I like those pics. I took my bike back to the lbs - the shop manager said that he also once had a Singleator which gave way and started to flex. We tried the new one that I'd bought and using both the flat wrench (for the spring) and the hex wrench (for the pivot bolt) together we got it to tension up. The shop manager then said that there was still a possibility of flexing if I took the bike off-road and he would let me change the Singleator for a rear mech which is what he would recommend. So my new chain tensioner is a Deore rear mech, lots of chain wrap and no flexing at all. More wrap means more resistance, so it doesn't feel quite as nice as the old Singleator did, but at least I know I won't have to walk every hill to get home.