Tangled Metal wrote:@rickh
The route I take also takes full sized bikes, but really only in theory. The practicality of getting a full sized bike onto a train that's already standing room only means it really isn't a possibility. Some people do however and that really goes down well. Personally just because you can doesn't mean you should. Especially when that involves pedals and other bike parts hitting other people in your attempt to squeeze on and stand holding your bike on a moving train.
Don't get me wrong, it's possible and indeed it's not always that busy. You just cannot be sure on a bike day it'll be quiet enough to fit a bike on.
I suppose I my point was, maybe rather long-windedly & not very clearly, that if you want to take a folder on a Northern train it doesn't really matter what sort it is as long as you are happy with it.
As far as being allowed on the train is concerned, anything goes (subject to space). A bike that is reasonably stable free-standing when folded, or that you can leave the saddle up to act as a handle while it sits on the floor, is probably better than not if you are likely to be standing with it.