There is s group of us who ride out from the centre of Cambridge on a Tuesday or Thursday evening, around 25-30 miles this time of year, couple of beers and then home.
We make the best of what we have and are a very sociable group. Google CAMMTB for the website and runs list. And yes, it is claggy this time of year but isn’t everywhere!

As a Royston resident, I’d be grateful if you could expand, as “decent hill-type trails” sounds a notch up from what I have ever found!

There’s a trail I found near Royston that certainly *felt* like it was uphill, but weirdly, looked completely flat. Several winters ago. I’ve tried to avoid it since….

The MTB club (that’s not a club) mentioned near Hitchin is The Windmill CC – (see their website & FB) but as mentioned it’s pretty claggy around Herts through the winter. They often ride to Chicksands & do some great weekends & weeks away MTB-ing. Also check out ‘Silly Grin MTB’ who meet up & ride around Beds. I gave up MTB-ing as it’s so mucky around here in the winter & turned to the dark side – although I do have a gravel bike & love blasting along the dry singletrack in the summer – including the mentioned Roman road which can be part of a good 50mi loop.

Not Cambridge, so less relevant, but I lived in Bedford for a number of years a while back (about ten years ago now). It was great for dirt jumping – went to Chicksands and Woburn about 4 times a week. Also a good BMX track in Milton Keynes – I think Cambridge has a decent BMX track too.

The only ‘XC’ trails I found were little bits around the edges of Chicksands & Woburn – not inspiring at all. Had a tentative look for trails around Cambridge and couldn’t find anything of interest. I had no interest in road riding so just didn’t bother XC riding and focused on jumps instead.

So my recommendation is get a jump bike!