mxpx242424

So yesterday I bought myself a trek 520 from some guy who just had it rotting in his garage. I bought the bike for 100 bucks, and it's a great bike, but I wanted to change some stuff out. Right now, I have all of the Shimano 600 groupset on the bike except for the crankset and the cassette. The crankset on there has 3 gears, and the bike just skips the middle gear. The cassette has 5 gears on it. Also, I would like to be able to put Shimano STI shifting on there rather than the current downtube shifting for a reasonable price.

Does anybody have any suggestions for what I should replace my crankset and my cassette with to make my life easier for adding STI shifting? I'm quite a newby, so I don't really know if the current derailleurs will shift with an STI set up. Anyways, I'll take whatever advice I can get. I really want this bike to be a learning experience and use it to intimately understand bicycles. Thanks!

demoncyclist

Detail photos will help us help you. Good chance that it is the chain, and not the chainring that is the culprit, or just the middle ring, which should be individually replaceable. That being said, if you really want to start upgrading to more modern drivetrain components, be prepared to spend some coin, and some time. If you have a 5s rear, the frame is probably spaced at 120 or maybe 126mm OLD. Modern stuff- 8S and up, is spaced at 130. You will need to cold set the rear triangle of the frame to allow easy wheel swaps. The you will need shifters to match the number of rear cogs (I would probably go for bar end shifters on a 520 and save a lot of cash over STI shifters), and derailleurs of similar vintage.

Good Luck!

bikemig 

That bike did not come with 5 on the back originally. In any case, there are a number of ways that this can be done but we'll need pics to know what is going on. Good score at $100 for the frame let alone the parts; this bike is worth fixing up.

jsharr

Yes it did.

https://www.vintage-trek.com/images/t...rekCatalog.pdf

Wilfred Laurier

if you want to swap to sti levers
you probably have a lot of upgrades to do
because old 5 or 6 speed stuff
will not play nicely with modern 9 or 10 sped stuff

my suggestion
is keep everything that is in decent condition
replace what is worn out or damaged
and find a set of friction bar end shifters

JamesRL

I would be tempted to just fix the issues with the current setup. The 600 wasn't the original derailleur, perhaps all you need is a new front derailleur and a tune up.

cycle_maven

Oh, Grasshopper, where do I start?

First, it's gonna cost some serious coin, no matter what- several hundred dollars. The rear wheel is not compatible with STI (it's freeweel not cassette) so that's the first thing. Then decide whether you want to cold set the frame to fit the new wheel- if it's currently 120 mm between the dropouts in back, it needs to be cold-set. If 126, then you can squeeze a 130 road hub in there with no issues. 1986, it's probably 126. But you need to measure. If you want to go with the touring standard it needs to be cold-set to 135. I always just cold set my touring frames to 135. If the current wheels are ISO630 (27") then it's time to change to ISO622 (700C), since you're only a front wheel from it anyway. Price tag: $300 for a decent touring wheelset, min.

Then, 9-speed is much more appropriate to a touring bike than 10-speed. That's because you can use mountain bike components to get the low gears you need to haul stuff over mountains. So, new derailleurs and shifters cassette and chain. Min of $300.

It's likely that your current crank will work OK, but you might need a new one. $100.

Then tires, cables, bar tape, etc- $100.

If it were my 520, I'd definitely do the wheels, and I'd use the existing shifters and derailleurs etc, but I'd get some of those Rivendell bar-end shifter pods and cable stops and move the shifters to the bar ends. And I'd go to 7-speed cassette. That way the existing crank, shifters, derailleurs can be re-used. You could probably escape for around $400 (most of that wheels), and you'd have a very respectable tourer, just not with indexed shifting.

bikemig 

I'll be darned. I have an early 80s Trek 720 and it came with 6 on the back. Plus I wrenched on a bunch of these bikes throughout the 80s. So I was working off memory but sometimes it's good to check the catalog first.

hueyhoolihan

it was a time of transition... besides, the doc shows three 5xx series trek bikes in '86: the 500 TT, the 560 Pro and the 520 Sport. the first two had 6's in back and the 520, the one the OP professes to own, had a, alas, 5. who can be expected to remember such detail? i can't even remember which sock i put on first this morning...

mxpx242424

mxpx242424

Thanks guys, I really appreciate the advice. I guess the stuff on there is probably stock. I didn't think the 15 speed was the stock for trek. It does have 700c wheels on it already, which is really nice. I'll probably will look into doing the bar end shifting instead. I really love the bike, but I'm not at the point where I'm willing to dump 700 bucks into it.

Wilfred Laurier

you must be about six foot six to fit a bike with that big of a frame

jsharr

One option to get levers to bars may be to use Kelly Take Offs.

Kelly Bike Company

AnkleWork

Yes, replace the crank and cassette with those from another bike. Actually, replace your bike with another bike -- one equipped with STI shifting. That will be cheaper and make your life easier. Sell what you have and you'll be ahead.

fietsbob

Realize STI stands for Shimano Total Integration so they designed the whole set to function together .

get everything as a set. shifters derailleurs cassette crankset .. the whole package.

nesteel 

Just shop for a deal. I managed to pickup a set of Sora (not top of the line Shimano, but still good) 2x9 STI shifters, FD, RD, a 9 speed cassette, Weinmann XP27 rims laced to no-name, yet perfectly functional, hubs with stainless spokes, all cable, and all housings for $130 shipped. I proceeded to convert my Lemans RS to 18speed, and have never been happier. Also, if you are mechanically inclined, and don't mind spending a minimum on some tools (if you don't already own them) you'll be bucks ahead not having to pay a LBS to do the swapping.

Also, I was under the impression that the Tourney "brifters" available now are compatible with old school 5-6-7 freewheel spacing?

oldskoolwrench

mxpx242424,

Actually, the Shimano crank set that's on the bike is a 600 triple (FC-6204). It doesn't say '600', but it's the same grade. If the Chain, Freewheel and the other two chain rings are in good shape (no worn teeth or stretched chain), I would replace the middle chain ring (110 BCD x # of teeth), and get a set of Suntour BarCon bar end shifters. Cheaper in the long run, less mechanical hassle, and will still be 'period specific'. You could probably find a donor bike with the BarCons for less than it would cost to gather all of the parts for an STI build. Remember that whichever way you go, you will need a set of Cable Stops that fit your shifter Braze Ons.

Afterwards, if you like the bike and the way she rides, then you can decide to shell out the ducats for all of that newfangled peloton candy.

dedhed

Can it be done - absolutely
Is it cost effective - Depends
Having done a couple I wouldn't hesitate to do it again, love the STI's. I put about $1K into the first one but that included the cost of the original bike, powdercoating the frame, decals, and new accessories such as rack, tires, fenders etc. I didn't think a $1000 was too much to pay for a full ultegra 10s bike set up just how I wanted it.
Biggest expenses were the 6600 ultegra group lightly used - $500 and a 130mm new wheelset open pros on ultegra 6700 hubs $300. This was a few years back on an '87 Trek


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