After sustaining my sixth puncture in 3 months I decided to fit Specialized Armadillos to my wheels to try and minimise the risk of this happening again. To make this all as clear as possible I have a Trek road bike running as a fixed gear.

Anyway, after fitting the new trye and a new tube I began pumping it up and as I got to about 115psi (the recommended pressure is 125psi) I heard a loud BANG! At first I thought maybe the tube had blown or at worst that the tyre had popped off the rim. No. Much worse. The rim of my wheel split! Right along the top edge for about 5 inches and about 2mm from the top.

I was wondering if this has happened to anyone else or if anyone knows what could have caused this. It was a Campagnolo Omega rim and was fairly old (about 9 years maybe).

Thankfully I am having a new wheel built anyway but unfortunately its gonna be another three weeks to order a Goldtec hub as they have to make more.....

This is due to wear of the sidewalls by the brakes. Some modern rims have a groove machined in the sidewall that gives an indication of how much life there is left in the rim.

Its fortunate this happened when you were pumping rather than riding.

Never heard this happening. Thanks for informing.

115 lbs per inch pressure is pretty substantial.


Maan, who would've known the rim is weaker than the tire.

Go Armadillos??

Too true. Though, if it had been the tyre I could've used a spare and wouldn't have to use public transport for the next three weeks.....

Guess you've gotta look on the bright side.

I'm almost frightened to put the armadillos on my new wheel though!

I absolutely understand you. Using public transport sux. I am in exact same situation, just had my bottom bracket broken. And I ride bike everyday. Now a car, bus or walking... neither is a good choice.

Have you considered using thorn resistant tubes?

I used to have constant flats as well, until these tubes, that never yet had a flat and it's over a year now.
I also put several layers of electric tape on the inside of the tire.

Shouldn't hurt. Weight doesn't matter that much, I have strong legs.

Hope you fix your bike soon!

And then again, maybe it's just your rim was originally a little defective or developed a micro crack that now gave up. Lots of people pump to those pressures...

No one seems to mention exploding like you did though...

Go figure..

It has nothing to do with the tire. That rim was so worn that it was weak. It is a good thing it failed when it did. You could have been going down a hill around a turn at some real speed. Don't be afaid of new armadillos. Be afraid of old worn out bike parts.

More testimony to maintain a second wheelset.

I agree. 115 psi puts the same force on the rim regardless of the brand of tire. The rim was worn out and ready to fail.

I had that happen to me once. I thought it was the tire itself, so I called Supergo, where I got the tire. They asked me if I knew how much pressure my rims could take. ??? Huh? I had no idea that certain rims only take certain pressures. Once I put in a new inner tube, and I blew it up to the pressure I usually used for my old tire (110 psi), I was good to go. I'd only blown the tire up to just past 120 psi when I had the problem.

BTW, my rims are fine- they don't even need truing, so I know it wasn't that...

Old non-hook rims generally cannot hold a tire on the rim at pressures much above 100 psi. I'm running 120 psi on a cheap 27 in. hook rim and so long as the bead is seated all around, I have no problems.

I've been beating that drum for quite some time (to mostly deaf ears) everytime somebody goes into the more air pressure is better mode.

Half of the interface between your tire and rim is the rim. Everybody looks at the air pressure recommendation on their tire and thinks that's the whole answer. As you've discovered, it's not. I also have personal knowledge of cases in which of tires blew off of rims that appeared to be undamaged. I'm a lot more conservative about tire air pressure than I used to be.

[/QUOTE]How about buying a puncture reapir kit?

Everyone else does, and THEY survive. Ever consider you might be at fault here?
******!
[QUOTE]

What the hell. Yeah I use a puncture repair kit - but it doesn't stop me getting punctures.... So I'm at fault because I wanted to fit armadillos? Sure. If you say so.

Spamming is lame.

That site SA (Somethingawful) sicked it's members on my kite+sand-surfing forum a while back.
Just because they don't have hobbies they reckon we shouldn't be allowed to enjoy ours!!!!

We're friendly enough- What did we do wrong? Do they not like bikes? =(

Simon

I think they're compensating for something.....

Jenny is gone, thankfully. Who's next? Lt. Dan?

Reported him and his doppleganger this morning. Kudos to the mods for quick action.

You called?!

My son's road bike has a max pressure on the rims. I think they dont normally do this because that number will only be good for new rims. I suppose on a rim with wear indication they could put the pressure when new and the pressure when worn to the bottom of the wear indication groove.

This had better just be a ************ coincidence.

It scares me that my Tufo tubular clincher tires are rated at 220 psi yet mount to a clincher rim. I never inflate beyond 140 psi...but I think I am already at the max pressure of my Velocity Aerohead rims.

The only good thing about having an astronomical high tire psi rating is you don't have to worry about the tire blowing if you underinflate it (LOL...underinflate is 140 psi!)....only the rim becomes the limiting factor.