Revolution Pendolino first run - factory fitted DCC and sound:
One driving car (marked "rear" when the body shell is removed) cannot be read at all on the programming track, or comes up with wild read CV numbers like 255 or 164, but will not write any CV's. I have gone back to the manual and tried the process of setting CV8 to 8 on this loco (factory reset) but as said it is simply not responding at all. This loco does not run at all even with the mad CV location "set"
Now my other Pendolino drive loco (marked "front") is running only at incredibly slow speed. I have tried a reset on this, putting CV8 to 8 but to no effect. There is no setup reason for this - other locos on the same track, running using the Z21 controller run properly.
Can anyone give me some tips please on what I can do to troubleshoot and solve this?
[Don't think this has anything to do with traction tyre issue!]
			
			
			
				When I got my ESU sound equipped Pendo's, many years ago now, I found that progranning on my Z21 programming track was intermittent, unless I connected a coach to the driving car.
I suspect that a combination of traction tyres and dirty and uneven track meant that the driving car on it's own wasn't getting good electrical contact.
Hope that helps.
Regardfs,
John P
			
			
			
				Which Pendolino batch? Which decoders? Factory fitted or fitted by you?
There are a number of idiosyncrasies on the Pendolinos frankly, particularly relating to DCC operation. 
			
			
			
				Thanks both
I've worked out at least for the front car that the speed was just down to the acceleration CV settings. Rear car is still essentially dead!
These are first batch Pendolinos, sound equipped, DCC's and factory fitted but hard wired so I can't begin swapping and testing if there is a chip fault. Will give it a go tomorrow with a coach attached but I can't remember that this model ever even had traction tyres!
The working front loco doesn't have traction tyres and goes full pelt now.
I have spare traction tyres and can fit to the rear driving car but difficult to see how that would affect the electrical pick-up?! 
I'm a novice and will follow any good advice though!
			
			
			
				
Hi there,
For clarity, the Pendolinos are supported by Rapido, not Revolution, at Rapido's request.
Obviously we at Revolution want you to enjoy your model, and will provide whatever limited assistance we can, but more in depth support queries should be directed to Rapido either using the email address in the instruction manual or via their support portal.
cheers
Ben A.
			
			
			
				They did have traction tyres, two per bogie. They cause other issues and IMO they run better without them!  They're irrelevant here though, as you identify. 
The power cars alone are notoriously bad for pickups (primarily because of the traction tyres you're sounds like it's lost) - adding a coach is well worth doing for extra pickup. Use a first class one with table lamps to confirm that the coach has good pickups!
They're not hard wired - they have Loksound V4 Micros on 6-pin harnesses, so you can definitely try a different decoder. 
It's a while since I set up one of my original ones, but I know they got confused having Railcom Plus enabled on both decoders, so I turned it off.
			
			
			
				Quote from: Ben A on July 21, 2025, 12:08:18 AMHi there,
For clarity, the Pendolinos are supported by Rapido, not Revolution, at Rapido's request.
Obviously we at Revolution want you to enjoy your model, and will provide whatever limited assistance we can, but more in depth support queries should be directed to Rapido either using the email address in the instruction manual or via their support portal.
cheers
Ben A.
To be fair to Revolution, I raised my unhapiness and immeditaely got some more helpful replies from "Simon". I've edited out my complaint in the original post. Still haven't got to the bottom of the unresponsive rear drive car yet. 
Although it's not the issue here - where do the traction tyres fit?
			
 
			
			
				On opposing ends of the axle on each bogie. If you look at the wheels you'll see one on each axle on the powered coaches has a small groove to fit a traction tyre.
I'm still confused by what you mean about the 'wild' CV values. Which CV are you trying to read? Is that CV1? That said, a CV8 reset should sort it, but the intermittent responses could mean it's related to pickups. 
I'd definitely try another decoder first, it's the easiest thing to try. I'm going to guess at an issue with pickups though. 
			
			
			
				Other possibility is that you've not quite got enough current draw for the signalling and readback to work correctly.
Sometimes moving the decoder to an actual motorised loco and programming it then moving it back helps. It'll also give you a clue if the decoder is dead or there is some other problem.
			
