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Advice on Upgrading 1983 Trek 620 With New Components

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Advice on Upgrading 1983 Trek 620 With New Components

Old 09-18-14, 08:05 AM
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srt19170
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Advice on Upgrading 1983 Trek 620 With New Components

I ride a 1983 Trek 620 with a 25" frame (it looks exactly like this bike) and I'm deciding whether to replace it or upgrade it with new components. I want to get to indexed shifting and "brifters". I'd appreciate your advice on how to best do that, what it will cost, and what problems might come up.

The 620 has a steel frame spaced at 126mm. I'm going to assume that it can be sprung to take a 130mm hub if necessary. It has a triple on the front (28-45-50) and I want to continue to ride a triple. The stock rear cassette is 13/14/17/20/24/28. The wheels are 27x1.25, but I assume the best cost option is going to require moving to 700C wheels. This will require long reach brakes (that will presumably need to be compatible with the brifters?). Currently it has downtube (friction) shifters and SunTour Cyclone MK II derailleurs.

I assume the best approach would be to buy a groupset (or some subset) and swap everything necessary. I don't have a strong preference for manufacturer, and I don't have any burning desire for top-of-the-line components. I'm a fairly slow rider and spend most of my time on the 45x20, so if it's reasonable I'd like to customize my rear cassette to be more in the 15-20 range than typical. I make a lot of use of my lowest combinations when hill climbing, so I'd like to keep at least a 1 to 1 combination at the low end.

So please advise me what component sets might make sense for me. I'd be happy to keep my current crankset, but I'm concerned about the tooth differential (22 teeth in the front) and that a 9 or 10 speed chain will fall between the chain rings when shifting. I'm fine with an 8 (or 7 or 6) gear rear cassette, but not if it requires me to use an oddball or retiring component set. I assume that my LBS can build me a cassette with whatever gearing I desire, but let me know if my choice of component set is going to make that expensive or difficult. And of course anything else you think I should know or consider!

Thanks in advance for any advice or help.
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Old 09-18-14, 08:21 AM
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Shimano's 10-speed 105 group (5700) has a triple crank option (comes 50/39/30 and the 30T is replaceable down to 24T) and is a good mid-line choice if you can find the components at a reasonable cost and can do the work yourself. Tektro and Shimano both offer long reach caliper brakes compatible with brifters.

However, you are getting into a fairly expensive project no matter what and, unless keeping the frame is super important to you, a newer (or even new) bike with the same group could be no more expensive.
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Old 09-18-14, 08:34 AM
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Originally Posted by HillRider View Post
However, you are getting into a fairly expensive project no matter what and, unless keeping the frame is super important to you, a newer (or even new) bike with the same group could be no more expensive.
First of all, thanks for the recommendation. I should have mentioned that I'm researching this because when I asked about new bike possibilities, I got a lot of responses suggesting I refurbish the 620. This is largely informational to get a clear idea of what that would entail. The cost itself isn't a huge obstacle (I've ridden the same bike for 30 years, so I've saved up some bike money :-) but it is one factor I'll consider. (The refurbish will require repainting the frame, which looks to be around $800 just in itself.)
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Old 09-18-14, 08:38 AM
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A repaint of your frame, assuming it hasn't been rust damaged, shouldn't cost anywhere near $800 unless you go for really boutique paint job. Again, even with a more modest repaint, the project will be expensive if you truly want to modernize the entire drivetrain and I'd give a new bike serious consideration.
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Old 09-18-14, 08:46 AM
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I have an 85 Trek 520 with downtube shifting and a triple front and 5 speed rear. I miss the gear selection of my other bikes when I ride that thing. I think pretty much anything that offers bifters will be an upgrade for you. I have one bike with a Shimano Sora groupset (3x8) on it and it works surprisingly well. I got the set as a take off from eBay and it only cost me $165.00 including the crank set and bottom bracket, brifters, brakes, derailleurs, cassette and chain. I wasn't aware that there was that much difference between a 27" wheel and a 700C wheel. Good to know if I want to swap over my Trek on day.
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Old 09-18-14, 08:54 AM
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Originally Posted by eastbay71 View Post
I wasn't aware that there was that much difference between a 27" wheel and a 700C wheel. Good to know if I want to swap over my Trek on day.
The radial difference between 27" and 700c rims is 4 mm so, if your brake shoes can be lowered that far, the wheel swap is feasible with no brake replacement. I assume your 520 has cantilever brakes so see if they will adjust as needed.

