thebiggestfish

Hi! I've decided to build a bike from some of the parts I've found on craigslist/ebay. I know everyone says its not the cheapest way, but I think for the experience its worth the extra money. Plus I figure I set the bike up with mostly used parts, but a few new things too (like a cassette) and I have a much nicer bike than I could buy off craigslist for the same basic price. Anyways, my question is how many of the bike's mechanical pieces have to match up? And what is it that matches? I read it was the gearing ratios, but how would that affect the shifters? This may be more obvious than I think, but I'm still confused! Any help would be greatly appreciated!

Thanks!

Al1943

Don't start buying parts if you do not have a full understanding of what the compatibility issues are. You will most likely waste a lot of money on incompatible parts. It would be more cost effective to buy a complete new bike.

AEO

there are a lot of things that can be incompatible, but the majority of bikes starting from about the 80's and made in japan or taiwan are more standardized.

stay away from french bikes and older raleighs, those two can be the most troublesome with parts.

fietsbob

Walk the rest of us thru what you want to do with this bicycle?
do you have a riding goal?

I have bits and pieces a number of bikes together over the decades.

1st thing to learn is what sized frame is right for your body proportions.

oldbobcat

About 4 or 5.

Sorry for the sarcasm, but the possibilities are so broad that it would be impossible for me to anticipate what you are trying to put together.

FastJake

Exactly. If you don't know, you aren't ready to undertake a project like this. You need to have at least some background before buying random parts.

My advice: get a complete bike and learn to work on it. Or read https://www.sheldonbrown.com/ in its entirety. Then you should be ready.

Jose Mandez

My area of concentration is late 1980's Trek road bicycles, so I am biased toward those. Generally, most Trek bikes, and other bikes of similar quality (i.e. not cheap Wal-Mart bikes such as Huffy) from that time period will have parts that are mostly interchangeable. You can probably pick up a decent frame from this time period on ebay for around $100 and build it up as you like. Here are some rules of thumb:

1. Make sure your gearing components (i.e. the shifters, deraileurs, and cassette or freewheel) are made by the same company. The major companies that do/did produce these components are Campagnolo, Shimano, Suntour, Sunrace, SRAM, and possibly a few others. Basically, if you deraileur is made by the Frank Kong bicycle company, make sure your shifters and cassette are also made by the Frank Kong bicycle company. Also when buying Shimano parts and wanting to use Dura-Ace, make sure all the gearing components are Dura-Ace.

2. Your crank needs to match your bottom bracket (BB). Most shimano BBs of any quality in the 1980's used the square taper bottom bracket, which is a square shape which can only take a "square taper" crankarm. Nowadays, I think a lot of bottom brackets and crankarms are "Octa-Link" or some such. Just make sure whatever crankarms you get are the same taper as the BB. Most importantly, make sure the BB you buy is the right size for the bicycle...the best way to do this is to have your LBS measure the BB shell of the frame so that you can ensure you have the right size. The threading of the BB also has to be compatible...generally, BBs made by Shimano (ergo most vintage trek BBs) have English threading.

3. Seatposts and saddles in 1980's bicycles are virtually always interchangeable. However, seatposts in modern bicycles, such as jillion dollar carbon fiber Lance Armstrong bicycles, are of a quite different design than traditional seatposts--make sure you research seatposts if using these newer bicycles.

4. Chains are usually not too hard to figure out--6-8 speeds on your rear cassette/freewheel generally take the same sized chain, whereas 9 speed and 10 speed generally take a specially sized chain for each.

5. Most road bikes were made for wheels that are 700c or 27"; 700c is just a bit smaller than 27"; often, a bike made for 700c will still take 27" wheels, and vice versa, you just may have to do some brake adjustments. Do not try putting a 27" tire on a 700c wheel (or vice versa), it will not work (not that I've ever tried it =P).

There is much more that I could go into, and the above information is far from complete, but I think these points might help give you a general idea of what you're getting into.

