Making distinctions, Medium or Low Profile Wheel Sets

[jagged ben]

The phyiscal tread never really left the rail. but only the flanges on one side were making contact.
The sideplay is the ability for the wheelset to be moved perpendicular to the parallel rails. No other wheelset I own does that, or if they actually do then it isn't noticeable like it was with the FVM low-pros.

Every wheelset I own does that.    They're supposed to, if gauged correctly.

I do agree that the fine tread FVM wheels are not very compatible with Peco turnouts.  You can blame this on whichever you like.  I choose to blame Peco for not having NMRA compliant flangeways.  This results in the FVM wheel dropping into the middle of the frog instead of picking up the rail it's transitioning to with the outside of the tread.   This can result in derailments in a few ways.  It is indeed the case that FVM narrow-treads drop into the frog because of the narrow tread, but if you put them over an NMRA compliant turnout, like a well built Fastracks turnout, you don't get wheel drop.

As far as flange sizes, I humbly submit that any flange depth between .025" and 0.35" is 'medium', and anything above or below is 'high profile' or 'low profile' respectively.  Let the debate ensue.

[jagged ben]

I should add that shimming the guardrails on Peco turnouts won't help, in fact it will make the problem worse.  Now if you mean shimming the wing rails and trimming the shims flush in line with the closure rails, then that should help.

[bbussey]

FYI — I just checked the latest MTL price list.  Low-profile wheels appear to be discontinued, as only standard-profile and high-profile are listed.

[Ron McF]

I should add that shimming the guardrails on Peco turnouts won't help, in fact it will make the problem worse.  Now if you mean shimming the wing rails and trimming the shims flush in line with the closure rails, then that should help.

No, he DOES mean the guard rail.

On Peco points the gap between the guard rail and the stock rail is quite wide. The idea of shimming the plastic guard rail with a strip of styrene is to pull the axle across, so that the wheel on the other end does not take the wrong path through the frog.

I've done this on all of the Peco C80 points/turnouts that I have in my staging yard, and it is quite effective. This trick is illustrated in the June 2007 issue of Model Railroader, but has been around for a lot longer than that.

Regards,
Ron

[Ron McF]

Between the low and medium flange from MTL, you want the medium.  Not really for the depth but the contour.

Jason

I totally agree. It's ALL in the contour.

When I converted my ~ 300 freight cars to low profile wheel sets several years ago I used a mix of approximately:
70% - Atlas plastic wheels
20% - MTL low profile wheelsets with the pizza cutter flange
10% - metal wheelsets from Atlas and Intermountain.

The Atlas and Intermountain wheelsets have given me no performance problems at all, although a few of the plastic Atlas wheelsets were prone to wobble.

The MTL low profile wheelsets worked fine when pulling cars, but when pushing cars the flanges seemed just as likely to pick point blades as the original pizza cutters.  I've since replaced those wheelsets with MTL's medium flange axles, and they are great.

The MTL medium flange wheelsets are now my wheelset of choice, unless I need to add weight to a car (in which case I use metal wheelsets.)

Regards,
Ron