Quite a few of the M+S chinos are still good for cycling with clips: I think I've two pairs of the current ordinary ones, one of the Blue Harbour Coolmax and one of the ultralights.
The [edit] inside leg [/edit] seams on the Blue Harbour Coolmax trousers seem to have gone sharp and started chafing badly! The ultralights are OK but have started to go a bit shiny, the ordinaries have both been damaged by a rough saddle
As for smart/fashionable from other chains,Burton's recent offerings were comfortable but wore out in no time, while Debenhams don't seem to have had much suitable since discontinuing Steve Redgrave's Five-G.
C&A's Businessbroek (office trousers in the UK?) used to be pretty good smart-but-OK-for-active and fairly durable but I've not bought any recently, as C&A closed their UK stores around 2000 and still no-one seems to have moved into that space, possibly because it's not enough to sustain a chain here any more. Anyone know if they're still any good, or have they gone downhill in a race-to-bottom-price like other chains? If they're still OK or no-one knows, I might see if I can visit a branch when next in a country they're still in as the farkers won't deliver to EU countries they don't have shops for ("de C&A Online Shop levert alleen binnen Nederland en in de gebieden van het Koninkrijk der Nederlanden die binnen Europa zijn gelegen. C&A heeft echter ook een Online Shop voor Duitsland, Oostenrijk, Frankrijk, Polen, Spanje, Italië en België (zowel Nederlands- als Franstalig). U kunt uw bestelling ook plaatsen vanuit een van deze landen.")