I have a Trek 7.3 on which I'm trying to install a Schwinn/Instep coupler for our child trailer. The coupler attaches to the back axle (quick release). However, it seems that the axle is just barley enough as is; when I add the coupler, the axle will not reach through to meet the nut on the other side. Has anyone else experienced this, and is there a solution? The couple attaches fine to my old junker hybrid, but I'd much prefer to use the new ride for the trailer.