I have just returned from a great break with family at Center Parcs in Elveden. One of the highlights, particularly for the kids was all the cycling.
It was interesting to look at our hired Schwinn MTBs - these must be abused like crazy and are permanently outside, but they work well - maybe it shows that obsessional cleaning and meticulous adjustments is a little over the top? I believe during 2013 these replaced the previous fleet of Mongoose MTBs which we had on our last visit three years ago, also good and I recall characterised by a strong whiff of GT85, perhaps they have upgraded the lubricant.
Despite the soundtrack of rattles and squeaks from every moving part, they are well maintained to a good standard, and whilst of quite basic spec, they are the perfect fit for the terrain and conditions with rigid forks, comfy fat tyres, gearing via a 7 speed Shimano rear derailleur and importantly, decent Shimano dynamo lighting. Given the suitability of the hire bikes and worries over the risk of theft, I wouldn’t consider taking my own bike.