RiddleOfSteel

So the first go-around with a 25.5" '85 620, I had a painted-black 620 frame with a dent by the BB shell (on the DT) and no fork. I found a 520 fork from the era as well as a 1985 620 fork from a 22.5" frame. After being in the middle of many projects, I eventually sold that project to a friend, who has taken it in his own direction. I should ask how it's going, but haven't yet.

A few months ago (September or so, I believe) I almost bought this frameset as a complete 'barn find' / 'estate sale' type bike. Present mental and physical (aka apartment, bike count) circumstances had me ultimately say no to it. Fast forward to today, and @ctak has an '85 720 that he drove many hours to buy, while I have sold a considerable amount of bikes and components (for numerous reasons), leaving me with just my venerable Paramount as the sole complete bike (and for a day or so, sole bike and/or frame!).

ctak's 720 is epic, and he loves it, and then he spots this 620, as a frameset, for sale in Portland. Turns out I sold a frameset to this guy before, recently. All the tall riders in the NW are part of one or several loose networks, it seems. Great fun! So I drive down there and pick up the frameset, talking to the guy for almost half an hour in the very cold rain. Great time, even if my fingers were numb!

Included in the sale are frame, fork, original Stronglight A9 headset, original frame-specific rear rack (blue), original (blue) water bottle cage, Shimano MC70 cantis with new pads, and the original wheels. The wheels will go to a friend's bike project, and the rack and bottle cage will hang around. The frame is used, with some 'veining' of the paint (seen it before) and a small ding on the top tube. Paint chips/scrapes in a number of areas. Not perfect, but a solid frameset that can be cleaned, polished, and touched up to present well. Price was plenty fair.

After initially seeing the dent, and being so 'out of the game' with frameset purchases, I was taken aback by the imperfection. I very quickly told myself to get real, it's a 35 year frameset that is actually in plenty decent shape and will be a fun project. So it feels a lot like 'back to my roots' here with a long-left-aside frameset (minus the Portland-based owner who built it up before realizing it didn't work for him, sadly) and me putting some elbow grease into the thing to get it back on the road looking great. The plan is to swap components from my Paramount and have the 620 as my sole steed, with the Paramount finding a new home some place.

So that's the preamble. Now let's get into numbers and photos!!

Serial Number: 176220 - mid-1985 model year build
Frame size: 25.5"
Seat tube: 63.5cm CTC - 64.7 / "65.0" cm CTT
Head tube length: 224mm
Top tube: 58.5cm
Frame angles: 73.0° HT / 73.5° ST
Chain stay length: 47.0cm (factory) - "47.0cm enough" in real life

Frame / Fork / Headset weight: 3533g
Tubing: Reynolds 531CS = DB 531 mains with a 501 running around elsewhere. Cast head tube + head lugs, with the "head tube" portion coming in at a whopping 3mm wall thickness!
Approximate Frame weight: 2615g
Approximate Fork weight: 830g
Headset weight (used here): 88g (range is 82-90g depending on who you ask it seems)

Mid-fork lowrider rack mounts, DT shifter braze-ons, three bottle cage boss pairs, rseat stay rack mount points, fender eyelets, internal chain stay RD cable routing (just like my former '88 560).

Canti brake post height F/R: 287mm/287mm
Canti brake post spacing F/R: 62mm/76mm

Frameset as bought:

polymorphself 

How does the geometry on these compare to the 720? It seems like as far as the frame/fork go that and the 501 vs 531 fork are probably the only things separating them?

And when you say sole bike do you mean complete? I’ve done essentially the same. My Voyageur is my one bike and I don’t plan to have another anytime too soon. I’ve got a 310 that is more or less apart and not at my house and will stay that way. If you’re only gonna have one a tourer is the way to go for me. What happened to the expedition you were building up? Was that you or am I misremembering?

RiddleOfSteel

I visited family for a few days, which was a lot of fun, even if I couldn't wait to get back to Seattle and work on the thing! This is a picture of the serial number / BB shell as it sat tucked away in the trunk of my car.


