2R wheels on 3R track

Yes many do. You may see a little bounce going through turnouts. The 2 rail wheels just need a flat railhead to roll on.

@PapaBear posted:

I apologize if this question has been a answered already, I couldn’t find anything via search. Is it okay to use 2R wheels on rolling stock on 3R Ross track? I have a minimum curve of O72 if that matters.

Yes. That said, the turnouts become more of an issue than the track. Also, a LOT depends on which 2-Rail wheels sets are used. Some 2-Rail wheels have a narrower wheel tread than others, thus the brands with the wider wheel tread profile tend to track better on 3-Rail track.

What Hot says. Some are better than others. Tire width and gauge matters. The closer the distance between the front of the flanges is to 1.25” the better.

Pete

I run many 2-rail cars on my 3-rail layout with all Ross track and switches (#4 and #5).  As others have said, occasionally more modern equipment with finer flanges will pick a switch (however modern Atlas works fine).  I've found that older wheels with slightly bigger flanges work reliably.

I ran 2 rail wheels on Ross track for awhile but ended up going back to 3 rail wheels for reliability reasons. Getting tired of taking drug tests every time I put cars on the ground lol For switching operations, especially shoving cars was always problematic. Dragging cars through turnouts was OK, but still not reliable enough for me to deal with. Kadees 100% a yes for me, but 2 rail wheels wasn't worth the trouble. 

Thanks all. I think I would probably be ok, I don't have a switching yard and my layout is fairly simple but I am probably going avoid going with 2R wheels.

I had a layout many years ago  using Gargraves track and I ran many cars and a couple locos on it that had 2 rail wheels.    At one point as I was considering 2 rail, I rewired part of the layout for 2 rail operation and that worked with the 2-3 locos I had at the time.

As long as you have flat top rail, running 2 rail wheels is not a problem.    Sometimes cars will climb a frog but that is easy to fix by increasing the height of the guardrails on the turnouts.    I did this on some of mine.

@PapaBear posted:

I apologize if this question has been a answered already, I couldn’t find anything via search. Is it okay to use 2R wheels on rolling stock on 3R Ross track? I have a minimum curve of O72 if that matters.

I have a lot of experience in this area and YouTube videos to prove it. The quick answer is yes you can. There are some complications, though.

• Turnouts: Ross turnouts generally will work, but curve-replacement turnouts (i.e. O-72) will likely have issues because the arc of the curve extends through the frog and the wheels may pick the frog and derail. Atlas turnouts will require shimming up the guard rails as they're lower than the running rail head. Ross 11-degree (#5) turnouts have worked fine in my experience (2 derailments total out of all that running I did at AGHR).
• Track gauge: If using Gargraves track, the gauge actually "floats" a bit and if the gauge is too wide, some cars may derail. Ross and Atlas track don't seem to have an issue.
• Kinks: You don't want them even in a hi-rail context, but they're really bad with scale wheels. You don't want vertical kinks either as wheels can lift up off the rails and derail. This also applies to twisting where one rail is substantially higher than the one across from it. I found some kinks on curves at the club layout where the track actually had a dip at the joint due to thermal expansion/contraction and they were deep enough for the locomotive to literally walk out of the gauge.
• Insulated rail: Won't work with 2-rail wheel sets as they're insulated and won't complete the bridge between running rails. Switch to optical (IR or Photocell) triggering. You can tinker with the trucks and add wheel wipers to bridge the wheels if you absolutely need them to trigger insulated rails.
• Kadees: Kadee couplers work great, but you are generally restricted to 36" Radius (O-72) or larger curves. You also have to be careful with car lengths because some longer cars (89-foot trailer flats, 86-foot box cars) have more "swing out" at the car ends. Long-shank couplers (Kadee 746) seem to remedy this, though.

If your track work is clean you shouldn't have a lot of problems, save for the couple of cars that will derail for no apparent reason. I have two Atlas and one Weaver car that appear to have nothing wrong mechanically, but they randomly derailed at the club. Never did figure out why. If you have a consistent spot where they derail, you have something going on with your track.

