DCC Fitting Series: Bachmann Class 25

Last time in the DCC Fitting series I looked at the Bachmann Class 03, and although it was a breeze to fit the chip, the performance left much to be desired. Let’s have a look at what’s next in line:

Class 25 by Bachmann

Bachmann really know how to make a good motor mechanism and on analogue, like the 03, this was one of my top 5 runners. More on that later, let’s start with the fitting process:


Bachmann Class 25 in BR Two Tone Green

How Easy Is It To Fit?

I’m happy to report that like the 03, this too is a doddle to get into… Simply remove the 4 screws shown…


Remove the 4 screws with a micro Phillips screwdriver

Hold the under-frame steady, and the body should come right off.


Body Removed

Bromsgrove Models talk of an 8-pin socket and also adding some insulator tape between the PCB board and the chassis. My edition however seems to be a later version and accepts a 4 function 21-pin decoder, and needed no further modifications. If you’ve got the 8-pin model, follow the link above for some additional advice.


“REV A” should be facing upwards, with the bulk of the components and pins also on the upper side.

The manual that comes with the loco (and the one that comes with the chip) should also help you figure out which way to insert the chip. It’s also made obvious by the PCB board having a helpful chip shaped rectangle printed on it as a clue.

It’s worth pointing out at this stage that it’s always best to test and address your freshly chipped loco before you put it back together (if possible). In the case of some models, like the 25, you might not be able to test the lights at this stage as the accompanying circuitry detaches with the body.


These contacts connect when the body is screwed back together. Be sure not to bend them in the fitting process.

Carefully place the shell back on the under-frame and replace screws. It’s that simple.

Fitting Score: 10/10 I feel there’s not much that could be done to make this easier, it’s a well designed setup that also doesn’t compromise an excellently detailed model in any way.

How Does It Run?

Once again I’ve opted for a Bachmann EZ Command chip (The 21-pin variant has reference no. 36-557), again on the basis it’s a Bachmann chip it should work perfectly with a Bachmann loco. It’s also the default brand I get given when I ask my local model shop for a 21-pin chip without specifying a make.

This time round I’m not disappointed. The loco, already fairly silky smooth on DC, glides effortlessly over the rails without so much as a whisper. The slow speed performance, which lets face it – is one of the best parts of DCC operation, is incredibly impressive.

The lights shines nice and brightly, yet not too much to burn-out the legibility of the headcode.

Is there anything negative to say? Well not really. I mean if I was being super picky, it would be good if there was a cab light, or if you could turn off the tail lights individually but this is more down to the design of the model rather than the installation of the chip.

DCC Chip/Running Score: 10/10 Even though some Forums shy away from the cheaper Bachmann chip, the combo seems to work perfectly. Job done!


Lights On!

Overall Score: 10/10 This was actually the first loco I chipped. So why didn’t I start the series with this post I hear you cry? I didn’t want to come straight out the starting blocks without a bad word to say for the DCC fitting process, especially as I know that the results have differed wildly. If I’d started by saying everything was hunky-dory then perhaps you wouldn’t have come back! The Class 03 was a good starting point as it instantly highlighted both the good (easy fitting) and the bad (cheap chip giving average performance) of DCC conversion. The Class 25 sets the bar high for DCC conversion. So was it all down hill from there?

Other Locos in the DCC Fitting Series

  • Class 03
  • Class 17 (coming soon)
  • Class 47 (coming soon)
  • Class 128 (coming soon)

– Andy Carter

DCC Fitting Series: Bachmann Class 03

The development of my new layout, Woodford Wells, has been an interesting one. Not least for delving into and learning the brave new world of DCC. (Not really new for most of you, but new for some of us!).

So far the DCC construction and design process has been fairly smooth. The track was easy to wire, the control system simple to learn and the point motors (iP Cobalts) work perfectly. I knew that the hardest part of the DCC learning curve would be upgrading my existing rolling stock. I’ve had to open up a couple of locos in the past to upgrade lighting or to trouble shoot faulty motors and it’s never been an easy process. The fear of damaging delicate and expensive scale parts is always prevalent even with older models. This is something to consider when ‘chipping’ stock yourself. Secondly there was also the assumption from myself that once a chip was inside a loco, the performance would dramatically increase…

This series of fitting guides hopes to shed light on how easy it is to fit chips to given locos (starting with the first 5 that have already undergone the upgrade process) and to investigate what the performance is like after the conversion.

