# knuckle vs rapido style couplers?



## dbhone (Jul 8, 2017)

I am wanting to convert a few older Bachmann cars from rapido style to knuckle couplers. Anyone know if I have to replace the trucks too? I have pulled the old trucks off yet without knowing what I am going to need.
Any knuckle style brand you guys prefer?

Thanks, Dan


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## KisNap (Aug 4, 2014)

It depends on the cars. Micro-Trains has a conversion sheet on their website that could help.

https://www.micro-trains.com/index.php?route=information/information&information_id=10


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## sid (Mar 26, 2018)

ive read a lot about this very subject and for the most part replacing the whole truck is way easier and better. Me my self i dont like them knuckle couplers ive had many problems with them on my layout mostly backing up my locos they tend to derail my cars but only the ones connected to my locos. i like rapidos much better for me. they just work no problems. But thats just me.


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## Againtrains (Mar 6, 2016)

*knuckle vs rapido*

Myself, I prefer the knuckle coupler. BUT it's your railroad do what is best for you!


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## KisNap (Aug 4, 2014)

I feel this way in HO and N scale. Horn hook and Rapido couples function better, but knuckle couplers look better. They work well enough to use them, but not as well as the others.


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## traction fan (Oct 5, 2014)

*Micro/Trains couplers*

00000


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## traction fan (Oct 5, 2014)

*Micro/Trains couplers*



dbhone said:


> I am wanting to convert a few older Bachmann cars from rapido style to knuckle couplers. Anyone know if I have to replace the trucks too? I have pulled the old trucks off yet without knowing what I am going to need.
> Any knuckle style brand you guys prefer?
> 
> Thanks, Dan


 dbhone;

Whether you need to replace the trucks depends on where, on your cars, you want to mount the new couplers. If your rapidos are mounted on the trucks, then by far the easiest way to convert to Micro/Trains couplers is to replace the entire truck with a M/T truck that has their excellent coupler already installed on their truck. The trucks come with directions and adapters to let them be fitted to different brands of cars. 
The other approach, and the one used by many experienced modelers, is to mount separate M/T couplers directly to the body of the car. If using this option, you could either keep your present trucks, or replace them with M/T trucks that come without couplers attached. If you chose to keep the trucks you have, you can clip the Rapido coupler and it's mounting box, off the trucks. (Note: Forum member sid might like your Rapidos, since he prefers them.)
The question of body-mounted, vs truck-mounted couplers has been around a long time. Each mounting location has it's fans. There are also some practical, physical, things that can affect your choice. 
Layouts with tight curves, (N-scale 9-3/4" radius, or HO-scale 18" radius) will work better with truck-mounts. Why? Because truck-mounted couplers stay in the center of the track on tight turns. Body-mounted couplers will tend to swing outward when traversing these tight curves. This may cause problems,since the couplers might tend to push the car's wheels against the outside rail of the track. This can cause derailments, or not, depending on the length of the car, the tightness of the curve, and particularly if the car is going through the curved route of an Atlas turnout, that is in the middle of a curve.(Other brands of turnouts, and Atlas's own"Custom Line" turnouts, don't have a curved route, and therefore less likely to be set in the middle of a curve.)
Body-mounted coupler work much better than truck mounted ones, when the train is backing up. The worst possible situation is to use some body-mount, and some truck-mount couplers. Pick one or the other, but don't mix types. Sid, has had a very hard time lately with a coupler body mounted on a locomotive, trying to push some cars with truck-mounted couplers backward.
As for the Rapido vs. Knuckle choice, Rapidos have one, and only one advantage. They stay coupled very well. However, this advantage also has it's downside. Once coupled, Rapidos are very hard to uncouple. There are uncoupling ramps for Rapidos, but they can only uncouple directly over the ramp. The uncoupled car has to be left right there on the ramp. The minute your loco tries to push it anywhere else the cars will re-couple. The end result is that if you want to do any switching, you're going to need a ramp for every single spot where you want to spot a car.
Knuckle couplers uncouple with a magnetic ramp, and can then be pushed, still uncoupled to another spot. They can also be easily uncoupled anywhere on the railroad with a small stick.
Among the various brands of knuckle couplers, Micro/Trains is by far the best made, and the most reliable, in operation. I use only Micro/Trains couplers, and highly recommend them. For any knuckle coupler to operate reliably, they need to be properly installed and all at exactly the same height. If you are going to use magnetic uncouplers, the trip pins that hang down below the couplers also have to be at the right height. Micro/Trains sells gauges to check both these measurements.
In short, Micro/Trains couplers are excellent, but require careful installation and somewhat fussy adjustment. Once adjusted though they should work very reliably, both at coupling, and uncoupling. They also look like real couplers. Rapidos couple very reliably. They are quite difficult to uncouple, and impossible to push while staying uncoupled. They look nothing like real couplers and are grossly oversized and leave much too large gaps between cars.

Hope that helps you;

Traction Fan:smilie_daumenpos: 

PS. The photos below show a very accurate gage I made for checking the height of couplers. I cut two notches in an NMRA gage. One for the coupler, and one for the trip pin.


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## KisNap (Aug 4, 2014)

That's a clever way to do it. I bought the micro-trains NMRA coupler height gauge. It worked really well for me.


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## traction fan (Oct 5, 2014)

*Yes*



KisNap said:


> That's a clever way to do it. I bought the micro-trains NMRA coupler height gauge. It worked really well for me.


KisNap;

Yes, I have a couple of those Micro/Trains coupler height gages. They are good, but the coupler in the gage can sag a bit, and these gages depend on eyeball alignment to match the heights of the two couplers. That's not difficult, but the Go/No go slots I cut into my NMRA standards gage are a little easier to use, and more consistently accurate.
Used properly the Micro/Trains coupler gage will get the job done. BTW I think that gage is made by Micro/Trains and, as far as I know, the NMRA is not involved with that M/T coupler gage. The NMRA does make the steel plate standards gages like the one in the photos, in all the popular scales. Both the NMRA standards gage, and the M/T coupler gage are good tools to have on any railroad.

regards;

Traction Fan:smilie_daumenpos:

PS One more pic. showing where the two slots were cut.


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