The "head tube" extension above the "upper head lug" or top tube is a bit more ambitious than most, coming in around 7mm or so compared to other bikes I've had, which end up being around 4-5mm. This normally doesn't matter unless one is deep into the front end geometry of bikes, calculating where this puts the headset--specifically the top surface of the top nut, for stem height possibilities. Think of it as the C&V "Stack" and "Reach" points that modern bikes/companies employ. Versus the Paramount, the 620 is 7mm higher in elevation and nearly 10mm closer to me. These developments are both a positive for me.


The "veining" I'm talking about. :/ but oh well!


Cleaning and shining up the canti brake components. The usual cleaning/polishing suspects make yet another appearance. Tons of parts!


Old grease smelled old. A9 headset all apart, and is joined by a host of bottle cage bolts.


Polishing up the front brake cable stop (with quick release!!) and a potential frame pump mount to counter the tiny nub that exists for a "pump peg" on the HT (seen above). Thanks, Trek!


Compounding and waxing the frame. I believe this is after I waxed it, so I'm letting it sit for a while so that the wax and the clearcoat become good friends when I go to wipe everything down.

RiddleOfSteel

The catalog tells you pretty much everything, thankfully. Additionally, 1985 was the only year the 620 and 720 shared the 47cm chain stays and the more or less identical geometry.

The "531CS - Which Tubes Are Where?" debate has raged both here and elsewhere in the past. I'm not going to get into it apart from there being 531 main tubes and 501 pretty much everywhere else. There is a definite weight difference between the framesets.

My friend's 24" 720 weighs, according to his scale, 3002g all in (F/F/HS). I popped the dimensions of a 24" and 25.5." frame into CAD and came up with a theoretical gain of 193g when bumping up to the 25.5" size, totaling about 3,195g for a theoretical 25.5" frameset weight. How does a 620 stuff 338g more into itself? I think there are more things about the 720--a model that was considerably more expensive than the 620 and sold in 1/3 the numbers--that would be nice to find out.

RiddleOfSteel

After being lovingly cleaned and waxed, this is where we are with things, pre-touch-up paint. This blue is one of my favorite Trek colors. The paint is very deep and the metallic sparkle is really something. Beautiful blue!


So here's that dent I was talking about. Bummer, but quite minor in the bigger picture. My mantra/future book titling of All My Favorite Bikes Have Top Tube Dents lives on.


This was a second, "almost dent" that I detected, though it really looks like paint loss. Looks more pronounced in real life, but...it's a nothingburger.


Paint touch up station! "Rotisserie" setup, how high-end.......


Frame gets its time on the stand.

RiddleOfSteel

These first two shots are in very direct light (since my apartment lighting and phone's camera have a hard time always cooperating), and show the beauty of the paint. Fruits of my labor. Two applications of Chrysler's Deep Ocean Blue (pearl/metallic) for the required areas, which is a very close match, as well as an application of clear coat.


Frame tubes are butted somewhere...


Headset all greased up and tightened down, along with the cable stop. It's ready to be built!


I am really enjoying a seat post opening that doesn't heavily scar seat posts.


"660 Series" if your a seller on Craigslist......


Bernard Hinault headset, which means he totally raced this exact frame in the Tour de France...


Space Trek graphics.


I never know how these head badges get corroded like this, but they do, and this one didn't escape it. It's a bummer, but I'll live.


You wanna talk 'shore lines'? Because this frame's got 'em!

RiddleOfSteel

The build will take place beginning tonight and running over the next few days, most likely. It's super soggy weather time here in Seattle, and the forecast is a copy-paste festival of clouds+rain. No rush to complete the bike in a day. Dry weather will arrive soon enough, and I will test ride the bike sans fenders to get the best idea of what this 47cm chain stay business is all about.

I anticipate the bike will weigh 11kg, exactly the same as the Paramount. The components are the same (save for the brakes), and the frames weigh within 20g of each other. I guess that makes the 620 'thinner' as it is both slightly lighter, and slightly taller (and longer).

