This one scared the snot out of me....

[srice]

I was 37 miles into today's century when I had a blowout. Normally, I am used to seeing the tire blown off the rim or the tire split. Today, my rim decided to sacrifice itself and save the tire. This wheel had about 540 miles on it when it failed.

[dixiesdad]

apparently the rim was not up to the task of supporting the SPEEDWAGEN!!!!!

[Pete Serotta]

Glad you came to a safe stop. Great handling skills on your part to do that.


Pete

[MattTuck]

Yowsers!

And that doesn't look like a crazy low spoke count wheel. I know the industry is pushing low weight, but I think I'd sacrifice a couple pounds for piece of mind.

In any regard, Happy to see that the Speedvagen didn't suffer serious damage, and more importantly, you seem ok.

Bummer though about the wheel. 450 miles should be to a wheel what 5 years old is to a human.

[srice]

This was literally the 6th ride on the wheel - I've done 5 centuries on the bike before today. The wheel was 32 spokes, Velocity Aerohead OC and Campy Record hub. I've really inspected the wheel after I got home and both sides of the rim are pushed out from the blow out. I was curious if overtension had started a crack, but there was no damage at the spoke hold in the rim. It ripped the brake pad out of the holder - I found the pad about 30 feet behind where I stopped. Fortunately, I was on a flat section when this happened and was able to skid to a stop.

[eddief]

but i have had tubes blow out right after being replaced after a flat. sometimes i am not meticulous enough and pinch the tube between the tire and the rim. and i'm using a floor pump with the wheel off the bike and sorta propped up right between my legs. if a blowout can do that to a rim and a brake pad...i am keeping wheels away from my privates when inflating tires.

[MattTuck]

I'm not an engineer, but I highly doubt that the air from the blow out was the cause of the rim failure. More likely, hitting something (pothole maybe) caused both the rim failure and the blow out.

[130R]

i would throw those velocity rims out and get open pros or rr 1.1's pronto

[Peter P.]

I've built Velocity O/C rears for several bikes, including my own, and have NOT had that problem. They're great rims that build into a long lasting wheel. Obviously, 500 miles is not a normal lifespan.

I've split plenty of rims before and it's ALWAYS due to mileage and wear, which I pretty much anticipated.

Over tension would not have cause the problem; the rim would sooner crack at the nipple due to localized stress. I know; I've over tensioned wheels to the point where I've cracked rims. There's no way a tire blowout could have damaged a rim like that.

It's likely there was an out of spec production run of that extrusion material.

Send an e-mail to Velocity and see if they reply. Send them photos, too.

[thendenjeck]

I'm really interested to hear this, as I experienced the exact same thing with a velocity rim.

about two years ago, I used to work at a bike shop, and we (not I, the other wheel builder at the time) built some kid a shiny new Deep V laced to a formula hub. the night he picked it up, we all went on a group ride. I was riding about 30 feet behind him going down a slight hill, he hit a pave-over spot in the road, about equivalent to one of those gradual suburban speed bumps, and BANG!! crazy blowout M-80 explosion, the kid goes down on his shoulder, and his brand new deep V with less than 20 miles on it was completely taco-ed. Velocity refused to help in any way, so we sold the kid another rim for wholesale and rebuilt his wheel, which, to my knowledge has been fine.

I dunno, I rode velocity's for two years with no problems, and I was really hard on my wheels. but this is the second velocity rim i've seen do exactly the same thing. glad for you that it didn't damage the SV.

[Jason E]

Wow. I have never seen a good condition rim blow out like that.

[BumbleBeeDave]

Originally Posted by Jason E

Wow. I have never seen a good condition rim blow out like that.

Same here.

Been riding for over 25 years and never seen one like that, especially from an almost new rim. you're sure you didn't hit a pothole or something that might have contributed to this? That still makes it scary, but at least a bit more understandable.

BBD

[srice]

I was on a fairly smooth road. It was chip seal, but no serious potholes. I've got four bikes with Velocity rims on them and this is the first issue like this I have had. Not a huge fan of Open Pros - had clicking eyelets that drove me nuts. Plus the offset rear rim on the Velocity just makes sense - I don't understand why everybody doesn't do that.

I do plan on calling Velocity tomorrow - not a ton of expectations, but I am willing to send what's left of the rim back to them if they are interested in failure analysis - as an engineer, I know that I would want to inspect any of my products that failed like this.

[markie]

Was there a brake pad in the brake before the rim blew?

[srice]

Yes, I usually run brake pads on both sides! The pad was ripped out and I found it about 30 feet behind me laying in the middle of the road.