Class 03 by Bachmann

For all of these guides so far I’ve had help from Bromsgrove Models, a site with a comprehensive list of DCC fitting guides. I’d recommend studying these before you consider self-chipping any of your own stock.


Bachmann Class 03 in BR Blue (Weathered).

How Easy Is It To Fit?

Very. And that’s why I’m starting with this model.

Simply take out the NEM pocket adapters (a small flat head screwdriver will help). This reveals two screws.


Remove the two screws circled.

Remove these screws, and bingo, the body lifts off with ease.

It’s then a matter of fitting the chip. For those not in the know (as I wasn’t but a few months ago) DCC chips comes in a variety of sizes, the most common are 8 or 21. But for some of the smaller locos, like the Class 03, something a little smaller is required: A 6 pin chip. The number of pins a chip has, and do correct me if I’m wrong, directly corresponds with how many functions the decoder can store. A function is a programmable ‘extra feature’ a loco may have beyond it’s motor drive (i.e. directional lighting, cab lighting, sound etc). The more pins you have, the more functions the chips seem to accommodate. Most of the time locos only come with the need for 1 additional function – lights. This is just as well as the chip I’ve bought – the Bachmann E-Z Command 36-558A – can only accommodate 1 additional function, but that’s all I need at this stage.


Pin 1 is identified by a small white square.

Make sure you fit the chip the right way round. Pin 1 (above) must align with socket 1 which is at the right-hand edge of the strip (bellow). All chips should tell you which pin is pin 1.


Pin 1 on right-hand side. Click to enlarge.

Refit the body and NEM pockets and you’re good to go.

Fitting Score: 9/10. Dead easy, just make sure you fit the chip the right way. Not as obvious as a 21 pin decoder, but it’s hard to get wrong.

How Does It Run?

On Analogue the Class 03 was one of the best (if not THE best) performers I had. The gearing is set up in such a way that you can crawl along the track on DC accurate to real life. It was like moving on silk it was that smooth of a mechanism. The Class 03 was high on my list of locos to get chipped when I started the new layout and I instantly had high hopes in terms of making that silky smooth performance even better.

I was quite disappointed.

The ultra-low speed operation is now jerky and uneven. It smooths off a bit when you get to the locos lower-mid range (perhaps a scale speed of 6-8 mph), but even at this pace it’s not quite as good as it once was on DC.

This is when I discover, with a little research, that there are differing premiums of chip. I wrongly assumed a chip would be a chip – how much can one manufacturer differ from another?! – and that a Bachmann at least one would work perfectly in a Bachmann model. Forum trawling highlights that many folk struggle to find a kind word to write about Bachmann’s 6-pin chip, and sometimes struggle to find anything nice to say about Bachmann chips full stop. I certainly have come to learn quickly from the fitting of the other 4 locos I’ll eventually do guides for, that the results of Bachmann chips differ wildly. But then this could boil down to the age old “you get what you pay for.” I’ve seen recommendations for Lenz and Zen chips, but as you’d expect some of these come at twice the price of the evidently budget Bachmann one.


Bachmann 36-558A E-Z Command Chip.

DCC Chip/Running Score: 4/10. I say all this without actually trying an alternative chip – I’ll try another decoder and report back, but until then, the Bachmann chip + 03 combo really doesn’t cut the mustard. Don’t get me wrong, it works (and the cab light looks rather smashing all lit up) but I was expecting more. It also causes a problem with push-shunting coaches with sprung loaded NEM coupling arms – I use delayed action Kadee couplers and the jerky behaviour sometimes frustratingly re-couples the knuckles.


Lights On!

Overall Score: 6.5/10. Bachmann are all over the place here. They’ve created a model that’s easy to DCC fit, and for that – for DCC newbies like me – I thank them profusely. However, the chip as far as I can tell is dreadful and doesn’t do a superb model and mechanism justice.

I hope you’ve found this guide useful, please check back soon for more loco fitting advice, oh and if anyone has any other suggestions/alternative chips for the Class 03 – please comment bellow!

Other Locos In the DCC Fitting Series:

  • Class 17 (Coming Soon)
  • Class 25
  • Class 47 (Coming Soon)
  • Class 128 (Coming Soon)

– Andy Carter