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

No worries, wasn't sure if I was reading too much into your comment!

@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?

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...

@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.

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

Hi

My Pendolino was from the first batch and certainly does have traction tyres.

Cheers

Paul

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?

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?

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.