After having the tumbler running for about 3 days, the replacement belt broke again! This makes two replacement belts down. I had been using sewing machine belts but the tumbler gets hotter then they are made to run.
Right know I am using large rubber bands as belts. They are working fine for the moment. The tumbler has been running for over 24 hours.
I am planning on buying replacement belts that are made for the Chicago Electric double barrel rock tumbler. I have read that they are actually better then the originals. I have a concern with the rubber bands. I have “visions” of what can happen if they snap! I hope that no one is near when it happens, if it does.

The Best belts for this type of tumbler are RUBBER or NEOPRENE O Rings available for a few cents from any bearing supply Co. or Engineering supply Co.
Myoriginal belt broke in first few hrs of running, I replaced with “O” Ring and its now run for MONTHS Without problems
Good Luck
Comment by Tony in Oz — August 9, 2007 @ 6:01 am
I bought the C.I. two-barrel for $35 on sale at Harbor Freight on Saturday. Another child’s toy tumbler I had wore out gears and only handled 8 oz of rock at a time so I figured if this new one goes bad it looked pretty easy to fix. Well after 2 days the belt broke. Superglued it back together, broke again after one day. Now I have a rubber band from the daily paper on it and it’s working fine and if it breaks I have hundreds more. In the mean time it appears a more flexible belt as Tony said above would work much better. Sometime this week I’ll add an extra fan for the poor lil motor.
Comment by Vince — September 4, 2007 @ 11:48 pm
I HAVE HAD A LOT OF PROBLEMS WITH THE HARBOR FREIGHT DOUBLE BARREL ROCK TUMBLER BELTS BREAKING.SOME ONLY LAST A DAY.BEEN THROUGH 8 BELTS SO FAR AND ONLY TUMBLED ONE LOAD OF ROCKS.GOT DESPERATE AND SEWED ONE TOGETHER TODAY WITH FISHING LINE.IT IS STILL RUNNING AT PRESENT.GOING TO TRY THE O RING IDEA SOON.I GIVE UP ON THE REPLACEMENT BELTS
Comment by angelo — November 27, 2007 @ 12:32 am
For my CI double barrel I use a sewing machine rubber belt. It lasted long enough to wear out the nylon shaft bearings.
Comment by JC — December 26, 2007 @ 6:17 pm
you can get the two-barrel for $25 now. thats amazing bargain.
Comment by Rock music — December 31, 2007 @ 5:29 pm
I bought the CI two-barrel and the belt broke before the first 24 hours of use. I went to Harbor freight and bought 4 more. I thought it was a great deal because they spares were only a couple bucks each. Each has lasted about 24 to 48 hours, not such a great deal. So I am down to my last belt and I will start searching for o-rings. Are there any belts/O-rings with fibers in them like the larger belts have for strength?
Comment by Jay — May 15, 2008 @ 8:13 pm