Update - Checkout the pinned comment from Worlds Worst Musician - I have since sold the bike and I can confirm that with the proper prep that I engaged in, The paint pen stayed. There were visible cracks but nothing you can spot from standing up next up. It was money well spent!
As with all painting, prep is key! You should flame treat the tyres first (especially if they are new) then apply an adhesion promotor or plastic primer (available in an aerosol can for a few bucks). Then apply paint. If you don’t like the pointy end of the pen, pull the nib out and turn it around. Most have a chisel tip on the other end. Also, the best paint pens on the market by far are the Milwaukie ones, available from any decent tool shop and they are only 8 bucks! Finally, when you are done and the paint is dry, hit the tyre with a quality silicone based tyre shine to protect em. Do this once a week or so and they will look good forever!
Best tire lettering video I’ve seen yet. I’ve done a few raised letter “tire stickers”, and surface prep is essential like you’ve said. They recommended using acetone and wiping the tire over and over til the cloth is clean. Well wipe and wipe, the rag is never TRUELY clean, but when it is way less dirty is the best it’s gonna get, I went with that. Very time consuming, so by the time you get to the third or 4th tire, and they seem to glue down ok with the adhesive they provide, I went that route. After a few months, the ones that the surface prep was cleaner looked way better than the ones that weren’t as clean because they began to lift at the edges after a while. Not only because of the surface not being completely cleaned, but also the tiny raised lettering under wherever I wanted to put the raised lettering on created small bubbles from a good surface to surface contact. When I redid the worst ones, I peeled them off with vice grips and used a burring bit in an air rosary tool to get the dried glue off, and sanded down the small raised lettering (that has max inflation numbers and such) to take them down flush. This also roughed up the surface for the glue to adhere to (summit racing sells what I’m talking about, they’re raised lettering “tire stickers”, and it much easier to take the tires off the car and put them on a bench than to spend all that time on your knees struggling. With that said, I realized the tread was worn though to the belts in a spot so I only had the new tire stickers on for a day or 2 before getting new tires….which leads me to you. My new tires have very large recessed lettering what would look great white, so im looking at different posts about painting lettering on tires. I’ve seen some bad ones, really bad, but you shaving your paint marker point down to a wedge was brilliant, plus the guitar pick wrapped in alcohol wipes was equally brilliant…then I saw you posted an update about it cracking over time and someone else said “white flex seal won’t ever crack”!! Now we are onto something. It’s going to be a little while, but I can get 16ounces of white flex seal and use detail brushes and try the insides of my tires to see how the durability is. Everyone coming together on this is going to lead to a success story. The lettering on my new tires is way larger than your motorcycle tires and a lot less letters as well, because they’re “Falken” on one side and “Azeris” on the other. I wish there was a way to attach photos in the comment sections because I could show you the Goodyear raised lettering I did and the Falken recessed letters I PLAN on doing. Thanks for this post!
The problem with oil based paint is it’s not flexible and prone to cracking from temperature changes and flexing of the rubber tire while riding and cornering. There is a product called Flex Seal that comes in all different colors including white that may be better than oil paint. It will stick to any surface and will waterproof and seal and is flexible (hence the name) so much less likely to crack. I agree this is a very time consuming and messy project that may not be for everyone. Only other suggestion is I just used a tiny and very fine artist’s paintbrush instead of the tip of the paint marker. The brush was much faster and more precise. I like the idea of the alcohol wipes and guitar pick. I dipped part of a rag in acetone then placed the dipped area over the tip of a flathead screwdriver to clean up large edges. On small edges I just scraped excess paint off with a razor blade/box cutter.
Thanks for the idea! Just got brand new tires, so I will do a test on the inside of one of the tires and see if there is any problems and try to discover any potential solutions. Great post and great comments