N Gauge Forum

General Category => N Gauge Discussion => Topic started by: mickster04 on October 03, 2017, 09:44:21 pm

Title: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: mickster04 on October 03, 2017, 09:44:21 pm
Hey team. I had a search around and rather than zombifying a really old thread or two that sort of cover the topic, I thought I'd create a new thread that really gets to my issue.

Firstly my assumptions, I assume that all pizza cutter wheels are one size (so poole and early china?) for most wagons? I have PGAs, HEAs, 100t tankers, FFAs and various mk1/2 coaches. I want to replace older wheels with newer ones, mostly for looks, but also for improved running (the flanges are giving me issues) and I assume they are all one size pretty much (coaches might well have bigger ones).

So then I would appreciate a list of current wheel suppliers. I know of N-train (https://n-train.net/epages/deba4b2c-2faa-4fd7-967f-c57d7bf70bd2.sf/en_GB/?ObjectPath=/Shops/deba4b2c-2faa-4fd7-967f-c57d7bf70bd2/Categories/Cabs_Etc), Graham farish do wagon wheels (http://www.hattons.co.uk/23578/Graham_Farish_379_410_Axles_with_3_hole_disc_wagon_wheels_Pack_of_10/StockDetail.aspx) and coach wheels (http://www.hattons.co.uk/23580/Graham_Farish_379_412_Axles_with_coach_wheels_Pack_of_10/StockDetail.aspx). Parkside Dundas used to do wheels, but they've changed now and their website doesn't let you order for N anymore, and the peco website doesn't let you order either.

Also, if anyone has any good definitions of various wheel diameters for various wagons, also is there a rule about spoked vs holed vs solid wheels?

MK1 coaches should have 7mm?
FFA (container wagons) should have 5.1? tankers too?
what about the two axled wagons, where they all the same? I see lots of posts asking about a specific wagon or coach so I'd be interested in a more collative approach.

What resources are there regarding this kind of information in regard to prototypical specifications?

Thanks all!

Mike
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: NTrain on October 03, 2017, 11:07:25 pm
I still have stocks of my 5.1mm wheels and I have a further batch of the 6.2mm disc wheels being manufactured now.

I have never looked at 7mm wheels, mainly because I have had no requests for them, and the expense of a new range of wheels would have to be factored in.
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: Skyline2uk on October 04, 2017, 12:59:13 pm
Another source of wheels is Peters Spares (Bachmann Farish wheels).

I have just replaced all the old "pizza cutter" wheel sets in my Poole 159 with newer finer equivalents.

Skyline2uk
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: martyn on October 04, 2017, 07:34:13 pm
I used to use Parkside wheels to replace Poole Farish and Peco wheels, but have now changed to using Farish ones; I think they run freer than the Parksides.

If you use 7mm wheels as replacements on coaches, this raises the overall height of the entire coach, and looks wrong, especially against the latest Mk1s or other makers' vehicles; they may also foul the underframe. I use 6.2  plain discs (or even in extremis, 3-hole discs.....)

HTH

martyn

Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: CarriageShed on October 09, 2017, 01:54:47 pm
I've used 7.0mm wheels for Farish carriage upgrades and rebuilds with no problems at all. The carriage height seems fine against other rolling stock (no Mk1s though, as I'm modelling 1930). Suppliers have been BR Lines, Etched Pixels, and Graham Farish, mostly based on the best price at time of ordering.
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: red_death on October 09, 2017, 03:28:44 pm
Some common wheelsizes:
BR1/Commonwealth bogies 3ft6 or 3ft7 ie 7mm (most Mk1s and some other stock)
B4 or B5 bogies 3ft ie 6.2mm (all (?) Mk2s and a few Mk1s)
BT10 bogies 3ft or 3ft1 ie 6.2mm (Mk3s)

Mk1 based DMUs all/mostly had 3ft wheels ie 6.2mm

Wagons are much more varied. Some have incredibly small wheels - IIRC the LTF 13 bogies under some FLAs have 540mm discs ie 3.6mm (I don't think anyone does anything that small - possibly some American wheels). The most standard will be 6.2mm but there were plenty that should ideally have 5.1mm wheelsets (eg FFA/FGAs, Cartics etc).  Then there is the question of disc, 3 hole disc etc!

Cheers, Mike
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: Jameswgm on April 13, 2018, 11:06:34 am
Would the MK4 BT41 be similar to the BT10 at 6.2mm diameter?
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: Papyrus on April 13, 2018, 01:37:55 pm
I'm glad you started this thread, Mike, as I am planning to replace wheelsets on some of my wagons and coaches. However, if I may ask what is probably an obvious question - does the quoted dimension, 5.1mm or 6.2 or whatever, mean the part of the wheel that sits on the track or does it include the flange as well?

