Training with aluminum (8 speed)

For the last two years I've been training using my time trial bike (bmc tm02), ive been using it for both flat surfaces and lots of climbing . I live and work in Beijing and it's always a big risk taking this type of bike out due the chaotic traffic. I can not afford a carbonframe road bike or even really decent aluminum one. I ended up buying a cheap first level entry bike which I will use for long ride for endurance. A trek series one (8 speed). Obviously it feels a lot heavier, and going slower . My Theory was to train on this bike for a while , maybe three months , and perhaps Due to the weight and all other aspects it would me me a stronger rider . So next time i use the tt bike I should fly. I don't know , what do you think? I couldalways sell the trek bike if i have made a big mistake