			
			
				It is motorised, both ends are on the Pendolino  :thumbsup: 
			
			
			
				Thanks all
I've tested the bogies and the conductive springs are drawing the same voltage as present in the track.
Although the DCC chip is not hard wired, the advice I got from Revolution is that to remove it, the wiring to the sound card needs to be desoldered. I'm not sure I have the surgical hands steady enough to do this so any tips on recommend repairers gratefully received!
Re wild CV values I only mean that the Z21 will read a loco address on CV1, but the address (rather than the CV I suppose) is wildly different every time/doesn't stick. If eg the loco address is 254 and I go into CV programming the Z21 won't write any other values [I've been trying to reset by setting CV8 value to 8]
Finally, a curiosity only maybe, but on giving the loco a little push down I got a small shock from the metal block nearest the lighting LED. Maybe some faulty wiring there that could have shorted the DCC chip?
			
			
			
				Sounds like it's time to stop tinkering and get in touch with Rapido UK.
			
			
			
				Trouble is that it's 10 years old, your right to any sort of recourse is limited. Rapido may offer a paid-for service, but it sounds like that's been explored already. 
You absolutely don't need to desolder anything. It's a 6-pin socket with a wiring harness, you just pull it out of the socket. 
			
			
			
				Quote from: njee20 on July 21, 2025, 05:07:31 PMTrouble is that it's 10 years old, your right to any sort of recourse is limited. Rapido may offer a paid-for service, but it sounds like that's been explored already. 
You absolutely don't need to desolder anything. It's a 6-pin socket with a wiring harness, you just pull it out of the socket.
Thanks for the reply - will have a look at checking the chip myself then but I've botched another loco with my "repair" efforts
Will contact Rapido - I'm not looking for a freebie and appreciate these are 10 years old but a little bit frustrating that it was only run in when first bought and then has been sitting on a shelf for 9 years!
			
 
			
			
				Definitely worth an email. They were very responsive with me and provided the spares I needed.
I would still try the decoder first though!
			
			
			
				(https://www.ngaugeforum.co.uk/SMFN/gallery/153/10996-210725190955.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=153806)
Again thanks for the help 
The DCC chip is definitely the culprit after testing with another working DCC chip (from the class 58 that I managed to botch soldering on while trying to replace the motor - if anyone wants a bodyshell and bogies let me know!)
I don't want to fry another chip. In the attached image when I was gently pressing the loco to the track I got a low voltage shock from the metal block in "circle 3". Wonder if there is some frayed wiring that has shorted the chip, but i thought there were some built in protections against shorts with expensive chips like ESU Loko?
The chip clips just underneath the soundboard (? the large black board marked N20-PCB Rear) but there definitely is a hard soldered wire, not quite the one advised by Revolution. The brown wire runs from the main board of the chip (hard soldered) to the speaker (hard soldered).
I could probably hold my hands steady enough (with a couple of Glenmorangies) to solder that but am I a barking up the wrong tree/what replacement chip is now compatible given the age of the loco /should I just give up and send for repair - if so are Rapido the only reccomended option?
Again thanks to all for the patient replies and suggestions
			
			
			
				Is this a stray wire strand or loose wire?
(https://www.ngaugeforum.co.uk/SMFN/gallery/153/5885-210725194958.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=153807)
			
			
			
				Quote from: ntpntpntp on July 21, 2025, 07:50:16 PMIs this a stray wire strand or loose wire?
(https://www.ngaugeforum.co.uk/SMFN/gallery/153/5885-210725194958.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=153807)
Thanks for the input - I'm not sure the fault lies there. There are three red wired soldered connections to that PCB including the one in your blow up picture. I checked the working front driving car and it has the same set-up and the loco worked with a new DCC chip!
			
 
			
			
				It's just a 6-pin interface. I assume that's what you've found?
(https://www.ngaugeforum.co.uk/SMFN/gallery/153/1147-210725214018.jpeg)
You've a few options. The original sound project was done by Legomanbiffo - he still sells the sound project on 6-pin decoders here: https://www.dckits-devideos.co.uk/index.php?route=product/product&path=221_251_229&product_id=1409
It won't be the same decoder, as the Loksound V4 Micro they used is now obsolete. You'll need to email them to request a single replacement, as they sell as pairs by default. They're very responsive.
You could also get the decoder repaired, I forget who the current agent for ESU is, but that may only be £35 or so.
Or you could stick a pair of silent 6-pin decoders in, and not have sound. I'd do both power cars or you'll have a horrible mismatch.
The only soldered connections should be from the decoder to the speaker. No soldering needed on the decoder (or the PCB), so installation isn't quite as daunting as it may seem.
			