I would recommend working on bikes that are already put together before I would start putting one together yourself (Heck, I've been tinkering with my own bikes for three and a half years now, and I still would only barely feel comfortable building one totally from scratch). Once you see how everything is supposed to fit together on a well-tuned bicycle and you get experience tweaking and replacing parts as needed, you will be in a much better position to put together your own bicycle. One idea would be to just buy a vintage bicycle that's already put together and in good condition, start gaining experience by working on it, then gradually begin upfitting it with new parts (new BB, cranks, more gears, new brakes, etc.)

All the same, I wish you the best on this venture of yours. I've never been mechanically inclined; I've always hated working on cars, house projects, etc., but I've found the simplicity and utility of working on bicycles to be a source of satisfaction in my own life.

cyclist2000

Building up a bike is a good way to get to know the mechanics of bike and develope mechanical knowledge. This isn't the best or most cost effective to get a bike or to get the mechanical knowledge.

I would suggest that you get a used bike and strip it down to do a complete overhaul of it. There are some specialty tools that you will need to strip it down and to rebuild it. I would look for a bike shop that has free classes or a co-op, then you would not need to buy expensive tools.

Using a used bike to work on should not present any compatibility issues unless the previous owner did some incorrect upgrades.

I find the mechanical knowledge invaluable, especially when I go touring.

Good luck with this endevour.

HillRider

I recommend the first thing you buy (or borrow) is a good introductory repair manual such as "Bicycling Magazine's Complete Guide to Bicycle Maintenance and Repair" or Lennard Zinn's "Zinn and the Art of Road Bike Maintenance". Read them cover to cover. Also, Park Tool's web site is a treasure of repair and installation tutorials.

That should answer a great many of your questions and give you enough background to return here with specific questions.

Retro Grouch 

Quick answer - EVERYTHING on a bicycle works together. You can almost never change just one part without having to change something else. A couple of quick, common examples:

1. OLD (over locknut dimension). Older geared bike frames had the rear dropouts spaced 120 mm apart. Through the years that has been gradually expanded to 130 mm or 135 mm. While there's ways around it, your choice of frame can drive every other component choice that you make.

2. Brake and shift levers. Many bikes have brake and shifters combined onto a single clamp. Shifters have to match your derailleur and number of gears. Brakes have to match the cable pull requirements of the caliper. If you want to change the just the brakes or the shifters you may find yourself replacing other parts in order to make everything work.

thebiggestfish

Thank you so much for all the responses! I realize I was a little vague so I will clarify. At the moment I'm watching a bunch of CAAD framesets on Ebay and one Rocky Mountain. I've ridden a really small Specialized bike for about a year now, and am looking to do some really low key triathlons in the spring so I figured I should get a decent bike (one that fits me!). I've probably spent $100 in gas in the past three weeks going all over Virginia looking at people's craigslist ads. They all either want way too much for the amount of bike, or have a bike too nice for my price range. So after reading a bunch, yes it was completely online so who knows how reliable it was, I found that I can get a (and I'm only really familiar with shimano) mixed component set of like 105, ultegra and probably even DA for a lot cheaper than buying a new bike (I had my eye on the Felt F-85 which runs for a $1000). I consider myself mechanically inclined, but I do agree building a bike from scratch is probably a difficult endeavor. I've read through some of Sheldon Brown, but I still don't quite understand how gearing would affect what type of derailleur I get! The frames I'm looking at all have headsets and BB, and I'm not going to buy any actual parts till I have a frameset in my possession and can get all the right sizes and whatnot from it. The way I see it (and I'm by no means right) according to my math, I'll get more experience and more bike for sacrificing new parts for used/slightly used and building it myself. Of course I have two local bike shops within 15 miles so if I have trouble it won't hurt anything but my wallet.

All right. That was a mouthful! Again thanks for the help!

FastJake

Unless you're buying everything used, this won't be the case. Even if you do get everything used at a good price, you'll still probably come out even or behind, with a bike that cost you $1000 full of mismatch parts.

If you're trying to save money, look for a used bike that needs a tuneup or some minor work. That's where you'll find the best deals. Or find a high end "vintage" bike ('80s or '90s) if something like that wouldn't bother you.