I just received my new Rennen Rollenlager chain tensioner that came in the mail yesterday. I have been waiting for a little over 2 weeks for this sucker. It is one nice quality piece. I got to admit I am impressed. The trouble is it doesn't fit my setup. The chainline doesn't line up with the wide pulley without moving the rear cog to the inside and there is nothing I can seem to adjust to make it work right. In addiiton it won't clear my chainstays in push up mode. The outside roller lip hits. It is unused and still brand new. Would it be asking too much to contact Rennen and request a refund given the circumstances? I don't know if that is a proper thing to do and I hate being stuck with a 50 dollar tensioner that I cannot use.