Hey guys,

I purchased a trek fx7.2 not too long ago and I love it, but recently I've been looking to go faster. I've always wanted a road bike but sadly I cant afford it, that's why I'm here, I'm looking to shed weight and try get a better performance from myself and my bike. Currently my average speed is 25 km h and max speed is 50 km h.

I've always heard that one of the best upgrades you can get for your bike is new tyres, is this true? Should I get new tyres?
I've only made minor changes to my bike, I changed the pedals for shimano pd-m540 and I've got the cleats to match, with a pair of mtb shoes that I got for 22 euro from Lidl. ( i cant afford decent shoes, id also like to stick with mtb shoes as they seem to protect the cleats more, I do enough walking in them to wear them down. I know i shouldn't..)

Is there anything I can do to make myself preform better and to reach new max speeds? I train daily on my cycle in and cycle home from work, my cycle in is a constant climb, I cycle as hard as i can for 30 seconds uphill then take a 10 second brake and so on. on the cycle home I just go full gas. This seems to be working as I can make my 9k cycle in 15mins, as opposed to 30 mins when I first started.

I'm not familiar with all the cycling lingo so if you could dumb it down for me that'd be great,
Thanks in advance for any help guys.

Check out opinions on the same question in this thread. Shaving weight is good. Shaving weight that rotates (wheels and tires) is better. Shaving weight that rotates and also decreasing rolling resistance (shallow tread if any, harder rubber, increased tire pressure to a point, decreased tire width to a point) is better still.

As far as conditioning goes, be persistent--gains will come with time. When pedaling, try to exert constant force on the pedals through their entire rotational cycle, pushing forward, then down, then pulling back and up. This is not easy and will take some practice, but will use more of your leg muscles than just powering down. SPD pedals, cleats, and shoes like the ones you have are fine. I have SPDs on my road bike.

Check out this thread.
Ten Tips for Improving Hybrid Performance

Work on the engine and technique - best bang for the buck is YOU!

+1
Training is the only solution that works. Buying speed ain't worth the tiny gain.
Build endurance and strength. Work on technique. Be careful w/ what you eat&drink. Be patient.
You'll get there eventually.

I "bought" a lot of speed & endurance for $60 going to cheap 28mm tires & tubes on my hybrid.
I've since built a set of "skinny" wheels and went to 25mm tires which gave me more endurance.

The 2nd thing is GEARING!
Chances are you likely have an 11-3X cassette.
You probably find the 11T cog useless and possibly the 3XT cog not needed.
Get a 12/13T small cog cassette with the largest cog no bigger than needed.
Maybe something like a 12/13-25/26T?
That will give you more closely spaced gears which will allow you to maintain a cadence that works best for you.

BTW- IF your seat height is too low, that can sap a lot of energy.

you could always pick up an old road bike, lots around with six speed and 27" wheels in my area from $50 on up. stick with at least six speed because it will have 126 or 128mm rear drop out spacing. 126 can be upgraded to 7 speed and 128 can can handle 130mm rear axles which will allow the use of 7,8,9,10 cassettes, should you want to go that route. here's my 7 speed puch with flat bars. even with the flat bars it is faster than my hybrid over my 15 miles loop.