If you drop your pace by a minute per mile on the run, you've saved yourself six minutes. Drop a minute per mile on the bike, and you finish 25 minutes faster. To do that, though, you need to invest time in bike training, and that's the piece many new athletes shortchange most when stepping up to Olympic-distance triathlon training.
If you can't get out and ride during the week, put in time on your indoor trainer. Just be sure to get out for the longer rides to build valuable endurance and bike handling skills.