[L U K I N]

I’m looking for feedback from someone with experience running the Velocity Blunt rim with a Schwalbe Racing Ralph 2.4 tire. Yesterday during a ride my front tire exploded off the rim. It was the first ride on my new rims; I’d previously had the RR 2.4 mounted to a Bontrager Race X Lite. After converting the blunts using the Stan’s strip I mounted the tires (it’s worth mentioning they’re the non-UST version) to the wheels with ease. I was running 29lbs of air and at the point of failure was rolling on a relatively flat section at a slow pace. I was able to remount the tire using an inner tube and it was fine for the remainder of the ride; I did notice the tire itself was stretched and seemed to barely fit the rim.

If anyone has successful experience with this set up please do share details as I’m quite fond of the tires and would like to continue riding them without fear of a catastrophic failure.

One other point worth noting while I was repairing the tire and my ridding buddies were recovering from getting the sh*t scared out of them from the gunshot sound the tire made they asked what pressure I was running. When I told them 29lbs they felt my rear tire which was a RR 2.2 and they all started saying “that’s way too much pressure, your pump gauge must be off, no wonder you’re tire blew off the rim…” I couldn’t argue with them because the tire felt as hard as a rock and after their comments I let some air out so the tire was softer. Upon arrival back at our cars we tested the accuracy of my pump with a digital gauge and it was spot on. We then started to speculate that larger casing tires like car tires might function on lower pressures, no one there was qualified to comment on the physics of this suggestion but it seemed to make sense. So, as a second part to my question has anyone else had similar thoughts about 29er high volume tires and air pressure?

Thoughts, comments, feedback please.

 

[MMcG]

You might want to check the diameter of your rim really closely.

 

[BruceBrown]

I'm looking for feedback from someone with experience running the Velocity Blunt rim with a Schwalbe Racing Ralph 2.4 tire. Yesterday during a ride my front tire exploded off the rim. It was the first ride on my new rims; I'd previously had the RR 2.4 mounted to a Bontrager Race X Lite. After converting the blunts using the Stan's strip I mounted the tires (it's worth mentioning they're the non-UST version) to the wheels with ease. I was running 29lbs of air and at the point of failure was rolling on a relatively flat section at a slow pace. I was able to remount the tire using an inner tube and it was fine for the remainder of the ride; I did notice the tire itself was stretched and seemed to barely fit the rim.

If anyone has successful experience with this set up please do share details as I'm quite fond of the tires and would like to continue riding them without fear of a catastrophic failure.

One other point worth noting while I was repairing the tire and my ridding buddies were recovering from getting the sh*t scared out of them from the gunshot sound the tire made they asked what pressure I was running. When I told them 29lbs they felt my rear tire which was a RR 2.2 and they all started saying "that's way too much pressure, your pump gauge must be off, no wonder you're tire blew off the rim…" I couldn't argue with them because the tire felt as hard as a rock and after their comments I let some air out so the tire was softer. Upon arrival back at our cars we tested the accuracy of my pump with a digital gauge and it was spot on. We then started to speculate that larger casing tires like car tires might function on lower pressures, no one there was qualified to comment on the physics of this suggestion but it seemed to make sense. So, as a second part to my question has anyone else had similar thoughts about 29er high volume tires and air pressure?

Thoughts, comments, feedback please.

Those suckers are big tires and on a wide rim, I wouldn't go too high at all with psi. I run my Nanoraptors on wide rims in the range of 16.5 - 19.5 psi (and at 22 psi they feel hard as a rock). That being said, I've given up on running the Racing Ralphs tubeless after tearing a 2.4's sidewall during a race.

I think they are safer and more durable with a tube, so a little sealant in a tube is the way I will run them in the future (gotta fight the thorns where I live and ride) for racing. Howver, I do have a pair converted to tubeless on my Karate Monkey (on AC rims). I've had Small Block 8's and XR 1.8's mounted tubeless on my Blunts. Currently, the XR 1.8's are on their tubeless with psi's in the high 20's (skinny tires need a little more pressure than the big meats).

Check the bead carefully on the RR that blew off. A lot of times, such an explosion will trash the bead and personally, I wouldn't trust that particular tire again. It's only happened to one of mine - a Nano when I took it up over 40 psi on initial inflation. I threw it in the trash after that because I'm sure that explosing stretched the bead and made the tire unsafe. Again, maybe others will chime in with their experience, but I think the RR is probably best with a tube - no matter the rim. If I was running them tubeless on my Blunts, I would experiment with psi's in the 16 - 23 range to find a happy medium. That's based on using tubeless on both the Delgado Disc and Blunt rims.

BB

 

[madcap]

I've had multiple bead seating failures with multiple different tires on a Velocity Blunt, exactly as you describe. Every failure happened with less than 31psi. I'm currently running a RR 2.4 on one of my Blunts and a RR 2.25 on another. I've kept them above 33psi since bumping pressures without a single failure, for about 9 months now. Try running higher pressure, it sucks, but the Blunts kinda suck too.

 

[L U K I N]

Are you running tubes? I'm thinking about running tubes injected with Stans.

 

[madcap]

yes, I run tubes with my Blunts