			
			
				njee20
yes 6 pin interface 
as always that is super helpful!!
much appreciated
			
			
			
				And, FWIW, I've had the body off one of my sound equipped ones for the first time.
Mine also has a single blue wire not connected to anything by the decoder, like item 1 in your photos.
Regards,
John P
			
			
			
				Yes, you can see it in mine too. It's the common return, because you could just chop the 6-pin plug off and hardwire it. The 6-pin plug uses one pin as a common return. 
			
			
			
				So - I've sent my Pendolino for repair to someone I thought was an expert with the model.
I'm not going to name them but they were, slow, expensive, & didn't respond to messages [in contrast I'd give a shout out to Hookstone Models who are the opposite with other sets I've had done even sending YouTube videos of the repair progress].
Traction tyres have been fitted and both DCC chips and the sound chip replaced and light bars fitted in all coaches.
Some woes remain if anyone can help!?
The two locos do not appear speed matched/one is much faster than the other which I think is a possible cause of frequent derailments. I'm running them through a Roco Z21.
I've tested running the full set of coaches with only one loco but still get derailments, so wondering how I should verify the positioning bogies and couplings. I don't know if this model is uniquely delicate and prone to derail but other long HST's (Kato/Eurostar whizz around the same curves/over the same points at considerably higher speeds without problem?
I've succesfully set up lighting and sound functions and originally all were working ok. Now, sounds like the horn only work when stationary. The coach lights also flicker a lot while doing a circuit (again other HST's with lighting don't do this and lighting "stays alive" all the way around, so I think I can rule out track feed problems).
Steps I've already taken without sucess
- I've followed the manual procedure for resetting the functions to factory default and reloading them into the Z21 app for the vehicle
- I've followed the manual procedure for increasing the volume of sound functions.
This is turning into a lot of frustrating time fixing niggle after niggle with an expensive product that should be close to being able to run straight out of the box!  :*( 
			
			
			
				I can't help with the DCC issues and I don't have a pendolino.
But....I do have a Voyager and I was getting a derailing issue on points and curves with just one of the carriages.
On close examination the coupling was not swinging freely in its socket on one carriage.
If I picked the carriage up it was fine but on the track it would not swing.
There was a tiny burr of plastic where the coupling slides from side to side in the groove that holds it.
Sitting the carriage on the track applied just enough pressure to make the coupling catch.
Once I'd removed the burr everything was fine.
Cheers
Martin
			
			
			
				I feel your pain. I recently got a Pendelino and have spent loads of hours already trying to get it to run adequately. I'm slowly making progress but still getting way too many derailments. It's all extremely frustrating. Feel like the traction tyres are to blame for a fair few issues. I would like to be able to pick up some non traction tyred wheels if possible. 
I've also found the two motors to run at different speeds. I've speed matched as much as I can, but they seem to run faster forwards than backwards so they'll always be a mismatch when the train is coupled together. 
I'll add checking the couplings for burrs to my list of things to try.
			
			
			
				Thanks both 
@Hightower and 
@port perranI also have a Voyager (two Voyagers in a consist) but they don't have these derailing issues constantly!
As a newbie I'm not sure what you both mean by "checking the couplings for burrs"? 
I can see on straight/level track that all couplings appear to be aligned and because the Pendolino conducts through the couplings to the light bars in the coaches that there appears to be good conductivity. As soon as the train moves everyting changes - lights flicker and wheels misalign with track. To reiterate this does not happen with any other long HST that I have running on exactly the same layout.
It's also a royal (C II R) pain in the arse to even rail the Pendolino and coaches to start - I have Kato railing tracks and re-railing tracks around the circuit but there is always a problem with one of the coaches or the locos!
Problem 1 - get it speed matched
Problem 2  - get it stay on track
Problem 3 - get sounds working
Problem 4 - no enjoyment unless 1-3 solved!
			
 
			
			
				Hi,
Just to add some balance here.
I have 4 original Pendo's with ESU sound decoders and 3 from the second batch which I have fitted with Zimo decoders.
All 7 of them run fine on my layout with no speed matching issues.
I use large radius Peco Code 55 Electrofrog points on my layout and I don't get de-railments.
I have to be careful in my fiddle yard as that has short radius points and sometimes they can be an issue.
As you are using a Z21, then as long as you are using the Z21 app you don't need to speed match the two driving cars. You can use the Traction feature for Locos in the App and time each one over a fixed length of track, then put them in a train together in the App and the Z21 will do the rest.
By the way, what make are the new DCC chips?
I don't know why you are having issues with the sounds, on my 4 sound equipped ones all the sounds work as expected.
Regards,
John P
			
			
			
				Burrs are just little bits of excess plastic.
The sort of thing you have to file off when separating plastic kit parts from their sprues.
			