Hope this helps.

I've a couple dozen freight cars...build from older kits...that have O2R trucks...with metal wheels.

My layout is all Ross/Gargraves and they run fine but with the turnout caveats mentioned in the prior responses.

I'm particularly happy with using O2R trucks on cabooses.  First of all, since they're on the tail end of the train, the tracking of the car is not 'stressed' by a following load.  Even though my curves are reasonably generous (072 min.), light or no following loads for the O2R cars can only help keep them from being prone to string line derailments.

I also found that some of the older Athearn wood/metal kits I acquired had O2R truck kits.  And, the flanges of those wheelsets are larger than the NMRA 'RP25' standard, but not as large as typical O3R Hi-Rail flanges.  In fact, when built and gauged correctly, they perform very, very well...IMHO.  And, being of total metal construction, the trucks add a lot of low CoG weight where it's of most benefit in operation.  Sadly, they're becoming harder to find as time goes by, in unbuilt or good condition.

The prototypes for the last 3 or 4 Ambroid caboose kits I built had older Achbar-esque style trucks.  I modified the yet obtainable Athearn plastic trucks, replaced the wheels with InterMountain metal wheels, and the truck coil springs with Precision Scale's leaf springs.  Look great, roll very well on Ross/Gargraves after a few easy tweaks.

Lastly, as others have suggested, if you try using O2R trucks and encounter random derailment issues, check your trackwork first!  Cars with O2R trucks on a Ross/Gargraves O3R layout can be analogous to the canary in the mine.  (Don't bother asking...it's an embarrassing answer.)

FWIW...

KD

@AGHRMatt posted:

I have a lot of experience in this area and YouTube videos to prove it. The quick answer is yes you can. There are some complications, though.

• Turnouts: Ross turnouts generally will work, but curve-replacement turnouts (i.e. O-72) will likely have issues because the arc of the curve extends through the frog and the wheels may pick the frog and derail. Atlas turnouts will require shimming up the guard rails as they're lower than the running rail head. Ross 11-degree (#5) turnouts have worked fine in my experience (2 derailments total out of all that running I did at AGHR).
• Track gauge: If using Gargraves track, the gauge actually "floats" a bit and if the gauge is too wide, some cars may derail. Ross and Atlas track don't seem to have an issue.
• Kinks: You don't want them even in a hi-rail context, but they're really bad with scale wheels. You don't want vertical kinks either as wheels can lift up off the rails and derail. This also applies to twisting where one rail is substantially higher than the one across from it. I found some kinks on curves at the club layout where the track actually had a dip at the joint due to thermal expansion/contraction and they were deep enough for the locomotive to literally walk out of the gauge.
• Insulated rail: Won't work with 2-rail wheel sets as they're insulated and won't complete the bridge between running rails. Switch to optical (IR or Photocell) triggering. You can tinker with the trucks and add wheel wipers to bridge the wheels if you absolutely need them to trigger insulated rails.
• Kadees: Kadee couplers work great, but you are generally restricted to 36" Radius (O-72) or larger curves. You also have to be careful with car lengths because some longer cars (89-foot trailer flats, 86-foot box cars) have more "swing out" at the car ends. Long-shank couplers (Kadee 746) seem to remedy this, though.

If your track work is clean you shouldn't have a lot of problems, save for the couple of cars that will derail for no apparent reason. I have two Atlas and one Weaver car that appear to have nothing wrong mechanically, but they randomly derailed at the club. Never did figure out why. If you have a consistent spot where they derail, you have something going on with your track.

Hope this helps.

Matt, I sent you an email with some questions I think you can answer for me'... QG

Has anyone tried swapping out one of the 2-rail axles for a 3-rail axle?  Would that help to keep the car from derailing when pushed on traveling through a frog?

Jan

I've swapped out many 2-rail wheelsets on Weaver plastic trucks, it's easy to stick in 3-rail wheelsets.  The Diecast Weaver trucks are more of a challenge to swap out the wheelsets.