Recreational & Family - Trail-a-bike tandem stability problems?

Can anyone share some experiences with the Adams tandem trail-a-bike? We recently purchased one used, and for a couple of weeks I pulled my 4 yo only with no problems while we waited for an Adams baby seat (supposed to be compatible according to their website) to arrive for my 2 yo. When we added the baby seat to the rear spot (along with the extra 30# or so of second rider), the thing became really unstable. It's a bit better if the baby seat is in front, but then my older daughter has her face too close for safety to the rear of her sister's baby seat. It's also a little better if the baby seat (in the rear) is dropped down so low they can't pedal, but that kind of defeats the point. Everything is tightened down as much as it can be. Have other people had any problems, or have suggestions for improving stability? Even for my husband (weighs about 2x the two kids put together) with the slop he doesn't feel comfortable because it yanks the lead bike about too much.

I have similar experience with my Tandem TAB. I weight 170lbs and my kids are now around 50 lbs and 45 lbs. It is wobbly and requires great amount of attention, comparing to my single TAB. We never crashed, but I'm really exhausted after few miles. Granted - in the TAB manual they recommend at least 200lbs (90kg) rider for the tandem TAB, so I'm little underweight and the weight ratio is only getting worse as kids get older. I tried to vary the position of the clamp on the saddle post, but it did not make a noticeable difference.

I have the tandem TAB, hitched behind my regular tandem. There is definitely enough moment-arm and play for the tandem-TAB to swing things around. Tiring and stressfull.

I weigh 190lbs, child stoker is 32 lbs, tandem is 40-45 lbs counting racks with diaperbag and lunch. TAB stoker is ~50lbs, baby-seat occupant is ~25lbs.

One thing that helped was my wife watching, and identifying when the bike lurched. It wasn't the younger kids leaning or turning, it was the TAB-captain switching from coasting to pedalling with a lurch and lean that really rocked the bikes. We're trying to get her to transition more smoothly.

I think I removed the rear cranks so that the baby seat could go lower, but forget exactly how that works.

One thing I noticed pulling single TAB's behind bikes was significant stability differences based on the bike. Pulling single-TAB behind my road bike, which attached high and had a steep seat-tube angle, was much less steady than behind my Mtn bike which attached lower due to the sloping top tube and has a more slack seat-tube. No idea which of those effects caused the stability difference.

Adam's had pulled this model from the market due to stability problems.

I don't even like pulling my single trail-a-bike due to my 38lb 4 year old being able to rock enough to make my 265lb +bike feel unstable.

Thanks all for the input - it sounds like it's an unavoidable issue with the design, not something we're doing wrong (or something that can be corrected, unfortunately). tgot, that's interesting about what makes it lurch, I had assumed it was the girls moving around (we also looked at removing the cranks, but it still wasn't stable enough for comfort). I think at this point we're going to look for a single TAB replacement, or possibly a tandem with child stoker kit.

I ride with the TAB tandem with the rear baby seat every day and I've found that you can minimize the wobble greatly. First thing you do is slam the baby seat as low as it can go with the pedals barely clearing the footrests of it. Next, check the clearance on the bike seat and lower the TAB mount until it's as low as it can go.

Then, work hard on teaching the older kids about 'no leaning'..

Can the TAB riders ride a 2-wheeler on their own w/o training wheels? If not, it would seem very likely that things could get unstable quickly. I probably won't even consider a TAB for my kid until he can ride a bike on his own, unassisted. Until then, regular bike trailer.