It was quite a challenge to get DUO's to fit without spacers, James.
REAR CHAINS:
I started with a much too large set which were exchanged for free and no shipping charge. I got the new chains working but they were a challenge to avoid the ROPs support. Besides that, the gaps between patterns were too large. That made for a rough ride and noticeable slippage.
At the end of the first season I modified the chains as shown here
http://www.tractorbynet.com/forums/attachments/268885-duo-chains-planned-modifications.html
and that noticeably improved ride and traction. It also made them easier to mount because the extra patterns moved the side chains higher on the tire wall and hold the chains more securely on the tire.
These still had a problem with the end gap which I filled with one standard cross chain. The chains still moved at that gap and this year I made the final modification by closing the gap with one more DUO pattern. I am fortunate because I can get bulk DUO patterns locally with no shipping, and at half the cost of
CanadianChains.com.
The last post (#32) in the above thread shows that modification. I have not used the tractor since but am confident that final change fixed any clearance concerns. To close the last pattern, I cut out the second last link of the cross chain and attached the single link thus freed-up to the cross hook on the gap's facing pattern, and used a pin coupler to fasten the other pattern to it (as seen in the last 2 photos of post #32).
The DUO's were so-so until I closed the patterns. Using another DUO pattern (instead of single chain) to fix the end gap has (I think) finally resolved the clearance issue. They are great now and I recommend them if you can get a decent price on a chain tool and extra patterns and don't mind the work. Of course adding rear spacers would eliminate the space problem more easily, but what would we do for entertainment!
One other thing I found is that the pin couplers are much easier to work with, and do a nicer job, than more common shackles. I keep a couple in the tool box for repairs, but don't expect I'll need them.
My DUO's patterns have 13 links measuring 12.95" inside the hooks. I think newer DUO chains for 43x16-20 tires have 12 links measuring 23.30". I think the 12-link cross chains would be a bit better.
FRONT CHAINS:
Because of our small wheels, front chains are even worse to fit than the rears. I had trouble this year with some 2-link ladders which are too worn to modify. So I bought some very nice H-pattern chains which are basically the same as my modified DUO's but lighter (7mm vs 10mm). They will not work "as is" as shown in this thread:
http://www.tractorbynet.com/forums/...hains-dk35se-cab-post4060838.html#post4060838
Since posting that I have confirmed that I can return the chains for a 20% charge or exchange them for free. I think the only way I can get a chain to work is to make small 2-link ladders using 5.5 mm square link chain. Even then, clearance will be an issue.
So, I am planning to add spacers and keep the H-pattern chains. Bro-tec shipped 2" spacers today and I should have them within 10 days. As long as they fit my wheels I know it will all work. I may just use the spacers in the winter.
I'll update the above thread once I have tried them.
