Join Date: Sep 2010
Location: Lubbock, TX
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Re: 275/60R20 & chains
Here is my recent discovery with chains. I couldn't bring myself to buy a set of those class "S" chains for my titan. So I went with heavy duty twisted link from tirechains.com on my 2011 pro4x. I have the stock 275/70r18's and they fit fine with a dry test. I am running heavy duty vbar on the rear with quite a bit of clearance. Didn't get the chance to run them hunting this year, but most likely will next week up in the mountains.
My tires are almost the exact same dimensions as those 20's, the difference will be how far the chains come down the sidewall. My chains hit at the widest part of the sidewall and I have a little less than 1/2" inch of clearance to the spindle. I would imagine that 20" tires would actually have a narrower sidewall (random tire choice showed .1" less-maybe more with a stiffer sidewall tire), giving a little extra clearance. Someone else on here used those class "s" chains and broke both very quickly off road.
If you go with the heavy duty ones, ask them how wide the chains are compared to the ones that fit 275/70r18's. If they are more narrow, that will also give more clearance as the spindle gets closer to the tire the further down it goes (closer to wheel). Also make sure and get ones with cams to help tighten the chains towards the outside of the tire.
Worst case, you can go class "s" up front and heavy duty out back.