Most seem to allow the kids bike to twist off to one side – child ends up pedalling a bike leaning 20* to the left….Not so good.
We used a proper tag along – old Schwinn one – and after a couple of additions (I wedged a couple of ‘washers’ made from old margarine tubs in the joint at the front) it worked brilliantly. No leaning, or rattling. Took our kids round all sorts of local rides, right up to red routes at Nanty-Arian, Mabie, Dalbeattie, Kirroghtree, Carron Valley and even bits at Wolftrax.
I would thoughroughly recomend a proper tagalong – and a cheap, strong seatpost (OnOne did one that was ace). I broke 3x seatposts through the years.