Thanks for the opinions
We're quite light people, and not completely inexperienced - cycled to the med before and doing it again this year, self supported with tent. We are more the MTB clothes, bike casual rather than full lycra clad. We always have a shower after a ride.
Up until yesterday I've not had a sore bum - but yesterday it was - but that was a combo of new
Altura padded shorts and differernt boxers (non silky) as the silky ones are in the "to pack" file. I can't get on with loose boxers - everything hangs too low

Needs to be fitted. yesterdays choice of boxers was poor
Some of the posts above are useful - and it could've been the shaped padding "pinching" (as well as duff choice of boxers). I'll compare with the Boardman padded MTB shorts I usually wear (and can wear casual post ride), so thanks for the suggestion.
And thus, cream is like marmite
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