How to Seal Motorcycle Wire Wheels to Run Tubeless Tubeless Tires.
by Mike Cecchini

Wire wheel sealant I use is Permatex Ultra Grey tube for caulk gun.

Most quality tires need only 1--2 oz to balance a tire properly, but for some reason your wheel assembly needs more than this to do a basic balancing, then rotate the tire on the wheel in steps of 90 degrees to see if this will improve the basic balance of the assembly. If this does not work, then I will use a slide-on spoke weight or wrap some thick old school solder (without rosin core) around a spoke like they use to do in the old days before stick-on or slide-on wheel weights. For vintage bikes I think this is a cool touch........but not for a bike that you will go over 70 mph. It might come off and do some damage to the bike or you.

One 13 oz. tube of Ultra Grey per get 3 tubes in case you put it on slightly thicker than you realize. You certainly don't want to run out towards the end and have two differently time cured applications.

Some vids to review for overview and guidance.

I cannot stress enough that the wheel and nipples must be scrupulously clean so the sealant can totally and completely stick to the rim and nipples.

Step 1.

First I cleaned the wheels with a good cleaner like Simple Green to get rid of all basic dirt & debris. Blow the wheels dry and clean.....especially in the nipples and nipple threads area.

Then use something like denatured alcohol or mineral spirits with a toothbrush to scrub the wheel valley and nipple areas very clean.
Using low pressure compressed air (15--20 psi) as I go along so anything I dislodge will be blown out of the area.

Caution......using high pressure air 80--120 psi has a tendency to blow the solvent down into the spoke nipple threads and around the nipple heads that will flush out the anti-seize I have put there so the nipples can rotate when I want to re-tighten them as the miles flex and stretch the spokes.

I do this twice to I'm sure all grease and dirt are completely removed. Crevice & spoke threaded areas are critical. Be patient and meticulous.

My final prep is to use a small terry cloth rag (1/4 of a face wash cloth) dampened (not wet) with lacquer thinner to wipe the entire wheel valley (spoke) area down several times to make sure everything is incredibly clean. Turn cloth often for fresh area. Blow dry with low pressure compressed air to ensure everything is bone dry and very very clean.

I then stand my wheels vertically in a metal 15 gallon trash can with cloth around the trash can lip so the wheel is held well upright and nicely, but easily rotated as I go around the wheel spoke nipple by spoke nipple.

Step 2

To start, use the long tapered caulk gun nozzle with only the smallest amount of nozzle cut off so you can get the nozzle well into each threaded part of the spoke nipple. Hold the nozzle in the nipple threaded hole as you squeeze the caulk gun handle to fill the threaded portion of the nipple first and pull back slowly and pull out of the nipple as you start a circular motion to go around the circumference of the nipple.

Use only enough sealant to cover the nipple completely. Goal here is to only have 1-2 mm thick coverage JUST on and around the nipple.
Full & complete coverage is essential..........but not thick coverage.

Do this for each nipple area. Let this cure for 24--36 hrs. in temps above 50 degrees F. Warmer the better.

Step 3. Tire valve selection & install.

The issue with a metal tire valve stem is there's precious flat area on narrow wheels.... if any at finding the smallest OD threaded stem is the first step. Angled or straight is your call.

I say metal tire valve stem because this valve stem will be in service for many years and if you use a all rubber one, it will be prone to rubber deterioration & cracking = leaks = cut it out and do it again.
Secondly, a rubber valve stem requires a large flat hole to seal.

I used this design of Camel Tu bless Valve Stem as it's the smallest OD and it has a recessed o-ring seal on the inside of the rim and a rubber seal on the outside covered with a domed plate to keep it in place.

Even with this metal design, because the rim surface is curved and the stem wants a flat surface, some careful filing to taper the outer edges of the metal is needed so it will sit down on the surface properly for the o-ring and rubber to fit as well as it can. I also used a smear of Permatex Ultra Grey on sealing surfaces to help in the sealing process.

Once fitted in place I removed the schrader valve and trim a round toothpick to fit into the schrader valve hole so I could apply Ultra Grey around it. I put a light smear of silicone grease on the toothpick so the Ultra Grey would not stick to it and when the Ultra Grey was cured (24-36 hrs in warm temps)......the toothpick will slide out and leave a clear clean hole.

Not knowing your exact wheel surface situation you will have to adapt things accordingly, but you now know the concept of properly fitting a metal tire valve assembly in your rims.

Step 4.

Make a cardboard pattern of the wheel tire area that gives 2--3mm depth of sealant above what you have on the nipples. Carefully trim any nipple sealant rising more than it's originally intended 2mm coverage. Fingernail trimmers work well for this......or mini-side cutters that are sharp. Avoid disturbing the cured sealant......just trim as needed.

Once you are satisfied with the card board wheel pattern is correct, then transfer this to a suitably sized plastic spatula painters use to spread dry wall paste on drywall.

Step 5.

Cut caulk gun nozzle down to max ID hole so you will have a 5--6 mm shaft of sealant coming out. Lay 10"--15" bead in the wheel valley and pull the spatula towards you to spread out the sealant so it JUST covers the valley where the nipples more.

Do this in steps around the wheel. Try and get it done with as few handlings of the sealant as possible. The more you mess with it ......the worse things get. Focus.

Let this cure for 24--36 hrs in temps above 50 F...... warmer the better.

When I mount tires I use big cotton swab like many shops do, but I only moisten the swab and lightly spread it just in the bead area of the rim and then on the bead of the tire. Avoid slopping it on......just a smear is all you need. Any more than this exacerbates & encourages wheel, nipple and spoke corrosion because of the water content.

I run FOBO Bluetooth tire pressure sensors on my wheels so I know at a glance on my cell phone what the tire pressures are at gas stations, across the garage and even while I'm riding if I like. It's surprising how much tire pressures rise as you ride. 10--15 psi is normal and how quickly the pressure drops even at short gas stops.

Let me know how it goes.

My best......... Mike
(301) 787-3114 cell