Hornby Coach wheel size

[Thane of Fife]

I am renovating some old Hornby GWR stock. 

 

I wish to fit more realistic wheels, with narrower treads.

 

I have found that the wheels are 12mm diam.

 

I thought that the majority of companies used wheels of around 3ft6ins (14mm) diameter.

 

I am wondering if the stock of 14mm wheels that I've built up is now of no use

 

GIbson do market 12mm Mansell wheel.

 

Which is right??

 

Thane of Fife

 

 

[jwealleans]

I don't do GWR, but all the LNER and constituent coaches I've ever built have 14mm wheels as do most if not all of the NPCCS. 

 

The only prototypical use I've ever found for Hornby 12mm wheels is on continental ferry vans.

 

How good are the Hornby bogies on the stock you're working on?  You may get better running replacing them with heavier kit built ones and fitting 14mm wheels to those.

[Dunsignalling]

I am renovating some old Hornby GWR stock. 

 

I wish to fit more realistic wheels, with narrower treads.

 

I have found that the wheels are 12mm diam.

 

I thought that the majority of companies used wheels of around 3ft6ins (14mm) diameter.

 

I am wondering if the stock of 14mm wheels that I've built up is now of no use

 

GIbson do market 12mm Mansell wheel.

 

Which is right??

 

Thane of Fife

Not the Hornby ones. 

 

There is almost certainly something obscure that I haven't come across but, in general, 3' 7" wheels were used on prototype coaches until BR introduced the B4 bogie under late Mk1 coaches.

 

John

[YK 50A]

Hello,

 

Which 'old GWR stock' are we talking about?  Much of the Tri-ang Hornby and 1970s origin models were fitted with underscale 12mm wheels.  Off the top of my head and from personal experience, I'm thinking the BR Mk1s and the representative LMS and GWR coaches (still sold in the RailRoad range).  No doubt many other models too.

 

Whether it is worth trying to fit accurate kit bogies or even butchering the Hornby originals depends on the models you have and how important it is to you.  The GWR clerestory's and Collet's aren't particularly accurate in any case, although they can be made much better.  Do an RMweb or Google search on the subject.  The problems you will have fitting 14mm wheels to bogies designed for 12mm wheels is fouling the underside and the brake gear, etc.

 

The Gibson Mansell wheels aren't 'wrong', they might be intended for wagons or 4 wheel coaches.  I don't know if looking through this set of pictures might help?

 

I have previously retrofitted accurate bogies (and 14mm wheels) to a Lima Siphon G and Stanier Bogie CCT, which improved the appearance no end.  They were originally fitted with HO bogies and 12mm wheels.

 

All the best,

 

Alun

[Adrian Wintle]

A simple change is to use the Hornby 12mm metal disk wheels as they should be drop-in replacements for the older wheels. Going to a a more accurate 14mm wheel may cause clearance issues, depending on which coaches we are talking about. The 7' bogies of the Hornby Colletts will take 14mm wheels relatively easily, while the 10' Dean bogies of the long clesrestories are more problematic.

 

Adrian

[naugytrax]

The original issue of the Hornby 57' GWR carriages were fitted with BR B1 bogies. Later issues had more correct GWR 7' bogies. Either way, the 12mm wheels were too small. If you fit 14mm wheels to these coaches the brake blocks do not interfere because they are not moulded in line with the wheels. However, the coaches will ride too high on the larger wheels. There is a boss beneath the coach floor which sits on the top of each bogie and forms the pivot. If you file these bosses down so that they are level with the bottom of the solebars, the coach height will be approximately right.

[JeremyC]

How old are the coaches? Older Triang-Hornby coaches had the buffer height too high [around 2mm IIRC] even with the incorrect 12mm wheels fitted so 14mm wheels will add another 1mm to this. The correct buffer height should be around 3 foot 6 inches from rail level [14mm in 4mm scale].

[mozzer models]

A simple change is to use the Hornby 12mm metal disk wheels as they should be drop-in replacements for the older wheels. Going to a a more accurate 14mm wheel may cause clearance issues, depending on which coaches we are talking about. The 7' bogies of the Hornby Colletts will take 14mm wheels relatively easily, while the 10' Dean bogies of the long clesrestories are more problematic.