I had an '83 Trek 400 that also came with 27" wheel and long reach (47-57 mm) caliper brakes. The brakes could make the needed adjustment and I successfully fitted 700c wheels to it.
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Old 09-18-14, 09:02 AM
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Originally Posted by HillRider View Post
A repaint of your frame, assuming it hasn't been rust damaged, shouldn't cost anywhere near $800 unless you go for really boutique paint job.
The vintage Treks are painted with Dupont Imron, so matching the original paint job becomes more expensive. Both Spectrum and Joe Bell quote similar prices of around $800 once everything necessary is included. (I realize that I could get a cheaper powdercoat or similar.) If anyone has a recommendation of a cheaper Imron option I'd love to hear that as well.
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Old 09-18-14, 09:08 AM
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Originally Posted by HillRider View Post
The radial difference between 27" and 700c rims is 4 mm so, if your brake shoes can be lowered that far, the wheel swap is feasible with no brake replacement. I assume your 520 has cantilever brakes so see if they will adjust as needed.
My 620 has DiaCompe 500G sidepull brakes. That's the same as on the 400, so it may be possible. If I switch to 700C rims, I'll probably just try it out and see if I can keep the same brakes or not. I'm really more concerned with whether the DiaCompes will work with brifters -- my admittedly poor understanding is that brifters generally work poorly with generic brakes that aren't matched to them.
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Old 09-18-14, 09:42 AM
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First of all. If it were me, I would get a new bike and leave the 620 alone. It's a sweet bike as it is, and you can never have too many bikes.

Now to answer some of your questions: You can cold-set the frame to accept a bigger hub. I would spread it to 135 to put a proper touring hub in there and some 700c rims. Your current brakes will work with a 700c wheel, but if you're going to upgrade everything else, I would get new brakes too. If you really want brifters, which I wouldn't put on a touring bike, 105 is a pretty good choice. Tiagra is also fine and it could save you a couple of bucks. If you got bar-end shifters, which would be more appropriate for a touring bike, a lot of other options open up for the other components. I expect you could do all of that for under $1,000, which would be cheaper than a new bike, but still expensive.
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Old 09-18-14, 09:47 AM
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Originally Posted by srt19170 View Post
my...understanding is that brifters generally work poorly with generic brakes that aren't matched to them.
this is not true

the only real compatibility issue is trying to use direct pull v brakes
with brifters
which with few exceptions
does not work well

any caliper brakes should work fine

as for the whole project
if I were you
I would leave most of the bike alone
maybe get new tires and handlebar tape
find a wider range freewheel like the ones from ird if that is part of what you are looking for
and upgrade to bar end shifters if it doesn't already have them

there is just very little to be gained by changing every moving part on an old bike
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Old 09-18-14, 11:14 AM
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I have a 1983 Trek 630 which I converted to 650b. I have a seven speed cassette an a 126mm free hub, and a 46-36-28 triple crank. Also I have Suntour bar ends. The 630 is very similar to the 620. It is a very nice frame with Reynolds main tubes. There are some posters on the C&V forum who could advise you on the bike. There is more on the Vintage Trek website.
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Old 09-18-14, 01:06 PM
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I also think that updating components and refinishing the frame won't be economically efficient. But, if you like the frame and want a good bike for light touring and commuting, you can't do much better than a Trek 620. It has all the right stuff- low gears, triple crank, cantilever brakes, all the right braze-ons for racks and fenders and water bottles. If it's not very rusty, it will last another generation.

So- my recommendation for a rugged touring build:
New wheels- 700C A719 rims on LX hubs
Cold-set the frame to 135
7-speed or 8-speed cassette with friction bar-ends for shifting

The reasons:
New wheels- Cassette hubs are just plain stronger and 700C tires are more available in better sizes.
135 mm OLD- Then you can use a mountain bike hub, which will have less dish and are therefore build to a slightly stronger wheel.
7 or 8-speed friction bar-end - You can use your old crank, derailleurs, 6-7-8 speed chains (cheaper and stronger) and bar-end shifters are the touring "go-to" shifter.

edit- I just looked at the 1983- it doesn't have cantilever brakes or many braze-ons. If I were going to refinish the bike anyway, I'd get canti brake braze-ons, mid-fork pannier mounts and water bottle mounts for 3 bottles added before painting. Otherwise, it might be better just to sell it and get a Long-haul trucker from Surly.

Last edited by cycle_maven; 09-18-14 at 01:17 PM.
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Old 09-18-14, 04:40 PM
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I did exactly what you want to do with my 1983 Trek 620, except I went with a double. I used old Shimano 74xx components.
A (lightly) used Shimano 6500 (Ultegra 9-speed) can be found in a triple (I use one on another bike of mine), is of good quality and doesn't look too modern.

I did not enjoy riding the Trek with its original components, particularly the rear shifting. Once I added new wheels with a hyperglide cassette, the shifting was much improved (even on the downtube).
Later, I went a bit further and added brifters, and think it is a great bike now.
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