Cheers,

Chris
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: koyli55002 on April 13, 2018, 08:23:43 pm
Across the wheel only, excluding flanges.
I used to replace my "pizza cutters" with Parkside, but for whatever reason, found the tyres coming off and leading to a lot of derailments. So now it's either Bachfar or else the "speedrollers" from N-Train.
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: PLD on April 13, 2018, 11:20:55 pm
Across the wheel only, excluding flanges.
Being pedantic; yes, but the quoted diameter should be at the point where the tread transitions into the flange... Rail wheels are normally conical so are slightly smaller diameter at the outer face (around 0.4-0.8mm on a typical N gauge wheel set)
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: NTrain on April 14, 2018, 02:31:34 am
(http://www.ngaugeforum.co.uk/SMFN/gallery/64/153-140418022935.jpeg)

Hope this explains the 6.2mm wheel sizes
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: PaulinSouthMidlands on April 15, 2018, 09:43:06 pm
But there are two different new profile blackened Farish wheel sizes available. 6.2mm (with flanges 7.1) for the older farish stuff  and the 7.1mm wheels with 8mm flanges used on Bachfarn Blue Riband, so which part number is which?
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: PLD on April 15, 2018, 10:11:26 pm
But there are two different new profile blackened Farish wheel sizes available. 6.2mm (with flanges 7.1) for the older farish stuff  and the 7.1mm wheels with 8mm flanges used on Bachfarn Blue Riband, so which part number is which?
Not quite...

There are two different wheel sizes available for products of all parentage...
6.2mm [379-410] for stock where the prototype was fitted with 3ft wheels (including mk3 coaches and most wagons) & 7.1mm [379-412] for stock where the prototype was fitted with 3ft 6in wheels (including Mk1/2 and most older coaches)...
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: PaulinSouthMidlands on April 16, 2018, 06:21:42 am
But there are two different new profile blackened Farish wheel sizes available. 6.2mm (with flanges 7.1) for the older farish stuff  and the 7.1mm wheels with 8mm flanges used on Bachfarn Blue Riband, so which part number is which?
Not quite...

There are two different wheel sizes available for products of all parentage...
6.2mm [379-410] for stock where the prototype was fitted with 3ft wheels (including mk3 coaches and most wagons) & 7.1mm [379-412] for stock where the prototype was fitted with 3ft 6in wheels (including Mk1/2 and most older coaches)...

Thank you for this. Most useful.

I would contend though that older poole models originally fitted with Pizza cutters had 6.2mm wheels regardless and 7.1mm wheels might cause problems on sharp curves with the wheel clashing with the underframe?
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: PLD on April 16, 2018, 07:46:17 am
But there are two different new profile blackened Farish wheel sizes available. 6.2mm (with flanges 7.1) for the older farish stuff  and the 7.1mm wheels with 8mm flanges used on Bachfarn Blue Riband, so which part number is which?
Not quite...

There are two different wheel sizes available for products of all parentage...
6.2mm [379-410] for stock where the prototype was fitted with 3ft wheels (including mk3 coaches and most wagons) & 7.1mm [379-412] for stock where the prototype was fitted with 3ft 6in wheels (including Mk1/2 and most older coaches)...

Thank you for this. Most useful.

I would contend though that older poole models originally fitted with Pizza cutters had 6.2mm wheels regardless and 7.1mm wheels might cause problems on sharp curves with the wheel clashing with the underframe?
No, because although the diameter over the tread is larger, the diameter over the finer flange is roughly the same...
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: red_death on April 16, 2018, 10:33:50 am
Most Mk2s ran on B4 or B5 bogies didn't they? In which case should be 6.2mm not 7mm.
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: woodbury22uk on April 16, 2018, 02:22:29 pm
For privately owned freight stock the standard wheelsize from the late 1960s to the late 1980s was 37.5 inches (953mm). This applied to prototype private owner freight stock with pedestal suspension, leaf spring suspensions and 3 piece (Gloucester/ESC/ etc.)/axle motion/Schlieren/GPS bogies. The standard wheel has a new diameter of 953mm (6.44mm) and a half worn diameter of 915mm (6.18mm). International/continental Y25 and LHB-type bogies typically have new wheels which are 920mm (6.2mm) and half worn 895mm (6.05mm). Bob Davies' 6.2mm suits both these in either half worn from 953mm or new 920mm condition. But I am fairly sure that model manufacturers have compromised on wheel diameter especially so the deeper flanges do not contact underframes.

This post has been corrected to describe the half worn diameters of the wheels, which I had wrongly described in the original post.
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: Papyrus on April 16, 2018, 04:49:46 pm
Blimey! I never thought my simple question about what the wheel size meant wasn't quite so simple after all!

Thanks for the very informative replies.

Cheers,

Chris
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: koyli55002 on April 16, 2018, 08:05:55 pm
Looks like the initial enquiry "steamrollered" a bit ?????
Title: Re: Correct wheel sizes, from older pizza cutters to appropriate replacements?
Post by: woodbury22uk on April 17, 2018, 10:55:39 am
I have made a couple of corrections to the meaning of the figures in post #16 above. I had described the half worn diameter as the fully worn diameter.