Can't get beads to seat (Pathfinder Pro)

Anyone have any tricks to getting beads to seat? I am trying to install Pathfinder Pro’s (42mm) on my Shimano RS-170 rims (23mm width). The tires were in their packaging for a long time, so when I get them on the rim they have a wavy appearance along the bead.

I tried with a pump, then removed the valve core and tried blowing air with my air compressor. No luck. So now I bought a Prestaflator for $60, but just tried it and had zero luck. I put in some sealant to try to seal up the edges. I have a big gravel ride planned for this Friday, so if I can’t get them on I’ll just put my Terravail Cannonballs back on.

Any advice is appreciated.

Is the bead of the tire too tight, or not tight enough?

Put a tube in first, then inflate it to pretty high pressure and let it sit for a bit. That can help everything stretch out.

Also get a bucket of hot sudsy water (most dish washing soaps should do). Sponge that around the outside of the tire on both sides right before using an air compressor to inflate the tire (without the valve core in). Makes it harder for the air to escape easily around the bead, and therefore easier to get pressure into the tire so it pops into place.


Suddsy water around the bead on both sides and the compressor.

It should help the bead slide outward as well as show where you might need to give the tyre a push/squeeze

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I just mounted the same onto HED Belgiums with no issue this morning. Another layer of rim tape? Do you have a blast pump?

I should be good on rim tape. They are holding air for a long time with my other tires. My compressor and the Prestaflator will be my blast pump.

I’ll try the soapy water tonight.

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This method has worked for me with difficult tires:

Skip to about 3:15.


Also worth trying with a tube in. Fully seat the tyre then remove the tube by taking the bead off on one side only if possible. At least then when you come to inflate again one side is already on.

Any dings in the rim? This is where my problems come from on my rear wheel. Tyre is fine once on, but it’s a struggle initially inflating.

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Echoing what others have suggested, I first use a tube to stretch the tire into shape and get one side seated. Remove the tube and if the tire is particularly recalcitrant, I’ll use a tire lever to seat the other side as far as I’m able.

As above - put the tyre on with an inner tube and leave for a few hours to straighten the tyre out. Remove the inner tube if possible only unseating the bead on one side. Then lube up the rim with a small amount of soapy water (or I think schwalbe actually make tyre lube) and then blast it with the compressor or blast inflator thing you’ve got.

This, for sure. Has worked 99% of the time when I’ve had problematic tyres in the past

Mine go on quite nicely with co2

This may be obvious, but since you’ve heard just about all the advice out there, it’s worth checking: get a good seal between the air compressor and the valve stem. For a lot of tires, a regular “blower head” does fine, but with a more challenging setup recently what finally worked for me was putting the actual Presta inflator head and latching it onto the valve stem, just as if the core was still in there. It made all the difference.