Changing Minitrix traction tyres (A4 and others)

[Justin Smith]

I bought a Minitrix A4 on E Bay and am very happy with it apart from the traction tyres, which come off all the time !
Can anyone please help me with some questions I have ?

Both tyres are on one side (the leading and trailing powered axles) and none on the other, is that right ? For a few reasons (including better traction on both rails as well as better electrical pick up from both rails too) I would have expected them to be on both wheels of the trailing powered axles ?

Is there a particularly good video about changing the tyres, removing the motion in particular. This one has a glitch right across where he is doing that bit!

The chap on the aforementioned video used this R913 tool for removing the motion, can anyone confirm that is the best thing for the job and also that it fits N gauge locos as well as OO (which is what the tool seller says it is for) ?

He also mentions using "silicone tube" for the tyres, is there any advantage to using that as opposed to the Minitrix tyres ?

Thanks.

== Doublepost prevention - post automatically merged: 22 Jun 2024 ==

Both tyres are on one side (the leading and trailing powered axles) and none on the other, is that right ? For a few reasons (including better traction on both rails as well as better electrical pick up from both rails too) I would have expected them to be on both wheels of the trailing powered axles ?

I have looked a a couple of videos of Minitrix N gauge steam locos and they both had the traction tyres on the same side on the front and rear driven axles. Does anyone know why this is ?

Useful article about the Minitrix A4 (and their other Pacifics ?).
This article might explain why both the traction tyres are fitted to the LH wheels. It also says that the front bogie picks up from the left hand rail (only) and thus that compensates for the less effective pick up from the LH drive wheels ?

Found another Youtube video on this subject.
Also the N gauge forum thread on Minitrix.

 

[DIW]

I see that there has been no reply so far to your query, so I'll offer the following.
I had a similar issue with an Arnold Rapido Bavarian S3/6. I was unable to track down a suitable set of tyres, so used 'Bullfrog Snot' instead. That has been working well so far. You can create a thicker tyre as required by adding further applications. Another advantage is that you can cut off the existing tyres (if they haven't fallen off already) and apply the product without the need to disassemble the coupling rods. Some modellers don't like Bullfrog Snot; perhaps my posting will provoke assistance of other sorts from them to your request.

 

[Justin Smith]

I bought the R913 tool and it does fit the N gauge Minitrix locos.
I also bought the Trix / Minitrix 12087800 (S) Traction Tyres (for Britannia/A3/A4) -Ex 72087800 mentioned in the opener.
I had some naïve idea I would be able to change the traction tyres without having to dismantle the valve gear but, obviously, that was never going to be the case.....
This page about dismantling a Minitrix Pacific was very useful, as was its brother page, rebuilding it again.

A few things I learnt : using a needle / large pin plus a fine hook was handy in putting the tyres on, particularly the front one.
I put a bit of blue tac in the R913 socket to hold the minute bolts, so as to then more easily screw then into the wheels.
At first I put the grey plastic crank in the wrong place, I think it was 180 degrees out, so I would recommend drawing a picture/plan of the valve gear or photographing it in its timing/position (relative to the wheels which will not move, unless power is applied to the motor ! ) just before you dismantle it.
Fortunately you only need to dismantle the LH valve gear as the traction tyres are only fitted on the (front and rear) LH wheels, they are the only wheels with rebates in them (for the traction tyres to sit in) to prove it !

I am very happy with the loco, it hauls 7 coaches no problem (though they are Lima, I find they do run easier, and derail less, than other types*) and nor does it derail on my tight rebuilt 1970s layout ! Unlike the Dapol A4 I bought the other year.....

* Even if they are slightly too small gauge wise !

 

[Justin Smith]

Oh dear.....
Flushed with success at successfully changing the traction tyres on my Minitrix A4 I thought I'd try doing the same on a Minitrix 2-6-0. I'd just bought it off E Bay and it did run but pick up could have been better and traction was poor. It would only just pull three coaches (round a fairly tight curve to be fair) so I checked the tyres and they were hard / brittle, they could not have been giving much traction at all.
I removed the body and was about to (just) remove the pins holding the motion onto the wheels (only using pins, not a screw so no spanner is req) when I saw this Youtube video where he changed the tyres by removing the wheels. I realised that would make the actual fitting of the new tyres much easier and additionally give an opportunity to clean the copper wipers onto that wheel. So I did remove the just front wheelset (on which the traction tyres are used in that model).
Then the problems started....
First you have to bend the wiper brushes back under the wheels whilst reinserting them, fiddly.....
Second you have to refit the axle with the gear in exactly the right position or the wheels and motion are out of phase. I had to remove/refit them once to achieve this.
Third, well I am not entirely sure what it was, but when I tried to run the loco it only went a few inches one way, and then locked up, then a few back the other and did the same. I do not know how it happened but the motion must have been out of phase somehow despite the fact I did not mess with it. Worse I then noticed that the (plastic) crosshead drop link on one side had broken.....
Fortunately I have some spares in the shape of a non working loco of the same type, my Dad bought it for me when I was about 14, so it has some sentimental value and, it seems, part of it will actually be used now ! But, particularly as there is some chance the phasing of the wheels is still wrong, the idea I may completely strip down the loco / motion, then change the crosshead and then it breaks again, is more than my sanity could cope with so I may get a model railway engineer to rebuild it.
The moral of this story is try and change the traction tyres without removing the wheels, i.e. like I did with the A4 above!

== Doublepost prevention - post automatically merged: 9 Jul 2024 ==

Does anyone know of a Model railway engineer who repairs N Gauge ?

 

[Justin Smith]

Does anyone know of a Model railway engineer who repairs N Gauge ?

"Dr Al" (off N Gauge Forum) repaired both my Minitrix 2-6-0 and reglued the steps onto my Grafar Black 5 (not a simple, job, I never manged it as well as he did), all for £30 plus carriage.
Result.