HCB

Just picked up a Schwinn dog bike trailer to tow around my old pooch. I plan on attaching the trailer to my 2016 Giant Anthem Advanced SX MB with thru-axle. Obviously I'll need a longer axle to compensate for the added adaptor. Is there a brand you guys recommend?

bboy314

Look up Robertaxleproject.com. They sell axles for this purpose.

noimagination

Seconded.

I'm using one of their axles for my Burley Bark Ranger. So far, so good. The website is also pretty easy to use, it wasn't difficult to identify and order the right axle. Delivery was prompt. No fuss, no muss.

veganbikes

Another plus one for Robert Axle Project and also a note make sure you install that thing properly and keep an eye on it. I also wouldn't take it off road. I wouldn't trust Schwinn for quality these days despite them having to put it on stickers on their bikes. I am sure it will be an OK low initial cost trailer but I always speak caution when carrying around loved ones. I did see someone recently flip their Schwinn Trailer on the sidewalk. Luckily nobody was in it and nobody was hurt and I don't think it was because it was Schwinn I just noticed what it was as it had flipped and it was recent enough the image is still there.

pettravelcare

I prepare 3 wheels dog bike trailer. It is more stable. It will not put extra pressure to the bike itself.

veganbikes

The problem with the 3rd wheel is it is not needed and doesn't really add stability. My first trailer experience was with an old friend in Colorado after some big event we hung out with some folks and we decided to ride downtown and she was small enough and light enough to fit in the trailer she didn't want to ride herself the trailer did have three wheels and kept coming loose and having issues as a result.

Now maybe you have figured out a better way to do it but you really don't need any more stability than two wheels for a trailer as it is quite stable on its own unless you have an odd shaped trailer and mounting but a standard Burley set up or similar is generally plenty stable.

Polaris OBark

My golden retrievers both flipped a newly purchased dog trailer. I wound up returning it.

Some dogs just hate that thing.

Robert Axle Project is te definitive answer to te OP's question, as others have noted.

veganbikes

Is that a product you are trying to sell?