Spent heck of a lot of time trying to get chassis running properly with these. Never really worked. Tires kept coming off and at first didnt put them back very straight. Crankpins were never particularly straight - didnt help when soldered washers on - realised there was a problem when a crankpin just fell out without unscrewing. Took ages to get axles fully in and they were never particulary perpendicular. At first fiddled with coupling rods, then realised was crankpins in wheels. Finally got it running with only minor wobble. Gave up and got some Romfords, they went straight on to axles with no filing (thats quite rare for me). Crankpins straight as always. Chassis with coupling rods smooth as a nut.
Whats other peoples experience - any hints apart from dont solder ....:-)
Cheers, Simon