I'm using my 88 XR600 for mostly commuting and noticed the chain is a NON o-ring DID 520 chain. Sprockets are 15/50. I would like to upgrade to a more reliable O-Ring chain and possibly change the sprocket sizes. I know that if you put on a new chain you should put on new sprockets too. My commute is 20 miles round trip on country 55 MPH roads. NO high speed highway in the near future. I will be doing some off road riding, mainly trails, no slow technical stuff. Probably 60/40 riding now. I'm wondering if the 15/50 is still a good ratio to go with? Also should I get a 110 or 112 link chain when I do decide? Any advise or help will be greatly appreciated.