Originally Posted by washed up

Might get more response if posted in the Clydesdale forum.
Im not familiar with the aksium wheel but if they are anything like the ksyrium you should be fine. I was heavier than you riding the mavic ksyrium and they are bombproof. However if the spokes are set up the same and you break one you may need to purchase new wheel...difficult to replace.
150 psi seems pretty high, at your weight I was running 100 to 110 with no problems or flats.
I used to get all hung up about if I was too heavy for a certain bike, frame or wheels or whatever...just get out an ride and dont worry about it. I was riding a carbon post and a seat with carbon rails at 275lbs against advise with no problems. Just ride what you have and replace it if it breaks.

Originally Posted by Wilfred Laurier

A catastrophic failure is very unlikely, but you may get spoke breakage after some time riding.

If I were you I would save my pennies until that day comes (if it ever does) and buy a new rear wheel (the front wheel is much less heavily loaded and generally you won't have an issue) with 32 spokes and a Shimano hub (I find Shimano hub bearings and overall construction to be the best).

Also, if the bike has 23mm wide tires, see if you can fit 25mm or thereabouts... this will allow you to run your tires at a slightly lower pressure which will then help transmit less shock through the rims and spokes and hubs.

Also, the 2014 Allegro 3.0 had 105 components, not Ultegra... so either you were misinformed or the previous owner upgraded the parts on it.