Fixed flange allows things like bike racks to be added easily. The towball would need changing to an Alko type towball if your caravan has an Alko stabilizer. Fixed flange towballs tend not to look as neat as a swan neck and are more likely to interfere with reversing sensors if your car has them.
Swan neck towbars will work happily with both Alko and non Alko caravans.
I wouldn't say that one type was better than the other. Over the years my cars have had both types and my current car has a detachable swan neck.
------------- The Chinster
Some people are just all show. I don't mind that if the show is worth watching, but .....
Swan neck looks tidier & suits any hitch, stabilizer or not so I'd go for that. If you have a flange type fitted then fit Al-ko compatable ball so you are also ok with any type of hitch.
If think you might be fitting flange mounted bike rack then you will have to go for flange type but be aware you cannot carry bikes on rack & tow caravan at same time due to excess load on hitch.
Yes standard ball size 50mm for UK/Europe. For flange towbar its best to fit extended Al-ko ball to allow you to tow caravan fitted with Al-ko stabiliser hitch or any other hitch. A swan neck is good for any trailer/caravan hitch & looks much better imho.
Another consideration is electrics, even though I only tow a trailer I went for the 13pin Euro socket type, with dedicated cambus electrics.
Reason was to not cause any car warranty issues with my firms 2012 VW Golf, also the 13pin connector is more secure than the traditional 7 pin type, and is a lot neater than having 2 sockets.
Also having the pukka campus wiring will integrate the car alarm system to your unit, and will disable the car stop/start function should you car have that.
For cars that have stop/start this should be manually disabled if you do not have the pukka cambus wiring, failure to disable stop/start whilst towing can damage the engine and cause warranty issues.
Thanks for the electrical info.. I have a Kia Carens 2 ltr diesel so no stop/start. I think I will get away with just the basic wiring with a bypass relay, not sure if the kia is cambus?
regards Ken
You will be able to get specific plug in towbar wiring for the car. Available for 7 or 13pin, ie here. If you wanted twin socket 12n/12s I guess you would fit 7pin kit + 12s upgrade kit.