You can guess what happened can't you??
I took some without the saddle as well, so just for reference here's a muddy Mr M at 498kg:
We've been out for a 20 minute walk today, his frogs have got thrushy again thanks to all the mud, but his walk is still completely regular on tarmac, so we'll keep treating with gentle road work and hibiscrub. Just for reference, here's the worst one (near hind) today.