I agree with your comment on the fork. I personally have not found rear suspension to eat energy (suspension that's under your legs) but front suspension hasn't been a problem for me. If you can lock the front fork, even better. If you got to the point of caring about that little loss, it's time to invest that money in a more road oriented bike instead, in my opinion. (700c wheels are also faster than 26" wheels, but require an entirely new bike.)

I don't know the min and max on your rim, but usually it's between 1.25" and 2.2". Like I said in an earlier post, I think 1.5" is ideal on a bike that came with 2" tires.
The difference between 1.25" and 1.5" in speed is very small, but the difference in comfort is rather large.
The different between 1.5" and 2.0" in speed is far larger, and the difference in comfort is rather small.
Also on loose stuff 2.0" has more of a tendency to slide around, 1.5" feels like it bites into the surface more and I feel more in control of the bike.

Obviously personal opinions differ, those are my thoughts. It's worthwhile to replace the tires with slicks, but once you get into replacing a fork your money would be better spent on going for a new more road oriented bike.

He's a troll.

Mountain bike to commuter is a pretty solid conversion and the result is similar to a German city bike. My Kona Cinder Cone has a Salsa suspension corrected steel fork, Specialized Nimbus slicks a rack and fenders all nicely bolted on to the eyelets on the dropouts. The end result cost a bit to buy a fork and tires but worked out better than getting another bike of comparable quality.

You replace-the-fork guys are killing me! This is an XT-level cross country racing bike with a Lefty Head Shok. It predates the time anyone wanted disks on a commuter, so I would not be surprised to learn it has no rack or fender eyes, and difficult if it did. Let it be what it is, and tell OP to get a hybrid!

He is being sarcastic, you are the troll...

or tourer, or sport tourer, or CX machine or... gasp... a purposed commuter: LHT? Sirrus? 7.5FX? I'm feeling you with post #18 .

Please stop the name calling.

Probably cant sell that and find another bije thats affordable right now (15% taxes in quebec) so I will buy some wide slick tires and see how that feels for now.

What was "bad" about the larger size town and country? Just curious, I don't have a ton of experience with them, just have a few hundred miles of gravel riding on a set of 1.9" not sure what I'm missing...no flats, they've seemed to perform just fine for me, but perhaps I'm not particularly discerning.

probably just minute personal preference. You could find just as many people who think the 1.9" blows away the skinnier one.

And, yeesh, that tire pressure he mentioned is so damn high. he's only a couple PSI down from what pressure I ran my 700x25 tires at. My fast, 700x35 tires are usually set to 60f/65 rear, and dropped down in the 50psi range for mixed road riding. Anything even approaching MTB sizes doesn't even get close to 65PSI for me. I don't even know why you'd run tires that wide if you're just jacking up the pressure and taking away any of the benefit. Unless you're a really big guy running a heavy load.

my 26x2.1 tires get set to about 35/40, and then don't get topped off for weeks. Usually the ride quality improves a week or so later. my balloon tires got set to about 30.

edit: hmm, this actually seems to be a common occurrence. Nearly everyone I've heard who didn't think wider tires were any good, almost always ran them at about double the necessary pressure. The whole point of wider is you can run less and less pressure with no negatives. Bumping it up above a certain point only make the ride quality and handling turn to ****, with no speed gains.

What?!? You need a light that will stand out in traffic, cars run ~700 lumens on low-beam. If your're running .5 watt (~90 lumens) in that crowd, you might as well have nothing.

Bike lights serve two functions, to been seem by other traffic, and to light your path. Think about a light that fits both needs. If you live in the 'burbs with little street lights, you want 700 lumens for night riding. In the city, with lots of street lights, you can run with a lower, ~25 lumens.

If you are using a bright light, be thoughtful about the adjustment/angle, you don't want to point a bright light at driver's eye-level. I like to turn on the light in the garage and see that the beam of the light is roughly a car-length out in front of the bike.

To the OP question, I commuted (11 miles one-way) by MTB with front suspension for years. It was just fine. When I decided to commit to daily bike-commuting, I purchased a new bike with drop bars and narrow tires. It made the ride faster (& funner*). I kept the MTB for winter riding and some single-track riding.

* Yes, I said "funner" and funner is not a word. Deal with it!

Anyone knows if just buying a cheap fixed gear might do the job? They look nice and I feel like it would be more fun to ride on the cycling roads and for commuting.

As long as your current bike that you're talking about fits you, it would really be fine as long as you put nicer tires on it. What you're running into here is the usual antagonistic posturing which unfortunately often happens on the forum - it doesn't really mean a lot. It's like people arguing over whether the black, red, or silver paint job makes something a better car.

Satisfaction levels with fixed gear bikes vary a lot. Some people love them, some people absolutely hate them. Generally the more the roads are flat the more people like them.

Nashbar City Slick - fast, light, long lasting.

2002 Cannondale F1000SL CAAD5 "Full Wood" easily converts to a blazing-fast, 700c commuter. The rear allows huge tire clearance, up to 35c slicks. The front is nearly unlimited, with a Lefty. I have the Volvo Team race version of your bike....fully converted to a flatbar, 700c Urban/Cyclocross machine:

It depends on what you mean by cheap fixed gear. Stay away from the "fashion brand" types that market super sweet fixie colors, bro!! Purefix is a great example. Horrible frames and components.

I got back into cycling on a cheap Bikesdirect fixed gear. I think it was $250 at the time, but this was also right as fixed gear bikes were really turning into a marketable niche, prices have probably gone up since. The frame and components were still entry level-ish (tires and saddle being complete rubbish), but a nice step up from the trash on the market nowadays, which can be hard to avoid.

Change the tires. Buy fenders. Get a saddle bag for a patch kit, pump, and spare tube. Have fun!

Welp then, guess ill go the most simple way and buy some slick fatties for now and see how that feels on my setup.

What kind of terrain is your town? I live in a hilly area, so with my Hard Rock, I left the gears alone. I need them all. I put on street slicks, fenders, a rack and shopping panniers. Reflectors and lights, toe clips, a kickstand, a trailer hitch, and another water bottle. And a lock. The only area where the bike suffers is that downhill, I run out of gears and must coast above 30mph. Small loss.

I put Kojak 2.0 slicks on my Ross and they were great for the summer and in town, but offered inadequate traction in the perpetual wet of the PNW on rural roads and MUTs.
Vittoria randonneur cross in 1.75 solved the issues with slick conditions, with little change in speed or comfort, and seem to be less susceptible to cuts.

It's hard to articulate what the differences were now, I do know that I didn't feel as comfortable getting as far over in turns with them, and that they generally just didn't feel as stable as they're slightly smaller version. IIRC, their flat protection wasn't the greatest either.

Yes it's possible to climb sidewalks and ride up and down the curbs with a fixed gear, you just need to be careful how you approach the curb and make sure that your pedal doesn't hit the curb. I do it all the time.

I recommend Panaracer Tservs in 1.75 (42mm). They are light, have good flat protection, and roll well.

I've used the Nashbar Streetwise, Geax Street Runner, and the Panaracer Pasela. I like them all.