PROBLEM: You install your bike tire, pump it up, and a section bulges or dips.
SOLUTION: Bulging is urgent. Quick, let out some air! A section of tube is under the tire bead (the inner edge around each side). If you continue to add air or try to ride, chances are high that the tube will pooch between the tire and rim and cause a big and possibly dangerous blow out.
Once the tube is deflated, work on the problem area. Lift, squeeze and massage the tire until the tube no long appears under the bead. Then cautiously add air, watching to make sure all is well.
In a properly seated tire, the bead line — the thin line molded low on each sidewall — will be just above the rim all the way around on both sides.
Dipping bead line. If the bead line dips below the rim, the tire will feel lumpy as you ride. To correct this when you have a high-pressure floor pump, you can sometimes keep adding air beyond maximum inflation, but only if you have alloy rims. This extra pressure with allow rims may pop the bead into place with a snap you can hear (then let out the excess air). WARNING! Don’t try this with your carbon wheels. Overinflating carbon rims can weaken, crack or ruin them and put you in big danger!
A safer way is to deflate the tire and massage the dippy section. Put it in the same position on the rim as the rest of the tire. Inflate and all should be well.
No again? Deflate again and rub something slippery on that bad bead. Lots of things can work, but don’t use bike grease, which could harm the rubber and get on the rim. Try a little liquid soap, bar soap or saddle soap. Good old spit can work, too, and might be the only choice if this is happening during a flat repair out on the road.
Pump up the tire again. OK? Good! Now skip today’s upper-body workout because you just had it.
Another thing that works well to lubricate the tire is talcum powder (baby powder). It’s good to use on the inside of the tire to keep the tube slippery as well. When I fist started riding wheels that had a more aggressive hook (to make them tubeless compatible) I found that after fixing a flat out on the road, I had a lump. It concerned me enough to stop and go through the steps you describe (lower pressure and massage the tire, then pump it up really hard). The lump was reduced but not eliminated. I wasn’t too far from home so I decided to ride home to my big floor pump where I knew I could put in enough pressure to pop the tire into place. In a couple of miles of riding, the rolling of the tire served the same purpose as hand massage, but with more force and frequency. The lump was gone.
Tires failing to seat completely has long been a problem, especially when combining cheap alloy rims with cheap (and sometimes not so cheap) tires.
Several years ago I purchased from Schwalbe Tires a liter bottle of their bead seat solution, a slippery soap-like solution. I just keep a small piece of sponge around, saturate it with the solution, and swipe it around both sides of the installed-but-not-inflated tire bead. It has always worked, allowing good bead seating without overinflating the tire. It seems to dry and leave no residue on the tire or rim. The liter bottle lasts a long time.
Talc applied to the tube and inside of tire casing is also very helpful.
You make an interesting point about beading tube. My wife was asking me about it the other day. I will definitely share this information with her.
Just spent the better part of a very frustrating hour trying to get the bead seated properly, before I read your article… Had an idea before reading it that pressure may have been a solution but your article gave me confidence to jack the pressure and see if the bead would seat after applying a little soapy water with a sponge… about 3-4 pumps beyond 40psi and “pop” and another pump or two and some massage around the spot that still wasn’t seated and another “pop” Amen… Halleluia… off for a rip before the sun sets, thank you for the great tip!
Glad to hear it was helpful!
Thank you. Also found this helpful with my new bike with 2 inch bontrager tyres. Soap, a little pushing back with my fingers to help the tyre lift up the side into the grooves on the side of the rim. A little extra pressure and “Pop” into place.
Really great tip to use some liquid soap….after an hour deflating and reinflating i got the tyres seated nicely within minutes. Nice one!
I spent over 4 hours trying to fit a GP5000 TL on a new (True) carbon wheel and was about to give up when I saw the soapy water technique posted. Like a fool, I resisted and thought its a defective tire or worse a defective rim.
At the 11th hour I snatched victory from the jaws of defeat by …. wait for it …. using soapy water. The bead popped like sweet buttered popcorn right onto the rim and seated all the way around.
Trust Science!!!
Dawn dish detergent comes through yet again. Had a terribly frustrating time getting a small area to seat no matter what. Pulled up this article, reached over to my cycling tool chest for the Dawn and voila – seated immediately.
I love the extremely practical solutions I often find on this site – well done, Jim and fellow wrenches!