Wheel and track standards was Gorre and Daphetid

> In the smaller scales like HO the improved
> > appearance of P87 wheels compared to HO finescale is not noticeable > > unless you are up close and looking for the difference. Only the > > track appearance between P87 and finescale HO is noticeable, but only > > if you are looking for the difference. > > This depends much of the design of the prototype rolling stock you > model. > > I agree that for stock built since, say, 1950 there not that much visual > difference, as for older US stock. But for older UK and Danish stock > (from around 1900) there is a noticable visual difference. > > -- > Best regards > Erik Olsen >
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P87 is a dead end. You are on the limit of practical tolerances, and the wheels are not a noticeable improvement when compared to HO finescale wheels. For example the difference in flange depth is only 0.3mm between exact scale and the NMRA maximum depth flange. If you use 2.1mm width finescale wheels with 0.7mm wide flanges, your tread width is the same as the proto87 wheel tread width. NMRA RP25-88 wheels will only be 0.1mm wider than the proto87 wheel, with a flange depth of only about 0.2mm deeper than scale. Also using HO finescale achieves scale wheel front face to front face distance, which solves most scale problems P87 also solves. Down under the RP25-88 wheel is commercially supplied as a HO finescale wheel, which is popular for early NSW era models, many are UK styled prototypes..