7 Ways to Seat Stubborn Bike Tires

Jim’s Tech Talk

By Jim Langley

For anyone who doesn’t know what it means to “seat” a tire, let’s start with an explanation. To “seat” or “seating” a tire is one of the final steps taken when installing most tires on bicycles and motor vehicles, too. 

Seating is important because it ensures that the inflated tire is fully and properly installed. If tires are not properly seated they can have low and/or high spots, twists in the tread and with the worst seating mistakes (high spots), they can blow off the rim. 

Is a Bicycle Tire Seated?

To tell if a tire is seated properly (even old tires might not be fully seated), you look at the seat line that’s molded into every tire (photo). When a tire is properly seated, that line sits right on top of the rim, equidistant from the rim for 360 degrees around the wheel and on both sides.

The most common seating issue is having the seat line get stuck below the top of the rim (shown in the photo), what’s called a low spot. This can occur at only one spot or in several different spots. 

When this happens, if you ride on the wheel, you’ll probably feel the low spot(s) in the tire each time you roll over it. And, because the tire is too low in one spot, it’s possible to damage the rim if you hit something at that spot.

To help, here are seven tricks for seating tires that refuse to. We’re talking about low spots, not high spots (see Tip). And for both standard tubed tires and tubeless.

Tip: High spot seating issues usually only occur with tubed tires and result from getting the tube stuck beneath the tire’s edge. To greatly reduce the chance of this happening, be sure to inflate the tube just enough to let it take shape before installing it in the tire. It’s easy to inflate Presta valve tubes up to the right amount for this by blowing into them like you do with balloons. Just remember, you need to make sure the valve is open first..

7 Bike Tire Seating Tricks

Roll the tire out with your hands

CAUTION: Do not put massive lateral force on the wheel when doing this “move” – or you could warp your wheel. Only put force on the tire.

This is the quickest and safest way to seat a tire and it works most of the time once you’re good at it. But, you have to do it a few times to learn how to do it and if you’ve never done it before, to even believe you can do it. Because it can take a few seconds of work before the bead slowly pops out or it might come right out, too.

You do it by holding the wheel between your legs and gripping the tire right at the low section. You want to use your hands however works for you to put maximum pulling force on the tire to try to roll the stuck seat line up and out from under the rim. I use the heels of my hands and rock them in an up-and-over action. 

Air pressure

This is the way car guys and gals seat tires and a lot of bike mechanics do it, too. It’s kind of fun because as the tire seats it makes loud snapping or popping noises. But, there’s always a risk of blowing tires off the rim, which can be dangerous and expensive. I wrote about such an incident a while back: https://www.roadbikerider.com/overinflation-explosion-a-cautionary-tale-about-very-wide-tires/.

So, if you want to use this approach, use only your hand pump (air compressors put too much air in too fast) and very gradually increase the pressure. Give the tire a minute or so to see if it seats before adding more air. And, don’t ever inflate a tire way past the maximum pressure (it should be written on the tire sidewall).

Soap

Speaking of motorheads, they typically have a big tub of tire soap next to their tire mounting machines so that they can slather the slippery stuff on before inflating the new rubber. While there are tire soaps made for bikes, like BullSnot https://amzn.to/2nSud9T , common dishsoap works just fine.

To apply it, find the low spot(s) on the tire and keep track of it – because you’re going to deflate the tire next. You could mark the spot(s) with chalk if needed. 

Deflate the tire. Then put a little soap on a brush and push the tire out of the way at the low spots enough so that you can get the soap between the tire and rim. Or you could drip it on the tire if you don’t mind risking making a mess and having a lot of clean-up. 

When you pump up the tire, the low spots should pop out. If not, clean and dry the tire so that you can grip it and try to pull any remaining low spots by hand. The soap should still be between the tire and rim and with luck, the low spots will come out. If not, repeat the process one more time.

Use the ground

CAUTION: Do not put massive lateral force on the wheel when doing this “move” – or you could warp your wheel. Only put force on the tire.

If you’re on a ride and you have a low spot after fixing a flat (common problem with tubeless tires), hold the wheel in both hands so that the low spot is facing the ground and at 6 o’clock with 12 o’clock at your stomach.

Holding the wheel like this you can tap the tire’s low spot on the ground to put a pulling force (more like a jolt or blow) on the tire. This will sometimes get the tire seat line to come out from under and seat the tire. Just go easy.

Riding and waiting

Sometimes it just takes more time than you expect for the low spot to rise up to make its way to where it belongs. If a tire won’t seat, if you give it a chance, it might be seated the next time you check it. This can happen out on a ride. You just have to be willing to put up with a “funny” feeling of a low tire spot for awhile and baby the wheel and not risk hitting anything.

Tire seating pliers

The photo shows my Park Tool Tire Seating Pliers, which I have made great use of for decades: https://amzn.to/2mpy5Pp . The only thing is that you need to be careful to grip only the tire with this type of tire pliers. But they work well for many seating issues.

Vise

People are always surprised when I use this seating trick so I saved it for last. Don’t use it if you have any concerns.

The trick is to use a vise to grip the tire (tire only!) low spot and rock the wheel to pull the low spot out. Woodworking vises like mine have soft wood jaws that won’t harm tires. You can also use a metalworking vise by putting blocks of wood in place of the jaws.

You tighten the vise just enough to hold onto the tire (never allow the rim to get between the jaws!) and you then gently rock the wheel so that the vice can tug on the tire and get the low spots to pop out.

There you have it. I hope these tricks cure all your tire seating issues.

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