Scale vs oversize wheel sets

[scotiatram]

My trolley layout uses ORR type (single point) transit turnouts and min radius curves of 6 1/8 inches. My magnificent new Peter Witt that I received for Christmas manages all left and right 6 1/8 curves with no difficulty and all left hand turnouts are no problem.
But with right hand turnouts, the lead truck refuses to track properly and proceeds straight through with the trailing truck following the diverging route to the right.
I temporarily weighted the front end with 1 1/4 oz, suspecting the lead truck was light, but that did not make any difference in tracking properly through right hand turnouts. 
All of my other trolleys have Bowser motive power and properly handle left / right and "Y" turnouts. I notice that the Bachmann wheel diameters and flange depths are smaller than the Bowser ones.
If the smaller Bachmann wheel / flange radii are the determining problem is there a solution - even if my beautiful model has to suffer having non-conforming wheel sets?

thanks
Scotiatram

[mhampton]

Well, smaller flanges almost always look better.  I would recommend you check the spacing of the wheels on the offending truck and the gauge of your track with an NMRA gauge.  Improper spacing of the wheels can lead to picking the points on a switch.

[scotiatram]

All good comments, however the point is that the Bachmann trolley's lead truck does not properly track through right hand turnouts but the trailing truck does. My 8 other Bowser units have no problem.

As I mentioned in the first post, all turnouts are traction style (single movable point) and the Bachmann trolley navigates 6 1/8 inch radius left and right curves easily and also has no problem with 6 1/8 radius left hand turnouts.

All 4 Bachmann axle/wheel sets conform precisely with the NMRA track gauge, so my conclusions are;
a) the lead truck's power train drive or wiring connection has very slightly more resistance to a right hand stress;
or
b) Bachmann's scale wheel diameter might have to be replaced with a non-prototype larger wheel. (which more closely will match the wheel diameter of the Bowser units which traverse the L/R points without problem. At this point I'll sacrifice a bit of prototypical accuracy for good operation.

What else might I be missing or might try.?
thanks
scotiatram