I've recently put together a bike with a triple crank on it. Everything seems to be working well, except when the chain is on the small chain ring up front. The chain doesn't release from the small chain ring when pedaling. When spinning, the chain starts to come off the small chain ring but there are some protrusions on the middle chain ring that 'hold' the chain for a second. It makes it very jerky and the small chain ring all but unusable.
The crank is an Ultegra crank, the deraileurs are 105 with a Shimano hg53 9 speed chain. Does anyone have any suggestions? Thanks.