Are all top tube adapter made equal? In other words, it wouldn’t matter if I bought a cheap one from ebay or an expensive one from my LBS? My wifes low entry globe won’t fit on the rack I recently bought, so I need a top tube adapter for it. thanx
Full disclosure: I know absolutely nothing about this topic. But since nobody else has posted, I thought I'd suggest going to a bike shop and asking them. I doubt they'll have one in stock (I didn't know they existed until a few minutes ago), but they'll be able to give you some advice. Then you have them order one for you, and--since you won't have to pay shipping--you come out about even.
Second thought: could you fabricate something or hang the bike from another spot, under the down tube or something? Tie a rope from the stem to the seatpost?
I wish I could answer your question, fact is I don't really have any idea. The only thing I can say is that you definitely should not do something silly like tieing a rope from the stem to the seatpost. Finding a different position for the bike that would work with the rack is one thing, but don't do something silly - if the bike falls off while you're on the highway, the bike is totalled and there's a small chance you might manage to hurt or kill someone else following behind you from the bike flying off the back of your car. Not to mention trashing the bike over a $30 part.
Not that you were going to do that, uh... :-D You asked a valid question. That's all I know - except that most bike stores around me do actually stock some of these items themselves, seems that it's not an uncommon problem (specifically, they're needed to carry most mountain bikes on a rack as well as mountain bike have a lower top tube for..."personal and painful injury" reasons...especially applicable to guys...).
I've tried all different configurations on mounting that particular bike and none of them seemed stable enough for my liking. Funny thing is, I can mount my kids 16" bikes on the rack, but not my wifes. Oh well, not like she does much riding anyhow. The bike is bout 2+months old now and probably has less than 10 miles on it.
I have now gotten away from the "hanging" type bike carriers and now exclusively use either fork mounts (in my pickup and Suburban) or a receiver-mount "tray type" carrier. I HATE those hanging types, even though I still have one (and the adapters)