Chain guard
 

I have a Sun Easy 1 recumbent that I have been riding for about 10 years. I am in a colder climate now and when wearing sweatpants I am getting oil on my pant leg. Is there a chain guard made for this bike? If not any ideas what to use?

Thread moved from Mechanics to Recumbents.

pants clips solution
 

Simplest solution is to buy a pair of "bicycle trouser clips" aka "bicycle pants clips" That will hold your sweatpants close to your leg so it never brushes up against the chain or chainring. Lots of sources from Amazon to eBay with varying prices from as little as $2,57 a pair with 3 week shipping from China to $7.35 for the same clips by a US seller with 4 day shipping, https://www.ebay.com/itm/315182598415 https://www.ebay.com/itm/364685744230 You really only need to use the right clip.

They also make fabric straps that attach around your ankle with velcro for <$10.
If that's too expensive, you can use a rubber band, although a rubber band won't have the reflectiveness of a strap. Or, if you don't have a rubber band, just tuck your pant leg into your sock.

PS. Have you already figured out that you can tuck the shoelaces in your right foot into your shoe?

It generally doesn't work well to use a chainguard on a multi-chainring crankset. A chainguard will interfere with shifting and stick out into the pedal arm's path

On derailleur bikes it's generally easier to fit the chainguard to yourself than the bike - get some cheap gaiters. Or you could try a different chain lubrication approach: wax lube is said by it's users to stay cleaner longer, so touching the chain won't stain your leg - the chain will last longer too, if they're to be believed.

It's best to keep the pant legs and shoelaces away from the chainring by way of clips/straps. Getting caught in the chain is no fun.