			
			
				I firmly believe the traction tyres are a cause of issues on these. There's a small inbuilt mismatch in the power cars, but because of the traction tyres they have too much grip on the rail head, and so just derail at the slightest provocation. It's exactly as you describe. I didn't have this problem originally, but I then discovered my original sets had lost all their traction tyres! I did have more gentle curves when they were new, I suspect it's exacerbated on all but the gentlest curves, which may explain why 
@jpendle doesn't have problems on his garage empire.
I believe it can still happen with a single power car because it will still snatch if it loses pickup instanteously, should be much reduced though. Is it still problems with the power cars derailing, or the intermediate coaches?
I've actually just sent off the CAD to someone to see if they can machine wheels without traction tyre grooves. I will have spares if he can. I've actually replaced the traction tyre-fitted wheels with 3D printed ones, but they're not tough enough to supply.
As for your problems:
1) should be fairly straight forward - couple one coach to each power car and do this in the normal way
2) I don't have a silver bullet here, it seems to be a problem which is much more marked on DCC, short of "remove the traction tyres"
3) No idea what's going on there, what decoders are we talking? Which sound project?
			
 
			
			
				Quote from: jpendle on October 09, 2025, 08:30:42 PMHi,
Just to add some balance here.
I have 4 original Pendo's with ESU sound decoders and 3 from the second batch which I have fitted with Zimo decoders.
All 7 of them run fine on my layout with no speed matching issues.
I use large radius Peco Code 55 Electrofrog points on my layout and I don't get de-railments.
I have to be careful in my fiddle yard as that has short radius points and sometimes they can be an issue.
As you are using a Z21, then as long as you are using the Z21 app you don't need to speed match the two driving cars. You can use the Traction feature for Locos in the App and time each one over a fixed length of track, then put them in a train together in the App and the Z21 will do the rest.
By the way, what make are the new DCC chips? I only know that the sound chip is ESU Loko
I don't know why you are having issues with the sounds, on my 4 sound equipped ones all the sounds work as expected.
Regards,
John P
Thanks for the input
It's difficult to detect what brand the replacement DCC chips are when the repairer doesn't supply any info and the chips themselves have no branding.
The repairer basically used as an excuse for delays and his charges the fact that I hadn't noticed there were no traction tyres.
Like others I feel these are the cause of poor pick ups and derailments but I'm not an internet keyboard warrior who can say that for 100% sure.
But my Pendo was from the very first production run and I'm not sure that they were ever meant to have traction tyres on that batch. I originally bought it for my son when he was too young to appreciate it and it's sat in a loft for years, so it's hardly ever been run and if there were traction tyres fitted originally it's really hard to see how they could have been worn off after 20 hours of running at most.
It's the locos with the traction tyres that derail the most. The coaches immediately adjacent to the locos also appear vulnerable to frequent derailment and the couplings between those and the loco appear ok but not much left to right travel in them. Occasionally also get derailments on centre coaches but think that is just a hazard of the hobby to be expected!
One thing I'm pondering - the light flickering might mean that the coaches haven't been put back together properly after light bar installation (?).  If they are gently pushed against the track, they pick up current and light up. When pressure released the lighting goes off or flickers. I'm obviously reluctant to use more force than is needed and damaging the model!
I have intermittent Kato re-railers around my circuit which work with every model apart from the Pendo. I have a 150/350/A4/TGV/Eurostar/Tomix Thomas & Percy/Class 58 & full wagon load/Voyager all of which rerail on circuits where there is a minor derailment- it has to be the most frustrating model I've ever had just to get it set up up on the track. So any tips on how to rail it correctly in the first place or any devices to help?
			
 
			
			
				Hi
My Pendolino was from the first batch and certainly does have traction tyres.
Cheers
Paul
			
			
			
				Hi,
Both batches of Pendo's, and the CL92 have traction tyres.
Both designed and manufactured by Rapido on behalf of Revolution.
You can determine the decoder manufacturer by reading back CV8.
e.g 145 = Zimo & 151 = ESU.
Regards,
John P
			
			
			
				@jpendle @PaulCheffus Thanks both
Question stil remains is the Pendo better off without the traction tyres when they still run witout them/constant derailments with them?
I'll have a crack tomorrow at reading the chips (the only thing I know is that they were supposed to be identical and compatible with ESU Loko sound chip). The sounds working only when train is stationary is probably down to the peculiarities of the Z21 though - by way of example (using the phone app) if I go into Vehicles/Functions on the Program Track, I can set a function but clicking the "Test" button has no effect. If I go back into the Steering/Vehicle section the saved function will work. Problem is that the app appears to forget saved functions and everything has to be re-programmed.
			
