We might need a taxi from Wurzburg to Lohr am Main for 2 adults, a toddler and 2 bikes. Is there anything possible like that in the city?
I don't think that's really a thing...but you can ask:
There is an email address via "Kontakt".
Lohr does have a train station so that might be the better option. Where are you getting the bikes in the first place? Can't you rent them after you get to Lohr?
We are doing a bike tour as a large family, from Wurzburg to Aschaffenburg, but one person has an injury (a broken tailbone) so she might not want to bike the whole trip. I'm trying to develop some contingency plans just in case she can't bike some of the time. The bike trip we booked doesn't have support vans etc. and so a taxi seems like one alternative. I know they can take the bikes on the train, but with a children's bike trailer too, it will be awkward.
I see. But then how do you want to fit the trailer onto or in a taxi? I'd say emailing above mentioned company is your best bet. But do mention the trailer.
Your better off with the train. Taxi rates in Germany are insane. Every city center and train station has a travelers aid that can assist you, German trains are very clean and nice. Also Germany is a bike friendly culture, so it's actually easier to get a bike onto a train than a taxi. Taxi's in Germany tend to be BMW's and Mercedes, so drivers may not be receptive to bikes.