Bicycle Mechanics - Blowout warped my rims! Do I have cheap rims?

I was replacing a tube in my rear tire. I'm pretty sure I aligned it right inside the tire. I pumped it up to just inside the max PSI (60). I turned around to look for my wrench and I look back and see a bulge on the side. I head over to see if I can release some air to prevent a blowout but I was too late. It popped.

I was really surprised to see that my rim had a warp or bulge right where the blowout ocurred. Do I have a cheap rim? This was an old 26" Fuji MTB. I had replaced the tubes before on this bike with no problems. I've heard of "double wall" rims. Do I need to upgrade? Thanks.

I would guess that a warped rim made it blow out, not the other way around. Check if any spokes were already broken.

With the bulge on the side, that means the tire wasn't seated on the rim right in the place, most likely, so was bulging out as it inflated- and one cause for that could be a warped rim.

I would guess that a warped rim made it blow out, not the other way around. Check if any spokes were already broken.

With the bulge on the side, that means the tire wasn't seated on the rim right in the place, most likely, so was bulging out as it inflated- and one cause for that could be a warped rim.

You think the rim was already warped? I've ridden this bike before with no problems. Not too long ago I spun it and it was true. It certainly wasn't as bulged out as it is now.

What's done is done, but will a high quality rim have prevented a warp from a blowout like this?

You can never really speak in absolute terms, but let's just say I've seen tires blow up and warp cheap rims, and it's been a really long time since I've seen a blowout warp a double wall rim.

You can never really speak in absolute terms, but let's just say I've seen tires blow up and warp cheap rims, and it's been a really long time since I've seen a blowout warp a double wall rim.

Thanks. I guess I'm relacing this wheel to a double walled rim.

Are you saying your whole wheel has gone out of true, or are you saying that you have a a localized bulge to your rim sidewall? If it's the latter you need to be aware that braking (assuming rim brakes)will eventually wear the brake track of the rim down to the point where it will collapse outwards. Higher presures of course makes this more likely, but it will eventually happen to any rim, double-walled or not.

Ive seen some really soft cheap rims come through the shop. So yes, a blow out can cause your wheel to go out of true. Go get a Sun CR18 or Rhyno Lite and you'll be fine.

I was really surprised to see that my rim had a warp or bulge right where the blowout ocurred. Do I have a cheap rim? This was an old 26" Fuji MTB.

Old rims get thin in the walls from braking and will eventually start to crack or separate; it's possible your rim started to fail before the blowout and the blowout put it over the top.

You'll need a new rim no matter what, but failure of a well-used rim doesn't mean you have to go with something extra beefy next time.

My wheel was true about 2 rides ago when I visually inspected it (lift the wheel and spin it). Stephen H said that my wheel may have been slightly bulging thus making the blowout easier to happen. I would think that a slight bulge would cause it to wobble slightly or look out of true, but I don't know. Right now it has a large protusion (sp?). I do use rim brakes. thanks, again.

I would think that a slight bulge would cause it to wobble slightly or look out of true,....
Well, sort of. If it's out of true then BOTH sides of the rim will have moved from where it's supposed to be. If it's one of the sidewalls giving up the ghost the other will usually remain intact and in place. It can also be seen by the way the rim will look more flared when and where the sidewalls are collapsing.

Just a thought, what caused you to replace the tube in the first place? Did you have a flat? If so what caused the flat? If you hit a bump or something and got a snake bite flat you may have dented the rim at the same time.

Just a thought, what caused you to replace the tube in the first place? Did you have a flat? If so what caused the flat? If you hit a bump or something and got a snake bite flat you may have dented the rim at the same time.

No flat. I was swapping out the knobby 26" MTB tire to a slick one for pavement riding.