Hello,

I am writing because I am developing fingerboard wheels as a new product within my own brand. I professionally manufacture fingerboard decks and concrete obstacles, and now I am expanding my catalogue with cast and machined wheels.

The wheels have approximate dimensions of 8-9 mm in diameter and 4-5 mm in width, with housing for bearings. In this small format, the behaviour of the material is critical.

I have tried various casting polyurethanes, mainly Shore D (65-75D) type rigid/semi-rigid resins, but the results have not been satisfactory:

-Too light in feel
-Low resilience
-Poor grip or, in other cases, brittle behaviour
-Issues with bearing housing (tearing / low deformation capacity)

I have also tested material from commercial skateboard wheels (marked as 102A), but at finger scale, they are too soft and have excessive grip, so they do not serve as a direct reference either.

Therefore, I am looking for guidance to find a more suitable material, without closing the door to any approach.

Indicatively, the material I am looking for should have:

-High functional hardness (high Shore A ~97-98 real, Shore D (65-70)
-Low surface tack (non-sticky)
-High resilience / good rebound
-Good tear and abrasion resistance, as well as being dense, in other words, having a high weight so that the fingerboard doesn’t feel light
-Good behaviour against mechanical interference (insertion of bearings)
-Suitable for small parts, preferably processable by casting in mould

The functional reference would be closer to urethanes used in high-speed industrial wheels or rollers rather than materials designed for impact absorption or high grip.

If anyone has experience with:

-High hardness elastomeric polyurethanes
-Low tack / high rebound urethanes
-Industrial systems for rollers, pulleys or even high-quality micro-wheels, even Shore D that do work in this type of application

I would greatly appreciate any material, manufacturer or product family recommendations, or even warnings about paths not worth pursuing (some of which I have already learned the hard way).

Thank you in advance, and I am happy to provide any additional technical data as needed.