Parked up the pomp this morning next to another fixed bike that had some sort of covering all round the chain, like this:

(the chain is there just completely covered).

What’s the thinking with these things? Is it primarily just to stop oil getting on yr sister’s jeans, or does it offer a meaningful benefit to the chain, protect it from the elements etc. Wonder if it has any impact on the drive, whether you would notice it was there or not.

chainrunner.de

primarily for trouser protection. water will find way in and can’t get out.

less maintenance can be achieved with a gliding chain guard

http://www.hebie.de/Chainglider-350-38-42-44.hebie350chainglider.0.html

sorry for my lousy English ;-).

That looks to be the convoluted tube used for vehicle wiring looms

there is some truth in paulwfs words, but chainrunner is using a slightly softer material which stops rotating, nose and wrinkles