Tim O'Connor wrote: "At a train club I belonged to, MANY cars with
Kadee wheels (mostly in non-Kadee sideframes) wore down the ends of the
axles to a round nub! In a high-use context, metal axles last longer...
But yeah, on a private low-mileage layout, it's probably not an issue."

======================================

Tim,

Were non-Kadee truck frames metal or plastic? Some of the problem of
wear may relate to what JP Barger noted in his presentations on truck
frames and wheel-sets that one wants metal axles in plastic truck frames
or the opposite. Kadee's older trucks always had plastic axles in metal
truck frames. It will be interesting to see how the new
plastic-on-plastic combination will perform long-term.

Bob Witt

Tim O'Connor wrote: "At a train club I belonged to, MANY cars with
Kadee wheels (mostly in non-Kadee sideframes) wore down the ends of the
axles to a round nub! In a high-use context, metal axles last longer...
But yeah, on a private low-mileage layout, it's probably not an issue."

======================================

Tim,

Were non-Kadee truck frames metal or plastic? Some of the problem of
wear may relate to what JP Barger noted in his presentations on truck
frames and wheel-sets that one wants metal axles in plastic truck frames
or the opposite. Kadee's older trucks always had plastic axles in metal
truck frames. It will be interesting to see how the new
plastic-on-plastic combination will perform long-term.

Bob Witt

In my rollability tests with the beautiful new Kadee Barber plain bearing trucks, both the Kadee and the Reboxx 0.088" tread replacement wheel sets (the latter with 1.020" axles) rolled only insignificantly better than the OEM standard wheel sets, not enough to make changes on that basis alone. With none of the tested wheel sets, however, did these Barber trucks roll beyond a mid-point "Acceptable/Good" level, a point just beyond half way to the "Superior" level of rollability achieved by a number of other contemporary trucks- most with replacement wheel sets.

A similar test (less the Kadee 0.088" wheel sets) with the equally new Barber S3 roller bearing trucks demonstrated about a 50% increase in rollability with Reboxx 1.025" wheel sets as compared to the OEM sets.

Denny S. Anspach MD
Sacramento

Tim O'C inquires about the effect of weight on truck rolling test data.

I do not routinely test truck rollability with/without weights, although I do so on occasion. My reason for not doing so is that I use the test data to conveniently guide my choices of wheel sets going forward (not excluding leaving OEM alone!) without having to parse out with testing anew with each install the usual small inherent differences resulting from both variable weighting, but also rollability differences caused by the common variability between nominally-identical trucks. Sometimes the weight improves rollability, occasionally in dramatic fashion; while at other times, the same weight can all but stop a truck dead in its tracks. Most of the time, in real time, it makes no difference.

As to the new Kadee trucks, I did indeed test the Barber S3 with and without weight. The weight (a 1-oz. lead block balanced on the truck bolster) caused the rollability to improve, but ever so slightly- remaining still in the midst of the Acceptable/Good field. This was why it was not mentioned.

Denny S. Anspach MD
Sacramento

Denny, a 1 oz load is about 1/2 the typical load of a freight
car. There are also rolling dynamics involved. And under load,
the shape of the bearing and journal, and the materials, makes
a big difference. Kato ASF A-3 trucks for example roll incredibly
well without a load, but as the load increases, the performance
is affected -- it's almost a straight-line correlation.

I roll test every car that I put together, or make ready for
operation. It takes a little time, maybe 20 minutes, to identify
the proper truck design for that model and then find a model truck
and wheelset combination that gives good results. It's makes no
difference to me how well a truck rolls "in theory".

For example, remember those old Lindbergh trucks? Those things
rolled like crazy, we thought they were miraculous in the 1960's.
Oh wait, until you put a car on them. Then your results may vary.

Tim O'Connor

Tim O'C inquires about the effect of weight on truck rolling test data.

I do not routinely test truck rollability with/without weights, although I do so on occasion. My reason for not doing so is that I use the test data to conveniently guide my choices of wheel sets going forward (not excluding leaving OEM alone!) without having to parse out with testing anew with each install the usual small inherent differences resulting from both variable weighting, but also rollability differences caused by the common variability between nominally-identical trucks. Sometimes the weight improves rollability, occasionally in dramatic fashion; while at other times, the same weight can all but stop a truck dead in its tracks. Most of the time, in real time, it makes no difference.

As to the new Kadee trucks, I did indeed test the Barber S3 with and without weight. The weight (a 1-oz. lead block balanced on the truck bolster) caused the rollability to improve, but ever so slightly- remaining still in the midst of the Acceptable/Good field. This was why it was not mentioned.

Denny S. Anspach MD
Sacramento