DCC Loco Conversions - 4 - Worth the Effort? – Part 2 of 5

4) Serrated Wheel Treads

Serrated wheel treads are those which have grooves across the wheel tread in line with the axle.

These were applied to some Tri-ang diesel locos and DMUs to give a growling sound when running, unfortunately they reduce the contact area between wheel and rail and even worse fill up with grime, and their surface is difficult to clean.

Three options here, replace the wheel sets with later smooth variants if available, part exchange them for re-profiled ones (e.g. on *bay) or replace unpowered wheels (except on the dock shunter of course) with metal wheel sets and add pickups to them so the power bogie wheels are only used for driving.

Retaining serrated wheels is likely to require a decoder with stay alive for reliable running.

5) Unplated alloy, Bronze or Brass Wheel Treads

These are a cleaning nightmare, they oxidise fast and accumulate grime nearly as bad as plastic wheels, IMO they should be discarded if possible and the locomotive re-wheeled, something I find is a must for pre-DCC Lima diesels for which as much time was spent cleaning as running.

The change of wheel sets and other changes is likely to cost more than the original loco so it really is a matter of preference.

Re-wheeling a steam outline loco is much more difficult as nearly every loco is different, so alternatives?

Well, the use of a stay alive or a brown out protected decoder will help but in the end the loco will still need wheel cleaning more often than a current design, both the tread and the surface on the back of the flanges where the wipers collect power.

This however is part of the joy of running any vintage vehicle, frequent maintenance is required.

6) Rubber Tyred Wheel Treads

These are a source of dirt, they accumulate dirt which eventually makes for lumpy rolling (loco behaves as though it is riding on cobblestones), crumble and even go sticky. Dispense with these if possible, easier on diesels as wheel sets sold for fine scale models are available. Also worn tyres can slip, and create uneven running as they perish.

These can be problematic on British Trix steam loco driving wheels too for dirt but I have found them to be in very good shape, flexible and gripping despite being some 60 years old. They appear to be more of a clear silicon rubber.

Cannot say the same for tender drives of the same era where the tender tyres have shrunk so much in thickness that they are below the surface of the rims holding them in place rendering them useless.

7) Chrome Plated Plastic Wheel Treads

Not so common but were used by Palitoy on loco wheels, once again you can be lucky but these can age badly resulting in cracks and finally disintegration, but at least this is easily visible without dismantling.

Associated with this is that the plating extended to the stub axles which fit into the notorious plastic axle tubes. The plating on the stub axle of the wheel passes electric current to half of the chassis and once worn means very poor or no current collection via that wheel. Addition of conductive grease can extend the life of these bearings for a short while.

I have a number of Palitoy steamers but very few are in a fit state for conversion due to aged wheel plating alone.

8) Metal Plated Wheel Treads

Plating on metal tyres fitted to e.g. Hornby Dublo is pretty hard wearing although it can wear through to a brass layer or even pit and breakaway, I have an R1 like that. Generally the wheel treads on Hornby Dublo locos are remarkably narrow for their era and generally last a lifetime.

Well worn plating on many metal wheel treads reveal a brass layer which is a poor conductor relative to the plated surface and will need cleaning often. This I have found on anything from British Trix A2 metal tender wheels to well used Bachmann and Hornby. A decoder with stay alive may be required.


Next, I continue by assessing Pickups and Chassis

Jim

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Image: Hornby tender drive 9F fitted with a Hattons DCR-8PIN-HarnessMini decoder.

 

Updated content of (5) including addition of unplated alloy wheels.