 
			
			
				You seem slightly confused about how decoders work. You have removed the ESU sound chips. There is one chip per loco, which control the motor, sounds and lights. The decoders that your agent has put in do not need to be 'compatible' with the ESU ones - they're wholescale replacements. Presumably he returned your original decoders? They won't be identical, as the Loksound V4 Micro used in the original batch is now obsolete. 
IMO they emphatically do run better without traction tyres. Nothing to do with pickup, the conductive couplers handle that, but the excessive traction/derailing. I have a sample size of 9 sets.  I'm not sure if I'm an internet keyboard warrior though, you seem to resolutely ignore everything I say. :-\
The couplings have long springs which feed through holes in the chassis ends to the pickups. The fact that pushing down on the coach roof improves things suggests to me there may be some issues here. If you sent the set to someone reputable though you'd have hoped they'd look at that...
			
			
			
				@njee20 Thanks for your advice. I'm not resloutely ignoring you and indeed you are right that I am easily confused  ??? 
[The internet keyboard warrior was a reference to my relationship with my inadequate repairer, not anybody else - I'm not going to be a warrior and criticise and name them on a forum in the manner of an Amazon review, until I know all of the facts]
My info is that the installer put in new DCC chips and new sound chips that are compatible with each other precisely because the first batch Lokosound chips are now obsolete. 
I'm not suggesting this was wrong - just that I can't set up the sound functions (or that I could set them up originally but the Z21 keeps losing the setup). I just don't know the brands but the CV's and functions can be read in the Z21, they just don't appear to save!
The main loss of enjoyment with the Pendo is the derailments. The repairer insisted traction tyres were needed. Others disagree so where to go - do I get the scalpel out?
			
 
			
			
				No worries, wasn't sure if I was reading too much into your comment!
			
			
			
				To remove the traction tyres, use a fine blade to pop off the bottom of the bogie.
Then the wheelsets will drop out, use a fine blade or tweezers to remove the tyres, then reverse the process to re-assemble.
i have found that my Pendos will not run up steep gradients (> 2%) without the tyres, but on the flat they are OK.
Also the DCC chips ARE the sound chips, so you have one decoder per motorised car, not two.
Also as the person who did the work presumably loaded a sound project onto the decoders they should have given you details of what sounds are on what Function key.
When you test functions in vehicle settings they will only work if they are meant to work when the loco is stationary, and a lot of sound functions expect the loco to be moving (e.g. flange squeal).
Once you have set them up in vehicles, there's no way that they would be lost by the app. I have dozens of locos setup in the Z21 app and have never "lost' any functions.
Regards,
John P
			
			
			
				@jpendle Did you find you needed all traction tyres removed? I've done a few runs with one removed which was fine at the rear of the train, but when it was the front power car I had constant derailments. 
			
 
			
			
				@jpendle @Hightower Thanks both
Did you find that removing the tyres reduces derailments? I only intend to run mine on the flat.
I still need to solve the speed difference between locos first and isolate that as the cause of the derailments before removing the tyres. I know there is a way to do that with the Z21 but it involves timing circuits with a stopwatch - don't know if there is a simpler way?
Re sounds and the Z21 app there are two frustrations:
In Vehicles/Functions screen illustrated below, the Test Function button does nothing. But the saved function does appear to work in the Steering/Pendolino screen.
What I meant by losing the function is that after setting the function, it appears to work once and then not at all or intermittently. This applies to both sounds that are only supposed to work when stationary/only when moving. Could it be the traction tyres are preventing adequate elctrical pick-up?
(https://www.ngaugeforum.co.uk/SMFN/gallery/155/10996-101025103235.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=155414)
(https://www.ngaugeforum.co.uk/SMFN/gallery/155/10996-101025103312.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=155415)
			
 
			
			
				Traction tyres have been used on continental outline models for years without most of the issues that British outline models appear to have with them. Is it the implementation of the way their owners are treating them?
If the Pendo keeps derailing then I'd get down to rail level and have a good look at what's going on. Does it happen randomly or always at the same location? Are any wheels riding up on the track causing the derailment or is the train catching on scenery? I don't know if it's possible to run the Pendo with just a powered car (or just a portion of the train), or with the cars in a non-standard order - if it is, does the problem go away if certain cars are left in the box? Does the problem move if cars are relocated in the train?
To be honest, if I were you I'd stop messing with it and contact Revolution Trains about getting it repaired properly. However they were caused, you shouldn't be having these issues and they're the best placed to get them fixed.
			
