Have a pair of Tandem rims that are very tight. To make it worse- I use Velox tape aswell.The way I get the tyres on is that as I work the tyre on by hand- I push the tyre well down in the well of the rim. When it gets to lever time- I put pressure on the lever and once again push the tyre bead into the well. Then lever tyre over the rim. Next levering and I do it again- Pressure on and push the bead into the well. Works every time but getting the tyre off is release the tyre from the sidewall and into the well all the way down and start praying.