A new shift cable will be required due to the much longer chain stay, and I'll have to drop to a 12-23T cassette to keep my RD from any awkward extensions it would have if I just leave the 11-28T cassette installed and use my current chain. At least I'll get a 16T cog in exchange for losing some low-range. Sporty tourer!

[44cm chainstay vs 47cm = +3cm per direction = 6cm total additional chain needed = 2.36" = ~5 links (0.5" per link), thus 28T-23T=5T and problem solved]

Classtime 

What fun. My 24" 85 620 also came with the blue rack and one blue bottle cage. Neat stuff. And installing that headset was pure bikebuilding joy. I moved mine along before I ever did an overnight tour but that bike loved to roll along at a good steady pace. You're going to love it but I dont predict a long term monogamous relationship. Slide your Paramount under the bed or something. Oh, the full length of a PC-870 was just right with the stock chainrings and cogset.

RiddleOfSteel

This 620 would have to be pretty subpar to have me ditch it. I've stated before that I simply wish the Paramount was a 66cm (CTT) in the seat tube, with everything else the same. The 620 will fit me better while looking more proportional due to it's higher (in elevation) top tube. It also has a brace of braze-ons, which the Paramount doesn't have (by virtue of its era)--I appreciate practicality, even if I know I can bike for 2.5-3 hours (steady state) in upper-40° weather without needing food and water. All that to say, the deck is stacked a bit in the 620's favor here.

Time will tell with this 620. I am very much looking forward to completing it!

ctak

Great photo essay, love following the progress. I've added "dark blue metallic" to my top 5 list

and may your future rides be well hydrated

RiddleOfSteel

As I just mentioned "off air," I think Trek should have called this blue Galaxy Blue Metallic. The paint depth is incredible (galaxy-like! haha), and the metal flake prominent yet not crowding (making it look like stars in said galaxy). Gorgeous color, and I'm glad I was able to bring it back with my efforts. Past experience has told me that silver/polished components just 'pop' against the dark blue, and as everyone will see, this build is no exception.

RiddleOfSteel

So the build-up begins. On go all the bottle cage and rack bolts, and then some shined up down tube cable stops (for the bar-end shifters). Trek put these shifter bosses pretty high on the down tube, which I prefer. Maybe some day I'll rock down tubes on this (I have the shifters). For now, though, bar-ends.


Some very approximately-positioned brake pads here. The clearance or width between the canti bosses' innermost part (the flange that captures the canti arm spring) is 36mm, and the pads allow about that much between them. Not bad. My "33mm" Somas shouldn't have a problem.


As is custom, the rear brake tire allowance is incredibly generous at the seat stay bridge. For whatever reason, I had one pair of highly-sprung cantis, and another with less enthusiastic springs. Knowing that cable and housing friction is real, especially for a rear brake arrangement, I decided--after matching canti 'spring rates' (they were laterally imbalanced upon initial installation, post-cleaning)--to have the softer-sprung cantis in back and the enthusiastically-sprung cantis up front. Like the front, the pads are approximately positioned.


Now we have the necessary components (plus a yet-to-appear bottom bracket) to disassemble, clean, and polish up. After a number of miles over damp roads, there was plenty of spray and road gunk that had found their way on to these components on the fender-less Paramount.

RiddleOfSteel

As always, the bottom bracket is the center of the bicycle universe. The eternal BB-UN55 (in 123mm form) is securely installed, ready for duty. The 1.5mm spacer on the drive side gets the chainline to Shimano spec (for triples), minus 0.25mm or so. It also positions the drive side Q-factor where it needs to be. Obviously, this shorts the (crucial) non-drive side Q-factor, so a 1.2mm pedal washer is used to get things where they need to be.


The Tourney-inspired (I kid!) large pulley wheels may look a little odd at first on this 7700 GS rear derailleur, but compared to the startlingly-long (and uninspiring-looking) cage on the 7800 GS rear derailleur (for 10-speed triple duty), this is quite an elegant, proportional piece. I appreciate how the barrel adjuster is 'warm grey' in color--you could even say it's a French grey--matching the "Dura-Ace" script on the parallelogram body as well as elsewhere in the 7700 groupset (not to mention the 'warm grey' chain rings!).