			
			
				@Steven B Thanks for the tips but I have been through those steps already.
Derailments are random
They happen when running the full consist or just one loco and a short set of coaches. The only time they don't happen is when running two locos alone coupled to each other. These have traction tyres hence my query of those who say to get rid of them. Link up some coaches to those locos and disaster happens!
Also no other multi-carriage HST's such as my Eurostar or TGV have the same problem on the same layout
			
 
			
			
				Could it be something as simple as back-to-backs on the Pendo?
			
			
			
				Quote from: Newportnobby on October 10, 2025, 01:39:48 PMCould it be something as simple as back-to-backs on the Pendo?
Sorry to ask nobby but what are back to backs??!
			
 
			
			
				The specific issue with the Pendolinos seems to be the fact they're a pair which are slightly mismatched, by design. The traction tyres mean though that the wheels have the most minuscule amount of tolerance before they 'snatch' on the rail and derail. I've spent literally hours on this. I've tried putting all the traction tyres on one power car, I've tried stripping the motor and gears out of one power car (don't do that, the set's too heavy for one power car). Removing the traction tyres works. Frankly simply removing them and leaving the grooved wheelsets works fine on code 55 track. I just found with code 40 the flanges ride the chairs. I've replaced the wheels in mine with printed ones. I've had quotes from China to get some made, but as I said yesterday I'm in dialogue with someone to get them made in the UK.
The back-to-back is the distance between the inner faces of the wheels. It's very unlikely to be the issue with the Pendolino, not least the design of the axles, with two wheels with stub axles and a plastic gear mean it's less likely to be out than a conventional axle design.  
The only bit I've not worked out amid my extensive testing is why my original sets worked perfectly when I got them. I can only think it's because the layout I had at the time had much more gentle curves and longer straights, so there was additional tolerance.
The HST, TGV and Eurostar all have only one powered unit, they're not equal comparators. They're basically just a loco pulling or pushing a number of coaches. 
			
			
			
				Thanks and appreciated 
@njee20 The tolerances do appear miniscule. I'm running on Kato track with a gentle wide radius but still get derailments that I didn't have when first purchased, only after "repair" that put the traction tyres back on (as well as reinstalling the DCC/Sound)
Also I appreciate the push/pull may be a factor but I have other HST's with a two motorised cars that don't derail like this.
[By the way 
@njee20 I saw elsewhere that you design waterslides for liveries. In the long term, after getting the basics working I might want to convert my Pendo from Virgin to Avanti livery, same with my two Dapol Voyagers. Do you have a link to where you sell them or was it just a personal project?]
			
 
			
			
				Quote from: bwj on October 10, 2025, 02:24:11 PMQuote from: Newportnobby on October 10, 2025, 01:39:48 PMCould it be something as simple as back-to-backs on the Pendo?
Sorry to ask nobby but what are back to backs??!
It's, as Nick says, the distance between the inner flanges of wheels. This will help show what I meant......
https://www.trainshop.co.uk/blog/post/1363-how-do-i-use-a-back-to-back-gauge.html
			
 
			
			
				Quote from: bwj on October 10, 2025, 04:00:26 PMThanks and appreciated @njee20 
The tolerances do appear miniscule. I'm running on Kato track with a gentle wide radius but still get derailments that I didn't have when first purchased, only after "repair" that put the traction tyres back on (as well as reinstalling the DCC/Sound)
Also I appreciate the push/pull may be a factor but I have other HST's with a two motorised cars that don't derail like this.
[By the way @njee20 I saw elsewhere that you design waterslides for liveries. In the long term, after getting the basics working I might want to convert my Pendo from Virgin to Avanti livery, same with my two Dapol Voyagers. Do you have a link to where you sell them or was it just a personal project?]
The experience of reinstalling the traction tyres mimics mine - the train ran far better without them, even just leaving the grooved wheels. That's just not an option for me on code 40 track. 
Must be a very old Poole Farish HST to have two power cars? Much easier to only have one, mitigates all of this!
I do sell the decal sets, the Avanti ones for the 805 (using a Kato 800) are on eBay. Problem is that they take a lot of effort, and as there's a Revolution Pendolino (and Dapol Voyager) in Avanti I haven't done those ones. I'm just finishing off the climate change and Avanti pride Pendolino sets though, but they'd need a lot of repainting from an original Virgin donor model.