 

Adrian

Up until Hornby did the 61foot gresleys then all there rolling stock coaches & wagons had 12mm wheels except the 4 wheel well wagon which was a ex airfix/dapal & this uses 10mm wheels

 

if you fit the new 14.1mm Hornby coach wheels then the coach will sit to high which will curse proplems if you are still using the Hornby couplings

[kevinlms]

Up until Hornby did the 61foot gresleys then all there rolling stock coaches & wagons had 12mm wheels except the 4 wheel well wagon which was a ex airfix/dapal & this uses 10mm wheels

 

if you fit the new 14.1mm Hornby coach wheels then the coach will sit to high which will curse proplems if you are still using the Hornby couplings

As well as look ridiculous, as they will look as if on stilts. Better IMO to stick with 12mm wheels, unless prepared to lower the body, in some of the ways already described.

[Thane of Fife]

Thanks for the interesting replies.

 

If the mounting boss on the underside of the coach is reduced then the ride height should be the same.

 

The bogies look like BR Mk1, and seem to accept 14mm Gibson wheels OK.

[YK 50A]

The bogies look like BR Mk1, and seem to accept 14mm Gibson wheels OK.

 

Hello again,

 

I am wondering why you would go to the effort of filing down the bosses to fit accurate scale wheels to the wrong bogies.  While I seem to remember the old Hornby BR1 bogies are a reasonable enough representation, they wouldn't have been seen underneath GWR origin stock.  Without knowing which coaches you have, I can't direct you to an appropriate type of bogie, but I think with my Lima Siphon G, the replacements came from a Hornby (Airfix) GWR Autocoach, which is a close match to most of the late survivors on the big railway.  There are also Bachmann and newer Hornby GWR bogies of various types, not to mention kits.

 

If you're sticking with the BR1 bogies, as one or two other people have suggested, why not just fit replacement 12mm metal wheels (note, the 3 hole wheels would have only been seen under wagons) or go the whole hog and give your coaches the correct footwear?  Your railway!

 

Alun

[Il Grifone]

There are only really three candidates for the coach types - The Tri-ang clerestories (BR MK I - should be Dean*), the 57 foot Colletts (early examples BR MK I, later GWR 7 foot bogies (correct)) and the later Clerestories which have Dean 10 foot bogies (again correct).

 

Unless you have the version with the awful open axleboxes, the Tri-ang/Hornby MK I bogie is not too bad apart from the top part of the frame being too thick and resulting in excessive ride height, despite the undersized wheels. They are, of course, totally unsuitable for any GWR vehicle and require replacement, preferably with white metal or etched bogies with the right sized wheels. The clerestories had Mansell and the Colletts steel wheels as built.

 

* As these are not strictly accurate for any GWR diagram, the correct version of Dean bogies is debatable. I think they are nearest to a D37 for the brake/third (the brake section is too short) and the supposed composite is a single class vehicle as all the compartments are the same length (ignoring the end compartments where the end panel is wrong) either too long for a full second (none existed AFAIK) or a short full first. Both ran on 10 foot bogies I believe.

[Dunsignalling]

If your coaches are the Collett style (like the ones currently in the Railroad range, albeit with different bogies) I would expect them to have the BR1 type bogie.

 

The obvious replacement is the GWR 7' type later fitted to these coaches by Hornby which come with wheels of about 13mm diameter but will accept 14mm ones. I don't know if these are currently available as spares but if you do use them it may be necessary to lower the ride height a bit (up to 2mm) by reducing the boss into which the bogie clips. Some years ago, I did this with the similar Southern coaches and did not encounter any clearance issues.

 

Another possibility is to fit Bachmann Collett bogies which I think are fairly readily obtainable, complete with metal wheels of the correct size. Appearance-wise, this is probably the best option but you will have to devise a way of fitting them as the Hornby chassis is designed to accept clip-fit bogies and Bachmann attach theirs using screws. Not rocket science, though.

 

John