and/or not up to RH spec standards. Check out that blog post:
Measure your rims „G height“. It’s probably not compatible with RH tyres or the whole rim is out of spec.
I mounted my RH 44 slick on my Gravelwheelset and let it deflate. The tyre stuck to the rim wall without air in it. I took that as a good sign and that the tyre is compatible with my rim. I wouldn’t have ridden it otherwise because RH tyres (EL especially) are so sensitive and seem almost fragile compared to other tyres I‘ve mounted in the past.
I tried mounting the fleecer ridge on a Nextie wheel and it wouldn’t seat tubeless either. So my best guess is RH tyres don’t work on nextie wheels because either the tyre is too big or the wheel too small for the system to work as intended.
I think this is the problem! I’m not knocking RH…I’ve had good luck the few times I’ve used their tires.
They have this chart elsewhere on the site (my earlier link doesn’t seem to work). This would indicate your rims are too wide, even if the Barlow Pass product page says otherwise.
I will measure the “G height” later tonight to see what it is.
I know that the rims have a ERD (Effective Rim Diameter): 551mm, I did remount the one tire without fluid and pumped to 45psi and let it sit overnight. It leaked out all the air, I will check to see if the bead is still seeded to the rim.
I most likely will not be using the tires on the wheels and am using this as an educational or learning experience at this point.
I‘m not 100% convinced the rims id is the problem here. I tried mounting fleecer ridge on 28mm id nextie wheels and 22.5 dt swiss wheels. Both wouldn’t seat tubeless with my silca chamber pump. I never had issues mounting tyres with this pump on either road or mtb and funny enough the fleecer ridge would seat just fine on my berd wheels with 25mm id.
This leads me to believe that bead diameter and g height are more important here than the rims id.
Tip: try it with more tubeless tape after ensuring g height is up to spec. Otherwise sell the tyres.
Even if not the problem, rims this wide and narrower tires are uncharted territory it seems. It’s outside of ETRTO specs so I doubt the manufacturer would be OK with it if pushed (especially if there was an accident … glad this blow off didn’t happen while riding!!!).
Totally agree, it’s not worth risking to ride the system like that. Those rims are just too wide for such a narrow tyre although I am of the asumption that you at least have to be able to mount the tyre without it blowing off the rim. The reason why it blew off is probably not due to the rims id though (imho). But who knows and who cares. Don’t ride that combo…
I could never get Oracle Ridge (on hooked 25mm internal) or Fleecer Ridge (on hookless 29mm internal) tires to mount without first installing a tube, then breaking the bead to sneak the tube out. Once installed with Orange Seal they seemed to hold air forever. They’re a little finicky in my experience but great once you get them up and running.
Can anyone articulate why the internal width of the rim matters relative to the tire size from a safety perspective? I have an assumption this is just a vague pseudo recommendation on the part of the manufacturer, like psi on the side of the tire. I mean obviously excluding something really crazy like 30mm rims with 23mm tires.
Different bead diameter of the tyre probably. I‘ve had a Schwalbe combo g one speed and g one bite. On the same rim the bite wouldn’t seat. I could see trough to the other side out of the rim the tyre sat so loose on the rim. G one speed was fine tough. Not every tyre works with every rim. That’s why we absolutely need those etrto standards to make sure every combo is save to ride and no one gets hurt because of a bad combo.
