Looking to rebuild old project bike :) Not sure how to find compatible parts

[JoshTrevisiol]

I made a post a long while back looking for info on replacing my derailleur and painkiller was wonderfully helpful in providing info about how serious the problem actually was with more than just the derailleur.

Now I've finally arrived at a point where I've got the time and money to bring my old bike out of the garage and back to the road. I originally received the bike from my uncle in rough condition several years ago. It hasn't changed much since aside from brakes/rims/tires replacement, but I'm definitely certain about rebuilding it. 
I'm looking to learn how to identify compatible parts for the following: cranks, pedals, sprockets, chain, rear cogs, shifters, and front/rear derailleurs. I've replaced a lot of parts before, but never this much and I'm not sure where to begin looking for parts that work well together. Shopping on amazon is really intimidating not knowing what parts are compatible.

We have a super cool bike co-op here in my town so I've got a place to do the build with the correct tools. The aim is to make it into a reliable mid-distance bike so I can do my beach rides again.

It truly is a shame I've let the bike get to this level of wear; I'm hoping that learning more about the parts will help me understand how to keep it in good condition after the rebuild. 
photo album for the bike:
http://imgur.com/a/GEeao

Thanks for your time!

[Painkiller]

Hello Josh, welcome back. where are you located? The U.S.? It so happens I am in the middle of moving and I may have some suitable decent used parts for your bike. If interested you can have them for postage. looks like you have a mid-90s bike and I deal with a few of them from this era.Let me know. I can save a little money for you at least.

[JoshTrevisiol]

(10-28-2016, 11:12 AM)painkiller Wrote:  Hello Josh, welcome back. where are you located? The U.S.? It so happens I am in the middle of moving and I may have some suitable decent used parts for your bike. If interested you can have them for postage. looks like you have a mid-90s bike and I deal with a few of them from this era.Let me know. I can save a little money for you at least.

Howdy, and thank you
I'm located in Corvallis, Oregon, U.S. I won't say no to a good deal; what parts have you got?  

[Painkiller]

This is kinda the deal on mid-entry level mid 90s rebuild. Assuming it is a 3x7 speed drivetrain. New parts today for 7 speed are of lower quality and geared towards more entry level bicycles. Some new 8spd compatible components such as Shimano Alivio/Altus can be used too, and are better constructed than the newer 7 speed stuff. I would consider new 7 speed gripshifters to be a down grade over the older ones. However the new 7 speed rapidfire shimano shifter pods are a fine replacement when it comes to a new part on an older higher end 7 or 8 speed Bicycle. Same goes with Cranks. In your case for a new crankset i would go with a Sugino Impel over a low end new Shimano. Looking at the pictures it is hard to tell exactly what you need to freshen her up with. The rear derailluer for sure. (I probably have that for you) but need to know if you are 8speed or 7 speed. Is your front derailluer good or bad. New chain and rearcluster. Sram again over Shimano for new here also. What chainring gearing are you looking for up front? If your front derailleur is bad, what is the clamp size, i will need that. So start by making a list of what you want to replace and I can give you recommendations to suit your bike. Funny, I used to sell Mongoose back in the day before they went Walmart. I have a couple in the stable as well. I hope your fronk fork is in good shape, if not that will be another issue of expense. If you do not mind spending $150 or so, you can have a nice working bike again for sure.

[JoshTrevisiol]

Oh wow that is a lot of info! 

Let me see!

The bike is indeed a 3x7 drivetrain like you guessed. I wasn't even aware I needed to find specific speed parts.
The rapidfire shimano shifter pods you mentioned look really nice. The shifter for the rear derailluer is broken and the front derailluer shifter is well-worn. The front derailluer itself is in pretty good condition though.
The forks I've got are in excellent condition actually; Im very happy with them
I'll also take a look at the sugino impel crankset. I couldn't find it on Amazon, do you have a recommended retailer? Would that require bottom bracket replacement as well?
As for the front chainrings I'm not sure what a good ratio is but my daily casual rides are at 34/11 with the highest available being 42/11 which feels pretty nice along the highway. I'd like to maintain something similar with the new parts.
If switching to 8-speed allows me to get more reliable parts though I may be okay with that.

The list of things I'm definitely looking for after reading your info:
•rear derailluer (7 speed)
•rear cluster
•chain
•both shifters
•cranks (current cranks are 175mm and very comfortable)
•chainrings: 3 (would like to keep a similar ratio range to my current. Highest being 42/11, lowest being 24/30)

 I haven't set a specific budget for the bike to be honest. I left it relatively open-ended because I wasn't sure about the parts I needed to get at all. Sub-200 would be amazing considering I expected to dump at least 400 into it.
I'm more than happy to provide more info if you need it!
Thank you again!

[Painkiller]

Good, sounds like you can do it well under a $400 budget. Here are some links to the new parts you will need. I may have a new Sugino impel crankset. i will get back to you on that. yes it may require a new Bottom bracket. The best way to figure that out would be to measure the chainline of your old crankset, then bolt up your new one and measure that. Then measure your spindle and adjust your new spindle length to suit if need be. http://www.sheldonbrown.com/chainline.html
cassette http://www.ebay.com/itm/201700004187?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Chain http://www.ebay.com/itm/SRAM-PC-850-5-6-7-8-Speed-Road-MTB-Bike-Chain-114L-fits-Campy-FSA-Shimano-/321851386473?hash=item4aefd66a69:g:PCkAAOSw7NNT78BC

Shifters http://www.ebay.com/itm/Shimano-Altus-M310-Black-Shifters-3X7/302103903880?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D39798%26meid%3Db0e7​937040ed444e8b01eddad1823a69%26pid%3D100005%26rk%3D3%26rkt%3D6%26sd%3D1621643776​20

Pick out grips of your choice, This should get you going for now. I will dig around for a rear derailleur and the crankset. In the meantime break it down and clean it up, true the wheels and have the co-op check and align the rear derailleur hanger.