Skate lube in a fingerboard bearing: what's known, what isn't

The question came from a post in r/Fingerboards by u/emilyy777y, put up on 13 October. They'd just got a set of Piro Performance wheels, have DGFB F3s in mind next, and want to run shielded bearing wheels only. Three specific things they wanted to know:

• Is normal skateboard bearing oil or lube a good idea in fingerboard wheels?
• If it is, how often do you apply it?
• Is there a technique, given the nozzle is sized for skateboard bearings and "getting it in the tiny shielded FB bearing might be tricky"?

They also raised viscosity — whether oil thickness matters more at this scale — and noted that a mini fingerboard-specific lubricant sold by some American stores isn't a realistic option with UK shipping.

That's a well-framed question, and it exposes something: there is no widely circulated maintenance guidance for bearing wheels at this size. Plenty for skateboard bearings. Not much for ours.

Start with what's on the record.

• Piro Wheels — Toronto, handcrafted urethane. The brand lists 65D urethane and ABEC-9 bearings, and also makes pivot cups and bushings.
• Dude Guy FB — DGFB, a Utah wheel brand going since 2020, hand-sanded urethane, F1 and F3 lines, known for community collaborations.

Now the gaps, and they're the important part:

• Neither brand has published a maintenance or lubrication page that I can point you to. At the time of writing, no official "use this oil, this often" from either.
• Whether the bearings in Piro Performance wheels and DGFB F3s have removable shields, and whether the two models use comparable bearing construction, is not confirmed.
• Whether servicing a wheel affects any warranty or return is not confirmed.

One note on the ABEC-9 figure: ABEC is a dimensional tolerance class. It tells you how precisely the bearing was made. It tells you nothing about what grease is inside it, whether the shields come off, or how it handles solvent.

General workshop practice, not a Piro or DGFB instruction — treat it as a starting point, not gospel:

Less is a lot less than you think. A skateboard bearing takes a drop. A bearing this size takes a fraction of one. The useful trick with an oversized nozzle is to not aim it at the bearing at all: put the smallest drop you can on a pin, a needle, a toothpick tip or the corner of a card, and transfer it. You get control over the amount, which the bottle will never give you.

Thin beats thick here, but excess beats both for causing trouble. The failure mode with a tiny bearing isn't usually too little oil — it's a bore packed with oil that then collects every bit of dust off the table and turns into grinding paste. If a wheel feels sluggish after lubing, you used too much, not too little.

Solvent is the real risk, not viscosity. Anything aggressive enough to strip factory grease is also in contact with urethane and whatever retainer is in there. Penetrating sprays and water-displacers are not lubricants; they thin what's already in the bearing and evaporate, leaving you worse off. Household cooking oils gum. I'd want a maker or bearing specialist to sign off on any specific product before naming one, and nobody has.

A fixed interval is a made-up number. Nobody can tell you "every six weeks" without knowing where you ride. Go by what the wheel is doing:

• Spin test. Flick the wheel off the board. You're not after a long free spin — a fingerboard wheel doesn't need one, you push the board with a finger and roll a metre at most. You're after a smooth one. Gritty is the signal.
• Noise. A dry or contaminated bearing changes tone. You'll hear it before you measure it.
• A wheel that stops dead under light finger pressure, or one that's visibly dragging against a hanger, is a mechanical problem — check the nut tension before you reach for the oil.

Conditions matter more than time. Concrete-surfaced parks and wood ledges shed dust. Wax picks up everything it touches and migrates to wheels. Carpet and foam leave fibres that wrap the bore. If you only ride a clean desk and a wooden ramp, you may go a very long time doing nothing at all.

• Prying at shields with a knife blade. If the shield isn't designed to come out, you'll deform it and it will rub forever after.
• Dunking a complete wheel in solvent to clean the bearing, with the urethane along for the ride.
• Degreasing thoroughly and then not relubricating. A clean dry bearing is a fast bearing for about a day.
• Over-tightening the axle nut to "take the play out". It loads the bearing sideways and no oil fixes that.
• Lubing as a habit. Oil added on top of contaminated oil is just more paste.

Honestly: on this specific question, not enough in public. The thread above is the question, clearly put, from someone who'd already thought about nozzle size and viscosity before posting. I'm not going to put words in the mouths of people who replied to it — if you've serviced bearing wheels and know what the shields on a given model do, that thread is the place to say so, and it's the page the next rider will land on.

The gap is structural. Bearing wheels are a bigger part of setups than they were, the makers are small and hand-finishing their urethane, and maintenance guidance hasn't caught up with the hardware.

For a new set of Piro Performance wheels: do nothing. They're new. Factory lubricant is in there and adding skate oil on day one is solving a problem you don't have. Ride them, listen to them, and keep them off waxy ledges you've just over-waxed.

When one starts feeling gritty, the lowest-risk move is mechanical before chemical: pull the wheel, check the axle and nut, blow or brush out fibres and dust around the shield, retension. A surprising share of "dead bearing" complaints is a dirty hanger or a nut a half-turn too far.

If it's genuinely the bearing and you want to lube it, use the smallest amount of a thin bearing oil you can transfer on a pin tip, work the wheel, wipe off everything that comes back out. Standard skate bearing oil is the thing most riders in the UK can actually get, and the scale problem is solved by application technique rather than by finding a special bottle.

The caveat I can't remove: none of this is confirmed by Piro or DGFB, and whether the shields on either model are meant to come out is unknown at the time of writing. If a maker publishes guidance that contradicts any of the above, theirs wins — they poured the urethane and they chose the bearing.