Ahhh, my long-loved 7400 crankset. It, along with a pair of 7402 calipers, are my longest-owned Dura-Ace components. We have seen many bikes and many miles. Now it wears the Specialites T.A. Triplizer ring set, and well. All mounted (with greased square taper spindles, crank bolt threads, and dust cap threads) and ready for, well, the rest of the bike!


7803 front derailleur is now mounted as well. Great derailleur. I'll probably add a chain catcher for the 26T small ring as there remain a few odd times when the chain fails to cooperate regardless of excellent shifter and derailleur operation. Dropping chains is ever vexing, so I hope to remove that potential for good.


Stopping for the day, er, night. So far so good. Very good! The wheels are next to be cleaned and mounted. The seat post and saddle will follow, as will the stem/bars/levers/shifters. Much work to be done, but I am looking forward to it.

bikemig 

Great write up and cool bike. The stronglight A9 is my all time favorite headset. It is virtually indestructible. It holds up better than a campagnolo NR headset. I also really like that paint job. I have the same paint on my 1979 Trek 510 which is a full Ishiwata, silver brazed frameset with an investment cast fork crown. It was a "lower" end frame because Ishiwata tubing was cheaper at that time than Reynolds or Columbus but it's seamless chrome moly and weighs the same as Columbus SL. That blue really pops in the sunlight. The 510 was one of Trek's "touring" model before they came out with 720s with the cantilevers and long chainstays in '83 and then also in other models like yours. I also like the write up on Reynolds 531 CS. My Trek 510 replaced a 1984 Trek 610 that I owned with Reynolds 531 CS. I should have weighed the frames but I knew the 510, for what it's worth, is a little lighter.

reconnaissance

I was looking at the top tube dent an want to share there’s a way to “soften” the contours of it with the bike stand clamp. Bearing in mind that the metal has molecular memory it sort of “wants” to go back to its original shape, you can place the slightly snugged clamp around the tube with the curved jaws around the dent and the gap of the jaws straddling the apex of the dent. Then just softly flex the tube with the clamp and some of it will “walk” out. Not too tight or you’ll introduce new dents.

Also possible with precision made frame blocks.

Kobe 

I saw this 620 up for sale on the Rivendell forum and was tempted. That blue really is awesome.

But I went down this road before and had the same problem as the seller, just a smidge too small.I built this 620 up about 5 years ago and it was really a great bike for all the reasons you have listed. Truly a great do it all bike if you are going to have only one. The only finicky part was the canti's have very little leeway on a 700c conversion. I tried modern Tektros and they would not work.




I am glad you got it because your write ups are so detailed that I can enjoy the build with out lifting a wrench.

RiddleOfSteel

Thank you for posting this photo and giving some extra context! Our saddle heights are going to be more or less identical. It looks like you like more reach than I do given what you've said and that stem. I've been thinking about getting some compact bars again (Nitto M151 this time, because pretty pretty Nittos) and going from a 100mm stem (with the Noodles presently) to a 110mm to maintain the same reach and gain some extra front end 'suspension' that those 10mm of stem length seem to provide (I've tested this before). My build may some day be remarkably similar to yours.

Thank you for your kind words on my build. I hope to keep it up, even if I know I have a good bit of canti brake fidgeting ahead of me. The MC70s have a good bit of wiggle room on their posts (compared to Tektro CR720s etc), so I'll see if I get four wolves howling at the moon when I go to stop or not. If so, then I'll shim them with some nifty super-thin nylon washers I picked up for my former Specialized Expedition.

Are those tires 38mm? I have yet to measure and determine maximum nominal tire size allowance, but will get to that today when I mount freshly-cleaned wheels.

RiddleOfSteel

As promised, the wheels were addressed next. Next to my 7402 crankset, this wheelset has been with me for some time, and it is one of the best wheel purchases, if not the best, I've made. It's had TB14s laced to its 7400 8-speed hubs, but I didn't like them, and I was able to find another polished Mavic MA2 to replace the cracked (at the weld/seam) rear one. New spokes for the front (that are now the correct length) and new spoke nipples all the way around.

