Rivnuts from Homestead,PA on 7/31/2024 10:01:09 AM:
While I typically take bikes with 35mm tires for trips on the Capital Limited route with roll-on service, I’ve never seen anyone check or look at my or others’ bikes for compliance with the tire width limitation. That said I’ve not seen anyone try to take a fat bike on the train.
While I’m not certain, I think the bikes on that route are simply loaded in the baggage car along with other checked baggage and not in hanging bike racks where the tire width might be a constraint. Other routes may employ hanging racks, so I’ll leave others to comment on their experience on those routes.