I have been researching a lot of SS/FG bikes to see if they are worth buying to replace my old '84 Trek 510 road bike that I converted to a single speed. I am considering buying a Kilo TT from BikesDirect (big surprise there) because I don't have a lot to spend on a new bike or upgrades for that matter and for my needs $400 is a decent price to pay without going too cheap. Also, I am worried about something breaking on my Trek and when I need to find a new part for it, I will not be able to easily get that part because it is such an old model. On this bike I have replaced the saddle, tubes/tires, pedals, and handlebar tape.

Right now the Trek is just my beater bike I use for riding to school and going a few miles around town every now and then.

Can anyone tell me if something like a Kilo TT would be considered an upgrade in quality from my Trek? Or would I be better off to just keep upgrading the various parts around my frame?

Where are the rest of the parts for that Trek?

A 510 can be worth a decent amount of $$$ if it's in good condition.

But, to answer your question; don't waste any money "upgrading" anything. Just buy a better bike, ride the **** out of it, replace what breaks and be happy.

Unless you're racing, the only upgrades should improve comfort or function. E.g., fenders or a better saddle are good upgrades. A new crankset even though your current one is fine is a bad upgrade.

The rest of the parts weren't in very good condition, hence why I decided to strip them. And I'm not talking about upgrading my crankset or anything like that, I mean important stuff like the brake pads, cables, housing, levers (they work, but they are quite stiff).

My front fork is also slightly bent, so that's another thing I could see needing replacement at some point.

Buy a new bike. That sounds like a money pit and a waste of time.

https://en.wikipedia.org/wiki/Diminishing_returns

Alright. I didn't know if a new bike that was only $400 would end up being a bigger money pit (because apparently for a bike that price, everything just breaks?) than my current one so I guess that answers my question.

There isnt anything weird about your bikes so you shouldn't have anything to worry about.

A cable and housing change should free up your levers. Judging by your picture, you have too much housing for the front brake and rear brake's rear housing loop is too short. A slightly bent fork can be realigned fairly easily and is worth doing so you dont have to compensate for the bike's tracking by shifting body weight.

No, some of the parts are low-end but they're not crap that will break. They're just heavier, or not as round or something like that.

+1, The levers are fine. With new cables and housing, on top of [urlhttps://store.velo-orange.com/index.php/components/brakes/pads-shoes/vo-cartridge-road-shoes.html]new (grippier) pads[/url] and some $10 hoods from veloOrange you should be able get that puppy working nicely for around $40. Once you've outgrown that level of conversion, and start thinking about dedicated SSFG wheels, it'll be time to think about a complete bike.

Treks of that era are very nice bikes- I have both a 610 and a 500, I've been impressed with both. Does that one have 27" wheels too?

I forgot to mention, those older brakes have very strong return springs. Upgrading to some new or used dual pivot brakes will make things much easier for your hands as well.

I tentatively vote fixing up the Trek. All the parts you have replaced are standard wear items (unless you get a particularly nice pair of pedals with nice bearings). Assuming the headset, bottom bracket, and wheelset are in decent condition, you already have a fairly nice bike on your hands. If all those components are blown out it might be more cost-effective to buy a new bike. Like hairnet said, you can probably get the fork straightened by a competent shop very easily, and upgrading to more comfortable, modern brake levers and stronger dual-pivot calipers will make a huge difference. Looks like the Kilo TT only comes with a rear brake anyway.

Just keep in mind that bikes with older, loose-ball bearings need periodic adjustment and repacking to keep them working smoothly. For example, a decent quality, properly maintained loose-ball bottom bracket can last years with occasional adjustment and repacking while a typical cartridge bottom bracket simply gets replaced once the bearings are worn to the point of developing play. Otherwise, brakepads, cables, tape, tires, etc. will need replacement just as often on any other bike. If you don't find much satisfaction in maintaining an older bike and keeping it on the road you may feel less frustrated just buying a new bike.

I enjoy maintaining and fixing up my bike so I might just stick with it for awhile. I'll think about buying a new bike when my wheel set wears out.