Tire Talc or No Tire Talc ?

[Coldrider]

Just changed to the Shinko 241 tires and used tire talc in the process and am now wondering if that was a mistake. On the second ride the rear valve stem ripped out of the tube and am wondering if that may have been because of using tire talc. One thing about it is that the problem was caused by something I did wrong. The other possibility is that I messed up in tightening the nuts on the valve stem. The tire talc is some slippery stuff but was careful not to get any on the tire bead. Any advice from more seasoned members than I would be appreciated.

 

[AZ7000']

The other possibility is that I messed up in tightening the nuts on the valve stem.

I have never tightened the nut on my tubes on dirt bikes in the past 10 years... The few bikes I do have with tubes I lock the nut against the valve cap. If I see it tilt in the stem it is usually low on air so I empty the air and do my best to square it up then reinflate. If it is tightened down you see no shift, it just rips out, as far as your question I have maybe used talc 5% of the time I change tires or tubes.

Others may disagree but that is one opinion.

 

[BaldRider]

How was the stem ripped out? How were the nuts tightened and where were they located? Could just be a faulty tube. I've never used tire talc but I did use regular talcum powder once.

I find it unlikely that the tire would slip and rip the stem out, especially if it didn't happen right away. Second time out seems really strange. There isn't much torque. Just strange.

 

[dmonkey]

I would suspect the valve stem nut was overtightened, valve stem not lined up, damage during install, or manufacturer defect before I would suspect talc as the cause.
Did you orient the tire in any way where you can see if it slipped on the rim? Red or yellow dot lined up with the valve stem hole?
Did the tube you used have two valve stem nuts, and was it installed with one inside the rim and one outside the rim?

 

[Coldrider]

I would suspect the valve stem nut was overtightened, valve stem not lined up, damage during install, or manufacturer defect before I would suspect talc as the cause.
Did you orient the tire in any way where you can see if it slipped on the rim? Red or yellow dot lined up with the valve stem hole?
Did the tube you used have two valve stem nuts, and was it installed with one inside the rim and one outside the rim?

 

[Coldrider]

The tube was installed with the convex shaped washer installed first, then the nut, and then the valve stem poked through the hole in the rim, and them the 2nd nut installed. Had ridden the bike a couple miles on the first ride but on the second ride the tire went flat and I found the valve stem totally detached from the tube. The tube was the correct 3" x 17" size for the Shinko 241 tire. It just seemed strange that the valve stem ripped out of the tube.

 

[m in sc]

thats how i typically install them (washer/nut order) never had an issue. and yes, snug them up, they are nuts for a reason. i don't mount my own tires typically, but on the rare ocassion i do (and i have done it a lot in the past), i usually just spray windex on the tire and bead. that being said, if the tire pressure is too low, it can cause the tire to slip on the rim, grab the tube and rip the stem out, i have seen that before. .02

 

[BaldRider]

I use No-Mar tire lube when mounting tires. I never worried about slippage. You make a good point about tire pressure. That's probably the cause. Maybe the tube was pinched and it lost enough air by the 2nd ride that it just slipped and ripped the stem off.

 

[TRF90]

I'll probably regret writing this, but I have never used tire talc in 50 years of riding. And for the last 20 years, my tire mounting lube has been a little bit of WD-40. Valve stems tear out if the tire rotates on the rim. Not likely on a CT 125 with more than 25 lbs of pressure. They'll also tear out right after a sudden loss of pressure if the tire bead breaks.