Okay, I just had a few chats with a few different folks regarding the belts for the CSR wheel using the part numbers from this thread of 267-3GT-9 & 270-3GT-11. Again, these are for the plain CSR wheel, NOT the Elite or CSW. Not sure if the older GT2/GT3 wheels use these same belts?
First off, here is a source where you can buy the proper 3GT Unitta belts, verbatim. P/n's are:
GBN 267 3GT - 90 and GBN 270 3GT - 150 (needs to be 110)
http://us.misumi-ec.com/us/ItemDetail/10302190510.html
The belts are not offered from stock at the 110 (11mm) width though, they are offered at 150 (15mm). So they will have to be cut to width by the distributor or yourself.
On to the easier available belts:
The info you got mrbasher was partially correct. The tooth profile for the Gates-Unitta "3GT" belts, which are Asian in origin, are slightly different than the Gates U.S. profile (These are actually called "3MR"). The reason, if anyone's interested, is that at the time the profile was created, Gates did not own Unitta, and they had created their own profile prior to being bought that was only being used in the Asian market. Once Gates bought Unitta, they decided rather than obsoleting all the pulleys and belts already out there, to just keep the different profiles in different markets.
Okay, now for the good news. The Unitta (GT) pulley
will function with a standard Gates MR profile belt, but the Unitta belt will
not function with U.S. MR pulleys (which doesn't matter to us). The pitch is the same, the tooth depth on the Unitta pulleys are just a tiny bit deeper and wider. So as long as the belts are properly tensioned, there should be no problem whatsoever using the U.S. MR belts on the Unitta GT (O.E.M.) pulleys.
Now, a problem. Gates U.S. (MR) belts only come in widths of 9mm and 15mm standard, so you will have to pay a little extra to get the 11mm width cut to width by the distributor or do it yourself. And the belts are only available in 267 length. That shouldn't be a big deal as long as they can be tensioned.
The part numbers I was given as cross-reference by the engineer were:
3MR-267-09 and 3MR-267-15
Here's the Gates website showing the product:
http://www.catalogds.com/db/service...showProduct&category=gt_pg&product=3MR-267-09
Another option is to purchase new pulleys with the U.S. MR profile and switch the Unitta pulleys out, but I sure wouldn't bother if it was me.