This is the front wheel in it's "dirty" state. Front wheels have such easy lives (in this way).


Easy shine-up job. Always glowing.


Rear wheel/rim. Yes! I can see what I need to clean!


11-28T cassette certainly needs some attention.


From the phalanx of cassettes I once had (now just a company of them), a 12-23T corn cob that will allow me to not have a stressed rear derailleur in the middle...well, any ring. At least on the big end of the cassette. I get a 16T cog as well as the ability to wind the B-tension screw out a bunch for even better shifting.


Grubby rear hub. Still spins beautifully and silently. Long live 7400.


All cleaned up and ready to be mounted!


This is going to be fun.

jlaw

Very interesting narrative - thanks for the detailed component info. I've been looking for a silver Shimano 10 speed RD and wasn't aware of the 7700 GS - for a vintage Trek project. I found a NIB 7700 GS RD on ebay UK for the friends-and-family price of $355! I think I'll keep looking....

You've got a beautiful shine on that bike and the components. What polishing products did you use? Any tricks or things to avoid?

Those MC70 brakes are really nice - and they have lots of adjustment mechanisms. The front canti posts are very close.

Interesting to see a '531' sticker on the seat tube - maybe a replacement for the original '531 cs'?

I'll be interested to hear your impressions of how it rides - those Cadillac 470 mm chain stays are really something!

Congrats. on finding a great bike and doing such a nice resto-mod.!

RiddleOfSteel

You're welcome! Glad you appreciate it. Yeah, the 7700 GS is a bit of a rare bird. I forget where I picked this up from--Seattle is an embarrassment of riches when it comes to bikes and bike components. Ebay prices are largely stupid now, it seems, and have no basis in reality, IMO. There are 6500 Ultegra GS RDs, and I would assume, 5500 105 GS RDs. The 7800/6600/5600 Dura-Ace/Ultegra/105 trio of GS 10-speed RDs should do very well as well, and be polished silver to boot. Maybe even find a mint Tiagra unit, but it depends on the "level" of componentry you want for that Trek.

As far as polishing products, I used Meguiar's Rubbing Compound as well as their Carnuba Wax for the initial paint work. The touch-up paint you can get at O'reilly Auto Parts (or wherever) and it's the Dupli-Color stuff that you see in the vertical "booklet"/rack of OEM colors. Two coats of color for me, plus the clear coat applicator (it has both color and clear).

These MC70s have zero tension adjustment features, so it's just me and my tuning abilities. I'll see how I do.

As far as the 531CS goes, since it was a mix, the "531 Butted Frame Tubes" is accurate and original, since Reynolds likely didn't want to make a separate decal for such a tubeset (as it wasn't too common, I think).

Regardless, I'm looking forward to dry days and a ride. Lots of work to do between now and then!

RiddleOfSteel

The cleaned wheels have finally been mounted, and let me tell you, the tire clearance is substantial!

Inner fork blade clearance: 47mm
Chain stay clearance: 47mm
Seat stay clearance: 59mm

I'd be fine running a nominal 42mm tire and fenders as there is sufficient vertical clearance for both. Since I haven't done that, I will let other '85 620 owners chime in (if they want) concerning their setups. But dimensionally, you can stuff a lot of tire underneath this bike. I'll be sticking to the 33mm Somas I've been using. Heck, original equipment was 32mm (27 x 1 1/4") anyway.

There is...some air between the tire and the stays, I'll say.


"Honey, do these tires make my frame look fat?" Or alternately, I have accidentally put 650B wheels on my bike...


Cockpit componentry comes next--I'm getting antsy! I was able to pick up some canti brake small parts that I needed, getting me much closer to being able to string up that system. Soon....

Dfrost 

You dang young-un’s and your crazy corncobs!

RiddleOfSteel

At least I have a 26T small ring to bail my youthful hubris out!

Kobe 

The Clement's were 35mm but with the knobbies measured closer to 37mm. They were not great tires, your Soma's will have a much better ride.

ctak

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