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MountainBikeReview.com's Forum Archives - Wheels & Wheel Building
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...mount UST tire, pump up, inspect closely, KABOOOM! (8 posts)
|  ...mount UST tire, pump up, inspect closely, KABOOOM! | singleminded
Jun 11, 2002 12:14 PM | | I think I'm suffering from a case of PTSD: Post Traumatic Stress Disorder.
And partial hearing loss.
Last night I decided to mount a new set of UST tires, Conti's Twister Pros, on my CrossRocs. The tires looked good, and I was eager to experiment more with this whole UST thing.
Off come the UST Pythons that came with the bike. Easy as pie.
Clean the latex goop out of them and off of the rims. Inspect everything carefully.
Start with front Twister. Ooooh. It fits nicely. Easy to mount but nice and snug once on the rim, awaiting air. Are UST beads stretchier? They seem that way. Nice. Gonna see how these babies do with no latex or anything.
I notice how the beads positioned themselves to slide into place against the edge of the rim once air was applied. So that's how it works!
Out comes the floor pump. Tire takes air super easy. Pump to about 60 psi. Probably higher cause the guage on this pump seems to err on the low side.
Inspect tire. Squeeze it. Bounce the wheel. Everything looks good. Bring pressure down to 35 psi.
Grab back tire. Mounts just like the front one had. Takes air just as easy. All seems well. I'm pumping to 60+ psi. I notice that I hadn't heard the bead "snap" into place like the Pythons had done. Then I realize that the front Twister didn't make that sound either, even though it sure seemed to have locked properly in place.
I give it a few more pumps. I hear a crinkling sound. Is it only now starting to lock in?!?! A few more pumps. No sounds of snapping into place. Ok. This is getting silly. I can't trust my pump's air guage. Does the tire have 60 psi? 70? 80?
Unhook the pump hose and tighten the valve. Pick up the wheel with both hands. The light in my basement is a bit dim. Let me take a closer look. Bead seems fine on both sides, so I'll... KAAAABOOOOOOOOOOOOOM! The wheel is on the floor. So is the tire. About two feet away. Laying like a rag doll. What happened? Have I been shot? I can't hear out of my left ear.
Take a deep breath. Inspect tire and rim. Both look fine. Mount tire again. Everything same as before. Takes air same. But this time I'm cowering as the PSI goes up. Stop just short of 60 on the guage, which may be 65? 70? in reality.
Hold wheel like a hot potato. Now I'm gun shy. All seems ok. From a distance I toss it on to the backyard lawn and watch it roll. No kaboom. More inspection. Seems fine. Let out all air to see if bead really is locked in place, despite no "snap" sound. It is. No doubt.
Pump back up and adjust to 35 psi. Both wheels on bike and off for a test ride. Jump curbs. Hop. Smack curbs. No problems. Tires are super fast. Surprisingly compliant ride for having so much less air volume than those monster Pythons.
Check bike this morning before work. All seems well. Tires seem to have lost no air overnight.
So why did it go KAABOOOOM!? I don't know for sure. But maybe pumping a tire beyond recommended max pressure is a bad thing. Maybe I should have expected it. Don't know. All I know for sure is that loud noises make me jump now. |
| re: ...mount UST tire, pump up, inspect closely, KABOOOM! | kam
Jun 11, 2002 7:09 PM | | hey man, how is that left ear now? man, the same exact thing happened to me about 1 week ago. i mounted my front tire with some soapy water, pumped it up to 60psi. i heard some poping noise while pumping, so the bead was sealing. inspected the tire to make sure the bead is alinged properly. set it down and start working on the other wheel...them BBBBBOOOOOMMMMM!!!! i'm disoriented and freaking scared to hell as what happened and look at the wheel. it was unmounted, so i take a closer look at the wheel/tire. no damage that i can see, so i mount it again, but this time i inflate to 50 psi for about 10 seconds, then decrease that to about 35. eveything has been fine for the past week. what the heck caused that tire to blow of the rim like that? i read many times as to inflate the tires to 60psi and have even heard to people leaving thier tires at 60psi for 24 hours before they lower to their riding pressure. mine couldn't even last at 60[si for 1 minute. if it matters, i'm running pythons on mavic x3.1 ust rims. |
| their nm | sp
Jun 12, 2002 11:28 AM | | |
| KAM-- where's that vultured dean?!?!?!?! | singleminded
Jun 13, 2002 7:21 AM | | I've seen no pics. |
| KAM-- where's that vultured dean?!?!?!?! | kam
Jun 14, 2002 3:49 PM | | hey man...the pics. will be up soon. i haven't been able to get to the powdercoaters in the past month. my step-sis just got married last weekend, so i was really busy with all the planning, guests and stuff like that. my bro just got me a 2.1 megapixel camera yesterday, so i'll have pics. of the unpainted (or sanded-by-a-mad-man) finish up on the ss board by the beginning of next week. beasure to check the ss board on tues.
cheers.
kam |
| Like this.......... | Mr.Tokyo
Jun 11, 2002 9:47 PM | | I know what you mean. I had a road tire de-bead itself @140psi, sounded like someone shot a shotgun. And This is at a Japanese gas station. Embarassing to say the least. I got the "Big dumb American in tight shorts just scared the hell out of everyone within a 100 meter radius" look. I also had to walk home too. |
| That reminds me of the day when... | BH
Jun 13, 2002 8:26 AM | | When I was 15 and riding my road bike along, I came across a nice Specialized Turbo/S road tire just laying on the side of the road. The Turbo/S was the top of the line and Specialized's first folding tire. Being the cheap SOB that I was (and still am), I grabed my prize and took it home. Upon arriving home, I mounted the tire and began pumping it up with my trusty Zefal aluminum frame pump. Back them, I couldn't afford a floor pump. Finally, after what seemed like 500 strokes, it felt like it was hard enough. I removed the pump and started to mount the wheel on my bike. But wait, what is that little bump? Better give that a closer look. That looks like a small rip. And that must be the inner... BOOOOOOOOMMM!!!!!!!
Getting up off the floor in a daze to the smell of rubber, that white inner tube powder all over my face and the ringing in my ears, I picked up the wheel and it finally dawned on me why that tire was just laying by the side of the road...
I learned my lesson that day and I haven't picked up any stray tires since then. |
| Been there, done that | Cloxxki
Jun 13, 2002 9:40 PM | | My neighbours must now think our neighbourhoud now officially has gone down the drain, after the shooting at the gas station. Modern guns don't make such hard booms, I'm sure.
It was a 700c*30 Michelin tire mounted with latex. It wrecked the rim, it makes a serious "chicane" in the place where the seperation started. I almost broke something in my hand, seems I held it firmly in the very spot of seperation. I will never start by inflating a latex tire to anything over 3 bar (and always wear a cheap raincoat), tough luck if I don't get the popping sound, I just want to ride. |
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